ahmad0658

We have an E55 2006 with 110K miles, having light blue smoke upon start up only. The car lost 2 liters in total and once refilled 2 days ago no lose again.

What could went wrong? valve seals? piston rings? something else?

zeus1

https://mbworld.org/forums/search.php?searchid=12317545

60nomad

Don't sweat it, my friend had 44k miles and it would do it once and a while too. Mine did it a couple of times as well and I have heard of others doing it. It does NOT do it all the time right? I looked into this and thought maybe that my oil was filled to high or the wrong weight oil was used possibly. It won't hurt anything but for my next oil change I will be sure to have the exact amount added and the exact weight that is recommended. If you did that all already then I still wouldn't worry about it.

typhoon43

Tends to be valve seals when you get a little puff on startup. My Typhoon had the same issue and ran another 50k miles without hiccups.

60nomad

I don't believe it is valve seals...if so it would smoke when you romped on it...mine doesn't blow one drop of smoke. I only had this happen immediately after my oil change so I am pretty sure that it had something to do with it one way or another. My friends car had 44k miles on it...don't think his valve seals were bad.

I posted about this a month ago and got very little response so maybe some peeps can chime in for you.

Toadster

that's the most common 'suggestion' - mine does it every once in a while, especially if I let her sit for 3-4 days

ahmad0658

Thank you for your feedback. In about 2300 KM, it will be the oil change time, but I think it is better to change it now.

Something I noticed earlier today on that car is that there is a leak of oil from the gaskets of the valve cover.

Toadster

pretty common on these cars, parts are cheap - but the labor is where all the work is...

Shadow5501

I've had two 55K cars and both have done the same thing. Very infrequently they will put out a bit of blue smoke on startup. Can't say that I've correlated it to anything; not oil changes, not sitting for days. If the oil level doesn't drop and it doesn't smoke every cold start, I would call it normal and not worry about it.

ahmad0658

It looks like that the car will need new piston rings, late today or tomorrow it will be confirmed. If any of the pistons is damaged too, they we will go with Weistic as the price is fairly ok for pistons upgraded from the OEM and having also the pistons ring with it !! But, if it is only piston ring, then we will look for upgraded one that fit on the OEM piston but with better performance.

Is there better piston ring produced to replace the OEM? if yes, who sells them and how much?

Critter

Ahmad0658, how did you come to that diagnosis? Piston ring wear would result in lose of power, excessive blow by which would make the car blow blue smoke all the time especially when hot and driven hard. Friends could follow you where ever you had been because there would be a smoke trail behind the car.

Critter

Also change out the valve cover gaskets before the next oil change or preferably right after the gasket change.

Redw20855amg

Spark plug tube seals..oil leaks past these and into spark plug chamber sits then seaps past the plug and burns off on start-up after sitting a valve cover service will fix this...I see this and get asked about this on a weekly basis here at my shop. now if it was a V8 BMW id say Valve seals 100% and tell you to "Buy More Wrenches"

Critter

Good advice on the spark plug tubes.
Saves a ton of money over a techs idea of piston rings.

ahmad0658

We have CEL when we scanned the car, cylinder 3 misfire and system is too rich, we found leak on head gasket that is on the driver side and also of course oil leak from the valve cover on the same area.

Tomorrow I will report the findings when I see the car. It could be only the valve seals or even the plug seal, who knows but from similar case before, we think it is the either valve seals or piston ring.

ahmad0658

Here is the result doesn't seem to be good at all, cylinder wall has crack


I hope that the picture can show something.

Critter

Now that is exactly what you do not need to find, obviously this is not going to be a cheap fix by any means, Good Luck with sourcing a new power plant. Any thoughts on bare block rebuild or just a drop in? Sad outcome for sure.

Redw20855amg

Car-part.com engine assembly

ahmad0658

update, all parts for rebuild are available now except for 2 items that can be installed when the engine is ready, the workshop will start working on the car. The estimated total cost (including spare parts and labor) will be around 2600 USD which is a good thing for my friend.

It Will take around a week or 10 days till the car runs back again because still we miss 2 items of spare parts that are not available in the middle east (what a shame on Mercedes Benz) !!!!!

ahmad0658

Engine was fired recently, but it shakes and the has CEL coming due to cylinder 3 and 1. Still the engine is running and observed. At the beginning it was shaking a lot but by the time it became less but still has some shaking and the engine is still not 100% smooth. It is not kind of shaking that sometime we notice on our engine when it is normal.

Any advise? Idea? What to check and monitor?

S2K750

If it's shaking and a cel from 1 & 3 then you're most likely not getting any spark and running on 6 cylinders. Double check the the spark plug wires. Maybe disconnected or the boots are flipped.

Max.H

Be careful, the violent shaking will destroy your motor mounts if not already.

What was the cause of the issue? Was it burning a lot of oil too?