Omega - oil leaking onto manifold - Chad.R
My neighbour's Omega ('94, 3.0 elite) has just had a coolant leak sorted out by replacing a leaking 3-way heater valve. It was also serviced at the same time. The mechanic (a Vx specialist) noted that the car had more than it's fair share of oil leaks (none of which were serious - rocker cover gaskets?) and that oil leaks were quite common on the 2.5/3.0 V6's and his advise was just to keep an eye on the oil level as fixing them would be fairly expensive.

However, one annoying and sometimes embarrassing leak seems to dribble a few drops of oil onto the manifold (drivers side bank) which results in smoke appearing from under the bonnet similar to a "boil". This doesn't happen all the time, only when the engine has got particularly hot, not overheated though and wasn't happening when the car was being serviced.

Apart from being a pain in the neck, is this dangerous?

Chad.R
Omega - oil leaking onto manifold - Ian (Cape Town)
At the risk of sounding like a smart-a***, I'd say yes, where there is smoke there is [risk of] fire!
seems to me that if the oil can be heated enough to smoke, it can be heated enough to reach flash point.
Hopefully another backroomer can confirm/assist.
Omega - oil leaking onto manifold - dave18
Polo did it for about 3000 miles when on its last legs, with temp gauge often on the red line because the engine was on its way out at this point (cutting out etc, first £200 car.) Obviously your's is fine mechanically. Doubt it would catch fire.
Omega - oil leaking onto manifold - Mark (RLBS)
My Lancia did, for exactly this reason.
Omega - oil leaking onto manifold - terryb
I suspect this, or something similar, was the cause of the Vx Frontera catching fire a month or so ago at services on the M4 while I was there.

Pi11ock drove it to the petrol pumps to really get it stoked up!

I'd get it sorted - can't be much to fix????


Terry
Omega - oil leaking onto manifold - Chad.R
Thanks for your comments and suggestions - I'll pass them on.

I don't know how much it would cost to put right. As I mentioned initially, this only happens when the engine gets particularly hot - typically on a day like yesterday when the ambient was 28'C and you get stuck in a jam the temp gauge reads just a little higher than normal and no where near the "red".

BTW, the Omega seems to run in the region of 88'-92'C at "normal" speeds and load.

Chad.R


Oil leaking onto manifold -possible fix - Shep
Chad,

Just encountered crankcase pressure in my long service omega 2.5 CDX (160k miles).

There is obviouslly oil leaking under pressure from either the oil filler or some other place which finds its way to the exhaust giving the old tell tale blue smoke. (has only done this once)

The engine runs absolutely fine and exactly the same as it always did. there is no loss of power whatsoever, no water loss, no abnormal sounds and the oil is the right colour. However, when you remove the dipstick or oil filler cap you get a sound not unlike opening can of beer.

I have booked the car into the local VX dealer for an exam but fear a big and possibly unnecessary bill. I was interested to read what you said about the breather system and was wondering if this is an easy job for a relatively experienced DIYer or something best left to a dealer ??

Perhaps there is an acid test to determine if the breather system is at fault?


Thanks in anticipation

Steve


Oil leaking onto manifold -possible fix - Rosanbo
Shep,

My Omega (recently purchased 150k) has also got a rocker cover leak.

Usually caused by excessive pressure which in turn can be caused by among other things...

Too much oil in engine, cure, drain a bit of oil out.

Blocked oilways inside engine, cure, take engine to bits and clean out

Blocked breather hoses which come off rocker cover and go to throttle housing, check by unclipping from rocker cover and having a look inside pipe, cure, wash out pipe with petrol or buy new pipes for approx 10 pounds each.

In my case it is blocked breather pipes and too much oil. I intend to buy two new pipes and drain oil from car, rinse out engine with flushing oil and refill. I might also be tempted to undo rocker cover and clean up and inspect what I can, wash rocker cover gasket with petrol before refitting and possibly use a bit of silicone to help gasket form a good seal.

once pipes are replaced, a good trick is to start engine with the air hose disconnected from throttle housing, then have a strong, 2cm thick, bit of wood, briefly place the plank onto the throttle housing opening, it will be sucked on tight, and the engine will suck air along the breather hose from the rocker cover thus unblocking any further cr*p that might be in there.


If you feel you can't do it yourself I reccommend fnding a good mechanic who is a lot cheaper than a VX dealer.
Oil leaking onto manifold -possible fix - Shep
Kev,

After much reading on this site I decided my problem must be something to do with the breather system and I took the Omega to a main VX dealer for confirmation.

To cut a long..... the Dealer had it fixed the following day and had fitted couple of new bits to the breather system £195 total cost !!. The car is running really well once again.

