Puzzling problem. Solace sought!

[ImpManiac]

Got a problem with my modern 'sensible' car. It's a steadily worsening coolant loss. I shall describe the symptoms.

It's no classic motor, so please don't shoot me! It's a 1997 Vauxhall Omega Elite, 3 litre V6. She appears to have lost about 1.5 litres of coolant since Monday morning. I've probably only done about 60-70 miles since then, so we're talking about a torrent of a leak somewhere. She starts, runs and drives just fine, with no overheating, no massive temperature fluctuations, etc. Heater gets nice and warm. No evidence of any oil in the coolant. Some build up of 'mayonnaise' on oil filler cap. No evidence of coolant on oil dipstick. No evidence of gas bubbles in coolant at idle or when engine is revved. Sometimes, I can smell antifreeze from inside the cabin. On rare occasions, I can see steam from the driver's seat, invariable when stationary. Also I sometimes see steam coming from under the bonnet on cold days. Exhaust does not appear to be producing water or excessive steam. No smoke from engine, even under hard acceleration and at high revs.

I've had the cooling system pressure tested at a local, friendly, independent garage where I know the guys (one is a Stag owner!). A couple of hose clips were leaking and were tightened and the loss was not so bad for a while.

There is scant evidence of any coolant leak visible under the bonnet. Once or twice, I have seen some on the offside cam cover.

My guess is that the leak is coming from somewhere where it is discharging onto an exhaust manifold and evapourating before it can accumulate.

Maybe it is a hose with a hairline split or a pinhole? I don't think it is the radiator, because the steam does appear to come from inside the engine bay.

HELP!! Does any of you have any insight? Had this problem with your car? I guess all I can do is pressure test again and look closely. A mate at work suggested UV dye and lamp - he used this to diagnose faults when he was a vehicle engineer.

I really hope it's not a head gasket. If it were, I think it'd run like a pig, overheat, boil over, etc.

Want my Imp back........

I'm

[iRocco]

It could be the head gasket.....

It may have blown between the water way and outside of the block, and as the block gets very hot the water evaporates causing steam. It may have also just blown in to one of the chambers - if this is only a small blow, then you probably won't notice any difference in performance (especially from a 3ltr).

When you checked the dipstick, was the engine hot or cold?

Have you checked the heater?

[Benmarina16v]

I've seen this before, if a head gasket has a hairline fracture then the car could still run smooth for a time..

My 1700 Marina had a similar fault, although on hard acceleration you could get white smoke out the exhaust..! Head gasket and thermostate changed and no problems. I would say another pressure test and uv/dye check would give final verdict.

[ImpManiac]

iRocco, one of the head gaskets could have blown as you described, on one of its outer edges. If it were a minor leak, the symptoms would be as I described. I am not a religious guy, but I pray it is not a head gasket!

Benmarina16v, you are right. All I can do is get it pressure tested again, maybe UV dye too.

Anyone got a nice cheap modded classic 4 sale??

I'm

[iRocco]

I doubt a pressure test will show enough of a pressure drop if it as a small blow in the head gasket.

Sounds like you might be taking the heads off (unless you know which one has blown). There is no easy way to check this...........! A compression test may show something, but it's a slim chance.

[ImpManiac]

I really cannot afford to have to shell out for head gasket repairs professionally and don't have the time to do it myself. I possibly could do it, but have you seen the engine bay in an Omega V6!!

Anyway, she's booked in to the friendly garage down the lane on Friday for diagnosis, etc. I shall be keeping all my fingers and toes crossed...

Knew I should have stayed with PROPER, i.e. classic cars........ At least I know I can fix them!

I'm

[iRocco]

My boss has got a V6 Land Rover Discovery, he's just been quoted £2800 to change one of the head gaskets

[ImpManiac]

Well the car "ONLY" cost £3k. If it were silly money to fix it, I'd find a s/h engine, do it up myself and swop it over. I have to be mobile and neither of my old cars are running at present. Maybe by Easter I'll have a race-prepped Imp.....?

That or spend the money on something nice and old and (maybe) modified.....

Cheers!

I'm

[Revolution 9]

Hope it's not too bad, but it does certainly seem to be head gasket/head related unfortunately. And they say Imps have head gasket trouble!

