0 PSI cylander 1 Mercruiser 3L (1995)

[boatdude100]

Engine shaking at idle and low speed forward gear. Easy to start when giving throttle. Runs fine high speed.
Compression test shows (starting from front of engine.... 0 180 148 122
How doomed am I?
Can it be a head gasket, valves or rebuild? Man, this has been a bad day.
Any positive thoughts?

I will do a leak test tomorrow am... I think I use mercruiser engine oil... a teaspoon full in each cylinder?
Thanks as always.......

 

[harringtondav]

Engines aren't my long suit, but with 23 yrs. and ?? hrs. on a four banger you could be worse off. I suspect you will be pulling the head, and hopefully your work will end there. I assume "runs fine" means good power. If you haven't experienced terrible oil consumption you could be good with some head and gasket rework.

 

[achris]

Pull the head (it'll have to come off anyway) and see what you see.

Chris.......

 

[Scott Danforth]

Engine shaking at idle and low speed forward gear. Easy to start when giving throttle. Runs fine high speed.
Compression test shows (starting from front of engine.... 0 180 148 122
How doomed am I?
Can it be a head gasket, valves or rebuild? Man, this has been a bad day.
Any positive thoughts?

I will do a leak test tomorrow am... I think I use mercruiser engine oil... a teaspoon full in each cylinder?
Thanks as always.......

with 0 on cylinder #1, it is something serious. could be head gasket, failed piston, bend valve, etc.
with 180 psi in cylinder #2, you have water in that cylinder.
cylinder 3 is normal
cylinder 4 is low

time to pull the head

 

[boatdude100]

Ever had 0 PSI in Cylander? 3L Cause?

Mercruiser 3L has 0 PSI in cylinder 1
Compression test shows (starting from front of engine).... 0 180 148 122

If you've had a 0, what caused yours?
Thanks!

 

[boatdude100]

Pull head Mercruiser 3L. Difficulty level?

I have to do this due to low compression. I'm pretty handy.
1) How difficult is pulling the head on Mercruiser 3L?
2) Assuming I have head reconditioned, is it difficult to re assemble and SET UP again? (valves or whatever)

 

[achris]

Please keep just the one thread to the one problem. Opening multiple threads on the same topic is very confusing... I have merged all 3 together...

Chris....
iboats mod team.

 

[Silvertip]

Adjusting valves is covered in detail in the engine service manual. Don't have one? Head to your local library or look at a few U-Tubes on how to do it. Yes -- if you have no idea what you are doing you can cause damage. No -- it is not a simple bolt on and torque everything down.

 

[boatdude100]

Wanted to share findings from my initial thread start with 0 psi in one cyl.
Pulled head, had bent valve, replaced, resurfaced head. total cost $800.

 

[Eric 3.7LX Alpha 1]

Thanks for the update.