Engine compression results

[pbottomley]

Right new car in this week, with a tired engine, did a compression test on it after I managed to get it turning over.

115 psi on all cyclinders apart from number 3 (20psi) I was very disapointed with that as its a nice looking SL90 unit and the PSI on all the cylinder should be higher than 115.

I added a drop of oil to the number 3 cylinder and the pressure rose to 85 psi! whicch with engine running for a few minutes dropped back to 40psi

Am I right to assume ist therfore shot piston rings and or scorred to hell and back bores?

Also when I take the plug out after a minute or two of running steam vents from the spark plug hole. It has no power when driving and white smoke comes from the exhaust.

With my skills and time (money) its easier to change the whole engine and throw the old unit away, but maybe just for once if its an easy fix I might go for it, advice welcome

[Sid]

Sounds like the head gasket to me.

Sid

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[pbottomley]

well yes the steam from the plug hole was a result of a gasket, but I wasnt so sure its the only problem!

I suspect that the bores are a bit scored and or piston ring cracked due to the period of time the car has stood without usage....

Your in agreement that whipping the head off is a good first check? (not mine the car!)

[Sid]

Yep, whipping the head off is definitely the place to start. Don't be deterred if you can't actually *see* a break in ther gasket as
they sometimes just leak between the gasket and the head or block face without actually blowing. Had this happen on my manta a few
times.
As you say, it could be that you also have a problem with the piston rings but for compression to be as low as 30 the rings would
need to have broken which would probably be evident by bore scoring or piston damage (sometimes a bit of broken ring can take a
visible gouge out of the piston. You'd also have loads of crankcase pressure and much blue smoke from the oil filler hole if it was
the rings though, so I still reckon theres a good chance this is just the gasket. Fingers crossed. Either way, head off is the first
job.

Sid

----- Original Message -----
From: "pbottomley" <webmaster@vauxhallviva.com>
To: <mechanicalhelp@vauxhallviva.com>
Sent: Monday, July 24, 2006 1:37 PM
Subject: Engine compression results


> well yes the steam from the plug hole was a result of a gasket, but I wasnt so sure its the only problem!
>
> I suspect that the bores are a bit scored and or piston ring cracked due to the period of time the car has stood without usage....
>
> Your in agreement that whipping the head off is a good first check? (not mine the car!)
> --
> [img:a7396710b5]http://www.danasoft.com/sig/vauxhallviva.jpg[/img:a7396710b5]
> _________________________________________________________
> This email was sent from the vauxhall viva owners club forum
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[pbottomley]

The word smoke from the oil filer hole ring a bell, there is smoke coming from it, whilst the engine runs and for a long time after as well, mind it could be steam??? things seem lubricated, to the eye, and there is pleanty of oil in the beast... (too much TBH).

Its going to be at least a week before I get time to get the head off the car, as its parked on the road side at the minute and until the builders finish fitting a new roof to the house I am not parking anything down the side of the house, as I dont like tile dents in the roof of my cars.

With the Possibilty that the engine is going to take loads of fixing, does anyone have a nice 1159 "90" engine spare thats good, near and cheap?

[MattHC1600SL]

Paul, before you do anything drastic, just stick am egg cup full of diesel down each plug hole and let it sit for a week. Might be just stuck rings, it has sat for a while that silver beast of yours hasent it? Diesel has never failed me yet, damn good stuff for freeing rings. Can't do any harm, might save you spending any money - that car is low mileage isnt it? Shame to change the engine if it still the original. I had an old Chevette once that had sat for 7 years in a barn, the rings had stuck on that on 2 cylinders, I left it standing for a week with diesel soaking in and after that it was fine. Good compressions and ran sweet as a nut. Matt.

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[pbottomley]

already on the case Matt, but alas damage is already done... suspect it was driven quiet hard at some point in the past with dry bores... I used the old diesel trick when i got it to free the engine off ...

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[MattHC1600SL]

Sorry, dont agree with Sid on the head gasket, no offence mate!
If the headgasket was gone you would get either oil and water mixing, high pressure and bubbles in the water, huge amounts of crankcase pressure (enough to force the dipstick out) none of which you mention. A bit of fuming out of the oil filler is normal, thats what the breather is there for. Steam coming out is most likely just condensation in the oil burning off, thats normal for an engine thats sat for a while. Ive never known a head gasket blow and just lose compression on one cylinder without causing one of the problems above, it could blow between two cylinders without causing any other problems, but then you would have compression down on 2 cylinders, not just one. Sounds like as you say the rings, but hopefully the disel will sort that if they are not broken. Good luck. Matt.

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[cossieviva]

paul,dont forget that car was sat in a garage for 9years befor i got it i carnt understand what went wrong with it when me and paul brought it back i changed the starter motor and it ran as sweet as a nut i took it for a quick spin and it was lovley now i can understand the headgasket failing but nut the rings
thake head off lap valves back in and new head gasket and i think it will be fine

[pbottomley]

Aye thats the plan, just getting ideas however as to what else could be wrong mate... I know the car was sat for a number of years and i wonder if they started it whilst it was dry as a bone?

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