Next week I'm taking my 1994 850 Turbo wagon to a quick lube place (I know the owner) for my first oil change. I do not know what kind of oil the previous owner used. My plan is to use Mobil 1 synthetic.

Can you please tell me... is there anything special that should be done to make sure that all of the old oil gets drained out properly (from the turbo, etc)?

Thanks.

I'm also thinking about changing the transmission fluid while I'm at it, but I don't know anything about transmission oil choices.

Squiggy

 

Make sure the guy uses OEM filter (MANN) or equivalent. If he uses aftermarket filter, make sure that he uses a filter that has check valve in it just like MANN. Replacing the crush washer for the drain bolt is a nice touch, though not an absolute necessity. I replaced the drain bolt with a magnetic chip-detector type. Mobil-1 synthetic is a good choice (probably the best) for turbocharged engines.

Drain oil from the oil-cooler. This can be done by disconnecting the lower oil-cooler connection. You may need to have new seal-ring, O-ring & the aluminium clamp. FCP Groton/eEuroparts should have them. You get about 0.9 quarts out of the oil-cooler.

For tranny fluid, NEVER use anything other than Dexron-III/Mercon. If wrong type of fluid is introduced into the gearbox, that's it.


See other members' suggestions as well.


JPN

 

Use 10W30 as viscosity for the oil. Other than that JPN has covered it.

 

On this topic... The previous owner of my car switched from synthetic to normal oil at about 45k miles (59k now). Is it safe to go back to synthetic?

 

Sure

 

Why not.


JPN

 

I use synthetic all the time. I never used to, but now I swear by it. Personally, if you have the tools and the know how, I would do the oil change yourself. It is not hard and that way you know it is doen correctly.

Just my .02

Glenn

 

Thanks guys, I asked b/c a friend told me that some car owners will switch from synthetic to normal oil when small oil leaks are noticed to 'plug' them up? Is that complete bunk?

 

I was under the impression if it is high miles like mine 165K not change to synthetic but keep it as is with regular oil. Is that correct? I really wanted to go synthetic but was afraid it might causeproblems.

 

Ours had 170K on it when we got it and I doubt the previous owner used synthetic oil. Either way, I put synthetic in it and have had no (knock on wood) problems

 

Acommon myth is that if you put synthetic oil in a high-mileage engine, it will leak out since it is so slippery and washes out gunks/sludges that have accumulated over the years. The verdict is that the engine would have to have an already-existing leak with regular oil to have synthetic oil to leak.

The advantage of synthetic oil is that it withstands extreme pressure & temperature, and has better chemical stability under varying conditions. Synthetic oil is most suitable for high-performance engines such as turbo, supercharged, or variable valve timing engines. Aircraft jet engines (gas-turbine engines) also use full synthetic oil (BP-2380, BP-2197, or Mobil Jet-II, all complying with MIL-L(PRF)-23699).


JPN

 

Thanks JPN for the clarification now I don't mind switching to syn.

 

Thanks JPN. Do you get paid for giving advice here? You should!

There is 'Mobile 1' synthetic and 'Mobile 1 High Mileage' synthetic (supposidly for cars with over 75K miles). I wonder if there is any advantage to the high mileage version? My car has 164K.