308 1.4Vti Several issues

[Dannyboy]

Bought a non runner 2010 308 1.4Vti at a knock down price. Was told won`t run , mechanic said it needs a timing chain. Worse case scenario was a replacement secondhand engine....took a punt. Fault codes were varied and looked like a stretched / work timing chain to me . 9 engine fault codes:
P0597: Controlled thermostat control open....permanent.
P0598: Controlled thermostat control short circuit to earth. ...intermittent.
P0494: Main fan assy status fault coherence....intermittent.
P1338: Cylinder 2 misfire. Intermittent.
P0172: Mixture regulation mixture too rich...intermittent.
P2178: mixture regulation mixture too rich ...
P2237: Upstream oxygen sensor charging resistance open circuit....intermittent.
P0053: Upstream oxygen sensor resistance fault resistance too high...intermittent.
P0011: Inlet camshaft dephasing coherence....intermittent.
Couldn`t find anything wrong with the chain or timing. Chain looked like it had been replaced in the recent past, not stretched and little wear on guides. Timing tools showed timing good. Both oxy sensors heating elements had resistance, cleaned and refitted them. Plugs looked well worn, replaced them and swapped coil 2 and 3 to see if that fault moved. Checked compression....No 1 cyl down ( after a splash of oil in each cylinder ) 100 psi, all others 150 psi.
Cleared all the fault codes. Decided to start it .....started first pull and ran smoothly and drove well, seemed a little down on power, didn`t like 5th gear on local hill. Car ran very cold and temp gauge hardly rose at all. All the fault codes stayed away except the stat . EML light never on. Replaced the stat, cleared the code , took it for a run, Engine ( and guage ) warmed up, fan never came on , even on extended idle , temp gauge showed 90 Deg while code reader live data showed the temp varying between 85 and 106 deg on the run. Got an " Engine ECU fault" warning on the centre screen and shut down and read the codes, P0494 returned ( cooling fan not working ) and P0342 “Inlet cylinder reference sensor signal fault” ( I believe is a cam / crank sensor issue ) at this stage car was down on power on the last run , coolant was gurgling in the tank, and then started to lose coolant. temp gauge never left 90 deg, engine didn`t seem mad hot.
I think the head gasket is blown , probably caused by the fan issue originally and didn`t show its head until engine ran hot enough. I also think I have a piston ring or valve issue on cyl 1 . For those of you who are familiar with these engines, should I bother doing the head / valves ( risk of broken piston ring ) or just get another engine ? . Can ran very smoothly , idled well , possibly less powerful than expected, when the stat was stuck open, even after a 5 mile run. I don`t hear a popping in the exhaust or intake ( valves issue ) during idle. I don`t have a cyl leak off tester or access to an air line to do a cylinder leak off test to see if valves or rings are the issue. Any advice from the experts appreciated. I`m considering pulling the head for a look / see anyway. Is pulling the pistons thro the top and replacing the rings ( if broken ) after a local honing in situ worth the effort ?
regards........Dannyboy 201062

[gwest]

Dannyboy, I think the lack of responses is because few of us consider ourselves experts! How did it work out when you pulled the head off? Am I right in thinking that the dud cylinder was at the gearbox end? I recently made a real mess of a head gasket job on my EP6 VTi (2007 Peugeot 207CC with 130k km). Firstly the Chinese head gasket had to be stretched to fit over the dowels, and next morning when I realised that this was not a good move and lifted off the head (not bolted down yet) I discovered that there was oil all over the rubber gasket material. I had reassembled all the valve gear and of course had oiled everything as I was assembling it. The excess must have been in the oilways and trapped there when the head was flat on the bench. On the engine stand it was on an angle.

