Xantia HDi Dash Lights

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Rhothgar
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Re: Xantia HDi Dash Lights

Post by Rhothgar »

Cheers Chris.

Am going up to mate’s garage either Friday or Monday to borrow a ramp.

I’ll try and find the elusive cylinder block drain plug too.

I could not get the bottom hose off today as no ramps.

So I took the thermostat out and too hose off, gave it a through flush then started the engine whilst flushing through the thermostat housing.

That got a load more out. It was so filthy. I’ve never done it in 8 years plus it had stood for 3 years after the clutch went.
Last edited by Rhothgar on 02 Apr 2021, 11:02, edited 1 time in total.

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Re: Xantia HDi Dash Lights

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white exec wrote:
23 Mar 2021, 21:16
Leave the heating blower off, and set to cold. This will speed up getting the engine to fan-cut-in temp.
Even with heater off, hot coolant will still be circulating through the heater matrix (it's always in circuit), so will bleed properly along with the rest of the system.

Colours don't mean much, although blue is commonly a standard glycol mix, while red tends to be 'long-life' or OAT.
Just don't mix them. If in doubt, go for the ethylene glycol type.
Finally getting around to using the Liqui Moly Radiator Cleaner tomorrow and the Prestone All Makes All Models Extended Life Antifreeze/Coolant! This Prestone stuff looks yellow. It says it's based on OAT (Silicate, Borate and Phosphate free). Also contains Ethanediol (which appears to be ethylene glycol). Nothing more than that. Not sure if it's the one I've seen in Aldi or Lidl before now. Anyway, the intention is to get this done just in time for the forecast freezing temperatures.

Interestingly the Prestone says it can be added to any coolant.

When I did an initial flush last week, it really was horrendous. The water was very brown indeed and the thermostat housing metal looks tarnished. It's alloy but the brown 'coolant' has imparted an almost anodised looking finish to the aluminium. Maybe it has anodised it. Aren't some Citroen water circuits known for having a slight current going through them? I read that is what causes the pinholes in the ZX heater matrix once. Something like 50mA current. I did measure Sylv's ZX once and it did have a current flowing through it (not caused by the water pump either). :rofl2:

Meanwhile, back on topic, is it right I can just add the radiator cleaner to the header tank? Apparently, (not looked yet) there should be two pipes to and from the header tank? I can't imagine much circulation occurring though unless one pipe feeds from the water pump side. If not, I will take thermostat housing off and dump it in there.

It'll be interesting to see if the heater matrix smell comes back once the antifreeze is in. I'm sure it will readily find any pin holes. I've got one can of Forte at the ready although I should technically use two on that size of system.

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white exec
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Re: Xantia HDi Dash Lights

Post by white exec »

If the header tank has several hoses connecting to it, including something like a 1/2" one, then it will be in the flow circuit. Most header tanks do, these days, so they de-aerate the coolant as it works its way round. OK to put the cleaner in there, ideally with a 'header bottle' on top, and kept half-full. This extra head helps drive out air when bleeding the system.
header bottle, corrected.jpg
header bottle, corrected.jpg (19.9 KiB) Viewed 89 times
When doing the final fill and bleed, get the system fully up to temperature - i.e. cooling fans cutting in at least twice.

As that Prestone is OAT, just don't mix it with standard stuff (or, to be safe, anything else), whatever the makers claim.

I've not clued up on currents flowing round cooling systems. Maybe not surprising, as they consist of mixed metals, in what can be an (organic acid?) fluid - the classic battery?? Would have thought that sort of electrolytic action was really undesirable, as it could take its toll on the metals 8-[ .

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Re: Xantia HDi Dash Lights

Post by Rhothgar »

Absolutely Chris.

I’ve seen a drawing of the proper bleeding apparatus in the factory manual. It has like a bar that goes down to a radiator cap which pulls up and locks into place to allow water to enter and exit the apparatus.

System has been properly flushed once so once I have the cleaner in it should neutralise any remaining molecules of former coolant.

The header take has two connections. One goes over to the radiator near the battery and the other comes off the thermostat housing so there’s definitely flow through the header it seems.