My regret is that I just didn't to this seemingly simple work myself as I consider myself usually to be more than competant and experienced. I guess lazyness and expediency took over !!. However, the bill will serve as a reminder for next time

Cheers,
Omega - oil leaking onto manifold - Rob E
Chad.R

I had exactly the same problem with a 1984 (A) Polo last summer. After I got worried about the steam coming from the bonnet (after a few weeks of it having done this) I got it sorted out. A new rocker cover gasket was fitted, and the mechanic steam cleaned around the area. Problem solved. Only cost about £20.00.
Regards,

Rob E
==========

Omega - oil leaking onto manifold - Peter D
Leaks do not get better.

Have if fixed.

Peter
Omega - oil leaking onto manifold - Andrew Moorey (Tune-Up)
Using fully synth will aggravate the problem. Use a good semi synth, replace the gaskets and change the breather and make sure that the small bore pipe from the rocker cover area to the inlet manifold is clear. This pipe 'sucks' crankcase fumes from the engine and if functioning correctly almost negates the build-up of pressure within the block. The 4 cyl Ecotec engines suffer in exactly the same way.
Omega - oil leaking onto manifold - Chad.R
Thanks Andrew,

I think when the car was serviced it was filled with Vauxhall semi-synth. I think my neighbour is planning to have the rocker cover gaskets and breather unit replaced in the next few weeks.

He's noticed that if you dont rev the engine over 2.5K until the engine oil is warm the problem doesn't occur - if you do and give the engine a bit of welly before it's fully warm you can see the oil drops leaking from the rocker cover. Is this due the oil or sludge build up that's causing the breather unit to clog up thinning and allowing it to function as it should?

He's looking forward to having the work done and being able to use the full power of the engine - otherwise he is extremely happy with the car. I've been in it on the M-way and it certainly cruises very well, but is a bit too big for nipping around town though.

Chad.R

Omega - oil leaking onto manifold - Chad.R
My Neighbours was discussing the latest dilemma regarding his Omega - just been to the local Vx dealer and had quotes for doing the rocker cover gaskets and they work out at approx. £220 per bank all inc.

Now the dealers told him that as it's just the drivers side bank thats leaking he can just have that side replaced.

He's not sure whether replacing one side is a false economy - considering that it's going to cost another £220 to do both side what are your thoughts?


Chad.R

Not all BMW owners are bad drivers - just the majority.
Omega - oil leaking onto manifold - Dizzy {P}
Chad - what a silly footnote. What is it supposed to achieve? It certainly hasn't encouraged me to help answer your question!


Dizzy.

A careful and considerate BMW driver who feels sorry for those who don't share that same pleasure!
Omega - oil leaking onto manifold - Chad.R
Dizzy,

The comment about BMW owners/drivers was purely tongue in cheek. Mainly in response to the "BMW driver bashing" that seems have become a public pastime these days.

I have owned and driven BMW's for several years now and have been a fan of the marque long before I could afford one. Though I would never class myself as a "good" driver, I am certainly competent and not one of the mindless, arrogant and aggressive drivers that unfortunately, more and more, seem to be attracted to the brand for all the wrong reasons.

I've been using that line as my "signature" - and YES, it has been generating some "mixed" comments.

PS. So, what do you think about the single rocker cover replacement then?



Chad.R

Not all BMW owners are bad drivers - just the majority.
Omega - oil leaking onto manifold - Dynamic Dave
The comment about BMW owners/drivers was purely
tongue in cheek.


Well, to stop offending people, how about a smilie at the end?
:o)
Omega - oil leaking onto manifold - Chad.R
Fair point Dave - but isn't it amazing how contentious all things BMW related still seem to be?....

......and nobody could be more offended as to the bad name that BMW drivers are getting these days than me!
Chad.R

Not all BMW owners are bad drivers - just the majority.
Omega - oil leaking onto manifold - Dynamic Dave
S. So, what do you think about the single rocker
cover replacement then?


If it aint broke, why fix it??
Omega - oil leaking onto manifold - Dizzy {P}
Chad, I completely fell for your little joke! Sorry about the insolent reply.

As for the rocker cover question, I'm not familiar with the Omega engine and I'm stumped. My only thought is to go to an independent garage that charges much lower hourly rates and get them to replace the bad side and to advise on the other side.

It sounds as though the Vauxhall garage has eliminated the breather as a possible cause of the problem. I mention this because a colleague was about to purchase a reconditioned engine for his c100,000 mile 2-litre Carlton a few years ago when he found oil running out of the bottom of the air filter. I checked the breather gauze (in the rocker cover on that engine) and found that it was blocked with oily gunge and causing a pressure build-up which pushed oil up a hose leading to the air filter. Replacing the gauze totally overcame the problem and he did many more thousands of further miles on the same engine.

