IHello everybody I’m new to this forum. I bought an 03 350 Z today. Paid $3100 for it. On the test drive everything seemed fine. I drove it from Baton Rouge Louisiana to Osyka Mississippi where I live which is about 50 miles. When I got almost got home with the car I noticed the transmission started slipping at interstate speeds around 75 to 80 mph at 2500 to 2800 rpm’s. I pulled over in Kentwood Louisiana at AutoZone and I checked the transmission fluid. The transmission fluid was almost the color of oil. I don’t know what to do because I bought the car as is. Anybody have suggestions or similar problems and if so what did you do to fix it?

 

5AT I am assuming?

 

 

Oh 5AT yes!

 

What is the mileage? Dark trans fluid could just be from fluid that is extremely worn out if it was never, or rarely, changed.

How was the level when you checked it? Slippage can result if the fluid level is too low or too high. The Z is extremely sensitive to either.

 

173,000 miles. The level looked fine.

 

I will check the fluid levels again tomorrow. If it’s too low I add fluid. But what if it is too high?

 

Drain it slowly, let it settle, then check it again If you happen to drain a little too much then just add some. 173k is not extreme mileage, but it is not low either. If the previous owner constantly ragged on it then it may be a good idea to start saving for a replacement.

 

Like any "new-to-you" car, just go ahead and change out ALL the fluids, change all the belts - especially timing belt if so equipped (which the Z33 is not). Baseline the maintenance to zero and do your regular maintenance based on when you baselined it instead of guessing. Hopefully a good drain n' fill of the transmission takes care of the issue.

 

Word of caution:

With such a high mileage transmission and no knowledge of whether the transmission fluid was changed at regular intervals, I would be careful. If you decide to do this then I recommend only doing a "drain and fill", not a flush, which may cause additional slippage. The idea seems to be that a flush removes all metal debris that would normally be utilized by an older transmission for friction. Understand though that even a drain and fill may cause problems so weigh the risks. Some have reported problems and others have not.

I changed mine out a few years ago with about 90k on it (don't believe it was done prior) and it seemed to cause slight slippage, but it went away after a few weeks. Now it runs fine.

Just food for thought.

 

Ok it may not be a Trans problem but I still need help. The “Slip” light comes on about 2,500 2,800 rpms at 75 80 MPH. Does this drop rpms and cause loss of power? I let the rpms drop to 2,000 ish or kick it up to 3,000 and it seems fine. I thought this was transmission slipping but maybe traction control?

 

Yes, the ECU thinks that the rear tires have lost traction and cuts power as a result.

Is your check engine light on?

 

Yes it is. One more question I added a bottle of Trans X for slipping Trans. Did I mess up or can I get a siphon kit and suck it out? And make sure trans fluid is right?

 

Pull the codes when you have a chance and let us know what they are. It may help to give insight into your problem.

My personal recommendation: never add any type of additives until you have exhausted all other options for what is causing your slip. I can't say for sure whether it will cause any additional problems or not.

I would not fully say that it may not be a trans problem. Something somewhere is telling your ECU that RPMs are rising unnecessarily (generally caused by your back wheels breaking traction). A slipping trans could, in theory, cause that same misinformation and trigger the slip light.

 

Ok Z people. My cars Transmission is fine so far. But the transmission fluid is over full.What is the easiest way to cure a transmission fluid over full problem in this car? 03 350z

 

drain plug