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white exec
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Re: Xantia HDi Dash Lights

Post by white exec »

If those are the only two connections to the tank - Are you sure there isn't a larger one underneath? - then they are not there to allow significant flow, but just to vent air from two of the usual "high points" where air can collect. They also allow expansion/contraction of coolant to/from the tank.

If that's the case, drop the coolant level by at least half a litre, then thrown the 300ml of cleaner in, and top up to the Cold level. That way, the cleaner will get down into the system, and not just sit in the tank!

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Re: Xantia HDi Dash Lights

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white exec wrote:
02 Apr 2021, 17:06
If those are the only two connections to the tank - Are you sure there isn't a larger one underneath? - then they are not there to allow significant flow, but just to vent air from two of the usual "high points" where air can collect. They also allow expansion/contraction of coolant to/from the tank.

If that's the case, drop the coolant level by at least half a litre, then thrown the 300ml of cleaner in, and top up to the Cold level. That way, the cleaner will get down into the system, and not just sit in the tank!
Hard to tell. I wasn't in the mood for trying to crawl under and pull away wheel arch linings after the battle I had with the window regulator...

I suppose I need to try and get at the bottom rad drain to drain the coolant from the correct section? I was hoping to put the cleaner in before driving to my mate's as that is 30 minutes away but I'm not going to risk trying to free that up at home with no ramp. It'll probably snap!

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Re: Xantia HDi Dash Lights

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There was a big pipe Chris into the bottom of the header tank.

Had a good chat with the diagnostics guy, at my mate's garage, who used to work for Citroen. I asked him about the proper tool.

Basically it is a radiator cap but without a spring on it and a plunger which lifts to allow water into the header tank and close to stop the water flow. There is a very good drawing of it in the factory manual. I'm going to make one someday.

The bleed point on the heater pipes is ridiculous. Unscrew it until you scald your fingers then try, in pain, to screw it back on again.

The Prestone coolant turned out to be green. The Citroen Handbooks states 11.1 litres for an HDi with air con. I put 7 litres in and it was full!

I fully drained from the radiator bottom drain. Forgot to check for a drain plug on the block.

Then went to another mate's garage who has a smoke kit for checking for leaks in the induction pipework. All good - no leaks. He noticed the MAF connector was a bit loose. The little blue rubber seal broke off some time last year when I was doing all the diagnostics.

I noticed on Lexia at the garage that the air temperature was at 16 degs then 50 then -25 then 10. Loose connection on MAF must have caused that.

So the car ran like an absolute dream on the way home. Brisk acceleration with no hesistancy.

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Re: Xantia HDi Dash Lights

Post by white exec »

Good news, on both fronts. Glad it all worked out.

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Re: Xantia HDi Dash Lights

Post by Rhothgar »

Back to the dash lights!

Xantia 2.0HDi Fan Behaviour - What should happen?

The STOP and red light are on because they is a fault with the air con / engine cooling.

There is no dialogue with the air con.

I've had the front off the car twice this week, broken the tabs on the fan relay cover, etc. You could say it's been fun.

I cannot recall exactly which test works now. I think it is the high speed fan relay test.

I seem to recall that the fans should spin up. On the high speed (left hand fan from front), the right hand top relay clicks. On the low speed, no relay clicks. Swapping the relays out they all appear to work. It doesn't mean they are not faulty in some way. Maybe they are not capable of taking the current?

I unplugged the coolant temp sensor wire and the left hand (high speed fan) kicks in but not the low speed. I am sure I have read somewhere that both should kick in.

So looking for advice on expected behaviour please.

Are both supposed to kick in at low speed or one high and one low?

I have two Bitron relays, black with red base and a yellow Hella one. They are all 5 pin although two connectors only have 4 spades within. Only the bottom relay has 5 spades.

I have tested all connectors today. There is some corrosion on some relay pins. I've inserted it, removed, inserted, removed and done the hokey cokey with them a few times and the STOP light and red light did not come on on the journey home. Neither did the fan when I have Lexia plugged in at 95.5 deg C nor when the coolant temp sensor connector was still unplugged.

