Peugeot 306DT high coolant pressure - Martin1981
I currently drive a 1994 Pug 306 1.9 Turbo Diesel with 149k on the clock and over the last month or so I've been experiencing coolant loss through excessive pressure. There is pressure in the system even 2 hours after finishing a long journey as when i remove the pressure cap there is a huge gush of water. Also I've noticed that the coolant is very foamy. I've tried bleeding the system using the header tank method but to no avail.
The pressure cap seems secure enough, so I'm assuming the head gasket is on its way out. The car seems to drive fine otherwise with no loss of power and the temperature never goes much above 80deg when driving normally. I've never let the car overheat and I've had the cooling system flushed and coolant changed twice in the 2 years I've had the car

I'm aware that head gasket failures are common on the 1905cc XUD engine so I've got a horrible feeling that's what it is.

Any advice would be greatly appreciated.

Peugeot 306DT high coolant pressure - Ross_D
Next time you start the car from cold, remove the header tank cap; if you see bubbles and pressure immediatly, then most likely the head gasket. If you have an exhaust gas analyser or a friendly mechanic, you could put the 'sniffer' (eg the part that would usually go up the exhaust pipe!) just above the water in the header tank. If the CO/HC/CO2 reading rises, you are detecting combustion gases in the coolant.
A head gasket job on one of these isnt too bad if you are handy with the spanners, they seem to have a bit of a reputation as being a huge job. As long as you use new headbolts, the newer type metal sandwich type headgasket and get a headskim, the problem shouldn't really surface again. Probably worth changing the cambelt and checking the tensioners/water pump whilst your at it.
Peugeot 306DT high coolant pressure - Martin1981
Thanks Ross,

I remember trying that the other week- starting engine with cap off and I remember seeing bubbles and the water level rising pretty sharpish.
Just wondering also if there is any stuff you can get to seal leaking head gaskets, like a solution in a bottle or something?

Peugeot 306DT high coolant pressure - RichardW
It does sound pretty much like the head gasket....

Try removing the cap with the engine cold and starting the engine. Look in the header tank - if you get lots of bubbles rising, head gasket has gone. Similarly, after looking, replace the cap and continue to run the engine for about 1 minute. Stop engine and remove the cap - if it hisses showing pressure has built up, this is another bad head gasket sign.

Taking the head off one of these engines is not easy, so you'll be looking in the £400 mark. At least twice that if the head turns out to be scrap (probably not if the engine has not overheated). It may well be time to look for another car if you cannot take the head off yourself.

Is it illogical? It must be Citroen....
Peugeot 306DT high coolant pressure - solara
Could be a faulty rad pressure cap. Cheap enough to replace and try.
Peugeot 306DT high coolant pressure - Martin1981
Thanks Richard.

I remember doing that a couple of weeks ago and I saw bubbles almost immediately and the water rising pretty sharpish, so I'm, beginning to fear the worst!

Also wondering if there is any solution you can get to seal leaking head gaskets i.e similar to the stuff for leaky radiators?

If it costs around £400 for a new gasket, how much do you reckon a second hand engine from a breakers would be? I don't really want to spend much more than around £600 on the car as its not worth much more than that anyway so I might as well sell it for spares and buy another car.

Peugeot 306DT high coolant pressure - P 2501
you could certainly get a new engine for 600, but to pay a mechanic to fit it would cost probably the same again.

I think it might be worth selling it honestly as a car with a blowing headgasket and see what interest you get.
Peugeot 306DT high coolant pressure - GrahamF1
I'd check the Haynes manual and see if you can do the head gasket replacement yourself. It's not as tough as some make out.
Peugeot 306DT high coolant pressure - Peter D
No there is no quick fix for a blown head gasket, or it had been a very slow pressurization then re-torquing the head down may have done the trick although perhaps only in the shorter term. The parts are not expensive but do you have the tools, the ability and knowhow to do this. I suggest asking around your friend or even the local Auto parts shop for a good independant one/two man outfit and get them to quote. If you continue to drive this car it will camage the head thus requiring skimming so act soon. Regards Peter
Peugeot 306DT high coolant pressure - P 2501
Be wary about doing this job yourself, some people may say that it isn't that difficult etc. But you do need to know what you are doing and you will need the right tools.

If you have no experience of a job like this then i think it best left to the experts.

Peugeot 306DT high coolant pressure - Ross_D
The only things I found difficult when doing the head on a 306DT, was removing the manifolds from the head. Also, getting the head back on without damaging the new gasket, but I improvised, cut the head off an old head bolt and screwed it into the block. This allows you to lower the head on and also has the added bonus of holding the head gasket in place.
I certainly agree with P2501 though, if you have no experience then its probably best left to an expert, but dont be put off from having a go! I know my bank balance would be a lot smaller if I didnt do all my own car maintenance, and the satisfaction of knowing I've done it right is great!
Peugeot 306DT high coolant pressure - Martin1981
Thanks again Ross,

I'm not very mechanically minded, nor do i have the tools to do a job as big as this. I'll probably get a few quotes from local garages, including the one i use for servicing. If I can get it fixed for £500 or less I'll go ahead with it but if its going to cost much more then I'll sell the car as spares on ebay and put that money towards another car.
None of my friends are very mechanically minded either so that doesn'y help!

Peugeot 306DT high coolant pressure - Ross_D
Well good luck with the quotes!
If your interested, I'm selling my 306 DTurbo. I know this isnt the place, but quick spec and pictures can be found at:
Peugeot 306DT high coolant pressure - Martin1981
Thanks for that Ross.
It's a great looking car but a bit out of my current price range unfortunately! If I was a grand better off I would definitely consider it. Mine seems to be holding out and I've not had to top the coolant up since last wednesday and have done 600 miles since! Must'nt be too hopeful though but I'll see how it goes. If needs be I'll flog it as spares and maybe get another 306 or 205 for about £800 - £1000. As long as its a Peugeot diesel and lasts for 6 months i don't mind!

Thanks for all your help- I'll keep you informed!

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