Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: terry paget on 10 January 2018, 10:51:22

Title: Smell of hot oil when engine is warming up
Post by: terry paget on 10 January 2018, 10:51:22
pfl 2.5 petrol manual estate
My favourite Omega has the above failing. I do not smell it after the start up whiff, thought that may be my nose only detecting change of odour. I have cleaned the breathers yet again, but to no avail. I suppose it is smelled when the heater fan comes on as the coolant temperature rises.
Title: Re: Smell of hot oil when engine is warming up
Post by: Lizzie Zoom on 10 January 2018, 10:54:00
pfl 2.5 petrol manual estate
My favourite Omega has the above failing. I do not smell it after the start up whiff, thought that may be my nose only detecting change of odour. I have cleaned the breathers yet again, but to no avail. I suppose it is smelled when the heater fan comes on as the coolant temperature rises.

Maybe a silly question, but you have done the breathers, did you check the spark plugs to see if any oil is around them after leaking from the cam covers? ???
Title: Re: Smell of hot oil when engine is warming up
Post by: Nick W on 10 January 2018, 11:14:42
You have cleaned the entire engine of all the old oil from the various characteristic oil leaks?
Especially the area's you can't easily see, like under the exhaust manifolds.
Title: Re: Smell of hot oil when engine is warming up
Post by: Omega Nige on 10 January 2018, 12:49:26
I had a similar problem and tracked it down to the 'o' ring seal on the oil filler cap  ;)
Title: Re: Smell of hot oil when engine is warming up
Post by: Enceladus on 10 January 2018, 15:18:22
To me this means the seals on the cam covers are leaking somewhere and oil is dripping onto one or both of the exhaust manifolds. Usually because the breathers are blocked or obstructed. Could be that the leak stops when the engine gets hot. If the breathers are clear then it might be that the cam cover seals are not the original spec GM. Also the original sealant, even when used with genuine GM seals,  will eventually fail. The newer black stuff is much better.
Title: Re: Smell of hot oil when engine is warming up
Post by: tunnie on 10 January 2018, 15:40:50
Only time I had oil smell in the car was due to failed cam covers, as above the oil would hit exhaust and burn off.
Title: Re: Smell of hot oil when engine is warming up
Post by: terry paget on 10 January 2018, 16:00:09
pfl 2.5 petrol manual estate
My favourite Omega has the above failing. I do not smell it after the start up whiff, thought that may be my nose only detecting change of odour. I have cleaned the breathers yet again, but to no avail. I suppose it is smelled when the heater fan comes on as the coolant temperature rises.

Maybe a silly question, but you have done the breathers, did you check the spark plugs to see if any oil is around them after leaking from the cam covers? ???
Good question. I certainly checked oil in plug holes last September, all was well then. Checked today, driver's side 1-3-5 was bone dry, passenger's side looks trickier. Can it be done without dismantling the wiring harness?
Title: Re: Smell of hot oil when engine is warming up
Post by: johnnydog on 20 January 2018, 11:39:03
A few days after you asked the question, but the wiring harness is an obstacle, but not difficult to overcome. You basically need to remove the wiring harness tray cover, lift up the harness and tie it up out of the way sufficiently to allow access, remove the tray itself, and you are in there.
Just be careful with the small plastic tabs on the harness tray cover - they break very easily.
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 20 January 2018, 12:35:39
This won't cure your problem, but will hide the symptoms: at the bottom of the pollen filter chamber is a rubber bung with a very rudimentary one-way valve ( a rubber flap) to allow water to exit but prevent underbonnet fumes from entering the cabin.
In my car, the flap had glued solid and retained rainwater. I could not manage to unstick it and on a visit to Serek, he solved the problem for me in a very technical way - he threw it away!
What I'm really asking is do you smell the hot oil from inside the cabin, or only outside?

