Volvo 2002: why does oil spit out of dipstick?

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eddystone

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Just having some second thoughts like do I really need to replace this engine? Having concluded now that my "steam" under load is maybe all white smoke no question injectors need doing, but engineer inspection (and he has a good reputation in the area) said oil spitting out of dipstick tube and heavy breathing evident when oil filler cap removed indicative of excess crankcase pressure oil blowing past rings (there is a film of oil over the water in the bilge). On a quick trip down to boat today I gave the engine a run. Although not under load as I didn't have time to go for a run, no white smoke even at over 3000 rpm, really good flow of water so no cooling issues (but definitely spits oil when dipstick removed) Also starts first time from cold. The suggested action was to have injectors overhauled, remove and skim head, replacing valve seats (and maybe exhaust valves) but recognising this may indicate more extensive overhaul needed. This would to me be acceptable cost if I get 5 years (250-500 hours) out of engine since the boat will probably be worth very little then with or without a newish engine. However, if dismantling shows need for more extensive overhaul e.g. rings and pistons, then a new engine makes more sense, I think. But if there is evidence that oil is blowing past rings in what circumstances could this not indicate the need for more extensive work than just a head job?
 
Oil blowing past the rings indicates the engine needs new rings at the very least, more likely a rebore and new pistons. Not sure why anyone would think it means a head rebuild ??
 
I've had the single cylinder version of this engine (VP 2001) that suffered from stuck piston rings, giving low compression and oil blow by. Thankfully, only new rings were needed, but that does involve stripping the engine down to get there.
 
Excessive crank case pressure is the only thing that will cause oil to spit out of the dipstick. It has two possible causes: 1 the crankcase breather is blocked, or 2 there is a problem with piston rings. This may be General wear, requiring a rebore, New pistons and rings. It may be a broken ring, simply needing a new one. It may also be stuck rings needing freeing off or probably replacement.

Anything to do with rings and bores requires a full strip down. A leak down test which pressurised each cylinder and checks the rate at which the pressure drops may tell an experienced mechanic whether the rings are at fault. 'May' because a leaky valve will prevent diagnosis of the rings, letting pressure down more quickly. A compression test will not tell the mechanic very much except somethi g is wrong, which we know already!

I cannot see how a head rebuild will improve worn or stuck rings though! However once the head is off bore wear can be measured, giving some pointer to pthe fault. But it's not worth rebuilding without taking the pistons out and checking imho.
 
The best treat you can give your engine is to fire the engineer and remove him from your boat!

Come on all you forumites the clue is in the post, quote (definitely spits oil WHEN THE DIPSTICK IS REMOVED). What else would you expect with several kilos of metal slapping around in a gallon of oil.

The fact that the donk starts well indicates reasonable compression.

Any engineer worth his salt would not be leading you into that sort of expense without furthering proving the point by means of a compression test.

As an aside is this engineer operating in the Plymouth, Saltash or Torpoint area? No doubt the excellent engineer that maintains all the cross channel ferries and did the LPG conversions on said ferries working singlehanded out of a white van. IKUN.
 
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I agree, oil will spit out if the dipstick is removed, especially if there's no long guide tube that some engines have.
If it starts readily and doesn't use too much lub. oil, I'd leave it alone.
OK, check the cc. breather if there is one!
 
I had aso-called "Volvo specialist" tell me the same many years ago. I decided to ignore him and eventually found the problem to be a £4 seal that had broken down.

Check your engine compression first. This will tell you if pressure is getting past the rings. Usually if this is happening, you will have problems starting from cold and the engine will smike like a chimney until it warms up and the rings start to seal better.

Take the oil filler cap off, and put your hand over it to see how much pressure there is. You will always get a bit (this is why there is a breater), but if you have piston ring issues it'll pretty much blow your hand off as the pressure builds.

If this all checks out ok, change the oil and filter, and give it a good flushout with flushing oil. Put a new filler cap/breather on, and see what that does.
 
Does your engine have a rubber hose going from the valve cover to the air filter? This is the crankcase breather, and should be checked to ensure it's clear.

I think the gasket for the valve cover has a hole in it for crankcase ventilation, and if the gasket is wrongly installed this would block the ventilation.
 
I don't know what the breather is like on this engine?
Some engines, there is a gauze or similar to trap droplets of oil from the gases the breather passes. Too much dirty oil will block or restrict this. So the symptoms of the problem get worse.
Sometimes rings stick when the engine is not used for a while. Some hours of running with good clean oil may free them up. 'clean' is a relative term in diesel engine oil.
Definitely worth checking out the breather before anything else.
If it starts well, the rings are not desperate.
Is it possible to take the bottom off the sump in situ? I did that with my a Yanmar a while back, all sorts of gringe and bits of sealant etc in there!

