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Volvo 2002 Valve Adjustment

robrichtx

New member
"Hi Guys - somewhat new to the

"Hi Guys - somewhat new to the Volvo 2002 engine. I am an old Atomic 4 guy - kept that engine running for quite some time now.

I retorqued my 2002's head studs today, and consequently adjusted the valve lash (clearance). The first three valves were okay - I got them to within the .012 inch factory spec.

However, the last valve (second on the aft cylinder) would not adjust. I was not able to fit the feeler guage between the top of the valve and the tappet, even after full adjustment on the push rod.

Any ideas why this rear valve is so tight? Is this just par for the course with this engine?

The engine has been great so far, with the exception of a few fuel problems. I only adjusted the valve lash at the recommendation of the service manual (valve adjustment every 50 hours).

Thanks guys -

Rob"
 
valve may be failing. remove r

valve may be failing. remove rocker arm assy. and check stem height with straightedge. DON'T RUN it without proper clearance. could cause major damage.
 
would suggest that before doin

would suggest that before doing anything - that you cofirm thhat pistion is at top of compression stroke then recheck your clearances.
 
"Rob
Why did you retorque the


"Rob
Why did you retorque the head? Did a manuel call for it.If not never retorque a head, you cause more problems then you could ever solve. You may haved crushed the gasket more then called for giving you less distance and setting up you valve problem.To tight a valve might signal damage to the rocker arm or push rod. Don't not roll the engine over until you clear the problem. Best of luck"
 
"WAAAAHHHHOOOOOOOOO!!!!!!!!!!!

"WAAAAHHHHOOOOOOOOO!!!!!!!!!!!!

Sorry, but these moments are so rare, I had to yell! So - here is what I found. Remember that I am an amateur diesel head, so go easy with the criticism. Also know that I consulted a marine diesel mechanic and had him lined up to come bail me out on Saturday if I couldn't figure it out.

I came down to the boat today and spent half the day "working" and the other half messing around with the fuel system. I noticed some contamination in the fuel when I was bleeding it, so I figured I'd clear that out. As I suspected - algae in the tank. Emptied tank, replaced w/fresh fuel. Engine still smoked and ran poorly, so I had to suspect that one of the valves was over adjusted and not sealing properly.

Took off the valve cover, checked the gaps - as before, three valves were in spec - the aft one was tight. After monkeying around with both valves on that cylinder with no resolution and multiple crank positions, I just sat back and stared at the valve train for a while. After a while I noticed a groove in the decompression cam - but it was only grooved to clear one of the valves - not the other. And the other, of course, was the problem valve.

A quick swing of the decompression lever rotated the cam so that a flat spot came to rest on top of the valve - allowing it to pop out to its normal resting position. Just for giggles I stuck the .012 " feeler guage in there and there was no room. Valve was over-adjusted. So - backed it off, readjusted it, checked it, and low and behold, the feeler guage fit. I checked the other valve, then checked both valves on the other cylinder just to be sure.

A few manual cranks on the engine confirmed everything seemed okay, so back down w/the decompresion lever, switches on, crank and... vrooommmm. Perfect. No smoke, immediate throttle response, full power. I was psyched!!!

The problem was that I was not rolling the decompression lever back over to its compressed setting, which of course affected the clearance. The service manual never mentioned this once - but they didnt mention using the compression lever to rotate the engine either, so shame on it and me. You'd figure if you're paying for a service manual, they might mention this fact. Then again, they might assume a level of proficiency... who knows.

I should also mention that before adjusting the valves, I loosened and then retorqued the headstuds, and did the same for the studs holding down the valve train. Once everything was equalized, I adjusted the valves.

Capt Myers - I was retorquing the studs at the recommendation of a good friend and mechanic - 52 ft/lbs per stud, in a crossing pattern across the head (18.2 ft/lbs on the valve train studs). I wanted to make sure none of them had loosened, as the engine is 15 years old now and likes to start on one cylinder, then fire on two after about 20 seconds. The studs were probably overkill, but I need to adjust the valves anyway...

So - if you need to adjust your valves, make sure to put the decomp lever in its normal position.

Best of luck -

Rob

aboard S/V Infinity - Austin, Texas"
 
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