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: terry paget on 20 January 2018, 14:09:21
This won't cure your problem, but will hide the symptoms: at the bottom of the pollen filter chamber is a rubber bung with a very rudimentary one-way valve ( a rubber flap) to allow water to exit but prevent underbonnet fumes from entering the cabin.
In my car, the flap had glued solid and retained rainwater. I could not manage to unstick it and on a visit to Serek, he solved the problem for me in a very technical way - he threw it away!
What I'm really asking is do you smell the hot oil from inside the cabin, or only outside?

Ron.
Inside the cabin. I presume it comes in when the coolant get warm and triggers the heater fan to run.
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 20 January 2018, 14:27:56
Yes, which surely means that it is drawing air from outside via the pollen filter - and that bung/flap valve at the bottom of the chamber. It may be stuck open?

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: terry paget on 20 January 2018, 19:51:00
Yes, which surely means that it is drawing air from outside via the pollen filter - and that bung/flap valve at the bottom of the chamber. It may be stuck open?

Ron.
Thanks, Ron. I had a look down below the pollen filter, and I could see nothing but mud, and a bundle of wires disappearing through a hole at the bottom, with a displaced grommet around it. After considerable digging in the mud I think I have found the drain grommet, hopelessly blocked. Luckily the water could escape down the cable hole. I took a photo. My inclination is to push the drain grommet  out. Good idea?
(https://www.dropbox.com/s/1pbpsac0bw2pajx/scuttleDRAIN.jpg?dl=1)
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 20 January 2018, 19:56:48
Yes, mine was like that! You can either remove it, give it a thorough clean and replace it, or apply the Serek Ultimate Solution - bin it!  ;D

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: cam.in.head on 20 January 2018, 22:39:03
i would imagine as others have said earlier that the drain grommet is in effect a one way valve with a flap to allow water out and hopefully no fumes back in. it was originally designed and fitted by gm and if it didnt need it they would have saved on production costs .theoretically there shouldnt be any fumes coming from the engine but as we all know these engines have a history of various oil leakage areas and after sorting them there are some hard to reach areas to clean off. so personally i would refit the cable grommet and clean up the drain grommet and refit .the valve realy needs checking regularly for blocking and cleaning. incidently when checking for oil leakage /smells on the passenger side its noted that the oil filler cap extention tube can leak on its bottom o ring and also from the cap especially if the o rings have hardened over time.
also a tip on a BASIC  check of the breathers to check they are at least partly open and not totally blocked is to get a piece of hose that will just fit onto the dipstick tube end and blow into it.if they are totally blocked pressure will build up and be very obvious but if there is a way through you will hear yourself blowing into the plastic ecotec bridge.a quick basic test if you are about to set off on a journey and dont want or have time to get dirty. i check mine this way when i check oil level and clean breathers out properly at oil change time
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 20 January 2018, 22:58:11
Good tips there, "cam.in.head", thanks.
I do agree with you that the drainbung has a purpose, but mine allowed a swimming [pool to develop and gave my carpets an unwelcome rainwater wash! When I managed to clear the debris, the flap was so tired it didn't work, so it got "Serek-ed" during a service!  ;D

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: Doctor Gollum on 20 January 2018, 23:01:40
Good tips there, "cam.in.head", thanks.
I do agree with you that the drainbung has a purpose, but mine allowed a swimming [pool to develop and gave my carpets an unwelcome rainwater wash! When I managed to clear the debris, the flap was so tired it didn't work, so it got "Serek-ed" during a service!  ;D

Ron.
Only because it had never been properly looked after...
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 20 January 2018, 23:12:05
Probably true, DG, but I didn't know there was a bung to look after until advised on here - another reason to love being here.  :-* :-* :-*

