oil leak and breather problem

[richard230sl]

I am having some breather issues and oil leak isssus on my 230sl:

Since my main dipstick was covered in mayonaise and oil, I disassembled my breather line (on the valve cover) again and cleaned it.
This made the dipstick covered mainly in nice and brown oil again  on the longer runs for 2 or 3 rides.
After that the breather tube was again partially filled with mayonaise scum so I tried to drive the car with the breather pipe disconnected.

This gives less mayonaise build up on the dipstick (there is some nice and brown oil to be seen with a small dot of mayonaise at the bottom of it)
I check if the breatherpipe on top of the valve cover stays open and this is the case, but it keeps on filling itselve with this white scum which sometimes drips out of it.
This is the case in longer and shorter trips in cold and warm weather. The coolant temperature is nicely 180 degrees so engine temperature seems to be ok..

Is there anybody who knows the cause for this phenomena?
I am using a good kind of 15W40 Q8 T520 monograde oil with scum suppressors in it.

A problem that might be related to this breather issue is the following:

I am sometimes having a one or two small drops of oil under the car dripping from the rear main seal I think.
For such an old car not a big deal BUT: on longer runs the leaking gets worse and on very long trips it becomes so much that i have to put a rag under it when I stop.
Could this be related to the breather problems?
Or can I solve this leaking by using a thicker grade of oil (drives of 30 minutes at 3500 rpm are not a problem at all, hardly any leaking then) but driving the car for a full day at 4000 rpm, the car will consume and leak more.... And it seems to be that sometimes the car does not leak at all, and other times the leaking is heavily.

Is there way for pressure to build up in the crankcase, causing this leakage?
Or is it a problem of the seals leaking when the engine becomes a bit warmer?
The valve cover breathing tube is open all the time now, and there is hardly any blowby and compression is of the pistons is ok.
The engine runs and performs great.

Looking forward to your reactions

Thank you

Richard









Since I had some issues with my dipstick (it was covered with mayonaise), I disassembled the breather tube

[stickandrudderman]

The mayonaisse is moisture that is contained within the engine mixing with the oil.
On cars that sit for long periods and only run for short times it is pretty inevitable that some moisture will accumulate but is easily dispersed by taking the car for a nice long run/italian tune-up.
However, if the mayonaisse is more persistant it could be a sign of a leaking head gasket.

[richard230sl]

Thanks Stick and Rudderman for your reply.

My car has been driven regularly and also a lot on longer runs and it consumes no cooling liquid whatsoever... So a leaking head gasket seems not to be the problem.
I drove the car last week from the netherlands to italy and back, so accumulate moisture is also not the problem.
And I can not figure out why this much moist is coming from the breather pipe, so much that hooking it up to the airtake (as it should be) gives blockades after a while.
On my previous post I heard that these 230 sl sometimes have a bit of a mayonaise problem on colder days, but I have it all the time also when the engine heats up...

And then there is this mysterious  oil leakage which sometimes occurs (mainly on longer trips) and sometimes doesn´t occur at all..


Hopefully someone recognises these problems; thanks for posting!

Richard

[ja17]

Minor engine moisture should not be a problem under most circumstances. Minor moisture accumulation is purged by the engine as the engine oil heats up. Your engine should be reaching full operating temperature to do this.  The valve cover vent (engine vent) should allow any oil vapor to be sucked into the engine and burned off. Anay blockage in this circuit could cause more than normal moisture to accumulate and may force it out somewhere else on the engine like the dip stick vent.

I suggest that you do a fresh oil change, clean all the tubes and fittings from the valve cover vent to and including the venturi fitting and see if the problem persists.

[ptooner]

I am happy to hear you are driving your 230 on extended trips.  Unfortunately, the problem you describe is almost certainly a head gasket allowing some coolant to get into the oil when the engine is fully warmed up.  I don't believe there is any other problem that will cause this issue.

Gerry

[ja17]

With no coolant loss, it can't be a head gasket.

[stickandrudderman]

With no coolant loss

I agree, except that the definition of "no coolant loss" seem to differ from person to person.

Is it:
a) I check the coolant regularly and I never have to put a drop in
or
b) She only uses a pint a month.

[richard230sl]

Thanks for all your replies:

Just to make my case clear: by saying "it consumes no cooling liquid whatsoever" in my previous post I mean that it does't use any cooling liquid at all..

Any thoughts about if an other oil type might solve the problem of the engine leaking trough the rear engine seal?
On trips of 30 minutes I do not have any leakage problems (only 1 or 2 small drops)

Thanks again for posting your replies

Richard
 

[ja17]

I do not think there is any easy fix for a rear engine seal.

[waltklatt]

Possibly a transmission fluid leak at the manifold? 
Automatic or manual?

[w113dude]

Thanks for all your replies:

Just to make my case clear: by saying "it consumes no cooling liquid whatsoever" in my previous post I mean that it does't use any cooling liquid at all..

Any thoughts about if an other oil type might solve the problem of the engine leaking trough the rear engine seal?
On trips of 30 minutes I do not have any leakage problems (only 1 or 2 small drops)

Thanks again for posting your replies

Richard
 

Richard,

If I were you I would leave it alone, a few drops is not a lot considering what it takes to get to the rear seal, my friend brought his 280sl to me to replace the rear seal, by time we were done  with it (two days later)  engine was out of the car with far more work than anticipated. it's impossible to get to the main pan screws without lifting the engine.
But of course once the engine was out we changed front seal as well in addition to steering pump, this way we made sure lower block was completely resealed.

[richard230sl]

Thanks again for the responses.

My car has a manual gearbox (so no cooling liquid is coming from the transmission)

The oil leakage is acceptable on trips of 30 minutes (only a few drops)
On longer trips it becomes embarrassing (I carry a rag with me to put under dripping engine)
So I suppose thicker oil can not "solve" this problem?

[ja17]

Make sure that the valve cover is not leaking. Oil from this area will often drip down at the rear of the block and look like a rear seal.

[Paul99]

sorry to say this does sound like my problem, in the end it was a cracked cly head, near a valve guide,  needed the head welded up  and pressure tested.  ok now, but wasnt cheap!

[richard230sl]

Thanks for all your replies and advise on this topic;

I have been trying to find a solution to my problems with the input of this forum and from some friends and found out the following:
I hope it might help other people with similar problems.

I hooked up the carter ventilation (on the valve cover) to the intake manifold, so carter ventilation is helped by the vacuum of the engine.
The result is clean, brown oil on the dipstick (no mayonaise) and no more abnormal oil leakage!

It seems to be that the blow by on this engine is a bit high, causing high carterpressure when the engine was used under faster driving, causing the seals to leak sometimes.
Having the carter ventilation hooked up to the intake manifold (I used a T-joint in the brake booster-to-inlet-hose) solved 2 problems at the time.

Of course in an ideal world ,on a overhauled engine, an open breather tube connected to the L-shaped tube at the throttle body should be enough, but in my case it wasn't.
-The compression of the engine is still great, performance (measured Horsepower) is very good and the car drives very well!

For the remaining problem; The oil level of the IP rises very slowly but I just refresh the oil once every while and it works fine.

Hopefully this case helps other people as well; sometimes a simple fix can save a lot of time and money. (thanks to this forum)
I drove the car on LPG, over 3500 km in the last month and it consumes 1 litre on 7.5km on average.. (It is a great vacation car now, without any leaks or mayonaise.....)


Thanks for all your help.