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Newer Model A4 Engine ran but not under load, would struggle at idle speed. Told that there was H2O in my 4th cylinder and needed a new head gasket. That's where I stepped in...Replaced Head Gasket, (two gaskets), replaced Manifold Gasket, Fuel Pump, Spark Plugs, Cables for Distributor and Coil, Removed cleaned and replaced Carb., cleaned cylinder head block of crap for the raw water cooling, new impeller, sucked out and replaced old oil, new batt(s), starter, solenoid, coil, oil pressure guage, etc. all working, now......No Compression...I am a typical sailor with a wet butt and an empty wallet. Any suggestions would help greatly, before I sell the Newport 30' with an engine that turns over but will not run.
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Welcome to the forum. "No compression" Stuck valves? Have you observed the valve motion while turning the engine by hand?
Dan S/V Marian Claire -
August W.
Welcome to the forum. We'll get you going. Hang in there.
In which cylinder(s) do you have no compression? What Dan was hinting at (I think) was a valve may be stuck in the open position due to the water intrusion.
Is the engine on the boat or on a stand? Rings, head, valves. Which is it that is causing the loss of compression? The first thing I'd do is have a look inside the lifter gallery.
You can check for comperssion with the piston at TDC compression with a rubber tip air pressure hose into the spark plug hole and see where the air escapes from. For example if the air comes out of an adjacent cylinder there is a blowen gasket between the cylinders. I don't think this is to feasible if the engine is on the boat however.
Stay dry.
TRUE GRITComment
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Both Dan and John have you going in the right direction. Sure sounds like stuck valves and it's likely the culprit. Have a look into the spark plug holes and look over toward the exhaust manifold...you may be able to see the valves. Spray a good penetrating oil in that direction and wait a few minutes and turn the engine over...continue to do so. You may try to push the valves down with an allen wrench if you can reach them. Another route may be take the side panel valve cover off the engine and move them from there. Continue to spray good penetrating oil in the spark plug holes directed at the valves...they should free up. If that doesn't do it you might have to take the head off again.Originally posted by Marian Claire View Post
All the best with that.Mo
"Odyssey"
1976 C&C 30 MKI
The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.Comment
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Compression on A4
thank you to all who have replied to my post. I will do the suggestions you have given and give you an update as soon as I can. Thanks again, very cool of you guys to give my the help.
EdComment
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