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: johnnydog on 21 January 2018, 00:08:57
I find the best way to clear the drain bung if it's full of crud is to fill the void below the pollen filter with half a gallon of water with a watering can or hose, wriggle your hand between the abs unit brake pipes, and squeeze the protruding end of the drain a few times, and the weight of the water will force its way through dislodging the crud, flushing the drain and flap at the same time. Far easier than removing the drain bung to clean it (getting it back is the hardest bit) or attempting to poke some wire through (which never works in my experience).
Title: Re: Smell of hot oil when engine is warming up
Post by: robson on 21 January 2018, 10:40:04
Why such a big problem having once had a cabin of water I regularly check the flap area, if needed flush out any rubbish and if dry  hoover out any debris.The answer is regular attention.
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 21 January 2018, 10:58:10
Dare I ask if anyone is breaking an Omega and has a serviceable drain bung on offer?

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: cam.in.head on 21 January 2018, 11:08:29
Probably true, DG, but I didn't know there was a bung to look after until advised on here - another reason to love being here.  :-* :-* :-*

Ron.
.  this is so true and i bet many an omega owner ,myself included only found out about the blocked flap once they discovered a gallon of water in the passenger footwell. a bug*** to dry out so now i check the drain regularly . all cars have these ,dare i say “design faults/issues” which only come to light as the cars get older. still worth it thou!
Title: Re: Smell of hot oil when engine is warming up
Post by: Bigron on 21 January 2018, 11:33:11
That is exactly how I found out about the skuttle drain.
I asked on here why I had a minor paddling pool in the footwell, as it didn't smell of antifreeze and only occured after an English summer, i.e. heavy rain! As my driveway slopes upwards, I got the benefit of a pool in the back as well.....lucky me!  :(

Ron.
Title: Re: Smell of hot oil when engine is warming up
Post by: terry paget on 21 January 2018, 19:11:58
i would imagine as others have said earlier that the drain grommet is in effect a one way valve with a flap to allow water out and hopefully no fumes back in. it was originally designed and fitted by gm and if it didnt need it they would have saved on production costs .theoretically there shouldnt be any fumes coming from the engine but as we all know these engines have a history of various oil leakage areas and after sorting them there are some hard to reach areas to clean off. so personally i would refit the cable grommet and clean up the drain grommet and refit .the valve realy needs checking regularly for blocking and cleaning. incidently when checking for oil leakage /smells on the passenger side its noted that the oil filler cap extention tube can leak on its bottom o ring and also from the cap especially if the o rings have hardened over time.
also a tip on a BASIC  check of the breathers to check they are at least partly open and not totally blocked is to get a piece of hose that will just fit onto the dipstick tube end and blow into it.if they are totally blocked pressure will build up and be very obvious but if there is a way through you will hear yourself blowing into the plastic ecotec bridge.a quick basic test if you are about to set off on a journey and dont want or have time to get dirty. i check mine this way when i check oil level and clean breathers out properly at oil change time
Thanks, cam in head, for your comprehensive advice. I performed your breather function test, all well there, and no hissing from cam cover gasket region. As shown in the pic, the grommet taking the wiring through the bulkhead was displaced, good thing too, because the scuttle drain grommet was completely blocked with mud. I failed to relocate the wiring grommet, so pushed the drain grommet downwards out of the scuttle bottom plate, hoping I could retrieve it from below; not so, there is a heat shield in the way. I tried to pull it upwards, but failed.
At least the scuttle will drain properly now. I suppose this is the state of affairs I should expect on an 18 year old 200,000 mile car. At least it has not flooded the cabin.
Title: Re: Smell of hot oil when engine is warming up
Post by: cam.in.head on 22 January 2018, 11:13:36
thats true cos its a sod to dry out when it does especially this time of year.
also re the breathers. mine is only a basic test to meke sure they are not totally blocked. i doubt you would hear air escaping from the cam covers anyway but on an unblocked breather you should hear yourself blowing through into the plenum plastic top section.on a blocked up breather you would not be able to do this and would end up creating a pressure inside the. crankcase as you blow.
sorry if i misunderstood what you just replied. you have many years more experience on omegas than myself so not trying to tell you how to do stuff.