nsantolick

After around 18 months, I finally got around to finishing up my car and getting it back on the road. Needless to say, I'm pretty pleased. :-)

I bought it about 3 years ago. I made a lot of mistakes, particulary with no PPI and questionable shops at first. Then my transmission blew (at around 78,000 miles.) It was rebuilt by Mastertech Transmissions in New York, whose reputation gave me a lot of comfort. With the rebuild, I had them install a rebuilt torque tube and a constantine clamp.

Shortly after that though, I had problems with my igntion system, and as the work list piled up, it ended up being parked and forgotten for a while. Since it was last driven, I've changed the spark plugs, installed new plug wires, new coils, caps & rotors. I've installed a 928 Motorsports aluminum radiator. Pirelli P-Zero run flat tires on Porsche BBS wheels off an 2003 car and an Orange brand tire pressure monitoring system. The battery has been replaced with a yellow Optima, which easily fit with room to spare. (Can't remember the size I choose, but I researched it here first...)

I finished it off with one of Roger's stainless rear muffler bypassess. (It's combined with his high flow catalytic converters and an X pipe.) SOUNDS EXCELLENT!!! ;-) Actually, it's quite acceptable at lower RPM ranges. When you're gunning it, it roars. I was concerned about the fatigue of the additional noise on long highway trips but don't feel it's bad at all relative to the original factory system. Just perfect for me. :-)

Wow. After most of this time being spent driving an 1983 Mercedes 300D Turbodiesel, the 50 mile ride in the S4 today was awesome. A few hundred more horsepower will do that, I suppose. ;-)

I love the way the car handles now. The Porsche wheels are awesome quality. They felt VERY light, relative to the aftermarket club sport II copies that my car had before. Love the tires too.

I did what I could to research run flat tire technology and, after finally driving the car, I absolutely love it. I heard about performance issues, but there's so little quality commentary out there, it was hard to understand. I feel that the extra thick sidewalls ARE NOT a problem. I understand that these tires weigh a bit more than tires with normal sidewalls but when comparing amongst 30+ tires online, I saw a wide range of tire weights too.

The fronts, as I recall, are 27 pounds. With the same size, normal tires averaged closer to 24. Not all that dramatic of a change, at least when one considers the range of wheel weights. Either way, although additional unsprung weight isn't great, the difference with the run flat tires I choose isn't much relative to the range of other tire or wheel weights. I read something about "centrifical weight" and its consequences but honestly haven't yet read enough to understand how it affects performance. I should also say that after extensive researching, I do understand how it is ESSENTIAL to pair run flat tires with a tire pressure monitoring system. I choose the Orange 409 model, and can't be happier. Simultaneous readouts in LED of all 4 tire pressures rotating with simultaneous temperature readings. An alarm will sound if either goes out of range, and identify which wheel is suspect... $139 delivered...

I debated, and overthought, of course, what to do about the 1/4 tank of 18 month old gas that was in the tank. The station that does the inspections for me is across the street, and they were possibly going to change the fuel pumps for me today, so after reading a few articles online about old gas, I decided to see what happened. The car started up without problems and although it wanted to stall when cold, there were no problems with the aged gas.

They weren't able to do the fuel pumps today, so I ended up putting around 45 miles on it before filling with super and adding two bottles of Techtron. Just wanted to comment though - I didn't have any problems with the older gas. I'm pleasantly surprised.

There is one problem though...

I lost a bit of transmission fluid, as I now understand is normal, from letting it sit so long. With the radiator, I believe I lost another quart or so of tranmission fluid. I explained the procedure to the shop to fill and provided them with 2 quarts of appropriate synthetic fluid.

I feel that they didn't add it to a properly warmed transmission. They used two full quarts to top it off. I'm suspiscious that it's overfilled and wonder what the consequences are. Is this something I should be particulary concerned about? Is it okay, if it's overfilled a bit, to drive it a few hundred miles and have it rechecked and adjusted when I get the fuel pump work done???

As far as the performance of the transmission, it was mostly normal, most of the time, but there were a few times where it seemed "off."

During one full throttle blip, the car didn't shift to third and its rev limiter kicked in. Another time, earlier today, with mild acceleration from a full stop, it didn't shift until around 4000 rpms, then shifted with a chirp to the tires.

Anyway, does anyone know if this can be related to excessive transmission fluid levels? It has sat, so who knows, but the transmission was recently rebuilt by a very competent specialist. Could this be vacuum related perhaps?

