c5 hdi coolant leak maybe

boristhespie · Post by **boristhespie** » 08 Mar 2010, 16:02

Anyway another 65 miles to come, let's see where this gets us.

NO more oil, but just really hot this morning and it came out when I took the cap off while HOT.

Quick explanation before lots of questions. Grateful for any thoughts from the knowledgeable bunch you are. Even if you are fed up with my rigmaroll.

Okay asked them to replace head gasket, pump and do timing belt.

Never asked them to diagnose problem. Based it upon advice here and from other garages (inc dealer) who said it could be headgasket.

Propr to this the radiator remained cold even after running for a long time so took thermostat out and radiator heated. Changed thermostat and radiator is heated in total which I assume is normal operation????

The guy at the garage concerned said that if it was pressurising it would be head gasket.

Can't see what else it could be any thoughts on this as the radiator seems to be functioning normally and the thermostat has been replaced. What else could cause either too much heat (The guage remains in middle) or pressure????

All pipes after 65 miles, this morning are very hot as is radiator and pipe from radiator to reservoir.

I took cap off and some coolant came out. It is hot.

Could this be caused by overfill???? It is on or just above MAX

Does it pressurise after longish run at 70mph anyway????

The coolant heating up could be because of what????

The coolant pressurising could be because of what???? (It was escaping through reservoir cap)

And what could cause it to disappear where there is no leak????

Really deperate to avoid any problems. Can't really afford car to be be fixed again nor for me to lose it as I would not be able to continue job. So any advice would be welcome, especially in order to avoid head gasket blowing in total again.

Anyway of deleteing posts?

dnsey · Post by **dnsey** » 08 Mar 2010, 16:45

What else could cause either too much heat (The guage remains in middle)

Well, if the guage is in then middle, why do you think there's too much heat? The idea of running the coolog system under pressure is that it can then reach tempreatures of above 100C without boiling, although that would be pretty hot for an HDI. A certain amount of pressure is therefore normal, and water will be ejected if the system's overfilled. Next time, ensure that the coolant's no higher than the 'max' mark when cold, give the car a run, stop the engine, and open the cap slowly and carefully (use a thick rag to protect your hands). Does it still spray out? A hiss of pressurised air above the coolant is normal, and if it's pretty hot, it may start boiling as the pressure decreases - neither is cause for concern.
Now, with the cap still off, start the engine. Are there bubbles rising in the coolant tank? A certain amount of turbulence from the water pump is normal.

boristhespie · Post by **boristhespie** » 08 Mar 2010, 17:52

Thanks for that. I am the sort who after so many things going wrong needs reassurance.

I drove back. The pipes in and out of radiator are very hot. Almost too hot to touch.

I didd feel the radiator and while it seemed to working previously I have to say this time the radiator is very hot at the top but cold as you go down it.

Last time it was hot all over but this seems different. Not sure how the liquid rotates in the system. The small diameter pipe to the reservoir from the top of the radiator is very hot also, like the one from the engine however the two on the floor are cooler but still hottish.

There is a small amount of flow through the slots in the filler in the resevoir but I don't see bubbles but then I never saw bubbles all the while I was losing coolant until the very end when champagne was the word.

HAve just been concerned re oil and when the guy opened it.

Post by **myglaren** » 08 Mar 2010, 18:49

If the system is operating correctly then the pipes will be hot after a run. There should be a difference between the water coming in to the radiator and that going out but both will likely be too hot to evaluate by touch. If you are really concerned then a pair of cheap digital thermometers fastened to the hoses would confirm.
At a certain temperature - nominally 80°C IIRC the fan will cut in to aid cooling and should the temperature continue to rise will go into high speed mode.
The fan is unlikely to operate while you are driving at >40mph as the airflow over the radiator is adequate without fan assistance.

As dnsey points out, the system is pressurised to prevent boiling which can otherwise occur at local hotspots (within the engine). Removing the filler cap too soon will cause a release of the pressure which could then cause the water in the engine water jacket to boil, sometimes violently, with results best avoided.

I am a bit baffled with regard to the oil but hopefully it is spillage into the water jacket from when the head was lifted.

I appreciate your concerns though after all the problems you have encountered with your two C5s.

boristhespie · Post by **boristhespie** » 08 Mar 2010, 20:25

New picture of Mylene. I'll stick with My Citroen 2CV drivn nun.

Thanks.

Will post the noice of my other car on here tomorrow if I can. Have to say, I turn the car off the minute I get it running. It's scary.

TopDonkey · Post by **TopDonkey** » 08 Mar 2010, 20:41

I did keep trying to post earlier, but kept getting timeout errors, lets see if it works this time round !

Is it possible that you are overfilling the expansion chamber ?, it should be about half coolant and half air to allow the coolant to expand into it as it heats up, if you overfill it, you will get coolant spurting out when you open it when its hot as it has nowhere else to go

can you take a picture of the coolant reservoir with the cap off and post it here ?

also, if you do overfill it, and it decides to vent itself whilst you are driving, it should settle at a normal level that doesnt give the low coolant warning, but if you refill it thinking its too low, it will keep spurting more coolant out when it gets warm again making you think its overheating when its not.

I would just drive it normally, if it spurts coolant out, let it, but keep and eye on the temperature gauge and dont let it get above 95 degrees, turning the interior heater on with the fan on full can cool the coolant down very rapidly as it takes its heat from before the thermostat

so just treat it normally for a week, but dont let it overheat and if the low coolant light comes on, stop and let it cool a bit and top it up just a little (not too much) and see if it does it again

I do think from your explanation that it is fixed, and that the oil is just leftover from when the gasket was done, if the garage turned the crank over manually when the head was off, it can pump oil out the block and into the coolant channels directly, and you would then see this as loads of oil in the coolant afterwards

boristhespie · Post by **boristhespie** » 08 Mar 2010, 21:13

dont let it get above 95 degrees

My GUage is just a red to blue jobbo not giving temp. It remains in centre of scale all the time. Not sure how reliable.

Will keep it going. Removed some oil tonight with tissue.