In a nutshell.

I bought a 1994 E420 W124 for my girlfriend.

53K with an aftermarket warranty for $12,000

I schedule her oil changes. Also this woman is a raving luntic when she is carless- you would think I cut off her right arm when her car is in the shop- automatically she will latch onto anyones car she can.

She knows she is not allowed to drive my E500 1994 but insists on it. (currenly she drives her ex-husbands car)

So at around 59,000 miles the A/c goes. After a long battle with the warranty company all is covered except for freon and tax...you would think she was gravely wronged by the way she acted.

At 60K miles her car is due for a service. A transmission service. I tell her its an $800 service at the dealership. She refuses to pay that- saying she can't afford it right now (I say better to put it on a credit card and pay it off over time- she says "no").

I say- pay a little now or a lot more later. She says....I'll do it later.

A few more oil changes and we notice oil leaking from the gear box.

Her gear box is replaced covered by warranty. (except for $100) She doesn't get an alignment at that time. Then she gets new snow tires...stilll no alignment.

Then at 80K miles her transmission starts slipping. She sends it into the the dealership and they can't reproduce the problem. It leaves her stranded a few times. She send sit into the dealer and they can't reproduce the symptoms.

The symptoms:
When she pulls up to a stop sign and then tries to go again the engine just revs. No gear engagement. If she then downshifts into 1st or 2nd gear the car engages and moves but still won't shift into 3 or 4.

IF she gets home and lets it sit it behaves for a few hundred miles more.

Recently there has been a grinding sound and a "oil like smell" coming from the car. Stil this is also intermittent. I've been in the car with her and experienced these problems.

I looked in the search function and thought perhaps her old ATF turned into varnish and is clogging her brake booster cable or her vaccuum modulator. Or perhaps those "plastic fingers" in the valve itself.

We took the car to a mechanic and had the old ATF flushed 5 times, dropped the pan and had it cleaned out + new transmission filter. It drove fine for about 300 miles...and again the same problems.

Any ideas?

Hopefully she will learn from this lesson - that if you don't do the required maintence you will almost always shorten the life of the car and end up with a huge repair bill.

Ideally I would like to be able to tell the dealership what diagnostic proceedure to try to pinpoint the problem.