Hey guys, got a problem with my 2001 A4 1.8 T quattro that I hope you can help with. Car seems to run a bit hot sometimes. Temp indicator sits at the next higher mark over center. Othertimes it will run normal. Also I seem to have no turbo boost about 50% of the time. Seems like I usually have more consistant boost when the vehicle is cold or for the first 5 minutes of driving.
I do have a check engine light, but I live in Wyoming and don't have anywhere handy to pull codes. Can a auto zone or Oriley pull codes on these?

Thinking maybe a diverter value issue?

Please help me out and give me some ideas of things to check.

thanks.

 

go to the store and have the codes pulled. odds are its your coolant temp sensor. if its never been changed you could put an updated one in there either way

 

Do you have a boost gauge or does the car just feel slower? When was the water pump/t-stat changed last?

 

Do you think the temp reading hot and the lack of boost are related or seperate issues?

 

Car just feels slower. I can feel it kick in and out sometimes. I changed the thermostat this June. Water pump has never been changed to my knowledge.

 

Hard to say without more info. If your car is over heating the ECU would pull timing so you don't asplode. That's why I asked if you have a boost gauge....

If you're seeing exactly 3lbs of boost, it's probably limp mode. If you're not seeing less boost but the car feels slower, the ECU is pulling timing because you're overheating.

 

Could the thermostat be sticking causing it to run hot sometimes and this would cause the ECU to reduce power? Thermostat is easy enough to change and either remove that from the list of potential culprits or possible fix. It has not run hot enough that I get the dash light with the thermostat symbol yet.

 

What's your boost gauge reading at WOT? The t-stat could be sticking, but I've never heard of a t-stat going bad in 3 months. What does your coolant look like?

Did you ever pull any codes? I'm leaning towards your coolant temp sensor at this point.

 

I'll try and get codes pulled this weekend in a bigger town. I don't have a boost gauge. thanks for the help.

 

Had the codes pulled today. Two codes came up. P0136 and P0411. Thanks again for the help on this.