[Dannyboy]

The saga continues..........took off the head, no visible damage of any kind, petrol wouldn`t leak down past the piston rings or past the valves when you filled the combustion chamber, head and block were flat using a straight edge. Fitted a new head gasket, new head bolts, bolted it down and fitted new camshaft sprocket bolts. All back together and started it up popping and surging but ran.......had ignition fault codes for cyl 1 + 2 and an inlet camshaft sensor code. It ran before with the camshaft code. Strange that two ign coils were acting up when they didn`t before. Checked the camshaft sensor, it was covered in gunk from the coolant spill. Cleaned it up and swapped the cam sensors..........started up all clear and the cam code moved to the exhaust......engine still popping and surging. Could I have timed it 180 deg out ? ..I did
Two more new camshaft sprocket bolts and retimed it . Ordered a new cam sensor and electric fan control unit ( Fan never ran even when very hot , but fan itself working, had gotten fan fault codes ) .
Started up , ran sweet, smooth and quiet, only the cam code........ran it up to temp , fan not working, thought the heater on full blower would cool it down.....it did for a while, then didn`t ...strange .........checked for air , bled at the two bleed points , no air.
Temp gauge followed the code reader live data up to 90 deg......gauge stayed at 90, reader went higher....stopped eng.....no new codes, puzzled.......had driven it , pulled much better in 5th gear on the local hill so head gasket did some good..........Driving it , getting air through the rad didn`t make any difference either.........idled some more , heater on full......then got 100 deg, "STOP" warning on instrument panel and coolant reservoir gurgling and overflowing with cap on.......??? Shut down. Top rad hose was hot.

Had lunch, thought about it ......the water pump pulley could be turned by hand when cold.....does it tighten up when hot ? .......it had not. Can`t see an electrical connector on it .....some thing I read said it is ECU controlled to tighten up and drive when the engine gets hot......I looked at it a few times and the pump was always turning. Now I`m thinking I have a water pump faulty friction drive so water not circulating and getting cooled by heater or rad ( car moving ) I had replaced the stat prev ( second hand on e-bay , didn`t feel like paying 100 euro for a new one at this stage ) it got rid of the stat codes, don`t think its sticking closed, top rad hose hot. .. Didn`t get a fan code this time.........hot water not getting to the fan stat / control unit ?

Think I have a faulty water pump drive unit and gauge sender sensor, cam sensor and a fan control unit.
The saga continues. A lot of S&*T wrong with this car.........think it started with water pump drive unit / cooling fan failing and cooking everything else. Luckily not paying labour charges...... let you know how i got on from here.........think I`ll go out and dig the garden for a while !!
Regards....Dannyboy.

[ksanturion10]

Checked compression....No 1 cyl down ( after a splash of oil in each cylinder ) 100 psi, all others 150 psi.

The difference is out of the allowed deviations for ICE. It should be not more than 25%, when comparing the worst with the best.
Have you checked the compression after the head gasket renewal? Have you made valve leak test?
You say, coils popped up now, this can also lead to overheating due to missfire while in motion.
Probably it was overheated before you bought it...

drBR
Martin

[Dannyboy]

Didn`t have an air source to do a compression bleed off test but the valves looked good and wouldn`t leak petrol past . Rings were the same. The coils issue was sorted by cleaning the crank sensor.....very mucky after coolant spill ( head off ) Didn`t do a compression test but the car pulled much better in 5th gear on a local hill.......before it wouldn`t pull 5th ...ok in 4th. The stat was stuck open ( Pre head gasket change ) on initial road tests with a stat code. Didn`t feel like paying 120 Euro for a new stat on a suspect engine. Bought a second hand one on e-bay ...30 euro......you get what you pay for.........I think that stat is suspect. The stat specs say it opens at 105 deg.......sounds mad hot......most stats open at 85/90 deg. Ran the engine / car again......water pump friction drive is definitely engaging despite the fact you can turn the water pump pully by hand when engine stopped hot or cold. Putting the heater on full with full blower does pull the coolant temp down. The bottom pipe and rad only got hot once
( about 90 deg on the code reader live data ) during this t/shoot and the coolant temp dropped accordingly.......couldn`t get it to do it again...afraid to run it above 95deg......didn`t want to cook it again.
Ordered a new stat today.....110 euro. The cooling fan was also u/s , replaced the sensor / relay unit and it runs now. I would definitely say the engine was overheated before I got it . The headgasket, fan and stat were all unserviceable. ......trying to t/shoot without wasting money on parts.....will let ye know when I replace the stat. A new problem is its faulting the ABS pump now....doesn`t seem to like battery connect / disconnect.......won`t stay reset at the moment.

