New 928 Owner needs help

[Raffaele Sottil]

I purchased a 1989 928 S4 that had been sitting for a few years. To make a long story short, I was having problems with the tranny slipping when the car got up to normal temperature.

When I hit the accelerator from a standing stop with the tranny in Drive, the RPM rev and all of a sudden it finds the gear. I had the Tranny rebuild as well as the torque tube, and other "might as well do it now stuff" 2 weeks ago ($4700.00).

I took it out again today and it's doing the exact same thing. Fluid level is fine. Does any one know what the problem might be. I love this car, but I'm getting to the point where stripping it for scrap aluminum might not be a bad idea.

[riber.bentsen]

Whoa, wait a minute before you call the tow truck and have it scrapped

Do you check the fluid level when the car is running nice and hot? Go for a long drive and get under the car with a torch and find that reservoir..

Could be as simple as that.

There is also some business about a so called "bowden cable" that might be acting up - but I don't know a whole lot about 'matics.

Car looks like a gem

[MPDano]

Bowden Cable has to do with how early or late it shifts as the RPM's go up.

For sure the fluid level "must" be checked when car is at operating temp "and" running. If that checks out ok, then use that $4700 tranny rebuild warranty. How about the condition of the Torque Converter?

[Raffaele Sottil]

The torque converter was OK (as per the Porsche Machanic). The car only has 120,000 KM and I bought it because the seller had all the documentation from Porsche, (All belts changed, new tires, water pump, regular oil changes ect....). I did the brakes and rotor, tune up, ALL fluid changed, new fan temperature module, OC sensors, and 2 weeks ago the tranny, torque tube, cooling lines above the tranny and other stuff.

I ran the car until it started acting up again, crawel under the car with a flashlight and checked the trans level while it was hot and running, it looked to be between 1/2 to 3/4.

I'm starting to think that maybe the tranny was OK and it's something else.

[JhwShark]

Happened after the "Tranny" work...so as Leo and Riber suggest check tranny Bowden cable...but make the shop do the warranty work as they probably did not check performance and connected the existing cable at the point (on the tranny; and did not do anything at the other endpoint) it was in prior to the work.
Jon

[Danglerb]

$4700 to fix the tranny and its clearly not fixed.

Who did the rebuild?

I would put it back in their lap until the tranny is perfect or you get your money back.

[harborman]

Take it back to the tranny shop immediately! Did you not test it before you paid the bill? Have the manager drive it with you in the car. I hope you took it to a reputable shop that knows this type of car. Get a list of what they did to it if you can, all parts replaced, anything found defective in it at rebuild time. You might want to find someone local who knows the 928. Good luck with it, the car looks really nice.

[neil30076]

Tell us where you are, maybe someone in the area can help you diagnose the problem.

[Pete R]

Tell us where you are, maybe someone in the area can help you diagnose the problem.

... or buy the car for the scrap metal price??

[Mrmerlin]

dont drive the car any further than necessary,
if its slipping your going to damage the new parts that were installed,
maybe the vacuum modulator pressure wasnt checked,
and or a new VM wasnt installed

[Raffaele Sottil]

OK guys/gals, sorry about the scrap metal comment, I’m just a little frustrated with the whole situation. I’m a car nut and I hated to see this car sitting there so I purchased it knowing it needed work.

I spared no expense and maybe I'm a little too trusting but I asked around and found a shop that specialises in Porsches. The mechanic who works on it own a 928 as well and apprenticed on these cars. I am in Canada just outside of Toronto. I did test drive the car after the complete tranny rebuilt and it drove great. Two weeks later after a long drive (2 hours) it started acting up again. This car now sits in a heated garage and is well pampered next to my 86 Mustang GT Convertible.

[pcar928fan]

Ugh...this is NOT FUN! Auto tranny problems are very bad and very hard to fix, you REALLY, REALLY have to be good to take one of these tranny's apart and put it back together, not to mention you pretty much have to work in a clean room!

Good luck... you should have purchased the '88 S4 transmission that Mark Anderson had before I got it two weeks ago... the purchase price and install would have been less than half of what you spent! Maybe Mark has another good one, but I would certainly take this up with the shop you paid $4700 to make it right! They OWE YOU!

[Danglerb]

Don't let it drag on, talk to the shop and put it back in their hands asap.

[MPDano]

Stat

[Raffaele Sottil]

I'm bringing it back after Jan 10th as that is when the shop re-opens after their extended holidays. I travel allot so finding the time to bring it in and pick it up is difficult for me. Having said that, the car is real good shape body, mechanical, and electrical wise (except for the Tranny). The previous owner took care of it he just got tired of it.

[Landseer]

As automatics go, these are straightforward.
4 speeds / no fancy electronics.
Internally they can be disassembled and reassembled with normal tools.
Very well-built and infinitely serviceable by a transmission shop.

A rebuild should have "held up". For that money you should have gotten very thorough rebuild, all new wear parts.
Do not despair. Its not some one-time hit/miss brain surgery. Somebody can fix it.

Are you sure its the transmission?
When the 32 V cars miss due to wires arcing for instance, it can feel like the trans is the root problem.

[Danglerb]

Originally Posted by Landseer

As automatics go, these are straightforward.
4 speeds / no fancy electronics.
Internally they can be disassembled and reassembled with normal tools.
Very well-built and infinitely serviceable by a transmission shop.

Plenty of "normal" even Porsche or MB transmission only shops screw these and other transmissions up. Its bad enough that my usual advice is just to buy a good used known running AT instead of rolling the dice on some typical shop doing a rebuild.

[Landseer]

Professionalism of the shop as a transmission specialist is really the only variable.
These are simple automatics.
All frictions, steels and seals should have been replaced at minimum, plus B2 piston with the update. Complete careful disassembly, cleaning and reassembly of the valve body, perhaps with a spring kit.

Could be fluid starvation due to bent pan blocking pickup, fluid level, or other issues that are simple. Assuming they did rebuild properly.

If the engine is missing under load before and during acceleration, even at higher speeds in 4th, and approaching and during kickdown, it will seem like a bad transmission problem but can actually be the engine. BTDT with my 85.

[XLR8928]

I hate automatics

[kennner]

Raffaele if you are in the Toronto area check out Nine a Part just north of hwy 9. He has all sorts of used and new parts and also does work of Porsche's.