my a4 blew up...

[setay]

hahaha, im sorry but i knew it would catch attention. but i really do have a problem, so you didn't open my thread for nothing. and just cuz i <3 AZ so much, i even went through the trouble of getting an actual picture of an exploding car.



ok, the problem is something is def. going on with the engine, not the tranny, i know that for sure. it actually feels as though my audi is pushing about 20hp, i put it into gear, to try and drive away and it has no torque to get it going pass 5mph. but even when i do get it rolling, no matter how much i rev to try to keep if from stallig, it does anyway. these are no exagerrations, i am being 100% serious.

the symptoms are very erratic idle, very poor throttle response (anywhere from 2 - 5 second delay at times.) seems as tho the engine is giving itself gas at times, because it will be fighting to idle and then all of a sudden shoot up to 3000 rpm (this may be the ecu trying to correct itself tho, so it may just be trying to fix the problem and not really the problem in itself). i HAVE to give it gas to keep it alive, if i dont it dies after giving a very short fight.

alot of people are gonna say coilpacks, but i highly doubt 4 going out at the same time. even 3 is very unlikely, but it does seem as though soemthing like that is up. timing maybe? anything else you might suggest? the MAF is clean, and the MAP is set correctly also. im on my way to get 5 coilpacks once i finish posting cuz i need them changed anyway, hopefully by the time im back ill get some replies.

Oh, and for the curveball. NO CEL..... hope you have fun with this one, i sure have.

thanks for the help guys.

and p.s. - i was not being hard on the car at all during my drive, not even days before this incident.

[Gallep]

VAG it and let us know what's up.

[Killerteve]

It still could be the MAF. When my MAF went out it was visually fine, but I had the similar symptoms to what u where describing because since the MAF was busted the car was running super rich and soaked the spark plugs. The result was 4 bad spark plugs and 3 bad coilpacks. Good luck.

[boy412]

I'll be curious to see what happens when you replace the coils...

[brewmastr]

ok i felt it would be better to provide more than a half ass sentance here so here we go with the edit:

ok first of all if all 4 coilpacks were dead the car would not run period, 1 coil pack dead=rough idle, 2 coil packs dead =extremely rough idle and stalling, in my mode of thinking right now, could be 2 coilpacks out or your maf could be screwed up, but you need to pull codes with a vag-com, even if you have no check engine light i would bet the incident set an event off in the ecu and there will be a code for something at this point. if you got specific cyl misfire codes replace those coil packs, if you got fuel adaptation codes probably a mass air flow sensor.

[setay]

thanks brewmastr, i appreciate your response. its not the coilpacks, for some reason the MAF doesn't seem like the problem.

whats going on is much more severe then what my first post must have made you all assume. i really do appreciate your efforts tho, in trying to help me out.

my worst guess is becoming more and more of a possibility. im thinking my timing belt skipped, damn it.

and one last symptom i forgot to tell about. everytime i step on the gas, the air is coming OUT of the intake. it sounds as tho the DV is splashing everytime i step on the gas, and makes no noise when i left off. and this is both IN gear and OUT of gear.

i <3 my audi

[A4TL]

so you haven't vagged it yet? sheesh. don't start the motor man. when that valve drops into the cylinder you will be sad

[absolutegtr]

Funny......you are describing the EXACT problems my 1992 Talon TSi AWD had.....I NEVER figured it out and just ended up selling it....

[old guy]

It sounds to me like you have a major boost leak. Check all of your hose connections. Check for splits in the hoses. Also check your intercooler. The plastic end caps on the intercooler tend to separate from the core and you will get the symptoms you have described. As soon as you start to build any boost the air dumps and you loose all power.

[Papachristou]

i too would say boost leak.. my racetec kit was shipped without the DV line and in my haste i forgot to put my homemade fix on and it wouldnt stay running or boost period

[surreal]

I would have to say a vacuum leak. The car has the same symptoms I learned about in school. Your DV valve is stuck open due to lack of vacuum on it. I would start at the line on your dv and work back from there. You can go rent a vacuum pump and guage at Autozone or Advance auto. If it was your MAF you would be pulling a code for it. Hope this helps.

