300SDL smoking at start-up?

Suggest you watch the coolant and lube oil for symptoms of head gasket failure i.e. oil in the coolant or coolant in the oil.

Or, have the engine's compression checked if you don't want to be in suspense. A compression test is always the most reliable diagnostic of a diesel's internal condition.

smoke

white = steam blue = oil black = rich mix or a lot of diesel fuel

the SDLs if run HOT warped the heads

i would do a comp test line like T G suggested. beats sleepiness nites

the case, minus a few cans!

I believe the smoke you see during the first mile of driving is coolant being burned out of the exhaust manifold. The engine's roughness is from poor compression and thus poor combustion in one or two cylinders.

These six cylinder diesels have an aluminum head that's prone to crack, particularly at #5 cylinder. It's thought that #5 is affected from the once installed, but now probably long gone, particulate trap that was alongside the #5 cylinder.

The only way to really know whether to remove the cylinder head is to check the engine's compression. Headgasket if you're lucky, cylinderhead if you're cursed.

I have some pix of a cracked head and will email them to you upon request.

I didn't get to see the orginal post, but the symptom in the subject line is exactly something that I live with everyday on my 300SDL.

Smokes like crazy (whitish/grayish/blueish....) and idles very rough for about 5 minutes or until I drive to the end of the block. Then...no smoke and smooth idle.

I've spent a fools fortune having my mechanic go over this problem.

Including the 'compression test'.

Found all cylinders to be well above 'acceptable limits'. I don't know what that is, but he told me that they were all above 415 something. EXCEPT for #3, which was 395 something (something = PSI?)

I don't know if those numbers are good or bad.

I'm bothered that I've got one cylinder being a non-conformist, but the car runs good.

I've checked the oil and it shows no sign of having water in it, and checked the coolant as much as I can in the resevoir, and see no signs of oil.

No bizaare overheating problems either.

Any other ideas?

I've got an '87 300TD and it does the same start-up song and dance. I've concluded that the stem seals and/or valve guides are the problem. I have not decided if the problem is worth addressing since the car has 270,000 miles. So far it has cost me a quart of oil between changes at 5000 miles.

Chas Hurst

Thanks.