Omega - oil leaking onto manifold - robert
My Omega 3.0 V6 also has a minor leak - also on the drivers side bank - toward the rear. It isn't a major leak by any means at all. I never have to top up the oil between services and doubt if the leak in more than a couple of drops a week.

When I got my car (14 months ago), I noticed an gungy oily deposit on the large bore (Stainless Steel) water pipe which is immediately below the site of the gasket leak. I cleaned it off and now only have to wipe it clean weekly. The build up obviously accumulated over the previous 50,000 miles when it wasn't cleaned!

I've looked at a number of other V6 Omegas in recent months, and the vast majority suffer from this symptom. My understanding is that if it fails big time then the whole of the rear of the engine becomes covered in oil. I've also been told that using a slightly thicker oil helps with the problem and will be switching from fully synthetic to semi synthetic when the next service is due.

Hope this helps .......


PS - took a mates new 325 for a 50 mile spin last week - felt noticibly more "cut up" then in my car
Omega - oil leaking onto manifold - Dizzy {P}
Robert,

Isn't semi-synthetic oil thicker than fully-synthetic only when it is cold, assuming the equivalent grade is used? Since the leakage occurs only when the oil is very hot I'm not so sure that changing to semi-synthetic will help. What do you think?
Omega - oil leaking onto manifold - robert
Thats EXCACTLY the point. It seems that the leak only happens when the engine is cold and goes away when warmed up - see a lot earlier in the thread.

My logic is that if this is true and that leak only happens for a few mins that a slightly thicker oil might help.

Regards
Omega - oil leaking onto manifold - Dizzy {P}
Robert,

I think we have got a bit confused by the different symptoms that Chad has passed on from his neighbour. He said:
"As I mentioned initially, this only happens when the engine gets particularly hot ..."

But a later posting said:
"He's noticed that if you don't rev the engine over 2.5K until the engine oil is warm the problem doesn't occur - if you do and give the engine a bit of welly before it's fully warm you can see the oil drops leaking from the rocker cover."

I assume it was first thought that the problem occurred only when the engine was very hot but was later found to also occur under hard use with the engine oil warm, not yet hot. However, it doesn't occur at all when the engine oil is cold.

Chad, is that correct?
Omega - oil leaking onto manifold - Chad.R
Sorry for the confusing symptoms as posted earlier, but we have nailed it down now after several weeks of "trials" -

The leak is quite small and as in Robert's case there has been no need to top up the oil in 5 weeks/2500miles. The leak seems to be at its worse, or at least most noticeable, in the first few minutes after a stone cold start and the car is revved to say more than 2.5-3K rpm. Then a small plume of smoke appears from under the bonnet from the drivers side for several seconds. Once the oil has warmed up there is no such symptoms and the car performs very well. (BTW the heat generated from this engine seems huge though, after a run when you get out you can really feel the heat wafting from the engine bay - my 535 is similar but not to this extent. Maybe it's because there isn't as much "free" space in the Omega's engine bay for the heat to dissipate quickly).

This leak has probably persisted for several thousand of the 93K miles the car has done as the oil has gradually seeped down and now completely covers the underside of the sump. Needs a good steam clean and then we can keep a better visual check.

Thanks for taking the time to try and sort this one out - Any more ideas about replacing a single rocker cover or both? I've never had a "V" engine before only straight 4's & 6's so not sure. My friend wants to get it sorted before the oil starts seeping into a plug hole and .....

Chad.R

Not all BMW owners are bad drivers - just the majority.
Omega - oil leaking onto manifold - Chad.R
>>Any more ideas about replacing a single rocker cover >>
>>or both? >>

Anyone?.... Anywhere?....Any comments? PLEASE.

Chad.R

Not all BMW owners are bad drivers - just the majority.
Omega - oil leaking onto manifold - Dynamic Dave
>>Any more ideas about replacing a single rocker cover >>
>>or both? >>
Anyone?.... Anywhere?....Any comments? PLEASE.