[brewmastr]

I would have to say a vacuum leak. The car has the same symptoms I learned about in school. Your DV valve is stuck open due to lack of vacuum on it. I would start at the line on your dv and work back from there. You can go rent a vacuum pump and guage at Autozone or Advance auto. If it was your MAF you would be pulling a code for it. Hope this helps.

i havn't played around with our dv's much but im pretty sure when its under vacuum it is opened, i think its normal state is closed but then again have not taken a close look so if it was not recieving vacuum that baby would be closed at all times, some of the more audi experinced tech's on this board maybe able to confirm for me on this one. now on this second matter, i dont mean to bust your bubble as you are still in school it sounds like, but being an experinced automotive technician for years specializing in driveability issues and working for mercedes-benz let me tell you MAF IS GOD! the computer almost never questions what the MAF tells it, only time i see MAF codes is when it is open circuit. it is very common that i see maf's that just stay at constant voltage of 1.2volts from idle to 4k rpm, with revving the engine with no load on the engine i should see a jump to around 2.4v and the computer should know with throttle angle opening up that more air is coming in along with the crankshaft postion sensor saying the rpm is at 4k rpm but alas no code because the maf is god in the total equation. The computer is praticall programmed to always belive whatever that maf says. this is where experince and training come into play, scoping the maf sensor and looking at fuel adaptation or as you may know it as fuel trim to see where you are at. simply saying a componet isnt bad because if it is it will have a code is the type of thinking you must get rid of in order to fix cars.

[old guy]

I would have to say a vacuum leak. The car has the same symptoms I learned about in school. Your DV valve is stuck open due to lack of vacuum on it. I would start at the line on your dv and work back from there. You can go rent a vacuum pump and guage at Autozone or Advance auto. If it was your MAF you would be pulling a code for it. Hope this helps.

The DV is held in the closed position by an internal spring. Vacuum is what opens the valve. So the valve would not be stuck open from a lack of vacuum. However, you are partially correct in that the DV will not properly hold boost pressure if the vacuum line is defective since that line also provides a boost signal to the piston (or diaphram) to help keep it closed under acceleration.

[surreal]

Yes I am still in school I graduate in august. I'm the top of my class. The spring in your dv helps in keeping it closed, but also under boost it also has the help of the positive pressure in the line. If you have a boost leak that’s making the car not run right you will pull a code about the grams of air per second is out of range. It tells it this because your maf and boost sensor are reading different amounts. Try this disconnect a hose clamp and slightly let the hose come off some. Not mush only like a quarter of an inch or so to one side. You will pull this code. Yes it’s possible not to have a code with a bad maf but what happening with your car is too much for a faulty maf with no code.

[setay]

i dont own a vagcom, but just ordered one... (gonna read the vagcom sticky right now too)

and thanks to all those that have responded, ive written down all the suggestions and will run through all of them tomorrow since its my first day off since this happened. expect an update tomorrow.

also ive ran through all the intercooler piping and every hose that is in anyway involved in intake. i have an upgraded IC so its not the stock intercooler coming apart.

i made the boost leak tester (the PVC elbow that i hook up to the TIP). so thats the first thing im doing tomoro. i really hope i find a problem, but i dont expect to find anything.

again, thanks to all.

one last thing. even if it was a boost leak, wouldn't there still be power from the motor? or no? its a serious question, i can see how it could be right and wrong, so i'd like some input.

[brewmastr]

surreal, wait until reality hits you in the forehead like a stack of bricks, the last thing any shop needs and trust me of this is a know it all, you know how many guys on this very forum come in and say "my car runs slow and i dont know why, i checked for codes and i have none" and then we in response say you need to check actual boost against requested boost as you probably have a boost leak, hell according to your methodology there bam i have a code, you may be at the top of your class and congrats for your effort, but dont think for a second when you walk into your first job you are a diagnostic technician. Too much for a code without a maf, dude you have got to be f'in kidding me, i had a car in the other day that woudnt accelerate over 10mph had to be towed in and had oil contamination in the maf, no code at all, obviously you dont understand just how much the engine management especially on german cars relies on that maf signal to be true and correct. Im a technician for Mercedes-Benz, with efi experince from me1 to me9.7, we have alot of maf problems, and when i say alot, i mean every single day someone in the shop is replacing a maf on something and were not a very big shop, they are pratically best sellers in the parts dept. i never see a maf code when i replace one period. fuel adaptation codes at part load maybe but nothing that says bam its the maf that is bad, take this as helpful advice because you gotta be able to fix the car when there is no codes, and if you cant you will be doing brake jobs and services your whole career, then again thats not so bad as you will learn the money is in the simple work, not the complicated.

[surreal]

Brewmastr I think you let your experience go to your head to much. I see where you are coming from but this is a turbo car not a N/A Benz. Everyday we work on live work and right now the last class I’m taking is advanced electronics and dialogistic. I've already blew right through the first one. I have all but my transmission ASE, which I’ll take this fall when they come around again. Then I'll be considered a master tech according to ASE, Also I’m the only one in my class that BMW wants to hire, so I will be working for them in august. The guy doesn't want to send me to there specialized school either he said it would be a waste of time for me. Do you get off degrading people? Reality check your full of yourself How about that ha-ha.

[surreal]

Setay I forgot to tell you an easy check of your MAF without Vag would be to unplug it. Our cars can run without it. It may go into limp mode but it will still run fine. If your symptoms go away that’s where I’ll start. I figured brewmastr would have told you this since he is the king of MAF sensors.

