blown head gasket

[dunephil]

i recently bought a 1998 v6 406 which was sold as having a blown head gasket, i have no residue on inside of oil filler cap, no water in the oil, or any clouds of white smoke from exhaust it was blowing back through expansion tank. I took off water pipes and lost no water from radiator, could the problem be a jammed thermostat and a cooling system that lacked enough water to cool engine and the blowing back through tank caused by water boiling off and having only that means of escape.

[V6Exec]

Compression test?

[madmadmax]

clean the oil emulsion off the cap and see if it comes back and check the thermostat in a pad of boiling water with a thermometer

[lozz]

Iagree, preasure test it the way to go!

also as above mentioned, check the thermostat, perhaps just removing it and running it withought it for a test might save a few quid
obviously you will loose warmth from the heater,

if its overpreasurising dont run it too long, pugs tend to blow back on the weakest part, normaly a pipe or Matrix can let go,
dont run it too long in this condition,

[dunephil]

hi all thanks for the suggestions have this afternoon removed the thermostat (which was jammed closed) have put housing back on and managed to get 4nhalf lites of water into her, ran it on drive forr half hour no bubbling through tank or smoke out of exhaust gonna take it for a drive later and see how that goes, will then invest in new thermostat.

[gumby6371]

Not 100% with petrols but if the only symptom is oil in your coolant it could be the oil cooler leaking, as already stated a compression test is the best first step.

[steve_earwig]

There's no mention of oil in the water, it sounds like the guy's got a bit of a result there

[lozz]

Yeah iagree sounds like a result,

it will be cold in there with no thermostat mind,

[dunephil]

i am an ex pat pomme living in new zealand and it summer here so not cold in car lol.
took her out for a drive and over 55kilometers it did not go over 80degrees apart from when i took it for a drag up a steep hill then went up to 90c came back down quick though, never missed a beat and on checking water level used no water, will invest in new thermostat and some proper coolant, yes think i got a result poor bloke that sold it was quoted 3 grand from a garage to change head gasket (which i thought was high even though he had misdiagnosed it). thanks too all the replies and hope i get some good trouble free motoring she got 140,000 ks on her and had new cam belts at 110,000 so should be good for a few more yet

[steve_earwig]

Splendid I guess you have to feel sorry for the previous owner and wonder if the mechanics in the garage were genuinely that incompetent or just planning on ripping the guy off

[dunephil]

more on the kiwi way, went to repco to price up new thermostat was told it dealer only part, so then asked em t look for either renault or citreon v6 around same age as they use same engine they found a thermostat quoted $140 plus gst(vat)so thought i would try dealer, dealer found part on north island (proper kiwi everything you need down south is in the north island) and the dealers price was $87 plus gst now how many times does the dealer part come up cheaper than car shop?
On another note the top drivers side engine mount bush is split is it posible to change this bush or is it a whole unit

[lozz]

ithink the engine mount is a throw away part,
ihavent seen a bush listed for them. other than the lower back mounts,

[406lover]

Reading you need a top engine mount on right side, I think you can just buy the rubber past for it.

If its the same as mine. Does it bolt to the car itself by to bolts and then come up to the rubber mount and then goes over the timing belt caseing and held buy then held by 4 bolts. My car is a 2.1 turbo diesel on a s reg.

If it is the same then you can just get the rubber. I've got one priced yesterday as I need to get one after finding out the whole rubber was in half doing a engine change.

Hope this is of help to you.

[dunephil]

yeah that sounds like you got the same problem engine rocks back and forth, gonna see if i can get it out and go t repco with it see nwhat they got.
thanks for the help, this is my first pug , really like the sound the engine makes cant wait t get a new thermostat into it and some decent coolant sort engine mount out and get it out onto the road
all the best for a great new year to everyone on here thanks for the help and will post more news as it comes up

[dunephil]

bit more on the engine mount, was told i had t buy the fullunit for top mount, i took off the mount and got the rubber out then took my ruler to it and measured all the dimensions armed with these i trawled the net till i found the right one and low and behold if the bush is not exactly the same as the lower engine mount one now why could my local dealer not tell me that, i bought the bush for 100 bucks and fitted it into housing ( they wanted 600 for a housing with bush) the part number is 180928 if anyone else finds they get the same info, and it is also same as a citreon part.