[iRocco]

If it is the head gasket, count yourself lucky - my boss just found out that it's the block that's cracked not the head gasket................

[ImpManiac]

Thanks for your kind words, guys!

I am bracing myself for the worst... ;D

I'm

[MOGGY]

hi. buried deep under the inlet is a oil cooler which has oil and water running through it. common problem on v6 omega's as they get older. typical symptoms you describe ie no idea where water going.

expensive to sort as parts alone are expensive. is diy able though takes a lot of time.
good luck.

trying not to be cocky with next comment but it might sound like it: bet i'm right.

[ImpManiac]

Moggy,

My friendly garage did that for me about three or four months ago. The leak remained, albeit better. But it was still leaking, so got it pressure tested. Found a couple of loose hose clips. Better again, but STILL leaking! Now it's worse than ever!!!

Let's see if they can sport it this time.

I have tried to see for myself where it's coming from. Sometimes, as I described, there's steam just visible coming out of the engine bay. Then, when I open it, it's gone! No sign at all!! That's why I reckon it's vapourising on one of the exhaust manifolds.

I think I'd need ramps to be able to get a really good look around the engine and spot the leak.....

Maybe it is still the heat exchanger.....? Who knows?

I'm

[MOGGY]

hi.
how much did parts and labour cost when you had oil cooler done?
did they fit new genuine oil cooler?

that really is nearly always the source of lost water on v6 omega if u don't know where its going

if it isn't that i will suggest further things after digging out my notes. we've had more vaux's with tricky probs in than i wish to remember and i keep notes.

I'm not curse word up wall, i own a garage.

cheers

[nickb]

ImpManiac said:

No evidence of any oil in the coolant. Some build up of 'mayonnaise' on oil filler cap. No evidence of coolant on oil dipstick.

An interesting problem. The above says to me that the "mayo" is a result of a poorly fitting / sealing oil cap if there's no evidence of it elsewhere (common Vauxhall problem). It maybe a pinhole in a hose or the rad, as it could come back into the bay....just a thought

I do know a guy who's quite a whizz at sorting these sort of motors....pretty cheaply too but he's not the kind of guy who likes to be rushed, if you know what I mean!

[ImpManiac]

NickB,

Any advice or ideas you can provide would be very helpful! Where is your garage located? Where is your mate's who is good with these sorts of motors?

I ask because, whilst my friendly garage are very good, cheap and friendly (and I trust them!!!), they would not be keen on doing the work if it were the head gaskets. My instincts are that it is not gaskets at fault. If it were, I'd have thought there'd be steam, smoke, jets of boiling water, sludge coming out of every orifice, etc, etc..... It'd be my luck, though!

Meanwhile, the car drives just about perfectly. I took her out lunch time and got her good and hot (oo-er), switched off the heater, etc. Temp. did not budge! No jets of steam, etc. despite a sound thrashing! I love a puzzle... but I despair!!

Gonna try a new radiator cap. It's only £3.29 and you never know... although there is no residue around the expansion tank...

Anyway, please let me know! If not here on the forum, then send me a private message. You might get some work out of it!

Many thanks in advance!

I'm

[MOGGY]

i agree with idea of trying new cap, but it won't be that. anyway garage would have tested that when pressure testing system if there any good.

[nickb]

Garage is in Bedfordshire about 5 miles from A1(M). The guy is a bit of an oddity really: It's all done by word of mouth - no telephone, no VAT, cash only and he works when he feels like it rather than any kind of set hours!

I'll put the feelers out and see if he's busy. He may even know what the problem is without even seeing it....

[mattblack]

"smell of antifreeze in car..... "

Heater matrix leaking maybe?

Just a thought......

[ImpManiac]

Thanks all of you for your replies and your thoughts about what might be wrong!

Another interesting symptom came to light during the last 24 hours. When the heater system is switched on, the air conditioning compressor usually operates unless you specifically switch it out (ECO mode). With the a/c on, she runs at a lower temperature and the engine cooling fan is almost never called into action. With the a/c switched out, she runs a little hotter and the cooling fan cuts in intermittently, usually only in traffic - not an unexpected occurrence.

I wondered if this might be connected with the coolant loss problem.

We'll get there! I shall keep you posted!

I'm