94 540i purchase

[mambodave]

Hi All,

I may be migrating from the Porsche forum.

Ive been eyeing a 94 540i with 124,000 miles on it. Automatic.

Im taking a 3rd and final test drive tomorrow. Any advice?

Car looks showroom condition, has some records. Drives and shifts good. no visible fluid leaks.

What specifally should I check on this car? All electronics apear to be working.


Thanks For any Advice

[Bob540iA]

The two major things to look for are the engine block and auto trans fluid.

The original engines were built with Nikasil. They had problems with rough idle because the sulfur in the U.S. gas was etching the cyliinder walls. A leak down test will show this problem. The engines that had this problem were replaced with Alusil blocks. You can check for which block you have by getting the block casting number off the engine. Go tp www.Koalasport.com, they have a very complete writeup on this problem.

The automatic transmission does not have a fill pipe or dipstick. It was supposed to be a "lifetime" transmission. The "lifetime" is up if you have over 80K on it.
I replaced the filter and refilled with Redline D4 trans fluid.
I was having "Trans Program" problems before I did this and this fixed the problem.
You will need to replace the fluid a couple of times unless you flush the trans. I did a second replacement after 3Kmiles to get the concentration of the D4 up.

[mambodave]

Great, Thanks Bob.

[x_atlas0]

When driving, you want to keep the rpms below 3000, as the cooling for the transmission isn't all that great. There have been times when i've been driving in the "m" mode in the rain, as the car is pretty squirrely on wet roads at speed, and since all the torque is gone, I had to rev higher. I could feel the heat from my transmission with my hand on the shifter.

Also, check to see when the water pump was replaced. Mine died right around then, so the one on that car might be ready to go. Other than that, mine has never had to go to the shop for unscheduled repairs. You'll love the car.

1994 540i

[mambodave]

Great, Im replaceing a Porsche 944. I wanted another Porsche, but I cam across the 540. I couldnt resist test driving the 8 cylinder.

BTW what is that switch on the consol? A or M?

Auto or manual? (Just a dumb guess)

[x_atlas0]

The "a" and "m" switch is on the wood-grained center area right next to the automatic shifter. It's like the sunroof button. They don't mean "automatic" and "manual", however. I think the manual described it as "adaptive" and something else. The effect, though, is like this: "a" is what you want to use most of the time, as it gives the performance you are used to. However, because the car can be nutsy in the rain, given all the torque, I put it in "m" mode, as that mode seems to take out all the torque, and therefore making the car much safer to drive on slick roads. It still is an automatic transmission, just a very slow one to drive that way. Also, there is another transmission mode, "s", which you can activate by switching out of drive, while in "a" and below 2000 rpms, into any of the number gears, 4, 3, etc. This changes the shifting patterns significantly, raising the revs to shift by about 1500 or more. The result is, you get a lot more of the power band when you do shift. The downside, though, is like i said last time; the trannie gets very hot, which i have little doubt it bad for it. Thusly, i only use "s" mode in very short bursts, then go back to "a" "d". if you want to see what mode and such you are in, it's right next to the digital odometer, on the center LED cluster, right above the steering wheel. Also, is this vehicle stock? If it is, I would chip that sucker right now. Not so much for the power gains, whcih are nice, but mainly for the better fuel economy. my vehicle has had 1 other driver, and the best mileage before chipping he could eke out of the car was 18.1 mpg. After chipping, it rose to 19.3. Right now, i'm getting 21.4. These are all city driving figures, by the by.

Oh, and the "a" mode, adaptive, is rather interesting. from what I've noticed, the car modifies it's shifting pattern based on the previous driver. Hence, I can tell when someone else has driven my car, as it suddenly revs higher than normal, because most people stomp on the gas to start moving. Given how I drive, this makes the car shoot off the line for them, but, because it's in adaptive, it eventually compensates for their driving style and lets the power come on later in the rpm cycle. It does, however, give the best gas mileage out of any mode.

Oh, and don't be suprised when a bulb breaks or something, the car will whine and moan like mad until it is fixed. James Bond wasn't kidding about "Don't let her push you around."

[mambodave]

Cool, Thanks.

I think Ill take it.

Dave