Synthetic Oil on M50 Engines - makes oil leak

[The Melmaan]

Hello Guys!!!!
I was just talking to my mechanic (BMW Specialist) when I was changing my engine oil. I was asking him if I could use Synthetic Oil on my E34. He said that it is not wise because the chemicals on the Synthetic Oil is designed to do some work on the engine gaskets and protect, but if you have older engine and you are just starting to use Synthetics, it will destroy your gasket end up with lots of oil leak that you cannot imagine.
Has any of you guys experienced this???

[BillionPa]

the reason is because it cleans up all the gunk wayyyyy to fast, and synthetic flows better. if you did 3000 mile intervals on 10W30, then going to a 5W40 synthetic like redline shouldnt cause any leaks.

if you were going 10000 miles on dino, then you are in bad shape.

if the engine is gunky, pick up some AutoRX and let it clean the engine for a few thousand miles before switching to syn.

[rob101]

the reason is because it cleans up all the gunk wayyyyy to fast, and synthetic flows better. if you did 3000 mile intervals on 10W30, then going to a 5W40 synthetic like redline shouldnt cause any leaks.

if you were going 10000 miles on dino, then you are in bad shape.

if the engine is gunky, pick up some AutoRX and let it clean the engine for a few thousand miles before switching to syn.
i don't know i think most Petrol engine synthetics now have less detergents than the earlier synthetics.
i've never really had any problems with my m50 running synth (castrol edge 0w-40), sure it uses a bit of oil but meh it has 250 000 km on it. whatcha going to do? doesn't really use more than with castrol GTX 3 (15W-40 mineral) anyway. although i might switch to 5W-50 or 10W-60 synthetic next oil change.

[wingman]

I'll get a smashing for this but by using an approved mineral you shouldn't have any problems. It might shorten the engine life from 500,000 to 450,000...

[shuriken]

Hello Guys!!!!
I was just talking to my mechanic (BMW Specialist) when I was changing my engine oil. I was asking him if I could use Synthetic Oil on my E34. He said that it is not wise because the chemicals on the Synthetic Oil is designed to do some work on the engine gaskets and protect, but if you have older engine and you are just starting to use Synthetics, it will destroy your gasket end up with lots of oil leak that you cannot imagine.
Has any of you guys experienced this???
I thought it was because synthetic oil is thinner but has a better sheer rate than mineral oil, so it breaks down less quickly and keeps it's "shape" for longer. Also the tolerances and materials used in modern engines is different to older ones. I may use synthetic if I had a 540 V8 as it has plated bores and a much tighter tolerance between the piston and bore. The same applies to motorcycle oil, I use semi-synthetic and not fully for just those reasons. If in doubt then use mineral. In UK Castrol make "Magnatex' in synthetic(for modern engines) on mineral (for older ones).

[Russell]

Noticed no leakage in mine with mobil 1 and Castrol synthetics for the past 40,000 miles. However, I do have a slight oil seepage around the plugs with relatively new (35,000 miles) valve cover gaskets. of course this is a known issue with the M50 engine regardless of oil type.

[Morgenster]

I still think switching from dino to synth is good so long as you change the gaskets and oil after a max of 5000km after that. From then on Synth shouldn't give you any probs.
I don't know how well the auto-RX product works but I can't find it in Belgium anyway.
My mechanic uses synth on all the BMWs he's worked on and hasn't had any issues. I saw an M50 with 350000 km on it still using synth and without leaking a single drop.

[Paul in NZ]

when i bought my car it had 145 000 km or so and i converted to castrol synthetic straight away,no leaks,some "seeps" tho.I use it because the lower viscosity gives better protection at start up which is when almost all the wear actually ocurs.Now at 210,000 km or so.I run it for the whole service interval,if i ran dino i would swap it at half interval,so the cost is prolly about the same

[shuriken]

I thought it was because synthetic oil is thinner but has a better sheer rate than mineral oil, so it breaks down less quickly and keeps it's "shape" for longer. Also the tolerances and materials used in modern engines is different to older ones. I may use synthetic if I had a 540 V8 as it has plated bores and a much tighter tolerance between the piston and bore. The same applies to motorcycle oil, I use semi-synthetic and not fully for just those reasons. If in doubt then use mineral. In UK Castrol make "Magnatex' in synthetic(for modern engines) on mineral (for older ones).
just been looking through my car receipts from when I had my sump gasket renewed and the BMW garage used Castrol synthetic........ I'll shut up! The theory to synthetic and mineral in old engines and new, is a valid one however, but if it works then use it. Just costs abit more.

