light blue smoke at idle?

[davids]

71 280 sl light blue smoke at idle more smoke at driving speeds, but not very bad.Did compression check 1st cyl,165 2nd cyl 170,3rd cyl 165, 4th cyl 140, 5th cyl 160, 6th cyl 170. all plugs looked very good no oil on them. any suggestions?

[dseretakis]

Cylinder no. 4 is a bit low. If it were my car I'd leave it alone since the car runs well. If it gets worst then maybe I'd fix it. I wonder of it's not a worn exhaust valve guide on no. four cylinder since there is no oil fouling of the plug?

[ja17]

Do you have a little more history on the car?  Mileage, service history etc.

[davids]

car has 120,000 miles ,been driving for past couple of years,before that was garadge keept for about 12years. we changed many many things on car but no internal engine work.

[ja17]

Hello,

If the car has been stored, drive it for a while to see if the situation gets better. Valve seals get a little stiff from lack of use. A fresh oil change could also help if your oil is dirty and fuel contaminated.

Nest, if yours is an automatic,  check your transmission fluid level. If the modulator diaphragm ruptures, you will burn off transmission fluid and the exhaust will smoke.  If this is the case, your car will begin to consume transmission fluid.

Next, you can remove the valve cover and check to see if any valve seals have jumped off their valve guides. Use a flashlight and bump the engine over as needed. You will be able to see the seals through the valve springs. A seal out of place is noticeably in a higher position than the rest.

We can go into the more complicated fixes after you check these.