I have a 91 wagon and it is a great car.

My suggestions:

The back pressure coming out of the oil filler hole probaly means that you have a clogged oil breather filter. Should be negative pressure (read sucking IN). Do a search in FAQ and there is a simple procedure to change this $5 part.

I don't know about the buzzing noise unless your blower does not shut off.

The "red glaze" inside the valve cover sounds like normal opil build up for 150K.

I put Bilstein shocks, all new strut bushings (with some poly), IPD swaybars and chassis braces on my 91 245. This with 15" steel 740 wheels and 195 sized Michelin tires.
IT COMPLETELY CHANGED THE CAR!
Now this box actually handles corners.
Next is IPD heavy duty springs on the rear.

If nothing else, the IPD swaybars are worth the $240 investment.

Stock 245's handle like a big "brick" on roller skates.

Changing the front struts can be a REAL BITCH. Hard to losen the top nut (need a special tool or even an air gun). I had my shop change the struts and the bushings (bushings need special tools and the old ones to be burnt out).

Also explore Turbobricks.com. More high performance oriented stuff but some good soimple modification info there. Just watch out for the idiot bench racers who post too often.

Unitek and Enem out of Sweden sell a really sweet cam called the V15 or Phase 1. About $250 but transforms the power curve of the B230F and makes highway driving a lot easier.

Or get a K cam and adjustable cam gear from Canada for about $150.

With a little $ and work a 91 245 can be a pretty nice driver.

As you can tell, I don't believe in keeping cars stock. Especially a model that has had over 20 years of research done to it.

Good Luck
Bert

Dick and Rob answered the tranny + other questions. I'll address the struts - cost is somewhat determined by the quality of the struts you put in. A lot of us here are fond of Sachs Advantage and Bilstein Touring, each around $60 apiece, but cheaper ones are available. Labor should run no more than 3 hours, and there should be an alignment done when the new struts are in. Depending on labor rates, probably around $300 to have the job done. If you're moderately talented. you can do the job yourself if you have decent tools. Just did my third set of 240 struts this weekend. Struts, shocks, brakes and a few odds and ends took me about 8 hours, taking my time.

Make certain the trans fluid level is OK, and as mentioned, do a flush of it. Use Dexron/Mercon type ATF, not Type F trans fluid.

Inspect your engine mounts for splits, especially the rear transmission mount- it's likely to be sagged and possibly separated.

The car should be smooth off the line- those two items are the likeliest causes of trouble.

It sounds like this car needs to get caught up on its maintenance. Do the fluid changes, then go from there: replace the oil cap gaasket, clean the throttle body; replace the flame trap and holder ($2.95 kit from FCP); do a tuneup- plugs, cap, rotor, and all the ignition wires if they don't look fresh (or if they don't say "Bougicord" on them.)
All this work is stuff you can do yourself with a not-very-extensive set of tools. Save the money on labor, and spend it on more new, quality parts.

Welcome to the Brickboard, by the way. Remember there are no dumb questions - someone here always knows what you're talking about.
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 228K, 88 744GLE- 212K, 91 244 183K-SOLD! Also responsible for the care and feeding of: 88 745GLE, 231K, 88 244GL, 146K, 87 244DL, 239K, 88 245DL, 246K

First thing I'd recommend is a transmission fluid flush, or at least an exchange. Look around and find the "how-to"--you can do it yourself in an hour or so at the cost of a case of ATF. It is inexpensive, can't hurt anything, might help a whole bunch.

Since you don't know the history of the car, go ahead and run a good engine flush through there. Best I know of, for quick flush, are made by AMSOIL and BG. One that takes longer, which I haven't used but have heard a lot of good about, is Auto-Rx.