Using lots of engine oil

[AlexH]

Hi,

I have an E300TE Straight 6 cylinder petrol W124, which I have recently got back onto the road. It has run 185K. I have run it for a few thousand miles now.

When I first had her running, I saw a thick cloud of smoke on a couple of occassions - It was suggested that it could be valve stem oil seals. After a couple of times doing this when I pulled away, it stopped - have not seen it do it since.

However, I am using quite a lot of oil. I am guessing about a litre every 500 miles. And I am worried and a tad confused.

Worried as I don't want it to be terminal. I have an E220 which has done 170K and does not use a drop.

Confused as I don't see any smoke! And there are no leaks from the engine.

I say that I don't see any smoke, I will qualify!

When I pull away from a junction I habitually check behind me - no clouds of smoke.
Whenever I start her up, I do the same, and no smoke.
If I race the engine hard, I don't see any tell tale 'cloud' in myrear view mirror.

The only thing I think I have seen was when I was motorway driving and I thought I saw a cloud behind me, mind it could have been that the rear window was dirty! It was a bright day too, so hard to tell, but I think it was smoking. I backed off andwhat I thought I saw stopped. I could see no evidence and did accelerate hard a couple of times to see if it was a head gasket issue. When I stopped, I sat and revved - No smoke.

So, if it were a head gasket, then I would expect - well, lots of smoke all the time.
If it were the piston rings, then I would expect puffs when I pull away and accelerate hard (?)
But not sure why it would 'come and go'.

My 'fact gathering' may be poor - maybe it is burning all the time, but I would have seen it at start up.

So,
Am I mad/useless in my diagnosis /observations?
Could there be an intermittent issue?
Could it spell disaster for the old girl?

Any thoughts gratefully received.

KR
Alex

 

[star]

What year is the car?

 

[ernieh]

Thecata

Hi,

I have an E300TE Straight 6 cylinder petrol W124, which I have recently got back onto the road. It has run 185K. I have run it for a few thousand miles now.

When I first had her running, I saw a thick cloud of smoke on a couple of occassions - It was suggested that it could be valve stem oil seals. After a couple of times doing this when I pulled away, it stopped - have not seen it do it since.

However, I am using quite a lot of oil. I am guessing about a litre every 500 miles. And I am worried and a tad confused.

Worried as I don't want it to be terminal. I have an E220 which has done 170K and does not use a drop.

Confused as I don't see any smoke! And there are no leaks from the engine.

I say that I don't see any smoke, I will qualify!

When I pull away from a junction I habitually check behind me - no clouds of smoke.
Whenever I start her up, I do the same, and no smoke.
If I race the engine hard, I don't see any tell tale 'cloud' in myrear view mirror.

The only thing I think I have seen was when I was motorway driving and I thought I saw a cloud behind me, mind it could have been that the rear window was dirty! It was a bright day too, so hard to tell, but I think it was smoking. I backed off andwhat I thought I saw stopped. I could see no evidence and did accelerate hard a couple of times to see if it was a head gasket issue. When I stopped, I sat and revved - No smoke.

So, if it were a head gasket, then I would expect - well, lots of smoke all the time.
If it were the piston rings, then I would expect puffs when I pull away and accelerate hard (?)
But not sure why it would 'come and go'.

My 'fact gathering' may be poor - maybe it is burning all the time, but I would have seen it at start up.

So,
Am I mad/useless in my diagnosis /observations?
Could there be an intermittent issue?
Could it spell disaster for the old girl?

Any thoughts gratefully received.

KR
Alex

The catalytic converter can mask oil consumption as it can clean up certain amount of blue oil smoke. If there are no leaks it must be getting burnt.

Ernie

 

[mikestrivens]

What year is the car?

it says 1992 in the OP's details.

 

[star]

Thecata

The catalytic converter can mask oil consumption as it can clean up certain amount of blue oil smoke. If there are no leaks it must be getting burnt.

Ernie

That was my thoughts, if an early model, no cat but 92 onwards, a cat was fitted.

 

[Steve@Avantgarde]

An old engine on 185k, combination of worn stem/seals and old components. There is probably puffs of smoke, but you can't see them to notice.

 

[AlexH]

Thank you all for your answers.

So, before I look to run away, hide and pretend all is well, is there any simple tests to determine the state of play? Is it a case of starting with the top and working down? Valve Stem oil seals, then piston rings, then?? Feeling a little worried on this becoming a money pit, but also would like to keep it running if sensible.

Really appreciate your answers.

KR
Alex

 

[Westheath]

Get someone else to drive it and follow behind.
Put it through its paces and observe when and whats happening from the exhaust.

Also check for leaks around the engine when its running.

 

[star]

If the compressions are ok, and if there's oil deposits on the plug/s, do the valve seals. If any more, live with it due to the cost.