[wingman]

when i bought my car it had 145 000 km or so and i converted to castrol synthetic straight away,no leaks,some "seeps" tho.


Hey Paul,
What is the difference between a 'leak' and a 'seep'? Both to me indicate that oil is breaching the gasket. I take it that you mean that a 'leak' is like what old Jags do and a seep is like what you get from the rear main seal in an old Torana.

[bimmerd00d]

I made the switch in my M50tu at 115k when i got it. I dont believe it had been using conventional, as it began leaking. It leaked for about 2 oil changes using Mobil1 10w30, and then it stopped around 125k. I changed the VC gasket only, and at 265k it didn't leak a drop anywhere. Synthetic supposedly conditions the seals and gaskets.

[rob101]

I made the switch in my M50tu at 115k when i got it. I dont believe it had been using conventional, as it began leaking. It leaked for about 2 oil changes using Mobil1 10w30, and then it stopped around 125k. I changed the VC gasket only, and at 265k it didn't leak a drop anywhere. Synthetic supposedly conditions the seals and gaskets.
i have also heard that they have seal conditioners also
i don't think the oil "destroys the gaskets" rather the detergents in the synth oil clean the crap from around the gaskets that may have been assisting with the sealing of the gasket and the gaskets may have dried out from not enough oil maybe because the sludge is a barrier?
i think there has been a tread to reduce the detergents from Petrol engine oil. if you really want to desludge an engine run some diesel synthetic oil through it.
that is the major difference apparently between 4 -stroke petrol and 4 stroke diesel engine oils the diesel has alot more detergents (because diesel is dirtier if it gets into the oil?)
however if you run this oil before major sludge builds up then you should be right. I have heard of serious problems running synthetic without flushing into a engine or gearbox of some sort. (this was from a maintenance engineer whom i highly respect and work with NOT ******** heresay) but i don't know, my personal experience so far... no problems going straight to synth. so i must say
I am confused
so i just run synthetic
in castrol we trust!

[jbourke]

Hello Guys!!!!
... but if you have older engine and you are just starting to use Synthetics, it will destroy your gasket end up with lots of oil leak that you cannot imagine.
Has any of you guys experienced this???

I wanted to start using synthetic and decided to call a respected oil company here in Holland (Kroon oil). Must have been my lucky day as I came to talk to a chemical engineer/BMW enthousiast. He told me that switching to synthetics after respectable mileage wasn't a problem at all with modern engines. Those horror stories apparently only apply to "oldtimers" which the M50 is certainly not. I personaly have switched ~10K's ago an no leaks whatsoever and no increased oil consumption (well it was leaking but that turned out to be 6 loose sump bolts!).

[The Melmaan]

I wanted to start using synthetic and decided to call a respected oil company here in Holland (Kroon oil). Must have been my lucky day as I came to talk to a chemical engineer/BMW enthousiast. He told me that switching to synthetics after respectable mileage wasn't a problem at all with modern engines. Those horror stories apparently only apply to "oldtimers" which the M50 is certainly not. I personaly have switched ~10K's ago an no leaks whatsoever and no increased oil consumption (well it was leaking but that turned out to be 6 loose sump bolts!).

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Boy, there sure is alot of unsure study on this. I have my other E36 oil changed recently and we are observing for oil leaks. My son said that he saw some oil spots the place where he normally parks but not sure if it came from the our car.
However my cousin have an old E34 and he switch to synthetics and started having numrerous oil seeps or leaks. We are not sure whether it is because of the synthetic oil that he used and the leak started happening and gradually worsen a couple of months later. He does not remember which oil he used. Maybe it could be some types of synthetic oils only and not all. My son used Union 76 Synthetic Blend and I hope it will not develop any leaks but from now on he will have to use synthetics.
Do you have any Email address of the person you talked to in Holland?