bobbyjames

I have a 2010 S63 with 30,000 miles. It smokes once it has been driven and warmed up. It is most noticeable when stopping at a signal light and a puff of smoke blows past. It seems rediculous that it should have valve guide or valve seal problems at 30,000. I have also had cyclinder #2 foul a plug with carbon build up in the electrode. This car has had the cats deleted and Kleeman long tube headers added along with a ECU tune from Weistec. Could this be an issue with PCV valve? If it were the valve seals can they be changed with the heads on the car?

chrisridebike8

Try the PCV valve first. It could be allowing oil into the intake in excess amounts. Blue and white are hard to tell apart. I have a '10 C63 and it needed valve stem seals at 87k. The amount of smoke was alarming sometimes. Wasn't consistent. It would just puff sometimes. But a BIG puff.

Or the scary part...if it is truly white and your coolant level is dropping, it could be headbolts.

roadkillrob

If it is white, it is water and if it is water on an m156 engine, it usually means that it is coolant and that you have headbolt issues which your model year would fall into - have you had the headbolts done? Does it smell a bit sweet? Otherwise fuel is a grey color so could be excess fuel since you don't have cats. Oil would be dark and smell like oil.

604 C63

Very nice. Lets just take a moment to acknowledge that lol.

Alex.currie44

My view exactly. Steam is steam.

JimGnitecki

Agree. Plus, given the 2010 model year, AND the presence of performance mods, shouldn't the OP assume the worst - headbolt failure - in order to improve the odds of not destroying the engine?

He apparently has no "low coolant" message or even worse, "oil level" message yet. So, if it IS headbolt failure, he can get it corrected BEFORE he hurts the engine bigtime by waiting until the coolant dilutes the engine oil and begins to proactively destroy the engine, right?

Jim G

BadCompany

Are you getting any misfires? If you are getting coolant into the cylinders (especially so much that you can see it burning), a lot of times you'll hear misfires. Have you noticed any change in your coolant level? As people already mentioned, what does the smoke smell like? Sweet? Unburned fuel? Oil?

Vladds

Bring it to a shop and get it diagnosed.
Btw, with a head gasket problem where coolant seeps in and then steam comes out, you don't see carboned plugs but plugs that look suspiciously clean, like they're new.
Also, coolant usually doesn't puff. It comes out.
Oil puffs.

bobbyjames

The engine runs strong and is smooth at idle. I do not have coolant issues, no low coolant light and the smoke I believe is from oil, does not smell sweet. I have had 2 S63's both used what I considered excessive amounts of oil but Mercedes said that this is normal. This smoke is another thing and it is also inconsistent. Does anyone know if the valve seals can be changed with the heads on the car or do they need to be removes in order to gain access. I changed the spark plugs to Brisk racing plugs after having a problem with #2 cylinder which was due to a fouled plug. The electrode was almost completely blocked with carbon, all other plugs looked good.

Alex.currie44

Well I can only suggest you find someone who has more experience with these engines to help you out because the rest of us are not apparently helping. You have perhaps a bad valve guide if you have convinced yourself it is oil and the only way to figure that out is pull the head and check #2 since you seem focused on it.
A guy in a shop here in Canada who I have seen work on Brit cars has a tool that allows him to see the quality of the fire in a cylinder when the engine is running. It is very cool actually to see how the flame colour changes when he adjusts the SUs. Maybe someone in and indy shop would have one and if you are burning oil in the cylinder it would could be seen in contrast to cylinders you think are OK.