A4 Clutch and Axle replacement.

[Cincy]

So my girl blew up what seems to be a replacement axle on my A4. First we thought it was the clutch, so we started pulling the tranny and then found the blown axle. Kind of funny how a blown front axle takes all the power and leaves the car immobile. We pulled the trans anyway which was a good thing since the clutch disc was on the verge of going. Got new parts coming and the car should be good to go come this weekend. It was a HUGE pita to get out, but should be easier going back in. A few pics.

http://i396.photobucket.com/albums/pp46/cincyTT/02062011238.jpg

http://i396.photobucket.com/albums/pp46/cincyTT/02062011239.jpg

http://i396.photobucket.com/albums/pp46/cincyTT/02062011237.jpg

[auditech79]

2.8L? Let me guess the axle broke inside the outer boot so you couldn't see the problem right?

[Cincy]

You got it. The boot was torn which i knew about and figured i would have to change the axle at some time. Thats right where it broke. I just got one from Autozone for $70 with a lifetime warranty. This way if it happens again, i shouldnt be out anything.

[Cincy]

New PP

http://i396.photobucket.com/albums/pp46/cincyTT/02122011242-1.jpg

Disc

http://i396.photobucket.com/albums/pp46/cincyTT/02122011243.jpg

Trans mounts

http://i396.photobucket.com/albums/pp46/cincyTT/02122011244-1.jpg

And my help...

http://i396.photobucket.com/albums/pp46/cincyTT/02122011245.jpg


Ended up breaking the slave cyl. which is ok, since im in there and it is probably 15yrs old anyways. So I need to replace the slave and then bolt back on the exhaust. Since it not in stock or available local, i have to order one from ecs.

[auditech79]

Don't feel bad about the slave cyl, i don't know a tech at audi that hasn't blown at least a few of those bad boys, it just take a little pressure when you're trying to get it back in before you blow the seal. I stopped trying to re-install them, and just cracked the bleeder on em. I think i blew up at least 20 of those f$*kers.

[Cincy]

i got the new one on and everything back together only to find the crank position sensor appeared to have died. Got a new one, just not sure when i get to install it...

[auditech79]

You stretched the cable dropping the subframe, i've done it a few times as well, it doesn't take more than 2" of dropping it (on a B5) to cause a break in the harness.

[Cincy]

I didnt drop the subframe. Probably would of been faster to get the last couple bolts if i did. I think it may have been acting up before hand since it had started and died just after before this happened.

[Cincy]

So i swapped the crank sensor and got the same code and just that one. 16721/p0337 signal to low. Car will not start and now im frustrated and need my car back. Any ideas? I really hope that the tranny isnt the problem cause i really dont want to pull that again. I never touched the fw so i dont see how the sensor continues to have problems.

[auditech79]

You pulled a sensor from your car? I don't those are compatible, but the vag com should be able to tell you that. Find the engine RPM on a data block, crank the engine, do you see any RPM'S registered by the ECM at all?

[Cincy]

I changed crank sensors but still get the same code. My oil and coolant lights flash when the car is on and the fuel light stays on. This is before, during and after i turn the key. Also the fuel goes from the proper level to E when the engine cranks. This is a non lcd cluster. I can

[Cincy]

I can try to find the rpms via vag next i get to work on the car. The old sensor was covered in grime. I searched and no one had any answers. The only logical thing i found was the sensor being more than 1.2mm away from the fw. I didnt change the fw and the sensor is all the way in.

[auditech79]

Thats what i mean, is the sensor you have the same length as the TT one you put in? I know they come in different lengths.

[Cincy]

No, i replaced it with a proper sensor for the 12v. I havent touched the TT in over a month.

[Cincy]

Silly question. Will the engine even show rpms while cranking?

[auditech79]

Yes, thats how i always diagnose a faulty sensor. If its not showing anything while cranking the sensor harness either has a break in the harness, bad sensor, or its not close enough to the flywheel.

[Cincy]

how would i move the sensor closer? It can only go in the hole so far and the fw was never removed. Can there be oil buildup causing a problem?