[gwest]

Some of the literature on the control of the water pump on these engines is obviously wrong- I think that it is only the turbo versions of the Prince engine that have electrical control of the friction wheel drive unit. It's pretty obvious given that the VTi units don't have any electrical leads going into them. On my 2007 1.6 VTi I too can turn the friction drive wheel while it is contact with the water pump pulley. The water pump still seems to work ok. I had put a new thermostat in (even though it was the one meant for a Mini Cooper).
I idled my motor until my code reader indicated a temperature of 104C and the radiator fan had still not come on. The car's temperature gauge was showing ~90C- that is pretty standard practice for car manufacturers so us users don't fret about minor changes. I then got into the vehicle and revved the engine and a few minutes later got out and observed the fan slowing down to a stop. There was hot water in the top hose well before this. When the code reader was indicating 99C, the top hose was already 88C. My Peugeot 207 Haynes manual has the thermostat opening at 82C, so I'm wondering if it is the fan that comes on at 105C? It comes on if I use the A/C.
After about 4 or 5 engine starts since my engine rebuild many of the initial faults (many light bulbs and engine) have disappeared, except for my ABS which remains. The car is not registered so I cannot really drive it. I have not tried to do a BSI reset, am just hoping that it might sort itself out like it did for the variable valve lift setup, where I didn't have to worry about setting end stops (and wouldn't know how to) - it just idled badly for the first couple of runs.
It would be interesting to see what the compression was with your new head gasket. I was surprised with mine that a squirt of oil could raise the pressure in a cylinder that had one non-functioning slightly bent exhaust valve caused by a partly dropped valve seat. The rocker arm had fallen off because of excessive clearance. It would have also been interesting to have got a hardness reading on your cylinder head- my engine reconditioner takes ages to do the job but will give me on the spot hardness readings with his pen-sized device. Mine were 100-104 Brinell. On MGFs anything less than 90-95 was unusable, but they did have protruding liners which the PSA engines do not.

[Dannyboy]

Hi Gwest, good to talk to somebody with similar issues. On the compression topic, didn`t test it after head gasket change but the car now pulls very well in 5th gear.....much more low down power so it looks like the compression is good and I did have a head gasket problem. . Not worried about that. Was happy to find the valves / rings / head warp all good. felt I had a good engine. On the ABS pump front, I`m presuming I have a glitchy connection somewhere or an intermittent pump. It doesn`t want to reset , then does ( one out of four attempts ) and then works fine on a drive . On next start up can reoccur , battery disconnected previously or not. This fault only appeared half way through my work on this car.
A bit worried about that .....NCT ( Irish MOT ) pending in a couple of weeks. Have to get that ABS issue sorted reliably.
My biggest problem is overheating. When I got the car as a non runner , got it going and it ran o.k. didn`t pull well in 5th on a local hill ( Does now ) but the temp guage stuck at cold and a fault code for the stat.
No problem, change the stat.....didn`t want to throw money at it at this stage ( worried about poor power )
bought a second hand stat on e-bay. Fitted it and straight away had issues as soon as it warmed up.
Had a scanner plugged in reading coolant temps ......scanner matched gauge all the way up to 90 deg, heater on full and full blower would pull the temp back a bit to 80 deg ( Guage and scanner ) . Rad and bottom hose stayed cold, but as soon as it got above 90 deg, ( on the scanner / code reader ) coolant gurgling out of the expansion bottle. ....obviously ( I think ) stat not opening. I did notice the temp gauge never went above the top mid scale position ( 90 deg ) while the scanner got to 105deg at one stage when it boiled over. have to be careful not to cook it.
Bought a new stat......nothing has changed !!. Symptoms are still the same.....bottom hose and rad cold.
Will boil over thro the expansion bottle if I let it get to over 90 deg. When idling with heater and blower on full I can keep it under 90 deg and all stays o.k. I`m convinced the stat is not opening.......I`m presuming the temp sensor tells the ECU to open the stat.....so have I a wiring problem to the ECU or an ECU problem ?
Is there a separate temp sensor for the ECU as on some other cars ? If so can`t find it . There is another sensor in the head above the stat but internet tells me that,s an oil pressure sensor , haven`t fooled around with it . If I still had the old original "stuck open stat" I would be tempted to refit to see will it run reliably without overheating while I trouble shoot. Once during testing on the e-bay stat, the temp dropped as you would expect and the rad and bottom hose got hot, a few minutes later the fan kicked in . Had a fault code for the fan previously and t/shoot showed it was the relay / stat sw, replaced that and it seems the fan issue is resolved. ( code gone ) It only did this , stat open " trick once then back to cold rad and bubble over .....hence i bought the new stat. Any experts out there on this issue ? .....what kind of voltages should I see from the ECU output to the stat and at the stat ? At what temp should it trigger it ....105deg C seems very high as the stat opening temp.....Coolant would be , almost ? , boiling at that stage ? My previous experience would tell me you need the stat opening around 90 deg to avoid overheat ? I`m thinking I need detailed wiring diagrams to sort this and perhaps get the e bay stat ( which seems o.k. now ) disabled into continuously open mode for now ( remove the internals ? ) to get the car running and thro the NCT. Had planned to start using it from 1st April. ......running out of time and ideas. By the way the scanner showed reference temp which didn`t make sense as it was a negative figure ( minus 50 deg or something like that ) making me think there is another sensor somewhere ? .....Rgds....dannyboy.

