No compression in 2nd and 3rd cylinder in 1989 GMC s15
November 8th, 2015, 10:23 AM
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No compression in 2nd and 3rd cylinder in 1989 GMC s15
1989 GMC s15 automatic 4 cylinder ...
I found that there is very low compression in 2nd and 3rd cyl. like about 5 psi but 1st and 4th cyl. have 125 psi
is 125 psi ok or it is sill low?
also, truck was not running ...can it run on 2 cylinders?
and is there any other reason why it shows 5 psi in 2nd and 3rd apart from either valves or lower engine problem?
I found that there is very low compression in 2nd and 3rd cyl. like about 5 psi but 1st and 4th cyl. have 125 psi
is 125 psi ok or it is sill low?
also, truck was not running ...can it run on 2 cylinders?
and is there any other reason why it shows 5 psi in 2nd and 3rd apart from either valves or lower engine problem?
November 8th, 2015, 9:40 PM
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At this point it could be just a blown (really badly) head gasket. If you try driving who knows what additional damage you could do to it.
How do the fluids look? Coolant and oil mixing anywhere?
I'd start by getting the head off and looking for problems on the top end.
As far 125psi being "ok", you'd have to look up the specs for that engine.
How do the fluids look? Coolant and oil mixing anywhere?
I'd start by getting the head off and looking for problems on the top end.
As far 125psi being "ok", you'd have to look up the specs for that engine.
November 8th, 2015, 9:48 PM
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At this point it could be just a blown (really badly) head gasket. If you try driving who knows what additional damage you could do to it.
How do the fluids look? Coolant and oil mixing anywhere?
I'd start by getting the head off and looking for problems on the top end.
As far 125psi being "ok", you'd have to look up the specs for that engine.
How do the fluids look? Coolant and oil mixing anywhere?
I'd start by getting the head off and looking for problems on the top end.
As far 125psi being "ok", you'd have to look up the specs for that engine.
I think it was empty before few months and I filled it and now its empty again..
Last edited by curiousvi; November 8th, 2015 at 10:14 PM.
November 9th, 2015, 12:01 AM
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Coolant can leak from a hundred places but if you don't see puddles that narrows it down to about 50 places, but those are the places you DON'T want the leak to be. Good news is that it isn't mixing with the oil.
You could recheck the compression on 2 & 3. Verify that you don't have a leak from the plug hole causing the tester to show that low. If it really is at 5psi though you are going to have to pull the head.
You could recheck the compression on 2 & 3. Verify that you don't have a leak from the plug hole causing the tester to show that low. If it really is at 5psi though you are going to have to pull the head.