[old guy]

one last thing. even if it was a boost leak, wouldn't there still be power from the motor? or no? its a serious question, i can see how it could be right and wrong, so i'd like some input.

Part of the reason I suspect a boost leak is based on your comments "and one last symptom i forgot to tell about. everytime i step on the gas, the air is coming OUT of the intake. it sounds as tho the DV is splashing everytime i step on the gas, and makes no noise when i left off. and this is both IN gear and OUT of gear." What happens when you have a serious leak is that the amount of metered air going through the MAF sensor is radically different than the actual volume of air actually going into the motor. Obviously this can play havoc with your A/F ratio and cause all sorts of issues. If you don't find anything when you perform the boost leak test you can try unplugging your MAF sensor and see what happens. If the problem is indeed the MAF you should see a noticeable difference in performance running without the MAF.

Good luck!

(And let us know how it turns out today with your boost leak test.)

[surreal]

Also Setay, what he can do is with the MAF unplugged and the car running ok you can have someone lightly load the car and you can listen for a leak. Have them lightly let the clutch out until you hear the turbo start to boost then just listen. I wouldn't do this for to long tho its bad for the clutch since your making it slip. Also I wouldn't get under the car incase it decides to move. Oldguy would you confirm this?

[old guy]

Also Setay, what he can do is with the MAF unplugged and the car running ok you can have someone lightly load the car and you can listen for a leak. Have them lightly let the clutch out until you hear the turbo start to boost then just listen. I wouldn't do this for to long tho its bad for the clutch since your making it slip. Also I wouldn't get under the car incase it decides to move. Oldguy would you confirm this?

I don't think I would recommend that for several reasons. First of all I don't think you would be able to safely put enough load on the motor to build any significant boost pressure. And even if you could the noise level would probably prevent you from distinguishing the existence and location of a leak. Setay's best bet is to follow through with a boost leak test as planned and go from there.

Cheers!

[surreal]

Yes by all means this is not the best way of doing it, but its a cheap quick test that can be done. I was stranded on the side of the highway one day and fixed it by doing this. A hose blew partly off I had my girlfriend pull the ebrake and load it I found the leak and got the car back home.

[old guy]

Yes by all means this is not the best way of doing it, but its a cheap quick test that can be done. I was stranded on the side of the highway one day and fixed it by doing this. A hose blew partly off I had my girlfriend pull the ebrake and load it I found the leak and got the car back home.

Glad it worked for you! Very innovative way to work with what you have available. What's that old saying? "There's more than one way to skin a cat?"

Cheers!

[chucka4]

it sounds just like when i had a boost hose crack on me. i kept looking for the ends to be falling off, or there to be a visible hole. but the crack was only visible when boost was going, then all the same things happened, fell on its face, would barely move. we ducted taped it till the new hose came in, but the hard part was finding the cracks.

btw, i really was kinda hoping that pic was your car on fire. mostly because if the title. over all im glad its not, but there was that side that said "man that sux and is bad ass at the same time" hahaa

[setay]

it sounds just like when i had a boost hose crack on me. i kept looking for the ends to be falling off, or there to be a visible hole. but the crack was only visible when boost was going, then all the same things happened, fell on its face, would barely move. we ducted taped it till the new hose came in, but the hard part was finding the cracks.

btw, i really was kinda hoping that pic was your car on fire. mostly because if the title. over all im glad its not, but there was that side that said "man that sux and is bad ass at the same time" hahaa

HAHAHA, well thats why i posted it. i didn't want to disappoint anyone by tricking them into opening my thread.

anyways its FIXED 100%.

before i say what i did, oldguy = the winner (along with the others that agreed with him i guess).

so like i said i ran the boost tester, i heard a very faint sound coming from the MAP sensor, the oring on it had a very very tiny gash in it. but of course that didn't fix it.

as i had the system pressurized i ran through everything again, just to make sure. as i was looking nothing was hissing, not even a little. so like i said im going through everything and dont notice anything. and i dont know what made me do this, but i started to shake on all of the piping. and when i did that, thats when i found it.

a RIDICULOUSLY huge rip in the turbo to intercooler transition hose. my motor mounts are blown, oozing the red gunk out (also must be the reason my snub mount doesnt line up right). so my theory is, i gassed it, the motor shifted and the weakest point in the system was the hose. i took the transition hose off, replaced it and its running fine now. but i mean its amazing to me how i didn't notice anything. so basically, when i gassed the car the hose opened up because of the motor moving and dumps all the air out.

so thats that. the thread is done (unless brewmastr and surreal want to keep going ). thanks to everyone that posted opinions and suggestions. i really do appreciate everyones help in getting this thing running again.

and like i said before, +1 goes to oldguy, thanks a lot

[old guy]

Glad to hear that you got it fixed!!