Xantia HDI 110 power loss problem / limp home ?

HDI · Post by **HDI** » 22 Sep 2009, 16:16

Hello all , new here and glad I've found it !
You will all probably groan when I describe the following faults , I hope u do , that means a solution could be close !

1/
The car drives mostly normally except for slightly erratic performance , but then intermittently there will be a dramatic loss of power and the engine just does not want to rev over about 3000 rpm. Turn off the engine for about 15-20 secs either at a standstill or coasting and it returns to normal and performs normally.
I have noticed that this fault occurs on some particular local hills but if I am careful not to exceed 75 mph or heavy throttle the fault does not occur but use just a little too much and bang , no power !
There is no engine check light during the fault or at any other time.
The only other associated things I've noticed is variable performance , some days it feels quick others it's a bit flat , occasionaly the fault feels like it's occured but if the throttle is kept down power suddenly kicks in at about 3000 rpm , but power loss comes back when the revs drop below this , and sometimes , quite rarely , the idle speed will go high then drop.
All this feels like some sort of limp home mode to me. I've gone through the Pains manual but there just isn't enough info on sensors etc.

2/
The rad fans don't switch in. They work if the aircon is switched on but they don't work otherwise. Mostly this isn't a problem as the engine shows a reluctance to overheat , but I would like them to work. I understand the ECU controls the fans but where the heck is the sensor ??!!

Last thing , not really a problem but I'd like to sort it. The engine oil temp gauge isn't working. Someone told me that to install a new sensor , which incoporates the oil level (?) the exhaust manifold has to be removed ??!!
Is that a fact ?

I'd really like to sort this car , it's the exclusive spec and I quite like it !

I'm very handy with spanners , have use of a workshop with 2 post lift and not much scares me !

Cheers for any help.

citroenxm · Post by **citroenxm** » 22 Sep 2009, 17:53

your first fault is something I have just had with a customers car..

Switch off, switch back on full power for a bit and it IS the little valve, to the left of the cam belt cover, near the sphere, which is connected to the VACCUM PIPE THAT GOES TO THE TURBO - NOT the EGR on the exhaust..

Its not controlling the Turbo Pressure and so the ECU is detecting a too high boost pressure and shutting down to protect the engine..

** Just re read your post - IT WILL be the Electro vac valve.. theres two of them...

I was lucky and had a spare one in the shed and it worked a treat..

2nd. Theres only one Temp Sensor, that reads the coolant temperture for all items, on the side of the thermostat house, with the blue plug on it..

If your fans are not working its more likly the speed relays, which are located between the two fans behind a triangular cover... remove the Fans cover under the bonnet to gain access... either a leg on a relay has rotten, or a break in a wire from there and the control box, located to the right side near the battery, sometimes under the passenger head light.

3rd The oil level sensor is on the rear ofthe block, yes, if you lie under - well with a 4 post ramp, stand, under the car, looking forwards towards the radiator fans look to the left of the block you'll see the plug going into it.. exhaust is close but you may be able to get to it.. I cant recall now after the engine swap..

Good luck

Paul

HDI · Post by **HDI** » 22 Sep 2009, 19:19

Thanks for that.

So if I read that right it's the electro valve connected to the turbo ?

On the fans , I don't think it's the fan relay's as they work when the AC is switched on.

citroenxm · Post by **citroenxm** » 22 Sep 2009, 19:44

Hi, Yes, if you look at the engine to the rear left, theres two valves sitting on a bracket over the cam belt cover, and an array of vaccum pipes, one if you follow goes to the EGR valve that you can see on the exhaust behind the engine, and the other goes to the waste gate on the turbo.. thats the one to replace..

Regards
Paul

Sid_the_Squid · Post by **Sid_the_Squid** » 22 Sep 2009, 21:10

Strange you would get into limp home mode without the engine light coming on, are you sure the bulb is good? it should briefly light up when you start the car.

Did someone else not have a similar problem recently with an HDi turned out to be a clogged CAT?
I'll see if I can find the thread.

citroenxm · Post by **citroenxm** » 22 Sep 2009, 21:14

I had it after an engine change, it was the Little electro valve..

It goes into a SOFT limp mode were a ignition switch off resets it...

It IS .. Im adiment, its the SAME problem as I had on mine, the CAT wont cause this because you can De CAT a HDi with NO problems what so ever..

Paul

citroenxm · Post by **citroenxm** » 22 Sep 2009, 21:15

Oh and, also when I did a Cam belt change on my mates HDi, I connected the two Vac pipes up the wrong way.... which lost turbo control..

He had no power, but when I swapped them over it was all ok again.. but it didn't put the ECU light on..

Paul

Sid_the_Squid · Post by **Sid_the_Squid** » 22 Sep 2009, 21:21

Strange, you would have though something like that would cause the ECU to raise an eyebrow.

Here's the thread I spoke of, don't know if its the same situation, but might help.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=27777

citroenxm · Post by **citroenxm** » 22 Sep 2009, 21:26

Interesting Sid.. Id not seen that thread, but jumped in because Ive JUST had this problem on the HDi I had in...

So theres two possibles then, the CAT and the EGR Solinoid valve...

A lexia wont help because from the signs of it Both faults throw up Wastegate Fault...

Hmmmmm interesting..

Paul

HDI · Post by **HDI** » 22 Sep 2009, 22:19

Sid_the_Squid wrote:Strange you would get into limp home mode without the engine light coming on, are you sure the bulb is good? it should briefly light up when you start the car.

Did someone else not have a similar problem recently with an HDi turned out to be a clogged CAT?
I'll see if I can find the thread.

ECU light works normally at start up. Thanks for mentioning the cat but I don't think it's that as everything is ok when the fault isn't active.

HDI · Post by **HDI** » 24 Sep 2009, 18:37

Just had chance to look at the solenoid valves. Any chance of confirmation which valve should be connected to the turbo ? Just trying to eliminate the possibility that they have been connected incorrectly.
The one currently attached to the turbo has a pink wire on the electrical plug going to it.

Also , going back to the fans , the temp sensor on the side of the thermo housing is for the temp gauge only , I've already replaced that due to the gauge reading nonsense.

There must be a sensor to feed the ECU with temperature info so that it can operate the fans ?

citroenxm · Post by **citroenxm** » 24 Sep 2009, 20:13

Nope - its the only one.. beleve me i know, Ive just done a complete engine out and swap over on a HDi 110, and thats the only one there...

Paul

HDI · Post by **HDI** » 24 Sep 2009, 20:39

Maybe I wasn't clear , there are 2 solenoids side by side , 1 connected to the turbo and 1 to the EGR valve. The one connected to the turbo has a pink and green wire to the electrical connector , is that the correct solenoid valve for the turbo ?

HDI · Post by **HDI** » 24 Sep 2009, 20:44

Just realised you are probably referring to the temp sensor.
If there is no other sensor how would the ECU detect a temperature signal ?

citroenxm · Post by **citroenxm** » 24 Sep 2009, 21:34

Its obviously wired into the ECU first, and it uses this as a reference for cooling, I would be inclined to check the relays (Not sure if this has already been sugested to you) between the Fans in the triangular box...

Or the fuses over by the battery, theres a few 40amp fuses..

I cant confirm wires to the EGR soliniods just now, as im not near a HDi Xantia, my guess is they are connected the CORRECT way round, just the solinoid has packed up..

Paul