Hello Guys,
I am new to the forums so please forgive me if I am posting in the wrong place or anything. I just have a question. I have an '02 A4 1.8, has always run fine, no problems at all. Have extensive maintenance records, everything always done on time and taken care of perfectly. Now as of a week ago, all of a sudden I have a very difficult time going up hills. I live in the mountains so have to do this all the time, and as of last week, when doing normal highway driving have no problems, but going up hills slows down to like 40mph and very difficult to maintain that speed. I have read some online, and see things like maybe a turbo problem? or maybe fuel issue? Does anyone know about this being a problem and what it usually is? I just want to see if there are some things I can try myself before taking it to the shop. Thanks everyone!

Larry

 

What is the's car rpm at when you are having the issue?
What gear are you in? What gear do you have to go to in order to get up the hill? Does it shudder or surge?

Manual tranny?

perhaps a blown diverter valve or a large boost leak. Do you have issue when wide-open throttle when not on a hill?

 

hey thanks for the response..
rpms anywhere from 3 to 4 as i always try to keep at 4 or under, and can get up the hill in 3rd gear, sometimes having to go down to 2nd again. no shudder or surge and fine when not on a hill. funny thing though, this morning I had to put gas in, and after reading alot on here yesterday about fuel, etc. I decided to try a different gas station. we dont have 93 here in CA anywhere, just 91, so opted for chevron instead of the cheaper gas, and right away when not on a hill could notice that the power was way back up again, almost to normal. then coming up the hill back home, was way better too. not quite normal again, but much much better, was able to maintain about 50mph even on the steepest grade, so I am guessing it is a fuel issue? wondering if I should run some fuel sys cleaner thru it, then maybe start adding octane booster each time I fill up? could fuel cause that much of a dramatic change in power like this?

 

I would go to Autozone or dealer to see if they can check for error codes. It could be a fuel issue, but you won't know anything for sure until you scan for error codes.
How much of the old fuel was in the car when you refueled with the Chevron? Might take a while to cycle it out completely.

Other things could be a bad MAF sensor. Perhaps a coil pack has died and you are only running on 3 cylinders - any vibrations?

I am actually still thinking it might be the diverter valve or a large boost leak elsewhere in the system. If the diaphram on the diverter valve rips (they usually do over time) it will vent a lot of your boost to the atmosphere.

 

brrman,
thanks again for the fast reply. so here is where I am now. I don't think it is a fuel issue. the problem was gone, but then 2 days later came back, and now been that way a few days. I even tried some octane boost didnt help at all. I am not sure what a MAF sensor is, but I assume it is part of the turbo system? mass air flow maybe? Have not done a ton of work on cars but worked aircraft for 8 years. LOL. anyway, so same problem, no power at all when even on slight hills. very very hard to get up hills. flat is plenty of power. I do doubt it is a cylinder problem, since there are no other symtpoms aside from the power issue. no shaking, vibs, noise or anything like that. I did have a local mechanic look at the turbo visually. he said the "boot" is not ripped or falling apart, which i guess is a normal failure? I guess thats what you called the diaphram? he said it looks ok. turbo was very very very hot when he looked. probably since I just had drove the 10 miles up the hill to home. so now I am afraid to even go down into town anymore since I dont want to blow something up driving back up hill. I did some checking online, a new aftermarket turbo only costs $275 TO $300 bucks? I am wondering if that is the problem, how hard it would be for me to change or how much labor would be for a shop? I am on a tight budget, since I am a disabled veteran, still waiting for my disability to come thru, so have very little money and this is our only car now. I will drive it around town for few min but afraid to drive too far or down the hill now since it gets so hot coming up the hill with turbo not working. Is that the most expensive part of the system, the turbo unit itself? I have read that it is a super simple job to change it, with videos even being on youtube to do it. I am mechanically inclined, that is not a problem, just have not done much work on my cars since I would always just let the shops do it, but not with little funds, I cant afford like a thousand dollar job. anyway, any advice or insight you can give is much appreciated. THX

Larry

 

also I forgot to ask, sounds like the diverter valve might be a cheap and easy thing to try first too. am I wrong? do you have any idea how much one of those goes for and is it pretty simple to swap out and see what happens. I have all the maint records for this car and i see the part has never been changed, so I am sure it cant hurt?

Larry

 

The diverter valve is a simple change on your car and costs like 50 bucks if I recall.
Did you ever get the codes scanned? Until you do that this is all conjecture.

 

I had a local shop check it and they said they came up with 462D: Boost pressure control above control limit. Charged my 80 bucks just to tell me that, and they were not willing to try and fix it since they say that code means it needs a new turbo? Correct me if I am wrong but seems like if boost pressure is above limit, the turbo is working, maybe just clogged up really bad or something? I dont know what to do now. I don't have a ton of funds to work with. I am thinking the clogged part might sound realistic but you would know better than me. Is that possible? and is there a way I can somehow clean the turbo out to see if that helps?

 

if there is anything I can do myself to try and clean this or check it, etc please let me know. They also wrote next to the fault code that it could be either a bad pressure regulator valve, diaphram or valve itself stuck open? but they said in all cases would need a new turbo installed. I dont feel real confident with that diagnosis. any advice for that error code would be appreciated. I read up some posts online about it and they vary from bad sensors, to dirty veins in the turbo? some even said cleaning it fixed it. I assume there is a way I can check or clean myself or at least be able to see if it is actually moving freely?

 

Sounds like limp mode, which really could be caused by quite a large number of things, the most costly being a new turbo. Steer clear of the "aftermarket" cheap ones. A turbo truly is one of those things where you get what you pay for. Limp mode will usually kick in when a problem is detected which will allow you to "limp" home or to a service station. I do not remember how to "clear" it to make the car run like normal again. If the only code was boost over limit, it is possible the waste gate didn't properly manage excess boost, tripping the limp mode in order to save itself. It's possible it was a one time occurrence and everything will be fine once you reset the limp mode. Or, it's possible the waste gate is completely shot (which I think on this particular car means a whole new turbo). It's hard telling not really knowing. However, if you had a bad turbo or a bad boost leak (such as a shot diverter value), the car would really be running like garbage, sputtering, vibrating, etc. and the CEL would be flashing. Do a search for clearing limp mode and see what you find.