3.0 GLP-J Cylinder Evaluation

[Smoky123]

The last two times at the lake we had some issues with the engine and just made it back to the dock.
I found the sparkplugs of cylinder 2 and 3 burned/ melted off like you see at the picture. I decided to take the motor apart to change the head gasket and the cylinders for damage.
I might will bring the head to the shop for proper valve setting. I don?t know what to make out of the lines in cylinder four. You see a small spot in the wall and some rings at the top.
You can feel them a bit but I?m not sure? I?m just an electrician?
Any input would be helpful.
Mike

 

[jerryjerry05]

That "line" looks like old water damage.
The plugs look like pre-detonation??
Timing off? Sucking air?
After the head's replaced, do a compression test.

 

[Assassin3F]

You already got the head off so you should swap out the gasket and do a compression test once it is reassembled. Make sure you inspect the valve assemblies as well one possible cause for that plug condition is head gasket...another is a sticking valve or a corroded valve. You can actually get the shop manual for the 3 liter by searching on boatinfo (in the adults only sticky on the main thread). I can't tell if the lines in your cylinder are engraved into the metal or just surface stains. One thing to remember is these engines tend to sit unused for long periods of time so it might be water related or it might be a bit of varnish from oil trapped in the ring seals outside the piston. If it isnt rust and it isnt goouged into the metal then you should be able to buff or scrub it out. Otherwise do the compression test procedure in your manual and that will tell you if you have a problem. I probably would be cautious about using anything more aggressive than a fine grade of steel wool and hand pressure to remove any stain...its just me but I wouldnt want anything that could possibly compromise my seals at the cylinder wall.

 

[Smoky123]

Hello Assassin3F,

Thank you for your note.
I found several issues which might also cause some issues I had last year with the overheating.
As I took the head of the engine I found one rubber section of the impeller in one hole of the lower engine block. This caused a reduced flow and caused overheating under load. I overcame the issue by removing the reducer plate between the manifold and the raiser.

I think at that time the damage to the head was already done.

I took the head to a machine shop and they found one intake valve which was bad and I had warpage.
I?m getting the head back this Thursday and then will put the engine back together.

 

[Smoky123]

No Title

I got the head back on Friday, they found a second valve which needed replacement. Over the last two days I assembled the engine again and ran it in the drive way. It runs very smooth but I still need to take it to the lake...

 

[jerryjerry05]

Do another comp test???

 

[Smoky123]

Hello, I didn't perform a compression test but I took the boat out on Friday, Saturday and we went wakeboarding today.
Yesterday we went on a 2.5 hour lake trip.
Somehow I must have disconnected the speedometer will someone be able to tell me if it is connected to the motor or if it is connected to a compression tube.

 

[jerryjerry05]

Could be hooked to the drive?
Could be hooked to a pitot tube on the transom.
Lots of times the pitot tube gets tilted up when trailering or lifting out of the water.
Pics of the transom?
The pitot tube hook to a small tube that runs to the back of the speedo.