I'm taking about the sensor for the ECU, not the gauge one. No you don't have to drain the coolant, just remove the plastic clip, pull sensor, then put in the new one.

What is "high", don't you think, a hot running car can be some of your problems?

 

i dont think its actually running hot even though the gauge says it is. it never used to read high, it does now though (over the halfway point). when you start it after it sits for a short period, the gauge reads maybe 5/8-3/4 of the way to hot. if it just idles for 30 seconds or so it goes right back to the middle. i had a 96 a4 that did the same thing when it hit 120k miles, although my s4 started doing this at about half the mileage.it must be a sensor issue. i didn't know there were multiple sensors for the coolant. thanks for the info.

 

ok, first 2k s4, you are the man. that sensor fixed my problem, my car is running awesome. second, i have another problem. the fuel pump whines when the gauge gets below 1/4 tank, and the gauge itself randomly goes all the way to empty anytime there's less than 1/2 tank. it seems like a bad connection somewhere or the sending unit is going, but i really don't know. do you think the two things could be related?

 

Cool.

Sounds like the FP in on it's way out. But, you might just want to change the fuel filter first. Chances are the FLS is going as well.

 

so the car ran great for about 2 hours....i was flooring it in first and something happened and the car lost all power, and now barely runs. it idles really weird and doesn't have the power to drive. any other sensors normally go bad? i hope its not the turbos.

 

tbb prob didn't rip, i have a full samco kit. i looked around, all of them seemed to be secured fine.i dont think its anything mechanical, it sounds tight, no whistling or air rushing, although it barely runs. i started unplugging stuff once again to see if it runs any better, and it does a little bit without the maf plugged in.is this symptomatic of a bad maf? i just replaced it about a year ago.

 

I can see you are going to have problems.

KISS (keep it simple stupid). If you flog the car, it's going to break a LOT. Now that you have full boost, the TBB either ripped of popped off. Start with the simple things, don't just randomly unplug sensors. Things will get worse.

If the TBB isn't the problem, start at the compressor & go to the TBB & make sure everything is tight & connected.

Also do a pressure check on the DV's the pistons might be blown.


BTW, you are in LIMP mode.

 

yea, you're right. a hose popped off. i always have problems with it running the way it's supposed to, and i usually don't drive it that hard. i always run injector cleaner in it, premium gas of varying brands, royal purple oil, i take such good care of the damn thing and it gives me so many issues. tonight it was running slow again, almost like that new temp sensor already gave up. i think i just need to start with replacing my fuel pump and go from there, or at least take it out and examine it. it drives so flaky, one second it will be so incredibly slow, and then randomly just go into high boost and be fast for half a second, run great, start knocking really bad (like it's running really lean? bad fuel pump or clogged screen or something?), stop knocking,run great,and then become slow again. could it be a sticky wastegate?everybody i've taken it to just tells me to start replacing stuff, and i really don't want to waste tons of money on stuff that probably doesn't need replacing. the fault codes tell you nothing, they are always misfires. btw thanks for all the help, maybe i'll just trade it in for something that actually runs consistently.

 

Start with simple things. First off, if you are going to try & diagnose it, you NEED a Vag-com. This way you can check the sensors as they are running, & only replace what is broken.

You may have a vacuum leak on the wastegate lines. You might also have a clogged fuel filter. I would rater replace a $15 filter then a $200 fuel pump. There might also be a vacuum leak on the FPR. Have you pulled the plugs & see what they look like? It might just need new plugs, or you might have a bad ignition amp (things on the top of the air box)

I totally feel your pain, & know hardly any shop out there knows what to do if the CEL is telling them what to change.

 

i have a vag com, but i dont know what to look for when i look at the measuring blocks where it says what the sensors are reading. they all look okay to me, do you know of any common ones that i need to look at? i have some ngk plugs in therethat have a needle point, they were about $100 for the set and i replaced them about a year ago, so i assume they're still okay. i've replaced the original fuel filter, which was super clogged, and nothing changed. that's the only reason i say it must be something else with the pump, if the problem is fuel related. what is the FPR? fuel pressure relay? where do i find it? also, is there any way to test the ignition amps?