Remnar

I am have and issue where when the car is cold that when I am driving slowly, approximately 30mph the car goes into a higher gear the engine seems to sound like rev is too high(a few hundred RPM, but it's noticeably loud), the sound is consistent and only quiets down when the car stops. After a few minutes of driving, this condition stops. I have taken the car into a transmission shop and they gave me a an excellent bill of health on the transmission. I have also tried to calibrate the TB, both on the STAR system and using the key and gas peddle, no luck.

This condition started after I replaced the valve cover gaskets.

Any help would be greatly appreciated. FYI, this is a complete stock setup.

Thanks

drothgeb

Sounds like a leak or disconnected hose some where. Check the 1/4" metal line that plugs into the back of the SC on the driver side. It's bolted to the valve cover and sits loosely in a grommet on the back of the SC. Check the T on the bottom of the TB as well as the valve cover sides where hoses connect, also about 1/2 inch hose that connects to the driver side intake after the filter box and before the Y pipe.

hachiroku

you'll need someone with STAR to view transmission faults. our computers will log slow shifting, fast shifting, etc and the occurrence. my car transmission did this when it was low on fluid. topping it off resolved this issue for the most part.

Remnar

So I gave up trying to find the issue and asked the dealer. It was at the dealership to replace the brake controller (love that 25yr warranty) and asked them to diagnose. The found the problem, and quoted me $3500! They say that my supercharger clutch needs to be replaced.

Now I have to determine the best approach. I feel that it may be time to install a 83mm pulley.

Anyone who has a good OEM or 83mm pulley, drop me a PM

Cheers

drothgeb

I wouldn't trust the diagnosis without my own troubleshooting before buying parts. Remove the SC belt and see if the issue goes away. The cars drive fine with the belt removed (just no power). There are two portions to the clutch, the pulley only has a friction plate and spring. The electromagnet is the big black portion on the SC that sucks the clutch in.

Remnar

That's excellent advice. I have noticed that it is getting worse, and with 180K on the car, it would not surprise me that the clutch is in need of replacement (bearing has 40k)

More power is like the saying "you can never be too rich or good looking" but I would like to keep this car for the foreseeable future, so additional stress on the engine may not be the best approach.

Cheers,

Remnar

Remnar

Well,

Drofgeb, you called it! I pulled the supercharger pulley and I still have the problem. So the dealer was going to charge me $3500 for a misdiagnosis. Now that I think about it, the last time I took the car in for service, an alignment, they wanted to randomly replace parts because they couldn't get the car to stop pulling to the right.

I understand that dealerships are going to be expensive, but I expect a certain level of competence. To think, they just replaced my SBC.

Well I guess something will stop me....

drothgeb

Well, it's a bummer you still don't know what it is but at least you aren't spending cash on a bad guess just yet. I'd still smoke check the intake for leaks. Or if you feel like it's tranny related try double checking there is no oil on the TCU plug wicked up from a bad conductor plate plug. Might be worth trying to hunt down some one competant with star to help out. Not sure if you have a good Mercedes indy local to you. You can check throttle position while running which will indicate leaks or not, as well as actuate it, actuate the super charger clutch to verify operation, and see any issues that were logged. Just takes some one competent to do the troubleshooting with it I guess.

Remnar

Well, it looks like I have a few things to check out. I have a Star system, but I am still becoming familiar with the system. It's saved me more than once, and worth every penny. I haven't found an Indy guy that I am comfortable. I may not be competent, but I am close and relatively cheap.

In the last year I have replaced all 4 Airmatics, Airmatic pump, sc pump, wheel bearings, flex plates, driveshaft bearing/support, upper & lower ball joints, torque struts, valve cover gaskets, plugs, wires, coils, a new set or rear skins installed and the dealer just replaced the SBC.

I guess it could be worse.

Cheers,

Remnar

drothgeb

Haha, well there is a test in the ME control unit some where for the SC clutch. I haven't messed with it but I know it's in there. Also, you can do a running test of the throttle body in the ME as well. It was tell you what angle the throttle body is at during idle, as what as what values are acceptable and that if you are below a certain value (closed too much) there is unmetered air. You can do a trans test, it runs through gears and checks pressures and stuff but I feel like there is only so much it can actually evaluate. I don't believe it will catch things like a failing conductor plate unless the issue is occurring at the exact moment it runs the tests, but I'm not sure.