Okay, my computer threw a P0455 a couple of days ago, and I know it's not the Gas Cap. Searching through the forums I found info on a valve (Purge Valve) in the airbox which helps build fuel system pressure. (I also have the no start on fill up problem). I took apart my air box last night, and found red fluid (2-3 oz) sitting in the bottom of my airbox. It didn't look like there was any on the filter. Is it possible that the last time the filter was changed the DAT spilled coolant in the airbox and didn't clean it up? Is there any other way that coolant could get in there? It can't be flowing in there, or my engine would die from inhaling coolant.

It's a 99 A4 2.8 Q, 82K Miles

Help!

Thanks,

Dave

 

do you have a stock filter?

 

Dave,

According to Bentley manual, P0455 is listed as "EVAP Emission Contr.Sys (Gross Leak) Leak Detected"... Not sure what to look for though...

D

 

Do you have an OEM filter in there, or do you have a high flow Oiled filter. If the latter, the filter is over oiled and is dripping into the box.

 

How do you tell the difference? Okay, I'm stupid, but... It's not what I'm used to seeing from an aftermarket filter (K&N Cone type). It looks like a standard filter, fits in the air box in the right place, has a red flexible rim, normal looking baffles and a screen on the front and back. Didn't see any badges or logos on it. No chrome or anything fancy. It may be aftermarket, I don't know what the OEM looks like.

My engine has since thrown three more codes:
P0451
P1136
P1138

Added to the original P0455, It sounds like I have a major problem. I also have a problem with my fuel pressure (guessing) when I fill up my tank. This ONLY happens when I fill the tank. From a suggestion on the forum, I tried only filling half way. It still hesitates and gives a hard start (need to feed it fuel via pedal to get it to stay running), but it will fire.

Other than that irritiation, and the CEL on my dash being on, I'm not having any problems. The car runs out great, never hesitates or stalls other than after a fill up, and gets 25 MPG. Is there anything here a two-left handed mechanic can troubleshoot on his own, or should I just bite the bullet and pay the Stealer to check it out?

Dave

 

touch the filter, if your hands get oily, then it is an aftermarket filter and someone reoiled in incorrectly.

P0451 - not listed?
P1136 - Long Term Fuel Trim Add.Fuel,Bank1 System too Lean
P1138 - Long Term Fuel Trim Add.Fuel,Bank2 System too Lean

the non-startup after fillup problem is becoming more common, search the forums and you'll find a lot of threads on that topic

 

If he had to take appart the filter box, this tells us that it isnt aftermarket.

 

Is it possible to have a high performance filter which goes into the stock air box? I just thought there were intake's/cold air intakes.

 

That's kind if what I was thinking too... But I don't know a whole lot about this subject.

Maybe someone thought putting oil on a stock filter would make it work better??? Is the oil used on aftermarket filters red? I assume so, or you wouldn't all be asking.

Further research (AudiWorld , AudiForums, AudiFans) on the quad error code problem (0451, 0455, 1136, 1138) looks like I'm down to a few possible causes:

1) Vacuum Leak (Somewhere) - Check all of the hoses, everywhere. Read on one site that pulling the dipstick on a car with a vac leak while running would Probably cause the engine to die. Should be a good quick check. Also, read that some leaks can be heard from outside the car when someone else revs the engine.

2) Stuck/Bad Purge valve - Need to find out more about diagnosing this one

3) Bad MAF - The most expensive, therefore most likely, problem. Not sure from what I've read, though, whether this would cause all of these codes to be thrown or just the P0455 / P1136 codes.

One of my primary concerns is that most of these posts seems to be directed at the 1.8T crowd. Not sure if behavior is the same on a 2.8.

I'll keep reading and hunting. If I find a definitive cause, I'll post it for the ages.

Dave

 

Quick update...

Pulled the dipstick while the engine was running...No change. Tried squeezing a few hoses to see if it made any difference... No change. I'll be taking the airbox apart again tonight to see if there is more oil in the bottom. Will try to check the Purge valve at the same time.

Updates to follow...Maybe

Dave