[gwest]

Dannyboy, the thermostat will open regardless of any electrical problems with the heater at 82C as it is basically a normal wax pellet, augmented by a heater for unusual situations when it is driven hard when cold. The symptoms sound like the problems Citroen had from 2013-15 when they loaded the wrong cooling software at the factory- overheating and coolant loss. They were very coy about the details of this recall but I am presuming it only affected turbo vehicles with electrically controlled friction drives? I will have to think about this.

[Dannyboy]

Hi Gwest, thats interesting....I pretty sure my stat was not opening ( see below ) also I now have a fan issue , thought that was resolved.....both issues are now leading me to think that I have an ECU problem or wiring issue to same, which may have been the source of all the overheating / head gasket / stat/ fan issues.
Perhaps as you suggest...ECU software ?....I think more likely intermittent internal ECU issue ? . Something has changed to cause the problems. The ( good ) stat did open once during testing and the fan did run fast , then half speed once after I changed the fan control ...thought the relay fixed that..not so. Intermittent ECU ?

I gutted my old stat , not straight forward, and yes it does seem to have a wax element but I presumed the wiring to it was to heat it up and open it. There are two valves inside operated by the stat...when it opens it closes off the old ( no rad ) direction. I had to screw a little aluminum plate in position to separate the two chambers.....now I have a fully open stat all the time ...lets see what happens.

Went for an extended drive.....car drove great , cool running as expected, anti skid and occasional anti pollution fault all clear, no warnings. Bottom hose and rad now warm. I had "zeroed the adaptives " ( ECU memory ) by touching the two battery terminals together ( not connected to the battery )..it works !....car running sweet . Did about 10 miles...great.....now what about when it is idling in traffic ? The only codes I have now are one for the stat and one for an exhaust cam sensor which I know about....waiting for an e-bay sensor.....neither fault will put the eng mgmt light on .

Heated up fairly quickly when stopped, had the scanner connected .....temp matched the gauge as before and gauge would never go above 90 deg , even with different temp sensors ( Don`t understand that ) ....temp climbed on the scanner waiting for the fan to kick in ...getting hotter ....105 ...108 deg...oh oh...waiting for fan or over heat warning or coolant gurgling / overspill....none happened, then temp dropped to 98 deg ?......discovered the fan was kicking in but running so slowly you could not hear it only see it turning slowly....enough to cool it down a little....it would cycle like this ....no faults , no warnings . Shut it down.....as soon as the engine stopped it would gurgle coolant thro the closed coolant tank . start it again and it would cycle as before .