 

[rayhennig]

Thank you all for your answers.

So, before I look to run away, hide and pretend all is well, is there any simple tests to determine the state of play? Is it a case of starting with the top and working down? Valve Stem oil seals, then piston rings, then?? Feeling a little worried on this becoming a money pit, but also would like to keep it running if sensible.

Really appreciate your answers.

KR
Alex

In your shoes, I'd get to a high speed on an empty road, maybe in 3rd gear, and release the throttle. Under those conditions, maximum vacuum draws oil down through the stem seals and it burns. You'll see a puff/cloud of blue smoke. New seals is probably the answer.

This based on my experience with a W123 280.

Bonne chance.

RayH

 

[oigle]

If it isn't smoking enough to be a problem, I would just keep feeding it oil - maybe a tad more viscous than you are using. The cost of the oil would be infinitesimal compared to pulling the engine apart. A litre every 500 miles would equate to an oil change every 3000 miles. No need to change the oil

 

[AlexH]

Hello All,
Really appreciate your feedback.

So, today I did a test with Liz following me. No smoke until I accelerated hard and hit >5000RPM. Then, by all accounts, not very much, but some.

However, the running at speed test - Yikes!!! Hit a fairly healthy (legal of course) speed and held for about 10 mins. When I eased up it was as though the head gasket had gone! Smoke filled 3 lanes and kept spewing out for about a mile or 2. Bit embarrassing, but I know not to do that again. Once it had 'cleared out' it was fine and I can accelerate with no signs of smoke.

I have not yet checked the engine for oil leaks when running, so will give that a bash.

So, I maybe have a couple of issues, but sounds like I need to replace valve stem oil seals. Can't be doing with the motorway fog situation - gives old mercs a bad name.

Any other suggestions are greatly received and thanks all for your help on this.

KR
Alex

 

[oigle]

That is a funny one. Stem seals seems possible I guess but that was a lot of smoke for that. Seems there is a buildup somewhere that only gets burnt under high vacuum. Are you sure it is engine oil? If it is an auto, I have seen auto oil suck in under vacuum when a valve fails. That makes for heaps of smoke.

 

[A.J.]

Get someone else to drive it and follow behind.
Put it through its paces and observe when and whats happening from the exhaust.

Also check for leaks around the engine when its running.

With my limited mechanical knowledge that is what was going through my mind, is the car wet underneath ?

 

[AlexH]

Hi,
Underneath of the car is wet, but not dripping wet. (and I have been greasing joints trying to find where a squeaking is coming from so that may account for some). One recommendation was to leave the enging running and check - I will give that a whirl in a bit and report back.

Anyway, gearbox suggestion - I have only just (in the last week) had the gearbox serviced - They said the oil that was in it looked ok. And based on using the engine oil I am still thinking that the valve seals are number 1. BUT....the gearbox needs setting up - does not change up when accelerating, so I have to back off the throttle and it does not pick up 1st from start most times. I had it serviced just to make sure I was starting from a known point and I think I need to get it set up properly - I believe that there is a vacuum plug that can be adjusted on the gearbox(?). A few weeks ago I also adjusted the throttle linkage and the cable from the gearbox as the enging was over revving (I cleaned up all the moving components and adjusted the cables to allow the throttle idle position to land on the little micro switch) - That made the engine rev normally and everything else stayed the same (the changing up issue was still there).

Anyway, I am not sure whether the gearbox can be related or not but certainly worthy of consideration. You mention a 'valve'; Is there a simple swap of a valve that may be worth a punt or are you talking internal gearbox components?

Thanks again
Alex

 

[star]

The smoke after a run like you describe, points to an overfill of the gearbox and the excess is pushed out on the overrun and ends on the exhaust, hence the white smoke. This is. It the reason for your oil consumption.

 

[AlexH]

Just a quick update. Ran the engine for about 20 mins today on the drive. No signs of 'splattering' or smoke from the engine directly. Gave it a good rev and no smoke blowing.

 

[star]

The smoke after a run like you describe, points to an overfill of the gearbox and the excess is pushed out on the overrun and ends on the exhaust, hence the white smoke. This is. It the reason for your oil consumption.

Edit, this NOT the reason for your oil consumption.

 

[oigle]

The "valve" I mentioned - I am unsure of this. I recollect a vacuum line from the gearbox to the inlet manifold that had some sort of valve arrangement. When it malfunctioned, oil was sucked from gearbox into inlet manifold under high vacuum conditions. Long time ago and memory vague on this. May not even apply to your vehicle as it was old tech.

 

[star]

Thats the modulating valve, you could pull the vac line off and see if there is oil residue in it, it should be bone dry. This could cause smoking but not engine oil consumption.