I recently bought an 2003 Audi TT, 180hp (non Quattro) with Transverse Mounted 6 speed Tiptronic Transmissions. The engine "appears" to run a little hot (Temp. needle one notch right of middle notch) after warming up. Is this normal?

When the temperature needle moves to the right of the middle marker then the transmission starts to shift with a heavy jolt (un-smooth shifts). Is the transmission shifting related to the engine temperature? Do I have a sticky thermostat or a bad Coolant Temperature Sensor?

Thanks for any advise.

 

you need to determine whether the temp gauge is reading correctly. you could also have a water pump that is failing. you didn't mention your milage.
the hard shifting is most likely valve body related. audi says that the transmission fluid is "lifetime". no fluid of any kind is lifetime. you should service your transmission every 20,000 miles. dirt and heat kill modern transmissions. fresh fluid and filter changes will prolong your transmission's life. if it's jerking and or slipping, revmax sells a rebuilt updated valve body that should cure your issue. my car had 170,000 miles and shifted poorly from 1 to 2, 2 to 3rd gear. i installed the updated valve body and the car now shifts like new.
Good luck!

 

Thanks for your reply, I changed the VB and shifting is smooth. Now got to deal with the cooling issue. Thanks again.

 

That's great news! please keep us updated as to what you find the overheating problem to be. i plan to start disassembling mine today to do the waterpump, timing belt, oil pump and cam chain and tensioner. i will be doing a thread on what i find as i've not done much work on european imports. it will be in the overheating thread that i started last week if you want to check it out.
tom

 

OK, I have the thermostat out, checked it against a new unit by putting them in hot water. Both of them (Old and new) open at the same time (just before boiling). I guess it should be the pump then. But service records indicate a new pump was installed in the summer of 2011. Just 10K miles ago.
Dread doing the timing belt and water pump now. Tired, haven't even recovered from the Valve Body job from last weekend.

 

I pulled out the water pump, it has a plastic impeller, but looks like in very good condition. Impeller is fixed tightly on the shaft. This pump was installed in the summer of 2011.
Now I am really confused, thermostat is Ok and Water pump is also OK, so what could be the reason for over heating?

 

I replaced all parts related to overheating a few times. I think it may be the fault of bad aftermarket parts.. Who knows. The last fix that fixed it was the Fan Control Module. Could also be the fan switch in the radiator, or the fans themselves. FCM and switch are pretty cheap fixes.

 

Are you sure it is running hot? The most common cause of this is the temperature sensor itself. A $15 part that is easy to replace. Confirm the temp using the HVAC readout to confirm that you aren't reacting to faulty info...

 

I wonder if your radiator is partially plugged, which would reduce it's efficiency and make it run hotter than it should even if the fan works. A friend of mine with a Mercedes Benz used some factory citric acid powder that the dealer sells. He flushed his system with this and was amazed at the crud that came out of his cooling system. If you have an infrared temp gauge can you run the car and see what temps you get on your radiator? I would think you'd get consistently different temps from left to right unless there was a partial blockage in the top, middle or bottom portion of the radiator.

 

Ok, so I installed a new timing belt. Then went out and bought a new infrared temperature measurement device from Harbor Freight and checked the engine temperature as the engine warms up. Looks like the temperature measuring sensor is bad. This is because the thermostat opens up just before 100 Deg C. Next project is to change the sensor and verify that this is indeed the case.