97 Jetta, need some help.

[MrDrProfJon]

Hey guys, long time reader, first time poster. I have a 97 jetta with the AHU that I don't know where to start with.

It was running and driving fine, then one day a couple months back I got a clicking noise that would go up and down with engine speed. I checked cam, lifters, timing, ran it without serpentine belt, couldn't figure out the noise. It would come and go, sometimes in the morning it wouldn't make any noise at all. Also it felt like the timing was retarded when the noise would get bad. Verified with vcds that the timing was spot on. Then one day I'm driving to work with the cruise set at 75 and I just feel a quick shake and lose power. I put it in neutral and shut it off instantly. It started right back up after verifying the timing belt was still tight. It just runs really really rough. I have checked the cam, lifters, and belt again and they all look fine. Could my IP have went? How would I check that? Any suggestions?
Thanks in advance.

 

[burn_your_money]

Verify timing to check the crank nose to make sure it’s not worn and moving.

Does the noise go away with the serp belt removed?

 

[MrDrProfJon]

I have verified the timing a few times. It doesn't look like anything has moved since I put that together.

The noise did not go away without the serpentine belt.

Also, after playing with it a little today, it will not start now. It tries to catch but it won't quite fire. It blows a good cloud of white smoke the whole time I crank it also. I also cracked all 4 injector lines and cranked and it looks like it really only sprayed out of the 3rd injector.

 

[Houpty GT]

Sounds like some issue with the pump or even multiple issues together. How many miles on the engine and pump?

Do a quick check for split wires and corroded connectors. around the pump and other engine wiring.

Check engine light? Any codes in the computer?

Replace that N109 relay. You should keep a spare in the car.

 

[MrDrProfJon]

Well, I bought the car with a blown engine and it came with a spare. The odometer has about 220k I believe and I think I was told the spare motor had 120ish.

Only codes are for egr and something glow plug related. They've both been on since I got the car running a year or so ago. It's also deleted.

 

[Houpty GT]

Are you also checking VW specific codes or only generic OBD2 codes? It's not a good idea to have the check engine light on all the time if you have an old car that you want to reliably use.
Use a screwdriver with the handle on your ear or a length of tube to pinpoint the source of mechanical noise.

 

[MrDrProfJon]

I tried that and couldn't locate the noise. The only time I could really hear it with the hood open is if I put my head down by the passenger tire on the outside of the fender.
I used a generic reader and vagcom. Both gave me the same codes.

 

[Houpty GT]

Verify timing to check the crank nose to make sure it’s not worn and moving.

Does the noise go away with the serp belt removed?

Well, the passenger tire is where the crank nose is located. I have never seen this since it is rare on the AHU/1Z engines but have heard it does happen. Something to try is, you can get someone to help you, then one person checks the bolt on the crank pulley, and another uses a screwdriver to turn the flywheel teeth to see if one side of the engine can be moved slightly without the other.

 

[MrDrProfJon]

Alrighty, I'll give it a look. Thanks for the help. I feel a little over my head here but I'm trying to learn. I also had all 3 vehicles break down within the same week so feel like I've been over my head with alot of stuff for a minute

 

[Houpty GT]

It happens to all of us. There was one time I had to take a skateboard to the autoparts store because all 3 cars were disabled and even my bicycle broke when I tried to use it.

 

[MrDrProfJon]

Is there a way to test the pressure coming out of the injection pump?

 

[Houpty GT]

Move an injector line so it points in the air. Hook up a spare injector if you have one otherwise you need to pull one. Bleed the line and crank the car. You should see it produce nice spray.
If you want to know the vane pump/case pressure, you will need to make a special banjo fitting on the engine side of the pump.

 

[burn_your_money]

Move an injector line so it points in the air. Hook up a spare injector if you have one otherwise you need to pull one. Bleed the line and crank the car. You should see it produce nice spray.

WARNING the fuel coming out of the injector has enough pressure to pierce your skin. If it does, the risk of amputation or death is very high. Stay clear of the spray.