Smoke out of the tail pipe for W124

[sub_zero]

Hi all,
I noticed lately that blue smoke is coming out of the exhaust at rpm 3500,I asked my mechanic and he told me that this is engine wear
I was really shocked,I really use this car in a proper way and change oil on time.
Did some search on the internet,there was a thread about a W124 M111 owner who was replacing the spark plugs and saw oil on the recess tray of 2 plugs.He was recommended to replace the spark plug seals and cam cover seals too.
I checked my plugs ,found that one plug is oily and even plug socket is oily too!!!
Could this generate smoke out of tail pipe?
Please advise.
Thanks in advance

 

[grober]

What's the car's mileage? The crankcase breather may be choked. are you sure its blue smoke not white? these engines are known to blow cylinder head gaskets. The classic blue smoke on the overrun is produced by an engine with a shut throttle causing a reduced cylinder pressure sucking in oil through worn valve stem seals.

 

[sub_zero]

Thanks for reply.
1-The clock say 350,000 km (~220000m).
2-Where is the crankcase breather? Is it the one I marked in white(see attachment)? if so,it is not clogged,it is a bit oily,and the oil came from the leaking spark plug seal I think.
3-What do you mean by 'shut throttle'? I cleaned the throttle body(with WD40) today and it is working fine.
4- 'Worn valve stem seals' Are these the one I mentioned in my previous post,the seals of spark plugs?!! or is it something else? if so how would I know if it is worn?
5- The smoke is not much (very light blue,near white),after some revs,the smoke disappears.I wait few minutes and rev again,I see smoke again.
6- I think oil at the spark plug may cause smoke.what do you think?
Again thanks for reply.

 

[sub_zero]

Pcv

Hi grober,
After extensive search on internet,I think I found the crankcase breather.
(some call it regeneration valve and some call it PCV)
Kindly see attachment.

How would I know if this breather is faulty?

Few years ago I replaced it as it was noisy leaking vacuum.
After replacing it,the engine became amazingly smooth and all rough idling gone!!!Didn't know that is valve may cause rough idle.

Thanks

 

[WDB124066]

Pull off the upstream rubber elbow connector, if it sucks constantly it is faulty. It should pulse when it operates, it operates under certain conditions only, otherwise it is normally closed...

I'm not too sure if there's a test to tell if the charcoal filter needs replacing or the other two components of the fuel evap system need attention, be nice to know if there was. Fallback position would be to replace the lot and blow out the hoses.

This system [when not operating properly] shouldn't give smoke out of the tail pipe though...??

 

[sub_zero]

Thanks WDB124066.
I replaced the crankcase breather because it was noisy leaking vacuum,not because of smoke.
The new one pulses ,but am not sure if it pulses as long as the engine is running or pulses under certain conditions only.

 

[sub_zero]

Hi...
A friend recommended to add oil treatment.

PPI - Pennsylvania Petroleum Products - Engine Additives, Fuel System Additives, Lubricants, Radiator and Specialty products

I'm really reluctant to use it,as am sure of my engine.

During searching on the internet,read that the symptoms of worn valve stem seals is that smoke comes out when engine starts,this is not my case.
Smoke comes out of tail pipe when high revs (>=3500 rpm),no smoke comes out when engine starts,only during high revs for some minutes and disappear.

 

[optimusprime]

Valve seals can show up on over run .On the road give it a run up to about 50 mph then take you foot of the gas. Do you see the smoke in the rear mirror thats being blown out the tail pipe. Other check is pressure test on cylinders .To see if its wear in them or piston rings .And seals on the spark plug wont cause this problem.The plugs are in the head so tight that they wont leak in to the engine ....Another check is your brake booster ,check the fluid in the brake fluid container.This can get in the engine,if the seals are worn , but then it will be white smoke .

 

[sub_zero]

Hello...
Would like to thank all who participated in this thread,I checked the car on the computer and the CO was sky rocketing,it was 3.78!!!!(don't know why)
The tech. reduced it to 0.5 and all smokes stopped!!!!!!!!!!!
Thank you again.

 

[WDB124066]

The regen valve when it fails makes the engine run lean because of vacuum leaks, now that it has been replaced the engine may well still have been at its rich setting causing the "smoke"....??