Stem seal - Ducati.ms

manga · Jan 27th, 2012, 12:59 pm

My 02 996 smokes when warmed up, particularly when taking off from the lights.

An older friend (60+)! thinks its a valve stem seal gone as the smoke is not there on steadyish throttle openings.

If this is so, and I have asked around a fair bit - can the stem seals be changed without taking the head off?

Anyone have an exploded drawing of the valve, guide, seal arrangement in the head?

SP3 · Jan 27th, 2012, 2:40 pm

You could do it in the bike. But, it won't be any fun.

916duc · Jan 27th, 2012, 2:47 pm

I'd have to agree with SP3 - while it may be possible, overall you'd save a lot of work and remove the heads rather than try to replace them with the heads on.

Dmitry · Jan 27th, 2012, 2:55 pm

I think it's an easy job to do it in the bike once the cams and rockers are out, but before you go replacing them I'd make sure they are the cause of your smoking problem. I damaged mine while doing the valve shims (screw driver slipped couple times) but decided not to replace them this time around, not willing to wait 3+ weeks for them to be shipped form Italy. I can smell oil, it burns little between oil changes, but there is no smoke.

kaos · Jan 28th, 2012, 9:47 am

Fwiw I would doubt its valve seals,best to do. Leak down test.

ducati2242 · Jan 28th, 2012, 11:36 am

Quote:

Originally Posted by kaos

Fwiw I would doubt its valve seals,best to do. Leak down test.

I would agree . Oil on start up then gone = valve oil seals (usually)
Oil from traffic light starts = rings (usually)

DukeDesmo · Jan 28th, 2012, 11:38 am

It might technically be possible to do with the heads on but would be much easier to take the heads off, especially with the rear cylinder exhaust valves.

Give you chance to clean and reseat the valves, check the guides and rings while you're there.

FWIW I doubt it's just the valve seals...

manga · Jan 28th, 2012, 12:16 pm

Cheers, what I will do is pull the plugs 1st to see if I can tell which cylinder is giving me trouble. Then a compression check (need to get a tester 1st).

Then I guess its engine out to check that cylinder.

Sigh - will have to be in the summer as its too cold in my garage in winter.

Or I could sell the bike on and get something else......

Dmitry · Jan 28th, 2012, 8:38 pm

I think your biggest mistake is to assume that you seeing oil smoke, sometimes rich running engine will puff grey smoke that is mistaken for oil.

second mistake is trying to fix it before checking your oil consumption, if you loosing less than a quart in 1000 miles, I'd leave it alone. All engines burn oil, some more than others, unless it's becoming a problem (plugs fowling up, having to add oil every week) ride it as is, you can relax knowing that everything is well lubricated.

First check oil level, than oil consumption, then plugs and compression (and oil breather) in that order. Once you have some results you will have a complete picture and someone here with more knowledge then me will advise you on the best course of action form there.

Also post a thread with a better title, like "996 smoking" and you will get better response, could be other reason why you seeing smoke. Pretty sure 996's have some fueling issues that cause rich condition from take off.

manga · Jan 29th, 2012, 9:53 am

Quote:

Originally Posted by Dmitry

I think your biggest mistake is to assume that you seeing oil smoke, sometimes rich running engine will puff grey smoke that is mistaken for oil.

second mistake is trying to fix it before checking your oil consumption, if you loosing less than a quart in 1000 miles, I'd leave it alone. All engines burn oil, some more than others, unless it's becoming a problem (plugs fowling up, having to add oil every week) ride it as is, you can relax knowing that everything is well lubricated.

First check oil level, than oil consumption, then plugs and compression (and oil breather) in that order. Once you have some results you will have a complete picture and someone here with more knowledge then me will advise you on the best course of action form there.

Also post a thread with a better title, like "996 smoking" and you will get better response, could be other reason why you seeing smoke. Pretty sure 996's have some fueling issues that cause rich condition from take off.

Thank you that is reassuring advice.