Scanner readings were as follows:
shortly after start ..cold. Coolant temp: 35 rising slowly ( stayed at about 55 deg during 10 mile drive ) , Coolant temp ref value : minus 48 deg ? Coolant temp reference value ( 2nd one ) 105 deg . Not sure what these coolant temp ref values mean...2nd one may mean stat opening value ...still very high...all the parts refs for the stats say it opens at 105 deg.
This figure did drop down to 99 deg at some stage during the drive.

When idling ..getting very hot: CT 108, CTRV minus 32, CTRV 2 105

After fan kicked in running very very slowly ( couldn`t hear it and it was turning slowly): CT 98 deg , CTRV minus 48, CTRV 2 105.

Looked at the ECU plugs....all clean and dry, no bent pins....wiring generally is in very good condition.
The Haynes wiring diagram for this is not detailed enough or one I got on the net. I would like to confirm the wiring is good before chasing an ECU. Looks like I need detailed wiring diagrams...will have to pay for them 60 euros the last time I got some. Looks like I can get a secondhand ECU, correct p/n on e-bay 55 Euro...get it virginised ( plug and play ) for 70 euro.....by the time I get it including new brexit customs charges ( 25 % ) .....150 euro ? ......might just go for the ECU....If I could get the fan running in the meantime I could put it in for the NCT ( MOT ) with a cool stat/ fan on all the time . Very hard to get NCT slots here at present due Covid backlog, don`t want to lose the slot. Would be interested in your view Gwest.
Regards....Dannyboy.

[gwest]

Most interesting Dannyboy- you have done a lot of work. As far as I know there is nothing electrical that will stop the wax pellet working in a conventional manner. I poured boiling water into the main chamber of my old thermostat and after a few flushes it opened as you would expect. If you then poured boiling water into the return from radiator pipe it went through in that direction too. So we can test that part of the stat and could also test the heater element as well if we wanted to, either by testing resistance or applying 12 V. It would be interesting to rule out a defective coolant reservoir cap, in case the system was not properly pressurised. Does your car have air con to help test the radiator fan? Grant

[Dannyboy]

Hi Gwest, don`t know about the stats working without electrical power. Must try the boiling water test.
I`ve had 3 stats on this car....first one stuck open running cool, threw it out ( Shouldn`t have ) when I replaced the secondhand e-bay one which would not open ( bottom hose and rad cold ) and the car would boil over.....third one brand new...did the same as the e-bay one. Both the ebay one and the new one showed 12 ohms across the two stat pins, so presumably both good.....but they still won`t open even without power, or when plugged in. . I think I`ll try 12V across the pins and see what happens also. Have since run the car with the manually open stat, runs cool but without any warnings/ faults/ problems until you stop......then heats up relatively quickly. as soon as it gets to 95 deg ( on the scanner ) I would run the fan
( temp wired independently ) and it would cool down quickly....its a powerful fan on full speed. So I think the cap is o.k, it doesn`t boil through it until the coolant is up at 105 deg or so, which is what I`d expect. It looks like the temp sense that triggers the ECU ( or the ECU itself ) to kick in the stat and fan, doesn`t work, yet I`ve had three different temp sensors ( on the three stats ) and they all do the same thing. Also when I unplug the temp sensor the guage and scanner drop to zero temp, so temp sensor seems o.k. From the haynes manual the ECU is the common unit. It looks like I can get a plug and play ECU for about 250 euro. Would like to confirm the wiring to / from the various units is good first. Engine management wiring checks wouldn`t be my forte but looks like I`ll be getting familiar. I need to talk to some wiring experts, I know some in the aviation sector. NCT ( MOT ) canx for now. Just a thought, I don`t think I`ve seen the engine overheat warning come on......you think it would at 105 or so ? Was being careful not to let the engine get too hot. Temp gauge on the dash is useless.....never goes above 90 deg...... maybe there is a hint in those last two statements. Aircon, doesn`t appear to work, is not cool and I noticed the fan didn`t come on when you switch it on as I would expect. I wasn`t worried about aircon or the cost of getting it regassed. Need to catch up on other house maintenance jobs in the meantime.
Will advise when I progress further...........appreciate your input / advise. .....Dannyboy

[Dannyboy]

Put the new stat into a large saucepan...gently brought to the boil ( sounds like a recipe ) ...got it up to about 95deg , measured on an infared thermometer ...couldn`t get it any higher than 95 deg but the water was boiling vigorously and no signs of the stat opening or even moving towards open. Then tried pouring boiling water from the kettle onto the stat with it out of the saucepan and same effect......stat did not open....looks like it needs the electrical input.....it probably opens without electrical input at 105 deg as per spec.
I believe pressurizing a cooling system raises the boiling point of water by 7 deg......so boils over at 107 deg ?.
sounds like whats happening to my engine. Will try 12V on the stat and do some wiring checks.

