Under Boost Questions

[Sundevil84]

Last week I was driving and the car was running fine and then all a sudden it says my coolant is low, I look and my car is about to overheat. I open the hood and all my coolant is gone, and is running out the back, by the coolant flange which I had replaced by a shop in January (I was pissed to say the least). Get it towed to the shop and they fix it (It was actually a faulty water hose) free of charge. Leave and I get a CEL 2 miles down the road.

I’m getting the dreaded P0299 (under boost) code. I have replaced my DV and MAF just to rule those out. I have hooked my compressor up and looked for leaks, and can’t find any. My next thought is that it is either the N75 or Boost sensor. Here’s what’s strange, when I first got the code I looked under the hood and my TIP was hanging off the Turbo. My thought is that when I lost all the coolant (a lot landed on the catalytic converter and steamed a ton) some of the steam went into my TIP and into the N75. Is this possible? Could that screw my N75 up and cause the CEL? The car seems to drive fine, maybe a little limp, but not too bad.

Is there anything else I'm missing?

Any ideas would be helpful.

*sorry this was such a long story.

[fitMINT]

i have the same issue. haven't figured it out yet though, it puts me in limp. 5psi all day :(

[Sundevil84]

Sorry to hear that Fit,

If I figure it out I will let you know.

I forgot to add that when I clear the code, the car drives fine and it wont come back for about 15 miles. I don't know if that makes a difference, but it makes me believe it is more of a senor issue than a physical issue.

[waldo1324]

you has vac gauge?
vac leak?

[Sundevil84]

I don't have a Vac leak anywhere. I did the test with a compressor at 15PSI and nothing was broke.

I do have VAG-COM. Is there something I can log that might help me diagnose this better?

[Sundevil84]

Paging Old Guy!

Paging diagnosticator!

I really need some help on this.

[A4SoftWalker]

If I were u I would have returned the car right back to the shop.

If u want to work on it urself, then I would concentrate my efforts at the area of your engine in and around the coolant flange.

This is what we benefit from working on our cars by DIY... and what I hate about going to shops.

Most likely during the process of working on the coolant flange area the requirement of the tech/mechanic to remove A LOT of hoses responsible for boost control introduced a problem somehow.

If something is not reinstalled properly then, there u go, possible massive boost leak/ no brakes/ and other associated problems

[daihashi]

codes and logs will likely point you in the right direction. go hook up vagcom