Hi all,

I have recently come into the care of a neglected 1989 740 Turbo.

I plan on first changing the oil, oil and air filters, then spark plugs, spark wires, belts next.

I know the oil has not been changed in a long time, possibly a year [:@]
it is dark black in color, also there is a small leak somewhere as parts of the engine are dirty with oil.

I plan on using Mobil 1 (any suggestions on what weight I should use, I live in a very warm climate, Arizona, so I was thinking something high like 15w 50, but I was going to do some research on that ), and OEM equivalent filters like Purolator Mahle, or Mann.

I am concerned about the old oil, and sludge build up due to the long time it has gone without a change.

My question is; will the cleaning additives (assuming that mobil one has some, I think I have read that it does somewhere) loosen any possible sludge causing the new oil filter to clog up any quicker than usual and require another change in less than the standard 3 months?
If so, should I first use a less expensive oil [and filter] at first and then change again (after a relatively short period of time) with the Mobil 1?

or should I not worry about it and just do the oil change now, and change again normally in about 3 months?

thanks,
Adrian

 

Just change the oil and check under the oil cap and see if it looks like sludge is built up in there.

 

What I've done in the past with used vehicles I've bought is put in the cheap oil along with a quart of Mobil 1 and a new filter. Run it for 500 miles then drain it, put on a new filter and then all of the good stuff (Mobil 1). This cleaners in Mobil 1 should clean things up pretty good within 500 miles so you should be fine. As to what weight to use in AZ, if you can find the 5W-40 Mobil 1 that's what I would use. Living in GA I typically use 10W-30 M1 or the 5W-40 Shell Rotella T Synthetic. I rarely stumble on the M1 5W-40 but when I do I buy it.

 

This happened to me as well and when I looked under the oil cap it was black.Well I drained the oil and puta cheap10/30 oil and one quart ofRislone and cheap oil filter.I let it run for a long stretch 2 to3 hours then drained the oil and put good oil w/half quart rislone and a Volvo filter and put 1500 miles.Then changed again with good oil and Volvo filter and under the cap was 80% cleaner.It was amazing.If the car is not runing smoothly I would go to a mercury marine store and buy a can of power tune and spray it down the trottle bodywihile running(follow instructions) and this will clean the s@%t out of all the carbon that may have built up over the years.Your car will run like new and the oil will be so clean that you will not be able to see it on the stick.Note that your car will leak oil because the seals will probably bedried outso do the timing belt and replace all the front seals and the valve cover gaskets and you should be good to go.Let me know how it goes.