Stopping Engine Oil leaks - Doug Halstead
My 1985 Volvo 240 estate (auto) leaves a small deposit of engine oil
on the drive. This drip comes from the torque convertor area and I
believe that the rear crankshaft oil-seal is the culprit.

Well, taking out the auto box and replacing the oil-seal is the 'right
thing to do', but has anyone knowledge or experience of products like
Wynn's Engine Stop Leak and such like. I would appreciate any comment.

Many thanks

Re: Stopping Engine Oil leaks - Charles

These additives work by revitalising and expanding the rubber in the oil seals.
I found that a syringe (my wife's a nurse!) I was using to remove a sample of ATF fluid out of a Granada Autobox seized up due this stuff expanding the seal on the plunger. So I have witnessed a 'Stop Leak' additive working.

Hope this helps

Re: Stopping Engine Oil leaks - Andrew Moorey (Tune-Up Ltd.)
Before rushing out and doing anything rash check that the crankcase breather is clear. This is situated above the starter under the inlet manifold and consists of a separator chamber with a rubber nozzle coming off the top. In the top of the nozzle is a plastic filter with a large pipe going off to the air filter and a small vacuum pipe going into the inlet manifold. Remove the filter part and pop it apart and clean it thoroughly. Then check the brass union in the inlet manifold and if not clear carefully drill it out with a 1.5mm drill. Renew the small bore vacuum pipe and reassemble. There is a good chance that this will cure your problem before resorting to additives.
Re: Stopping Engine Oil leaks - Martin

Audi 80 16V same problem - must check breather!!!


Re: Stopping Engine Oil leaks - Reverend Pickled Onion
So sayeth the Lord. "The Volvo 240 is indeed a sturdy car chiselled from the same type of granite as many monuments - which will give many years of trouble free motoring provided you are not afraid to spend a fortune on fuel."

It upsets me that such a bastion of "proper" motor cars should fail in this way.

Please tell us what was wrong and renew our faith in this vehicle

Re: Stopping Engine Oil leaks - Doug Halstead
Thanks every-one for your comments.
Further info: The breather system on this car is clear. Charles has mentioned how his syringe was effected by ATF which contained a 'stop leak' additive.

Does anyone know if these products are reliable or best left alone?

Many thanks

Re: Stopping Engine Oil leaks - David W

Bear with me on this one!

I work (on cars) in latex gloves all the time. Sometimes petrol, diesel or other fluids will make the fingers swell from tight to 30% oversize. The next stage is that they fall apart. I would say the "fluid" had ruined them.

Again for various car uses I have large horse syringes. Sometimes a fluid causes the seal in these to swell as Charles mentions. The rubber expands by 10-25% and feels much softer. In any case it ruins the syringe.

Now I'm sure the major companies have all sorts of claims for these stop-leak additives but at the end of the day they are just taking advantage of the chemical property that expands (damages?) the seal rubber.

Engine oil seals are normally quite hard and I would expect this softening to seriously shorten the remaining life, they may hold well for a while then let go in a big way.

But I'm afraid I have no actual experience of the product because I would never use them, not on my car or a customer's.

My highly opinionated verdict based on overall experience of similar products/devices is that they may be a "bodge to sell" method.

I would love to hear from anyone who has used them for over 12,000 miles though for a true report.


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