Temp sensor resistance cool was 8-9 ohms......dropped to point 45 ohms @ 75 deg
Resistance on stat pins was 15-16 ohms all the time, didn`t change as expected.

[gwest]

Dannyboy, I was wrong about my thermostat test in boiling water- I repeated it and it didn't open. On this forum if you search for electronic or piloted thermostat you will see detailed information from GiveMeABreak about the operation of these thermostats. This confirms that the normal operating temperature of these engines is 105C. And that the wax starts to melt at 105C. The engines can run at lower temperatures under certain conditions such as heavy load, but as Marc explains there are many variables involved.
On another forum: https://bobistheoilguy.com/forums/threa ... at.225373/
" My Peugeot 207 1.6 is acting up as I get an overheating alarm but the car is totally cold, checking in other forums it seems that is a common fault of the temperature sensor or of the thermostat, ... This was cured by replacing the thermostat.
And: My Mercedes has something similar to this (not sure if it's exactly the same), but I know how it works. It has a normal wax pellet type thermostat, but it is set to open at a very high temperature of 110 C by itself. It also has a "heater" built into the thermostat so that the car can "fool" the thermostat into opening a lot earlier. According to the service manual, the car can decide to open the thermostat anywhere from 80 C to 110 C, although I personally have only ever seen a variation from 85-95 C in the driving that I do. So, if I were to put my thermostat in boiling water, it wouldn't open. But in the car, with the electric heating element working, it can open as early as 80C.

The fact that the temperature gauge only ever reads about 90C during normal driving is just a cunning ploy by the manufacturer to keep us happy. And PSA are not the only ones who do this.

I am guessing that at the moment you are running just water as coolant? My engine reconditioner would have me run plain water for 600km after a head gasket replacement, but I am now wondering if this could cause localised boiling without the raised boiling point provided by the glycol?

[Dannyboy]

Hi Gwest, tks for the feedback , its good to bounce ideas around. I have since tested the electrical part of the stat and with 12v applied it starts to move after a while and in about 2 min its fully open. I can see if the stat is surrounded by hot coolant it would be even quicker. Had a look at that forum link you provided.
Yes, it looks like that is how it works.....with the electrical part not working the stat ( and ECU ? ) seemed to control the temp at 105 deg approx ( scanner temp ). It was close to boiling and then the temp started to cycle between 105 and 95 deg with the fan running very gently ( I thought there were two speeds, full and half speed ? ) while the temp was reducing .
You couldn`t hear it and could just see it spinning slowly. if you stopped the engine it lost that cooling effect and quickly bubbled over thro the coolant tank cap. Start the engine and the cycle continued. No overtemp warning during this time and the gauge stuck at 90 deg ( useless idea for hot conditions ) I tried a temp wire up of the fan but if you break into the control wiring for the fan relay it brings on the EML. ( sees an open circuit ) Wired it in temporarily ( separately) when I had the manually open stat fitted and as soon as the temp got high at idling , bringing on the fan brought the temp down very rapidly...on full speed its very powerful. At this stage I was fairly sure the ECU was the common denominator with the temp sensor
( working ) , fan control wires, stat control wires all feeding into it.
Couldn`t get any worthwhile wiring diagrams ( that I could see ) on the internet, there were some free ones but they were block diagrams only. The Haynes manual fan cooling circuit one was the best I had, but had wiring numbers , not colour codes on it and no inclusion of the stat wiring. Got down and dirty yesterday with the wiring and had continuity between all of the wiring from the temp sensor , stat control and fan control wiring to the ECU using the colour codes. Wiring all in good condition and no signs of damage / corrosion. ECU and its plugs were easy to access. Will go ahead with getting that ECU tomorrow. Approx 250 euro for a plug and play secondhand unit. No hassle with recoding and not worried about losing the immobiliser.

