Hi, I just bought a 1995 Audi cabriolet with 70k miles. The dealer said that there were no problems with there did happen to be some.
1. It get horrible fuel economy, I have to put gas in all the time and it doesnt seem like its getting 17/26 like its supposed to. I thought I'd do some things to fix this: oil and filter change, change the radiator fluid, fuel injector cleaner, inflate the tires to the proper level, and replace the brake fluid. I used to have a mercedes 300e and I did all the work on it just fine, but I'm having trouble with getting the bottom cover off the car to drain the oil. Does anyone have some advise on how to take this cover off and what kind of tools I should use?
2. The thermometer on the dash always is to the far left on cold, however when I leave it in idle for about 15 minutes it will start to rise. As soon as I start driving it goes all the way to the coldest reading. The heater does also not blow warm air while driving fast during cold weather here in chicago suburbs ( -10 to 20 degrees F).
Does anyone know what seems to be the problem?

 

Your Dealer sucks!

1. Purchase a Bentley manual for your car. It will tell you all you need to know.
On my S4 the bottom cover is held on by 1/2 lock nuts, there are 2 extra plastic ones in the wheel wells.
It might be like that on the TT.

2. Your thermostat is bad. You car is running is "warm up" mode, running really rich & cutting the timing.
THIS is what is causing the poor fuel economy. Your putting a lot more fuel into the oil, & this can cause a sludge problem.
Also not good for carbon deposits. GET IT FIXED ASAP!

Your car will feel brand new after!

 

Alrighty, I ended up having the oil changed at jiffy lube and they said that there was sludge in the engine so they did an engine flush. I just ordered a new thermostat but it might take a few days to get here. Is it okay to continue to drive the car until then?

 

It'll actually come tomorrow and I'll be able to put it in. Is it easy to do myself or do I need a mechanic? Does anyone have any quick instructions or a DIY guide on how to replace the thermostat?

 

I also have a '95 Cabpurchased with 70K miles. Go to www.12v.org for a great site on the engine and some in depth repair procedures. The bentley's manual is a must have. Most likely at your mileage, you need a timing belt, water pump, and thermostat replacement. This is an interference engine. That means when the timing belt breaks, the pistons hit the valves. It isn't suppossed to be needed until 90K or 6 years. If it wasn't done, it needs to be done. Naturally, special tools required. I get 22mpg in the city and 32 or better on the road.If I hadn't checked every tank of gas for a year I wouldn't believe it. I probably need new oxygen sensors, but I need a Vag - Tool even more. Send me a PM and I'll help you all I can. Others are more knowledgable, but I've been where you are at. Premium fuel by the way.