Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Andy Cas on 09 November 2008, 21:15:43

Title: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 09 November 2008, 21:15:43
Hello, my 2.0 16v petrol omega estate (N reg) has a strange problem. Since I first bought it 2 months ago it has sounded like a diesel when cold - gummed hydraulic tappet/s I know btu this sound dies down generally, but it has been louder recently, and after a motorway run, it belched blue smoke when I accelerated on to a roundabout. When I had a look at the motor earlier, I saw a gas coming from the oil filler cap (on the intake side). When I removed the cap it was clear that exhaust was coming from it! I revved the engine and more came out! I also heard an irregular rattling noise. The gas was slightly black - unburned fuel obviously, but how the hell it it coming out this side? Anyone heard of this before? I am guessing it's... a gummed up tappet has let the camshaft damage a follower, and push a valve in the wrong manner, damaging the valve stem seal and now the valve dosen't seat properly (on the intake side), letting exhaust gases back to the intake side and up through the stem seal, out through the top..? I traced it by cleaning out the idle valve as it was gummed up - again. -Now I know why!!
Anyone heard of this before? I certainly haven't
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: MutantCav on 09 November 2008, 21:36:09
How do you sort out the gummed hydraulic tappets?
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Abiton on 09 November 2008, 21:42:46
Blow by, blocked breathers, not far from a SNAFU TBH.  ;D
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 09 November 2008, 21:43:31
(I must get round to it) - The tappets can be removed (get a haynes book of lies), and google "cleaning hydraulic tappets" . Basically you can disassemble them and clean up the mating faces with real fine wet and dry until the internal piston slides freely, fill them back up with oil and reassemble. They then adjust themselves as they should and the engine runs silent from cold.

I am quite apprehensive about doing it though as if they are buggered (or I bugger them up), they are about 20 quid each (and I have 16 of them)

I have to take my big golden whale off the road now as I can't risk dropping a valve this early into owning it!
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 09 November 2008, 21:45:48
What do you mean by SNAFU TBH? I havent heard that before
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: ngrainqey on 09 November 2008, 21:50:42
maybe he means fubar :P
both bars though haha!
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 09 November 2008, 22:01:58
I guess it's a bit dirtier than I first thought!

I only paid 600 notes for it so I expected some hassles. Looks like it's a head off and recondition job then, hopefully not a damaged piston too. If I'm going to that trouble I may as well drop the sump out, clean out the oil pump and strainer too along with all the hoses and oilways I can get to.

That will solve the problem! Bloody vauxhalls. They're all the same.
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: jimmas on 09 November 2008, 22:02:58
sounds like a mixture of worn valve stem seals and piston ring wear, both will cause blue smoke out the exhaust and one will cause blow back up through the oil filler cap were it build back pressure.
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Abiton on 09 November 2008, 22:15:07
Quote
What do you mean by SNAFU TBH? I havent heard that before

Google SNAFU, I thought it was a common phrase, but contains a naughty word, so I'll not elaborate here  :o.

TBH = To Be Honest.

Meaning, overall, that your car is probably not as sick as you have decided.  There's a guide or two in the Maintenance section for getting all the breathers sorted out.  Jimmas has neatly summed up the situation with regard to the origin of the exhaust fumes.
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 09 November 2008, 22:30:07
Yes, you are right. It has only done 98,000 miles with a good S/history, but the oil is blacker than black (obviously). Just a shame. It's the gamble you take when buying an old car. I can do all the work myself over a week or so to save on beer tokens.

Strange thing is, the exhaust is normal - clear all the time, except for twice when it belched blue smoke. Worn rings would mean a smoky exhaust all the time...?

Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: markfree on 10 November 2008, 09:58:05
Try dumping a couple of cans of Ametech (engine restore oil) into your sump - it will cure your compression problems - you can also drizzle it neat onto your valve gear which may/maynot cure your valve problems.
 It ain't cheap (about £15/250ml) but it definitely works. My old honda crv suffered from your problems and after I dumped a couple of cans in the sump and 500 miles later it was running as sweet as a nut - fleabay or AmericanTechnology.co.uk to buy :y
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Martin_1962 on 10 November 2008, 10:22:43
Start by cleaning all of the breathers and do a couple of weekly oil changes, this SHOULD sort it.

Only after this try putting anything else in.

I would still prefer a rebuild to bunging in odd substances
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 10 November 2008, 13:35:49
The problem really is a previous lack of maintenance. A top end rebuild WILL sort the problem. I'll do ALL the breathers and the sump / pump at the same time. Lots of work but well worth it in the end as I'll have a motor that I can confidently trust!!

I'll take pictures along the way and post the news of my success / catastrophic failure. If it goes really wrong you might see it on youtube as well. :y
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Marks DTM Calib on 10 November 2008, 14:09:02
Black oil and a good service history record sudgest a fraudulant service history record or the absolute bare minimum carried out!

In would do as sudgested, regular oil changes to help clean the internals and a good breather/throttle body clean up as a started for ten.

The statement that a top end re-build WILL sort the issues is a brace one......what IF its the oil pump worn due to poor servicing, worn bores etc?
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: Andy Cas on 05 April 2009, 23:02:29
Hi Guys/Gals. In case anyone is interested, I finally sorted my rattly omega out.
Top end strip recondition and rebuild. It turned out that the cambelt was one tooth out on the camshaft sprockets (from the last owner doing the head gasket), and it was running "late" all the time, hence the backing up etc.
ALL the stem seals were shot along with six hyd. lifters being siezed solid. Water pump was on it's last legs too. All replaced, back together with new hd bolts, gasket, belts etc etc etc. New oil/filters and a few long runs to fill the new lifters up with oil... And it seems I have missed one lifter. It either knocks on the one lifter (too low), or horribly sticks too high, and I get one of the valves headbutting a piston. With the rocker cover off they all look identical. Ah well, I'll sort it out. Forgot to take pictures though.

I cleaned the whole car up today with the intention of selling it, but discovered that it really is a nice car when it is immaculately clean, and also discovered that the front seats tilt back!! I never knew that. It's now like driving a shiny barge down the road whilst sitting in an armchair.
Title: Re: Exhaust coming from oil filler cap!! - help!
Post by: mark.adams on 06 April 2009, 08:50:13
Quote
I cleaned the whole car up today with the intention of selling it, but discovered that it really is a nice car when it is immaculately clean, and also discovered that the front seats tilt back!! I never knew that. It's now like driving a shiny barge down the road whilst sitting in an armchair.
Now you've been bitten by the Omega bug.
They may be money pits or 'Friday Afternoon Cars' but we love them all the same and once you've done most of the work on them, you know their history and are loathe to part with them