(T) Compression test

j1mbo · 25-03-2010

Hi all,

Having a slight issue with a smokey 1.2 16v engine. There seems to be a bit of blue/grey ish smoke coming out of the exhaust when revving over 2000rpm. Just done a compression test and the results are as follows.

Cylinder 1 - 210psi
Cylinder 2 - 195psi
Cylinder 3 - 200psi
Cylinder 4 - 210psi

Doesnt seem very far out to me, what should it be roughly on a ood engine? also the car hasnt been run for a while and had a misfire problem which has been sorted.

rallycinq · 25-03-2010

I presume this was the dry test. Did you have a wet test done as well?

Cheers

SPD

bredsticz · 25-03-2010

Should all be very close together and one of my cars runs at 14 Barrs, another runs at 12.8 barrs. Depends on the engine, too much difference there and to me looks like a head gasket job! Heater working, any loss of fluid levels?

rallycinq · 25-03-2010

Originally Posted by bredsticz

Should all be very close together and one of my cars runs at 14 Barrs, another runs at 12.8 barrs. Depends on the engine, too much difference there and to me looks like a head gasket job! Heater working, any loss of fluid levels?

Calm down to a frenzy!

They are close enough and all around 13 bar.

Cheers

SPD

j1mbo · 25-03-2010

Originally Posted by rallycinq

I presume this was the dry test. Did you have a wet test done as well?

Cheers

SPD

I did the test myself and it was a dry test ill do a wet test tomorrow.

rallycinq · 25-03-2010

I'd not bother really, just wanted confirmation that was the dry one.

Compressions are all within reason, nothing to worry about there.

Blue/gtey smoke could be unburnt fuel burning off, if you've had an ignition derived missfire a heap of fuel will be all over the inside of the exhaust system.

If the car hasn't been run for a while, check your levels and get it warm then out and give it the full moooo.

Cheers

SPD

reddy4bed · 25-03-2010

compressions are ok. Get someone to follow you along a fast road, get some speed up and and allow engine to overun as it slows, stick the throttle down hard and watch for blue smoke. If evident, then its oil control rings or valve stem seals (if used).
Tony.

tinytim · 25-03-2010

agree; figures are all within 5% of the average so are ok

bredsticz · 25-03-2010

Ahh sorry, I was in a rush before, I only know barrs so don't know the difference between psi.
I just saw 2 of the together with lower pressure.
15 psi difference may not be anything then!

25-03-2010	#2
rallycinq Autotest Special Join Date: Mar 2002 Location: Lake District....Moist Posts: 23,487 Thanks: 1152 Blog Entries: 3 Trader Rating: 1	Re: Compression test I presume this was the dry test. Did you have a wet test done as well? Cheers SPD __________________ My Rock Radio
	Quote

25-03-2010	#3
bredsticz I like to be different! Join Date: Jul 2009 Location: Manchester Posts: 4,479 Thanks: 213 Trader Rating: 1	Re: Compression test Should all be very close together and one of my cars runs at 14 Barrs, another runs at 12.8 barrs. Depends on the engine, too much difference there and to me looks like a head gasket job! Heater working, any loss of fluid levels? __________________ Any MK2 punto parts needed? Let me know! I have 2 punto's worth of parts for sale
	Quote

25-03-2010	#4
rallycinq Autotest Special Join Date: Mar 2002 Location: Lake District....Moist Posts: 23,487 Thanks: 1152 Blog Entries: 3 Trader Rating: 1	Re: Compression test Originally Posted by bredsticz Should all be very close together and one of my cars runs at 14 Barrs, another runs at 12.8 barrs. Depends on the engine, too much difference there and to me looks like a head gasket job! Heater working, any loss of fluid levels? Calm down to a frenzy! They are close enough and all around 13 bar. Cheers SPD __________________ My Rock Radio Last edited by rallycinq; 25-03-2010 at 14:50.
	Quote

25-03-2010	#6
rallycinq Autotest Special Join Date: Mar 2002 Location: Lake District....Moist Posts: 23,487 Thanks: 1152 Blog Entries: 3 Trader Rating: 1	Re: Compression test I'd not bother really, just wanted confirmation that was the dry one. Compressions are all within reason, nothing to worry about there. Blue/gtey smoke could be unburnt fuel burning off, if you've had an ignition derived missfire a heap of fuel will be all over the inside of the exhaust system. If the car hasn't been run for a while, check your levels and get it warm then out and give it the full moooo. Cheers SPD __________________ My Rock Radio
	Quote

25-03-2010	#9
bredsticz I like to be different! Join Date: Jul 2009 Location: Manchester Posts: 4,479 Thanks: 213 Trader Rating: 1	Re: Compression test Ahh sorry, I was in a rush before, I only know barrs so don't know the difference between psi. I just saw 2 of the together with lower pressure. 15 psi difference may not be anything then! __________________ Any MK2 punto parts needed? Let me know! I have 2 punto's worth of parts for sale
	Quote

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