As I said earlier, if it ain't broke, why fix it!!
Why disturb the non leaking rocker cover?
Omega - oil leaking onto manifold - Geoff D
Chad - I have had the cam covers replaced on my 2.5. A local guy did them and said it's 4-5 hours labour. We only suspected that the nearside on was leaking (the oil in my case was diagnosed as leaking out of the back of the cover). However the vast majority of the labour is removing/refitting the induction and other gubbins related to aircon/climate control on top of the engine. Therefore it makes some sense to do both while you're at it. He first replaced just the gaskets, and since it didn't stop the leak he put on the new type cam covers (apparently there is a weakness in the design of the original type). He didn't charge labour the second time. The bad news is, that still didn't stop my leak - the rest is in my reply to Ian. (Except I didn't mention that the Vauxhall dealer, when looking elsewhere for the problem, said that the new cam covers had been fitted properly)
Omega - oil leaking onto manifold - robert
Hi,

Sorry for slow reply - I've been on hols.

So, my theory of using a slightly thicker oil sort of makes sense then.

I'll have to look at mine on a cold start and see if I can see any signs as described.

I agree with the shall I/shan't I change the gasket struggle - just think ourselves lucky that it isn't the other back!

Regards ................ Robert
Omega - oil leaking onto manifold - Crombster
I have suffered from the leaking gaskets myself. Two rocker cover gaskets cost around £50 from Vauxhall and I put together a picture guide to doing the job yourself.

www.theloft.dynip.com/camcover.htm

Someone might find it useful,

Stuart
Omega - oil leaking onto manifold - Geoff D
I have a '98 Omega 2.5 V6, which had oil leaking onto the nearside manifold. Quite a bit dripped onto the floor, too after a run. A local garage fitted new cam cover gaskets, as this was assumed to be the problem. However it still leaked, so they replaced the cam covers with the new, improved (?) type. Still we had the leak. They actually gave up at this point (£300 worse off), so I took it to a Vauxhall main dealer. The said that the cam covers were ok, and the problem was the oil cooler. 3 days(and £400)I got the car back with a new oil cooler the promise it was fixed. A four-mile drive hom revealed the same leak, but slightly worse I believe. I returned the car and I am told it's ready to collect tonight, after another 4 days in the workshop - watch this space. >> My neighbour's Omega ('94, 3.0 elite) has just had a coolant
leak sorted out by replacing a leaking 3-way heater valve. It
was also serviced at the same time. The mechanic (a Vx
specialist) noted that the car had more than it's fair share
of oil leaks (none of which were serious - rocker cover
gaskets?) and that oil leaks were quite common on the 2.5/3.0
V6's and his advise was just to keep an eye on
the oil level as fixing them would be fairly expensive.
However, one annoying and sometimes embarrassing leak seems to dribble a
few drops of oil onto the manifold (drivers side bank) which
results in smoke appearing from under the bonnet similar to a
"boil". This doesn't happen all the time, only when the engine
has got particularly hot, not overheated though and wasn't happening when
the car was being serviced.
Apart from being a pain in the neck, is this dangerous?
Chad.R
Omega - oil leaking onto manifold - Ian J
Geoff
Re oil cooler - it sits at the apex of the V halfway down the engine right in the middle surrounded by coolant. If it has an oil leak it should leak oil into water mine certainly did. The car would be losing oil but it would be leaking into coolant. Re cam cover gaskets for some reason drivers side tends to leak more than passenger side. If you suspect the cam cover gaskets are leaking by taking out a plug lead you should see lots of oil on it and in the plug recess ; it also tends to leak oil on to the exhaust on the drivers side - lots of smoke. I will be interested to hear what your problem was.
Ian
Omega - oil leaking onto manifold - Geoff D
Thanks Ian. Got the car back and the same drive home (only 5 miles)didn't produce any leaks. It was late & no one could tell me what had been done - I'll have to check Monday (they had it 4 days). The rear of the engine has been cleaned up and the only traces of oil I could find were on the exhausts where they curve to the horizontal (part of that is a shield by the look of it). There was just a hint of the dreaded burning smell, but I hope that may just be residual. Looking promising anyhow. It's a CDX auto and goes like a dream otherwise, and it is wonderful for towing my small caravan, that's why I'm persevering with this problem. We don't depend on it at other times, doing only about 3000 miles/year.
Omega - oil leaking onto manifold - Geoff D
Full marks to the main dealer - they have resealed the necessary parts of the oil cooler connections etc (it was an external leak, so there was no oil in the coolant. I now have a leak-free motor and it all now seems worthwhile. Pity the other garage I took it to misdiagnosed the fault as being cam covers, however no harm in having the new type covers I suppose.
Omega - oil leaking onto manifold - Richard Turpin
Congratulations to cromster for his brilliant post.
I had the same on an Audi 100. Easiest cheap "repair" is to squirt some "gunk" around the leak every now and again. This cleans it and the oil accumulation has to start all over again before it gets to the manifold. I did this for about 2 years and it never caught fire.

 

Value my car