Myb

I recently bought a '97 A6 C4 2.8l and I suspect there is something wrong with the thermostat, but I would very much like it confirmed if that is the case.

- Temp gauge inside car shows normal temperature (90°C)
- Fans are not coming on
- If the car is left running for a while, there is heat in the tube coming out of the radiator, although not as hot as the tube at the top. Radiator is slightly hot. Obviously, this has been done in cycles do prevent damage to the engine as it will boil when kept running for too long.
- I have added at least 10 litres of water to remove any air in the system. There is water in the tubes (top and bottom).

Should also add that the car has been idle for about four years, which might have caused the thermostat to get stuck from not being in use for so long.

There are also two other issues;
- Heater barely blows air, but I can hear the system working on full. Some filter problem perhaps?
- When I accelerate to about 3-4k RPM and hits "the pedal to the metal", it doesn't accelerate much and it feels almost like it's choking, in lack of a better explanation. I believe this could have something to do with the fuel filter, which I'm going to remove from my '96 C4 and put it on this one. If I accelerate slowly, however, it still accelerates. This issue is the same regardless of gear (transmission?). Is there any other potential causes for this?

I'm not very experienced when it comes to cars and I'm norwegian, so please use language that is easy to understand and excuse my somewhat lousy English.

I appreciate any help!

varia

cars have turbulator style radiators, which means instead of having open tubes running horizontally across the radiator, those tubes have wavy strips of metal inside them. This is done to slow down the flow of coolant, and get more heat transfer. The downside of the design is that it traps all of the crud that occurs in a cooling system. The radiator's performance drops off over time, and at the point that the head gaskets and heater core start failing, the radiator is probably (this is a guess) only about 50% efficient.

In most people's cases, they may start experiencing blown head gasket symptoms.......the coolant tank boils over or the coolant starts being pushed out of the tank in small amounts, but only on longer drives......when in reality, it's the blockage in the radiator that is causing the coolant "overflow" and then ultimately, the heads warp and the head bolts may even be kinda loose when you tear it down.

Myb

Thank you for your reply. That makes sense. Is this something you can say fore sure based on the information given? If not, is there some way for me to troubleshoot this issue further to make sure the radiator is the problem?

varia

join this forum, much better knowledge: https://forums.quattroworld.com/a6100/