Anyway, it was great to move on after all these problems I've endured. I have a lot of other projects planned for my car and generally liked doing most of the work myself. Sure, I burnt my finger and have arms that are scraped to all hell but, dam, it was worth it.

Hope this transmission thing isn't anything serious. Any input would be most appreciated...

Bill Ball

The tranny should not leak from sitting even for months. Yes, it's common but not OK. That usually indicates a problem with the reservoir cap seal or the overflow hose that attaches to the top of the reservoir. The reservoir does overfill on sitting, but these two items prevent it from leaking.

If your tranny was truly 2 quarts low, it would not have shifted at all. So, I agree you might suspect an over fill. Ask them how they did it. You either need to learn how to do this yourself or find someone who is more familiar with 928s.

If done with the engine running, but not fully warmed up, and they used the upper mark instead of the lower, it would be overfilled, and it would be over the upper line if checked when warmed up. But the difference between the upper and lower marks is maybe 8-12 ounces. I don't know how they got 2 quarts into a previous filled tranny even if you had some on the floor after sitting and lost some doing the radiator. When I did my radiator, I lost maybe 4 ounces from the lines dripping.

Speedtoys

How about 12yrs?


And yes, I keep making a mess of your garage with it.


Didja post that June run to the list?

nsantolick

I did remove the old radiator, and consequently needed to make up for the new radiator, which I understand is around a quart itself. Time had lapsed and some amount more did spill out from the lines. I did run the car a few times, once for 45 minutes before taking it over for the state inspection. I rowed through the gears to some extent, holding it in each gear.

I think they more or less did the fluid topping correctly, except, with a car with a cool transmission/engine and most certainly to the upper line.

Could an overfill cause those intermittent shifting problems I described?

Should I panic or is it probably safe to leave for two 120 mile highway trips before correcting? I needed to get back to Philadelphia tomorrow night and because of the holiday, I can't get it in a shop in time. They're not open tomorrow at all. I can take the, ugh, diesel again if I had to, but I just don't have the time now before I leave to do it myself.

nsantolick

lol - AND, my alarm just went off. I did take it through a brushless car wash just a few hours ago. I know my door switch is flakey. Need a quick, yet proper fix for this, otherwise I may have to disconnect the battery should I take it to Philadelphia, as planned. It seems like a nice, quality, metal switch. I'm okay with replacing it soon but I wonder if spraying electrical parts cleaner spray into it and wiggling it around may clean up any questionable contacts inside it?

Since I got the car, the drivers side door lights are often a little blinky, and I know it's that switch being, lol, a little "off."

Bill Ball

Overfilling is bad. You need to correct this. These trannies are very sensitive to fluid level and will shift improperly with as little as 4 ounces off the correct amount. If they put the car on a lift and run it in park, it should either be at the lower line when cold or not above the upper line when warm. The upper line when warm is the proper final check. It's easy enough for them to siphon off some fluid from the reservoir.

Mrmerlin

drive the car for 10 miles then run the shifter through all the selections,

then with the engine running and in park,
lay on a piece of cardboard and look in front of the RR wheel,
you will be able to see the trans reservoir with a flashlight ,
look at it the level should be about 1/2 inch from the top of the tank if the whole tank looks filled then you have and over filled tank,
otherwise if its low then you should add fluid before you do any more driving

nsantolick

Having read all this, I'm quite certain it's overfilled. I'll try to correct it myself sometime before leaving. I'm still curious though if these occasional shifting anomalies are what would be expected in the case of an overfill...

Mrmerlin

get the fluid correct first before worry about shifting issues,
it might be OK once the level is correct

Bill Ball

The alarm can be bypassed. What year is your 928?

nsantolick

Dammit. lol The car alarm keeps going off. I disconnected the ground terminal from the battery. I didn't research this lately, but my recollection is that the factory system is controlled by door, trunk & hood switches. I feel that my drivers door one is bad. Ugh...

nsantolick

Oops. My car is an 1989...

Bill Ball

The control box for the alarm is behind the glovebox. You need to remove the door and interior of the glovebox to get at it. You'll find the box usually tie-wrapped to a crossbar there. It has a blue connector. Pull that off. On the control box will be a wiring diagram. You want to put a jumper wire between 30 and 87 in the blue connector.

nsantolick

Awesome. Thanks for the information. :-) I'll start with trying to clean the door switch and go for the bypass if need be. Just goes to show you. It's always something... lol

https://rennlist.com/forums/928-foru...ir-w-pics.html

Jon B.

I'm curious about the need/want to run Runflats? The performance difference between a performance tire and a "comparable" runflat are Night and DAY!

Plus, the car has a spare.