c5 hdi coolant leak maybe

[myglaren]

Will you be in Aberdeen long? Maybe if you took your car then someone there could attend to it at a more realistic cost.

Don't forget that the dealer will charge £71 +VAT too!

You do seem to be having more than your share of bad luck.

Have you kept bleeding the system? What sort of results do you get if you have?

[boristhespie]

I leave the house at 5.30, get there at 7 and leave at 5 to get home at 7ish, 6.30 if lucky. Don't ahev any time to get to garage, that's the bummer. The garage here I left car overnight and borrowed one.

JUst have to see if dealer can do sniffer test as as far as I can see this is the only fullproof way (Although I read it's not 100%) to find out the truth re the cars head gasket.

Can I ask I was quoted 1500 euros to replace, how much should I expect to pay here for head gasket. And is it worth getting new water pump and anything else while I am at it (eg timing belt)?

[myglaren]

I'll ask around here to get an approximate price for a new head gasket fitted.

Definitely replace the cambelt when doing this job, and the water pump too.

The guys who did my engine did a Puegeot 307 a few weeks before so will have an idea of the price. That had a snapped camshaft though IIRC. Would text them now but left my phone at work

[RichardW]

Sniffer test might not pick up HG leak on a diesel - it doesn't make any CO that the sniffer would pick up. Not sure why your local garage can't do it - all they need to do is wave the gas analyser over the header tank

You can do some tests for HG failure yourself:

1. First thing in the morning, engine cold, take the cap off the tank - does it hiss, showing there is residual pressure in the system?
2. Put the cap back on and run the engine for a minute or so, switch off, then take the cap off again. Has it built some pressure already?
3. Now start the engine again with the cap off, and look in the header tank (remove the level gauge tube if it's got one) - are there bubbles rising into the tank? Do they get worse if the engine is revved?

If the answer to any of these tests is yes, then HG is stuffed. If yours is losing so much coolant, then I would expect test 3 to show LOTS of bubbles. (Be a bit careful with this test though - some cars (eg ZX TD) have a tube in the header tank that makes it look like its bubbling.

TBH HG failure is pretty rare on the HDi engine, compared to the old XUDT - but not unknown If it does need doing, then you're looking at 100 quid for the bits, 100 quid for a skim, and 300 - 500 labour, depending on the rate and how much trouble it throws up.

I reckon a leak is much more likely - I'd be looking at the bottom of the timing case to see if there's evidence of water leaking out - with the amount you've put through it, it ought to have left SOME signs!

[boristhespie]

Good to see you got the forum up and running again. Well done. I need you.

Myglaren and I have been having a conversation I will put it up here and you have a shifty and see if you concur folks.

As the forum is down yet again I'll use email instead.

It seems that the head gasket would be approximately £550. This is unlikely to include that cam belt and water pump though.

Before embarking on that do try and ascertain that it really is that though. One possibility that struck me is that it could be the thermostat that has stuck closed and the coolant is overheating, boiling and creating steam which will overpressurise the system and be the source of the air in the system.

Replacing the thermostat is a DIY job and a thermostat is only a few pounds, well worth a go in view of the cost of a new head gasket.
MYGLAREN

THanks for that quote. Not as much as I was thinking (I was thinking 1- 1.5 k).

The french dealer who says they are 35euro and hour (Bollocks) said it would cost 1450 euro. Including 15 hours on work. The head gasket and another 300 euro on something else they have to do to get the car all balanced or something. Not quite sure with my french and french wifie doesn't understand technical terms to translate.


Anyway at 70 quid an hour that will be a lot. The Bosch garage in Arbroath charges 50 quid an hour which is a bit more than other local garages but I kinda trust them even if they never found the fault but charged 80 quid. They specialise in japanese power cars and they come from all over Scotland to get remapped and one of the boys worked in Citroen etc.


Anyway something for you regarding the heat. I drove up to Aberdeen. The level of coolant in the car was okay after, yet when leaving I checked and the reservoir was nearly empty. This is how it is. It seems okay then you leave the car for a couple of hours and it drains away. Not sure if that is just it returning to engine after pressure drops.

I topped it up, there was a really small hiss opening the cap, but no more than opening a coke bottle if not a lot less. I am not sure if it is going in (Vacumn) or out (pressurised). Anyway I topped up a litre!

I drove back, 2 hours at 70mph and checked reservoir. OKay level but new hanky ( had used snotty one before) indicated that liquid had escaped. HOWEVER I did check the heat of the pipes and they were hotish. The big pipe to radiator was hot and although more pressure still a little squeezable so the pressure is not huge I guess.

What supprised me however was that the left side of the radiator was stone cold while the right side(looking at car) was hot. The thin pipe directly to the reservoir was also stone cold. All the others were hotish.

Is this a sign of a problem in the radiator or pipe or a sign of airlock? Anyhow no heat got to the radiators left side despite the 2hour 70 mph drive.


As for the thermostat, is that the thing at the top of the reservoir going into it?

Boris

Boris

I am feeling a bit more confident that the culprit is the thermostat. If it doesn't open then the water won't circulate which would explain some of the pipes and part of the radiator being cold. The static-ish water would then boil and generate steam, forcing some of the coolant back into the reservoir and out through the cap - there must be some form of pressure relief in the cap but I couldn't see it.

One fortunate thing about the cooling circuit is that it appears to follow the Xantia model and the heater matrix always has full flow, temperature being regulated by the vent flaps, and this circuit bypasses the thermostat, so there is some flow and cooling.