[auditech79]

Can you remove the sensor and make sure its actually lined up with the flywheel, i know it may sound dumb but it wouldn't be the first time its happened after a trans removal. Oil build up shouldn't affect a pulse type sensor, unless its REALLY bad. You have to remind me, is the sensor bolted to the block, or the transmission bell housing?

[auditech79]

Nevermind, only automatics have the sensor on the block. Pull the sensor at shine a light in there to veirfy its lined up.

[auditech79]

Just to verify this IS the RPM sensor you replaced located towards the top of the trans right?
http://www.ecstuning.com/Audi-B5_A4-FWD-V6_12v/Engine/Electrical/Senders_-_Sensors/ES9437/
If you replaced the speed sensor located on the side of the trans thats not the right sensor.

[Cincy]

Its bolted to the trans and is that sensor.

[auditech79]

Alright then, did you see any RPM's when cranking?

[auditech79]

Anyways, once you find that out i'll go ahead and tell you how to test the sensor thats currently in there. You need an ohm meter and a meter that can read A/C voltage.
The sensor you have should be a three pin, you need to find which pin is the screen, the screen should have continuity to ground, so put one terminal on the negative terminal on the battery (or body ground) and find which pin has continuity. Then clamp the positive and negative of the meter on the other two pins (it doesn't matter which way since its alternating) then crank the engine over. It should generate between 0.5V-1.0Vs. Maybe a pinch more, a running engine would generate around 3Vs. If you get voltage there, then its the harness to the ECM.......or the ECM itself.

[Cincy]

Ok, so i got about 1.5v on each terminal when it was grounded and then upwards of 4v with the ends touching the 2 active pins. Sounds like the sensor is good and the ecu is at fault correct?

[auditech79]

Its either the ECM or the wiring from the connector to the ECM. Do you have a bentley manual with a wiring diagram for the car? We can test the harness real quick with an Ohm meter just to verify its not the engine harness at fault.
I would also follow the main harness from the ECM and feel around to see if its rubbing up against the fire wall or anything that could cause a break in the wire. On B7's, the harness gets cut from the bottom of the firewall.

[Cincy]

I dont have a bentley. I pulled the ecu and everything in the ecu compartment is clean and the wires are still wound in the stock cloth wrap. Im back home now and about 40 miles from the car. I found a place in ohio that has an ecu and will ship it listed for $60.

How can you test the harness? Its just seems odd that this is the only thing the ecm is having issues with. Another thing that sucks is the radio is now in safe mode and i dont have the code :mad:

[auditech79]

Hahaha, gotta dealer trip then. You can pull the serial number off the back of the radio and maybe bribe a mechanic to pull the code for you for cheap.
The harness is easy to test if you know which pins to test, you basically put an ohm meter on the correlating wires from the ECM connector to the pin on the connector to the crank sensor. You should get less than .2 ohms on each wire, if you get too much or nothing at all thats your problem. If you don't have the manual you can pull back the little rubber cover on the connector and check the colors of the wires, then do the same on the ECM harness and locate which pin that wire is going into, then test it that way. They should be the same color at the ECM as they are at the sensor harness, for instance red with a black stripe would be the same at both connectors. I would say its a higher probability that its a harness problem more than the ECM but stranger shit has happened.

[Cincy]

Tried a new ecu and still nothing. My hall/cam sensor is bad. The plastic part is broken and some even call int a crank sensor. This HAS to be the issue.

[auditech79]

I agree, so there is visible damage to the cam sensor huh? That would make sense, and it would piss me off all at the same time because it SHOULD throw a cam sensor fault code, german cars.......

[Cincy]

So I finally got it running. Turns out there is two crank sensors and it was the bottom one. It attached to the block and was never removed. However, it was pinched between the engine and tranny causing a short. Cut and spliced the wires and now it works.

Pic in post 15 is what got me looking again http://forums.audiworld.com/showthread.php?t=2794279&page=2

[auditech79]

Interesting, its usually the RPM (engine speed) sensor thats faulty, never seen a crank position sensor go bad. I guess i should have forseen that because you might have pinched the harness, i didn't even think of that being the problem. I also didn't know that would stop the engine from running because i've had that connector disconnected before with the engine running.......hahaha i'll never fully understand the wiring in these cars.