Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Rods2 on 16 May 2010, 17:14:08

Title: Head Gasket
Post by: Rods2 on 16 May 2010, 17:14:08
I've been reading articles on your here for a few months and have found it a very helpful friendly site. I have a poorly 1999 3.0L Elite Estate.

I've been losing water for sometime which has got progressively worse. It is not the HSE valve as this was replaced, when I started losing water, this slowed the rate of loss down, but did not stop it. It is now misfiring on tickover, once the engine has warmed up, but is ok underload above 2000rpm. There is also no steam from the exhaust on a hot day when the engine is cold, only when it is up to temperature. The dis pack and plug leads were replaced about 15,000 miles ago, but there is oil in the plug holes (cam box gasket leak?). There is no oil in the water and there is no white gunge on the oil dipstick.

I have done the test suggested in one of your help articles by filling the radiator expansion tank to the top, left the cap off and there is air returning through the top tube on this when I rev the engine, it also smells of exhaust fumes!  :'(

Yesterday I did a compression test on a warm engine (I think is it the nearside bank of cylinders that is missing as the plugs were cooler than the offside, when I removed them). What is puzzling me a bit are the results, as I would expect the compression to be lower if a head gasket had gone, but for two of the cylinders, on the nearside bank, it was much higher. The only reason I can think for this is that water is being drawn into the cylinders and this means that there is less room for the air to compress and making the reading higher?

The results were:

drivers side:
back: 230psi
middle: 252psi
front: 238psi

nearside:
back: 297psi
middle: 265psi
front: 235psi

Any advice on whether you think head gasket has gone would be appreciated as I don't want to strip the engine down and replace them unnecessarly!
Title: Re: Head Gasket
Post by: Elite Pete on 16 May 2010, 17:25:30
No6 cylinder reading does look high and I think its that one that causes the most problems. Have you tried removing the plenum and inlet manifold and pumping air into the cooling system to check for leaks in the V of the engine and pipes to the rear?
Title: Re: Head Gasket
Post by: JamesV6CDX on 16 May 2010, 17:44:17
Quote
No6 cylinder reading does look high and I think its that one that causes the most problems. 

If it was problematic though - would the reading not be low?

Maybe it's a tad higher due to some oil dripping into the bore when the plug was removed, causing a slightly inaccurate reading?  :)
Title: Re: Head Gasket
Post by: Elite Pete on 16 May 2010, 17:49:45
Water could be getting drawn into that cylinder.
Title: Re: Head Gasket
Post by: Rods2 on 16 May 2010, 19:04:31
Thanks, for the advice. I will remove the phenum and inlet ports next weekend and do a pressure test, as I going to fix the problem causing oil leaking into plug holes anyway, even I don't have to go as far as removing the heads.

The high reading could have been due to oil in plug holes as I did have this on all the plugs, but some may had more oil than others. :-/

There is no signs of any water under the engine from a leak and I've now losing alot of water, about half the header tank in warming up engine and it cooling down again for the compression test!  :-[

Unfortunately the losing of the water and the misfire on tickover but not under load are the same I had years ago when the head gasket went on a 960 Volvo that I had, so I'm fearing the worst.

I will let you know how I get on.