What oil are you using? Something with good detergent qualities might help clean things up. But that needs getting the motor properly warm for a few hours.
 
third engines said:
Come on all you forumites the clue is in the post, quote (definitely spits oil WHEN THE DIPSTICK IS REMOVED). What else would you expect with several kilos of metal slapping around in a gallon of oil.
Click to expand...

Indeed, that's probably why most i/c dipsticks, particularly on higher compression diesel engines, have some kind of rubber sealing O-ring on the dipstick to maintain crankcase pressure and prevent the oil droplets spraying into the engine bay. Guess what happens if you remove the dipstick whilst the engine is running? ;)

Richard
 
oldharry said:
Excessive crank case pressure is the only thing that will cause oil to spit out of the dipstick. It has two possible causes: 1 the crankcase breather is blocked, or 2 there is a problem with piston rings. This may be General wear, requiring a rebore, New pistons and rings. It may be a broken ring, simply needing a new one. It may also be stuck rings needing freeing off or probably replacement.

Anything to do with rings and bores requires a full strip down. A leak down test which pressurised each cylinder and checks the rate at which the pressure drops may tell an experienced mechanic whether the rings are at fault. 'May' because a leaky valve will prevent diagnosis of the rings, letting pressure down more quickly. A compression test will not tell the mechanic very much except somethi g is wrong, which we know already!

I cannot see how a head rebuild will improve worn or stuck rings though! However once the head is off bore wear can be measured, giving some pointer to pthe fault. But it's not worth rebuilding without taking the pistons out and checking imho.
Click to expand...

Does a leak test involve any dismantling? I'll have to check where the crankcase breather is on the 2002.
 
eddystone said:
Does a leak test involve any dismantling? I'll have to check where the crankcase breather is on the 2002.
Click to expand...
A leak test demands a supply of compressed air and other devices valves etc. You only need a simple compression test. Injectrs out and a fitting to replace the injectors with an adaptor to fit a pressure gauge, spin engine and note readings. Made one to fit our test set with an old injector.
 
The very simplest compression test is to bar the engine over using a socket spanner on the bolt on the end of the crankshaft. If the compression is good it will take considerable effort to turn it over top dead centre. This is somewhat subjective but will give you a first indication. The usual test to be carried out next is to turn the engine over on the starter and squirt oil into the intake. This coats the bores and temporarily seals leakage past the rings. If the effort required to bar the engine over now increases you know there is a problem.
 
third engines said:
A leak test demands a supply of compressed air and other devices valves etc. You only need a simple compression test. Injectrs out and a fitting to replace the injectors with an adaptor to fit a pressure gauge, spin engine and note readings. Made one to fit our test set with an old injector.
Click to expand...

Well yes, on any other engine not a problem, but this is a VP 2002 with those copper seals. The injector might come out okay or it might bring the copper seal out too which is then a head off job.

Can't recall were the engine breather is on my 2003 version of this engine and nothing goes to the metal air filter case, perhaps PVB is right its a gap in the gasket.

If the rings are sticky when was the oil last changed and has it had an Italian tune up recently?
 
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vyv_cox said:
The very simplest compression test is to bar the engine over using a socket spanner on the bolt on the end of the crankshaft. If the compression is good it will take considerable effort to turn it over top dead centre. This is somewhat subjective but will give you a first indication. The usual test to be carried out next is to turn the engine over on the starter and squirt oil into the intake. This coats the bores and temporarily seals leakage past the rings. If the effort required to bar the engine over now increases you know there is a problem.
Click to expand...

Exactly.
But you know it starts Ok, so the compression is not that bad.
I would sort the breather out before touching anything else.

The breather is probably just strip clean re-assemble, maybe the odd cheap gasket.
On an old engine, you want to get all the 'very cheap to fix' bits on your side before paying out real money.
 
Pete7 said:
Well yes, on any other engine not a problem, but this is a VP 2002 with those copper seals. The injector might come out okay or it might bring the copper seal out too which is then a head off job.QUOTE]
Total fantasy, but, it will cost many shekles to buy the tool.. Can point you in the direction of someone that has the Volvo tools
if necessary.
Click to expand...
 
PaulRainbow said:
Great thinking, let's all ignore the smoke and the excess crank case compression through the filler. :encouragement:
Click to expand...
Do you remember my recent quote concerning an engineer that destroyed a small oboard by overzealous use of fogging oil? See #6 post of this discussion last paragraph and put 2+2 together. I may be totally wrong but the story smacks of his modus operandi.
 
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