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Compression Test Results On 1275Gt
#1
Posted 07 June 2017 - 08:50 PM
2. 135PSI
3. 135PSI
4. 155PSI
No1 being closet to radiator, done a wet test in no.2 and read 180 PSI, is this a piston ring issue?
#2
Posted 07 June 2017 - 08:53 PM
I'd say it's blown between 2 and 3, as they're both consistently low.
Do a wet test on 3 aswell, for the hell of it. But ultimately you need to have the head off and see.
#3
Posted 07 June 2017 - 09:03 PM
bit concerning, though from those readings being how they are
would you suspect the head rather than the rings
#4
Posted 07 June 2017 - 09:21 PM
he dose not, he said you need to take the head off to inspec whats wrong, head gasket,crack in the haed or block ect
#5
Posted 07 June 2017 - 09:23 PM
I'm expecting the head gasket to have failed between cylinders 2 and 3, due to both readings being low and consistent with each other. The head itself is probably fine, unless it's an uneven head surface causing the issues.
It could be the rings, but it's unusual for 2 cylinders to fail in such a way that the compression readings are exactly the same if it was the rings failing.
Edited by RooBoonix, 07 June 2017 - 09:25 PM.
#6
Posted 07 June 2017 - 09:26 PM
i'd say more like rings do a wet test an see the results
whu did you replace the head in the first place
#7
Posted 08 June 2017 - 03:49 AM
#8
Posted 08 June 2017 - 07:28 AM
With a blown headgasket I d expect less compression tho?
Exactly. if the gasket was "blown" you'd see a much lower figure than you have, you can do a wet test on all four (Don't overdo the oil, you only need a small amont) Does the engine have a problem? If it were mine I'd just run it and not worry if its not doing anything annoying............
#9
Posted 08 June 2017 - 09:00 AM
#10
Posted 08 June 2017 - 07:06 PM
Dry
1. 150 PSI
2. 139 PSI
3. 134 PSI
4. 150 PSI
Wet
1. 182 PSI
2. 200 PSI
3. 180 PSI
4. 196 PSI
Any ideas? I only drive the car occasionally so is it ok to do so if it is the rings or I take it they will get gradually worse.
#11
Posted 08 June 2017 - 07:32 PM
these results would rule out the posibility that it is the head gasket, however i dont think it can definitely be put down to rings yet, try a leak down test.
#12
Posted 08 June 2017 - 07:36 PM
Ok redone the compression test
Dry
1. 150 PSI
2. 139 PSI
3. 134 PSI
4. 150 PSI
Wet
1. 182 PSI
2. 200 PSI
3. 180 PSI
4. 196 PSI
Any ideas? I only drive the car occasionally so is it ok to do so if it is the rings or I take it they will get gradually worse.
How are you carrying out the test - is this on a cold engine or after taking it out for a run to get up to working temperature?
#13
Posted 08 June 2017 - 07:41 PM
#14
Posted 08 June 2017 - 08:08 PM
#15
Posted 08 June 2017 - 09:40 PM
Yes leak down test is a much better test for diagnosis than a simple compression test. whilst the cylinder is pressurized you can listen at the exhaust, intake, and oil filler, if you can hear hissing at the Ex. or In. it indicates a valve problem. Oil filler is a bit trickier and involves a bit of experience as you will always hear a bit of hiss there just depends how much!
PS your compression test results are all over the map! I think maybe your technique or equipment is a bit suspect. However once again If it's not causing a problem I'd be inclined to just drive it............................
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