chrysler 318's sticky rings

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hello i just bought a 32 ft luhrs with twin 318 chrysler inboards after doing a compression test i found 15 cylinders @ 135 to 150 psi and just 1 cylinder @ 120 psi the repair manual says 120 to 150 is right, my question in preventive maintance what could i add to the oil change to loosen up with believe is a slightly sticky ring, the motors are old and hardly used in the last 3 years thats why i am thimking a not bad but probley carbon build up on the one piston any ideas will be appreciated. I would like to see these engine run another 42 more years if take good care of Thanks Bob

 

[HT32BSX115]

Re: chrysler 318's sticky rings

Howdy Bob,


I am thinking that you should just change the oil and run the boat. Run it fairly hard. There's a lot of snake oil products out there that claim to free sticky rings but just changing the oil, running it, and getting up to temp will go just as far to do the same thing. Use a good grade of oil.

It's also possible that it's not sticking rings but intake or exhaust valve, or a bad cyl or rings...


Good luck,


Rick

 

[circle hook]

Re: chrysler 318's sticky rings

rick i shoot marvel oil down the cylinders turn the engine over a few turns and redone the compression and the readings were 150 accross the board, i waited 2 days and the compression droped in the one cylinder but was still 10 lbs higher she started at 120 and is 130 now so i put some also in the gas to see what happens so far so good rick Thanks Bob

 

[HT32BSX115]

Re: chrysler 318's sticky rings

rick i shoot marvel oil down the cylinders turn the engine over a few turns and redone the compression and the readings were 150 accross the board, i waited 2 days and the compression droped in the one cylinder but was still 10 lbs higher she started at 120 and is 130 now so i put some also in the gas to see what happens so far so good rick Thanks Bob

Yeah, dumping a little light oil will always do that. I think just running it will bring it back. Just make sure you run it long enough each time to get the oil fully up to temp.

I would not however put any kind of solvent in the oil to speed up the process. Doing that increases the change of a "sludged" engine shedding some of that sludge too quickly. If the sludge happens to be on the "wrong side" of the filter you risk the chance a spun or starved rod, crankshaft or cam bearing

Non-use is what kills most marine engines behind freeze damage!!

 

[circle hook]

Re: chrysler 318's sticky rings

well rick i aggree and rick do you know if i remove the 2 set screw bolts in the flange on the drive shaft to the transmission will i be able to remove the drive shafts out the rear of the boat to replace the packing box hose, Thanks Bob

 

[HT32BSX115]

Re: chrysler 318's sticky rings

It would depend on what type of set up it is I suppose

http://www.marinehardware.com/downloads/running_gear.pdf

If it's a tapered keyed shaft to the coupler, you might need some sort of a puller and a slide hammer to get it apart.

http://www.marinehardware.com/downloads/running_gear.pdf

It would depend on what trans you're using. That PDF above indicates what sort of coupler connects to various transmissions.