As a by the way, on a side problem, it looks like a cam sensor can cause an "anti pollution fault " message on the centre screen. Seemed to bring on the EML sometimes also. Replaced that sensor after moving it from intake to exhaust position and the fault code moved too. . Only fault codes I have now is the stat code. I also discovered a wiring expert on u tube..... " scannerdanner " from Ravensdale tech. Teaches youngsters how to troubleshoot engine management issues......very good and very practical. The American management systems seem to be very similar to the european ones. His goal is to find the problems without wasting parts....my goal too. So far it looks like I`ve still managed to buy an extra stat and fan control relay I didn`t need...about 50 euro. Hope the ECU fixes it !! My daughter cant understand how sitting in front of the tv with a glass of wine listening to a guy talking about car wiring is relaxation ! Must be the technical mind or I`m a nerd, or both !. . .....oh and I was re using the same coolant with top ups .....it was in good clean condition despite the head gasket issue. Will replace it with fresh coolant when I`m done and dusted.
Will hopefully have good news when I get the ECU and replace it ......regards...Dannyboy

[admiral51]

Not sure if this will help but was posted in relation to my lads 2009 207 1.4

Here's some info on the system incorporated into the TU3AE5 engine, which uses a piloted thermostat Colin.



Its role is to accelerate the engine temperature increase in order to improve the exhaust gas emission control and to obtain a higher engine operating temperature to reduce friction and fuel consumption.

The thermostat is open (whether in piloted or non-piloted mode if the temperature is above 105°C).

During normal operation, the thermostat is not piloted, it regulates the coolant temperature at 105°C.



For full engine loads:

• The injection ECU controls the regulation of the thermostat at 89°C
• The injection ECU controls the piloted thermostat heated resistor (26) in order to add the 16°C which the coolant lacks in order to melt the wax (25)

Time	Operating Phase	Description of the Operating Phase
t0 and t1	Partial load	The engine management ECU does not activate the piloted thermostat regulation control. The engine coolant temperature is regulated at 105°C guaranteeing a reduction in consumption
t1 and t2	Full load	The engine management ECU detects a full engine load and controls the opening of the piloted thermostat by means of the internal resistor which melts the wax, simulating a temperature of 105°C. The engine coolant temperature decreases and stabilises at a temperature of 89°C
t2 and t3	Full load	The engine cooling is regulated at an engine coolant temperature of 89°C in order to avoid an excessively high engine operating temperature
t3	Partial load	The engine management ECU detects a partial load and no longer controls the activation of the piloted thermostat internal resistor. The piloted thermostat again regulates the engine coolant temperature of 105°C

The piloted thermostat opening control is determined in relation to the following parameters:

• Vehicle speed (Guarantee of the performance of the engine cooling)
• Intake air temperature (Guarantee of the performance of the engine cooling)
• Ambient air temperature (Guarantee of the correct temperature under the bonnet in cold climates and of no adverse effect on the temperature in hot climates)
• Engine load
• Engine coolant temperature

Note: Bleeding of the cooling system uses a special injection ECU strategy.

Conditions necessary to inform the injection ECU of entry into a cooling system bleed phase:

• Zero vehicle speed (For 10 seconds)
• Engine speed above 1450 rpm (For 10 seconds)
• Engine torque below 5 m.daN (For 10 seconds)

Example of the reference speed of a dual speed cooling fan unit (in %)



Key:

• 50% = Slow speed
• 100% = High speed

The piloted thermostat opening control is determined in relation to the following parameters:

• Vehicle speed
• Intake air temperature
• Ambient air temperature
• Engine load
• Engine coolant temperature

The parameters of the cooling fan post-cooling triggering and duration map are set by the coolant temperature and the exhaust line temperature sensor.
The energy stored by the catalytic converter determines the activation of the cooling fan unit control.

Colin