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

What I would do is run a few short mileage oil changes. I would fill the car with a good group III oil such as Castrol GTX and run it for 2000 miles and change it out. The second change I would run for another 2000-2500 miles. Then the third change go to a 3,000 mile oil change. Then change over to the M1 which is good for 5K miles.

With my 87 745T the additive package is pretty well shot by 5K miles. Although I do run a lot of short trips with my daily driver. I would use only the Mann or OEM Volvo filters. The reason for the short changes is to clean out as much of the sludge and gunk in the oil galleries before filling with the M1. The M1 like most synthetics is very good at cleaning the garbage out. That is why you should do the short changes with the mineral oil and get most of the crud out before you fill with the pricey synthetic oil.

:00000732:

I pretty sure the owners manual states you can use 15W40 in warmer climates.

:amen:

Here are some simple car maintenance that will help keep your car in good condition as well as help to increase its gas mileage

1. Check your tire pressure. Improperly inflated tires can reduce your car’s gas mileage by up to 2%.
2. Replace dirty air filters. An excessively dirty or clogged air filter can cause your car’s gas mileage to drop by as much as 10%. This happened to me, so i bought Volvo air filters which i'm using now.
3. Replace worn spark plugs. Driving around with worn or fouled spark plugs will cause your car’s air/fuel mixture to be ignited less efficiently, and will reduce your car’s performance and fuel economy.
4. Check your gas cap’s gasket.If your car’s gas cap doesn’t get a proper seal, you’re going to let gas simply escape from your car. If the gasket looks old and cracked, go ahead and get a new gasket from your local auto parts store.

I use three litres of ATF as a engine cleaner.......... start with a hot engine. drop the oil, in with 3l of ATF run it for 4 or 5 mins (Don't take it for a drive, just let it idle) ......... Leave it overnight, Drop the ATF & goo, On with a new oil filter & fill up with the oil of your choice ....... Its clean now :)