I am not certain of the location of the stat but am guessing that it will be at the engine end of the top hose. There is usually a minuscule emergency valve in them that will allow a small flow of water if the pressure becomes too high and that would pass the steam into the top hose.

I don't have the actual details of the thermostat in question though so this is to a large extent self-referential logic. I think we need to put this to the others on the forum, cachaciero and wheeler being the most likely to either confirm the theory or shoot me down in flames.

The first thing I would do is to identify the location of the thermostat and drag it out. No thermostat is not a good thing but is better than overheating which will cause damage sooner or later. The cold weather has probably saved you from the worst of possible damage up to now.

I'm going to check my car now and see if I can locate the thermostat and send a photo.

Steve.

PS - if the forum should come up then c&p this into the thread so it can get some quick attention.

[boristhespie]

Just by way of update (PLEASE READ THE ABOVE POSTS).

Only half the radiator is hot, (the right side when looking from front) while the left side is completly cold as is small pipe from radiator to coolant reservoir.

Does this indicate an airlock rather than thermostat problem or a blocked radiator? Eitherway the liquid is clearly not circulating. Could this cause it to boil?

[boristhespie]

Just by way of update (PLEASE READ THE ABOVE POSTS).

Only half the radiator is hot, (the right side when looking from front) while the left side is completely cold as is small pipe from radiator to coolant reservoir.

Does this indicate an airlock rather than thermostat problem or a blocked radiator? Either way the liquid is clearly not circulating. Could this cause it to boil?

Eurocar parts were to deliver but of course I wasn't in. Asked them to deliver to another adress, against company policy, asked them to leave ina safe place, against company policy. Looks like the 6 quid bit is going to cost 20 quid from the dealer as quoted. Bugger.

Anyway please look at Myglarens assessment and commnet on it please.

[Xantidote]

Hi Boris, wondered how you were managing with the cut in communications:

Myglaren could well be right - a thermostat failed in closed position could give the symptoms you've got (alas they don't fail safe). Of all the possible faults suggested, the thermostat's probably the easiest and cheapest to sort as a first step.

A closed thermostat would cause local overheating of the cylinder head, and maybe steam in the cooling system and the top hose. A closed thermostat would also stop (most of) the flow of hot coolant into the radiator. Until you've changed the thermostat, suggest you keep the heater going full blast to get rid of as much engine heat as possible. if you can't get replacement thermostat, try running without one, on temporary basis. At least you'll then know if you've pinpointed the problem.

Edit: I'm still at a loss as to where the lost coolant is going

[myglaren]

While the forum was down Boris and I have worked on this through email.

I suggest that the coolant is being lost through the pressure cap which although I couldn't determine the mechanism for it on visual examination only, there is coolant being ejected from there and my hypothesis is as yours, localised overheating generating steam and overpressurising the system.

As the car was subject to a pressure test in France I think that, touch wood, the gasket is still OK as there is no other evidence of coolant loss and no signs of contamination of the oil or coolant.

Here's hoping.



(anybody's guess what the grindy motor noise is though)

[Xantidote]

Another (stretching the imagination) possibility is a problem with the water pump, and it not pumping the coolant around, though I fail to see how this could happen.

[RichardW]

Surely if there was problem with either the stat or the water pump sufficient to boil the coolant and eject if from the header, the car would overheat (yes, even in this weather!) on the gauge - and the tank would be very hot when stopping after a run?

Have you done the cold engine tests on the header tank I described?

To check if the water is coming out of the overflow, you could direct it into a pot then go for a drive of 10 miles or so, and see if there is water in the pot.

[boristhespie]

where's the overflow?

There has been a hiss when opening occassionally not a great his. I did notice once the level of the liquid rise when I opened it.

There is NO bubbles whatsoever.

I noticed the pipe from engine to radiator was hot but radiator was cold. This morning after same 60 mile trip, radiator was warm on right side (looking at it) and stone cold on other side (left)

if circulating surely the entire radiator would be at least warm.

Guage never goes above middle.

[RichardW]

Presumably the heater is working? If no WP, then I doubt the heater would give out much heat. I wouldn't worry too much about the temp of the rad - this weather with the heater on, the radiator won't need to work very hard to keep things cool - especially if you're not working the car very hard. If the gauge is not showing overheating then the stat is unlikely to be away (although I suppose it's just possible the heater is taking enough heat out - does the temp rise if you switch to cold for a while?).

The overflow is a tube coming off the header tank next to the cap - usually just disappears down into the side of the engine bay / wing.

Still think it's leaking out somewhere, but it ought to be obvious given the amount you have lost!

[boristhespie]

Heater is working

If no WP, then I doubt the heater would give out much heat

?

does the temp rise if you switch to cold for a while?).

No

Will be taking thermostat out tonight if possible ( if I am home before 10 likelast night), as per Myglarens advice to see if it makes a difference. Don't have new one yet but if it is that then it will be obvious, if not likewise.

Radior cold, the small pipe to the header tank was hot last night, Would this not be cool if the radiator was doing its work?

[myglaren]

The overflow is a tube coming off the header tank next to the cap - usually just disappears down into the side of the engine bay / wing.

There is no overflow pipe on the C5 - see photo above.

Edit - that is no help unfortunately, it doesn't show that one pipe goes to the radiator and the other to the cylinder head/thermostat housing and is a closed system except for the pressure cap.

Radior cold, the small pipe to the header tank was hot last night, Would this not be cool if the radiator was doing its work?

The small pipes will heat up as the coolant expands into the reservoir, this is normal and exactly what the expansion tank is there for.

The overflow is only a secondary safety function to prevent excessive pressure in the cooling system.