Piston Ring CLeaner

[aroona]

I have a VP 2002 which is drinking a bit of oil, before I start major surgery I thought I would try a bit of keyhole.

Has anyone had any success with a piston ring cleaner added to the oil? If so how long before it worked?

 

[nigelmercier]

Takes me back to pouring Redex into the carburettor on my car, with plumes of white smoke.

 

[robmcg]

I have seen some of that oil additive stuff that is supposed to stop old car engines from smoking, added to a boat Diesel engine. Must admit I was there with my skeptic hat on. The visible results were pretty remarkable and smoke was reduced by a heck of a lot. Engine was still going strong a few years later, and the bloke seemed pleased. Oil consumption was down by a fair bit. Not sure if it would qualify as a 'scientific' test and I can hear the echo of someone shouting snake oil!

 

[tokoloshe]

Be careful you don't end up with no cylinder compression.

 

[sailorman]

http://www.stp.eu/uk/products

 

[vyv_cox]

http://www.stp.eu/uk/products

But then, STP have been prosecuted several times for making false claims, most particularly for their PTFE additive that was proven to have wrecked engines.

 

[sailorman]

i guess the only way to free a stuck ring is to remove the piston

But then, STP have been prosecuted several times for making false claims, most particularly for their PTFE additive that was proven to have wrecked engines.

 

[aroona]

Thanks for the link - I'll try the oil treatment for diesels - i've got a feeling it could be an ongoing experiment!

 

[Sans Bateau]

Rather than it being a stuck piston ring, it is more likely to be glazed bores which could be the result of incorrect oil and/or the engine not getting to high enough temperature. Out of interest, historically, what oil have you been using?

 

[aroona]

Rather than it being a stuck piston ring, it is more likely to be glazed bores which could be the result of incorrect oil and/or the engine not getting to high enough temperature. Out of interest, historically, what oil have you been using?

This is quite possible - engine oil is volvo branded (not sure of exact type I would need to check) - The boat is relativley new to me and has previously spent the last 3 seasons pottering round the bay so the engine not getting up to temp is very likely . What is the best way of cleaning the bores ?

 

[wotayottie]

I have a VP 2002 which is drinking a bit of oil, before I start major surgery I thought I would try a bit of keyhole.

Has anyone had any success with a piston ring cleaner added to the oil? If so how long before it worked?

The engine is an old one and is quite likely to have worn a bit. But how much oil are you using anyway? If all you are talking about is needing to top it up every so often, then I would not be bothered too much. If like one of my engines, it is going from full to empty on the dipstick in 24 hours running then you do need to do something.

There are endless engine treatments and most of them are "snake oil". There even was an abrasive compound you could put through the air inlet on big diesels and which they reckoned would de-glaze the bores. Quite what happened to the bits that found their way past the rings I hate to think.

Do you find that your engine smokes for a minute or two after its been idling warm? If so what you are likely looking at is bore wear with the pistons cooling and shrinking a little bit when idling and then expanding and fitting better under load. The 2002 can go on like that for years but if you want to cure it then the only answer is a re-bore. On the other hand you may have oil coming past the valve seals which would give you a smokey engine all the time - not that difficult to deal with by whipping off the cylinder head and and replacing seals and valves as necessary. Its an easy DIY job.

But the main thing is noit to create unnecessary work or expense for yourself. Its an old used engine so you cant expect it to behave like a new one. ,If the oil consumption isnt too bad then oil is cheap compared to engine work.

 

[steadyeddy]

Piston ring cleaner

A few years ago i had a BMC petrol engine which smoked,i drained the old oil and and refilled with fresh oil and STP,about 30 miles later the engine started misfiring blowing out smoke .after driving it home i removed the cylinder head to find a hole in the piston.It ended up fitting a new engine.It seemed rather odd this happened after putting STP in the engine.The only to cure glazed bores is to work the engine hard under load.or hores honed.

 

[aroona]

It doesnt smoke all the time - mostly when its warm & running about 2000 rpm - but even then the smoke comes & goes.

Its used about a litre over approx 20-25 hrs, as you say its an old engine but apparently it was rebuilt about 5 yrs ago (although there no proof of reciepts etc so could have just been a filter change!) & has done very little since.