I couldn't tell you what voltage I got where. I suppose I'll have to do it again and paw over the wiring diagram a bit more too.

I did observe some strange fluctuations on Pin 1 or 3 of the right hand relay from 8V - Batt Voltage.

I am sure the earth is OK by the battery. There is a splice E096 but it is up near the top of the radiator. I imagined the infamous E620? splice under the radiator might factor in somewhere but it doesn't.

The fault possibly lies between splice E096 and the fan or the fan coils are burnt out.

I did bridge pins 3-5 without the right hand relay plugged in but nothing happened unlike when I bridged 3-5 on the high speed side.

I'd like to know how the ECU controls the fans. Presumably it takes the reading from the coolant temp sensor and when it reaches a certain level earths the relay to one fan and then the other when the temp reaches 105 deg C?

A mysterious layout of relays for sure.

I can see this is going to be a proper head scratcher.

Didn't @CitroJim have some spare fans?

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mickthemaverick
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Re: Xantia HDi Dash Lights

Post by mickthemaverick »

Yes Jim had some fans but they have been sold to another member. :(

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Re: Xantia HDi Dash Lights

Post by admiral51 »

Hi Roger
Twas me that got the fans from Jim. :-D
I do feel your pain with the fans so have a look Here .
Lots of details on the operation and diagrams are in there plus the fact i have not got to the bottom of mine yet but getting closer. [-o<

Colin

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Re: Xantia HDi Dash Lights

Post by Rhothgar »

admiral51 wrote:
10 Apr 2021, 09:17
Hi Roger
Twas me that got the fans from Jim. :-D
I do feel your pain with the fans so have a look Here .
Lots of details on the operation and diagrams are in there plus the fact i have not got to the bottom of mine yet but getting closer. [-o<

Colin
A very worthy recipient.

I seemed to recall this was recently and I thought he had got rid.

That looks to be a great thread. I'll go through it now.

I cogitated a little over the problem last night whilst reading the thread with the Peugeot link (not ideal) and think the A/C pressure switch may need checking because there is no communication with the A/C so there must be a link somewhere there that is not helping>

Of course, I will let you know how I get on as it might aid you.

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Re: Xantia HDi Dash Lights

Post by admiral51 »

Roger if you have the same set up as mine then you will have a Blue plug on the thermostat housing, and the control of the fans is done by 2 or 3 ECU and not the infamous Bitron relay.
From memory it was referred to as Bitron because that was the name on it :lol:

Colin

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Re: Xantia HDi Dash Lights

Post by Rhothgar »

It seems you largely have yours sorted Colin have read the post this morning or are very close.

I am some way behind you on this.

I do have some signs of corrosion on the odd relay terminal.

I am going to mull it over more and start by load testing the wires individually to see if there is high resistance in any of the wires. Once I have ruled any wiring defects out then I will start to look at the components again.

I’m not sure I got my fans working on slow. I may have done. I need the missus by the side of me to write my findings down.

I could wire up the oscilloscope to see what voltages occur where if I need to go that deep. Not sure I do as of yet but I could at least see which ECU wire gives what signal to where at different stages by setting up 6 triggers on pins 45,46,35,83,86 and 8 at the ECU.

I most definitely found a potential wiring fault on the left hand (from driver’s seat) relay (1503).

I really don’t fancy having to strip the radiator and intercooler out now that I have just down the coolant replacement.

May have to resort to the certified Jim method of removing the fans.

I may have another look tomorrow to do those tests that Chris last mentioned ie fan testing first.

Seems strange that the right hand fan motor is extremely noisy and the left is smooth. I think that probably says that there is an internal resistance in the windings which is not allowing enough current to fire up the left hand fan.

Citroen ownership. Tis fun!

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CitroJim
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Re: Xantia HDi Dash Lights

Post by CitroJim »

mickthemaverick wrote:
09 Apr 2021, 23:02
Yes Jim had some fans but they have been sold to another member. :(
I may have another set but it'll be a day or so before I can check on my stash...

Roger, let me know if you may need please...