Volvo Penta spinning, not starting, no compression?

[gilgsn]

Hello,

I hope someone can give me some pointers.. Just as I was getting ready to finally leave, my engine won't start! It's a Volvo Penta 2001, one cylinder diesel.

The last time, I ran it for ten minutes just to check, no problem. This time, the engine spins but there doesn't seem to be any compression. I used the hand crank just to see, same result, the engine turns easily, without the decompression lever on. I should feel a good resistance, but nada..

The decompression lever feels very loose, as if not connected to anything. So, I removed the valves cover, as far as my expertise in diesel engines allows me.. When I turn the engine with the hand crank the two valves go up and down.. Again, no compression felt. The rod on top of the two valves that the decompression lever turns does turn freely with no resistance..

What broke? I really hope this isn't a big deal because my cruising kitty can't take the hit of professional repairs..

Any idea, suggestions? Thanks a lot!

Gil.

[deblen]

http://www.bluemoment.com/manuals/vo...002_worksh.pdf

[deblen]

VP2001 Valve train.pdf



Parts diagram

[deblen]

Link to complete parts manual for VP 2000 series diesels.

Volvo Penta Schematics - Marine Parts Express

[deblen]

The decomp. lever & it's shaft will hold the exhaust valve (right side valve) down (partially open) when set to decomp. position.
The exhaust valve will still be operated by the rocker & pushrod when decomp. is set,but the valve will not rise far enough to seal.
Has the roll pin-Item 23-fell out so that external decomp lever is not turning the decomp shaft?
Can you turn the decomp shaft with pliers in place of it's lever? carefully.
If decomp shaft turns ok,then something else may be keeping exh valve from fully closing.
Is there some clearance between rocker & valve when both intake & exh. valves are closed. Should be .004 in I think. Specs are in back of shop manual I posted.
Cheers/ Len

[deblen]

Just re-read ur post. You say the decomp shaft turns freely. That would indicate it is not holding exh valve open. Hmm..

Suspect sticky exh valve-not closing fully.Did the engine sit un-used long enough for some rust to make on exh valve in combustion chamber?
Try tapping on rocker arm while valve is in closed position. Use a wood block-do not hit on adjusting nut/screw with metal hammer. Sometimes bouncing the valve with tapping will clear the rust enough to get it operating again.
I don't know of any easy way to lube a valve in these engs. Possibly spraying some PB Blaster or other rust remover into the intake manifold while hand cranking would work on this 1 cyl. The distance from air intake to valve port is not that far so it might help.Remove air filter first.

/ Len

[hamburking]

I have a 2002.

You seem certain its a compression problem. I don't doubt you. But I have to ask...is there fuel? Is fuel getting to the injector?

There is a trick with the 2000 series...pull (and release) the engine stop fully ONCE. This sets the engine to "cold start". I don't know what that really means, but it has worked for me.

If you are correct about compression, then yeah, it has to be a valve issue I guess.

[kennyarmes]

Pull the injectors make sure the tips didn't break might be lodged up in the exhaust valve that happened to me once

[deblen]

Originally Posted by hamburking

I have a 2002.

You seem certain its a compression problem. I don't doubt you. But I have to ask...is there fuel? Is fuel getting to the injector?

There is a trick with the 2000 series...pull (and release) the engine stop fully ONCE. This sets the engine to "cold start". I don't know what that really means, but it has worked for me.

If you are correct about compression, then yeah, it has to be a valve issue I guess.

The cold start proceedure in manual is:
(1) Advance throttle (in neutral) to 1/2 (or more-I believe)
(2) pull out fully & push in fully on stop cable.
(3) Crank engine

This works on my 2003 anyway.

Cheers/ Len

[gilgsn]

Thanks Len, and others, I will either dive into it when I get back out there or have someone look at it for me, depending on finances.. Everything else is pretty much done on the boat and ready to go!

Gil.

[Boatyarddog]

Sounds like the exhaust or intake valve is possibly stuck in the open position.
Remove the valve cover and check, it's pretty easy to loosen them up.
Try first some Aerokroil Penetrant on the valve guide, and even warm the area with a heat gun or propane torch.
Just spray it down and lightly pull up on the valve spring upper washer where it connects to the valve stem.

You may even tap lightly on top of those stems with a light brass hammer or plastic dead blow hammer.
Just be gentle if this is the case, it happens pretty often, mainly when the engine is laid up for awhile without preparation.


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