When I first bought it I had to clean the diesel tank & lines due to a lot of c**p in the tank - no bug though.

 

[Sans Bateau]

That is not huge oil consumption, but needs to be watched. Does it start easy enough? If the answer is yes, then the bore glazing is unlikely. With what you have now described I'd tend to be thinking along valve guide seals. I have a 2003 with around 1600 hours on it (1995) and t uses no oil between changes. Dont be afraid to give the engine a bit of a trash every now and then. These engines are too often run at low revs and using oil which is too good for the engine will kill them. Go back to the post by Vyv Cox, click on his link and find the information on engine oils, its very important to get the oil correct, and dont let anyone tell you its not.

 

[CAPTAIN FANTASTIC]

It doesnt smoke all the time - mostly when its warm & running about 2000 rpm - but even then the smoke comes & goes.

Its used about a litre over approx 20-25 hrs, as you say its an old engine but apparently it was rebuilt about 5 yrs ago (although there no proof of reciepts etc so could have just been a filter change!) & has done very little since.

When I first bought it I had to clean the diesel tank & lines due to a lot of c**p in the tank - no bug though.

There is no easy solution and no magic treatments. The only thing you can do is to change oil regularly and ensure that the oil contains detergents to break down carbon deposits as much as possible; also, run the engine on full power, few short bursts, to burn the carbon inside the cylinders. When the engine starts to use oil, there is no way you can stop it; If your engine burns one litre over 24 hours, then live with it; however, if the engine has difficulty starting due to low compression then it is definitely time for an overhaul.

 

[Westerly Jetstream]

The branded Volvo oil will probably be synthetic, absolute disaster on an old engine use only a good diesel mineral oil.
The bores will be glazed as engine will only be used occasionally and not working hard. Live with it. You could over winer remove engine strip it and hone the bores and fit new rings BUT unless the engine is worked hard it will only happen again.
Cylinde bores glaze very easily if the rings are not bedded in at start by sheer hard work. On the race car engines I build I do not run them in and only use mineral oil changing it at 300 and 600 miles with a filter change before converting to synth. Poor old marine diesels have a hard life never getting up to proper temp and rarely working hard enough.

 

[fishermantwo]

I would not put additives in the oil. Additives in the fuel is a different matter. Years ago the Gardner main engine in my fishing vessel started using lots of oil and I was leaving a smoke trail about a mile long. We had been spending several hours each day droplining and the engine idling. The bores had glazed and the rings probably gummed up. I dosed the fuel with a locally made snake oil that cures glazing. The following day we had 3 hours of steaming to the grounds and as the sun came up I wandered about the deck and noticed the exhaust was dead clean. When I checked the oil we had gone from 2 to 3 litres a day to virtually nothing. I have sold the vessel now and retired. New owners still work the boat and that Gardner is now 68 years old, still all original and runs sweet.
Lot of the new high tech car engines running on modern oils are suffering from gummed up rings. The Toyota branded snake oil is apparently very good for curing this.
Make sure you use the correct oil for your engine, even if it means going to a tractor dealership!

 

[vyv_cox]

Have you tried the Italian Tuneup? Drive the boat at maximum revs for about 20 minutes. There is usually significant smoke at first but this should reduce after a few minutes. The effect is burn off excess carbon that has accumulated throughout the combustion surfaces. Yanmar recommend running flat out for 5 minutes after every two hours of normal motoring.

 

[Westerly Jetstream]

Works even better if you tie her to the pontoon ( well sprung) and try and take it with you

 

[wotayottie]

It doesnt smoke all the time - mostly when its warm & running about 2000 rpm - but even then the smoke comes & goes.

Its used about a litre over approx 20-25 hrs, as you say its an old engine but apparently it was rebuilt about 5 yrs ago (although there no proof of reciepts etc so could have just been a filter change!) & has done very little since.

When I first bought it I had to clean the diesel tank & lines due to a lot of c**p in the tank - no bug though.

The puzzle is smoke coming and going. I would expect both valve stem seals and piston bore/rings to be reasonably constant at constant revs and load so your symptoms suggest its something else. I cannot remember enough of the 2003 that I had to suggest something specific to look at that would be intermittent - best to ask your local Volvo Penta dealer or there is a good one down Portsmouth way who are happy to give advice.