No compression, won't start.

[taylorgang.]

hey everyone,

here's the deal. I replaced the timing belt on a friend of mines 2003 passat 2.8. everything went smoothly, replaced tensioner and water pump as well. car was running perfect for 2 whole months, until a week ago she said it started to idle high (around 2-3000k). still ran fine, just had a abnormally high idle. a couple days later, she tried to start the car and wouldn't budge.

I just now looked at it, cranked it over and sounds like it has no compression. this stumps me because I know that it was perfectly on-time. it is sounding to me that the belt has slipped, but what could cause this?

thanks in advance.

[kfzmeister]

Not sure about yours, but i just had one that had rubber chunks from the back of the balancer cause the timing to jump a notch or two. It bent two intake valves in two different cylinders.

[taylorgang.]

Not sure about yours, but i just had one that had rubber chunks from the back of the balancer cause the timing to jump a notch or two. It bent two intake valves in two different cylinders.

so in your case, you're saying that the crankshaft pulley caused the timing belt to jump teeth?

[taylorgang.]

just pulled hooked the scanner up to it and retrieved 4 codes.

P0118: engine coolant temperature sensor - circuit high input

P0171: system too lean (bank 1)

P0174: system too lean (bank 2)

P0507: idle control system - rpm higher than expected

I'm stumped and in desperate need for help here.

[kfzmeister]

Did you loosen the bolt that holds the cam gear ? if so, it is possible that the cam gear has moved. It is not keyed.

And yes, my high mileage V6 jumped timing due to a rubber chunk from the pulley at the crank.

[taylorgang.]

Did you loosen the bolt that holds the cam gear ? if so, it is possible that the cam gear has moved. It is not keyed.

And yes, my high mileage V6 jumped timing due to a rubber chunk from the pulley at the crank.

if its not keyed, then how would you know it's aligned with the cam? I'm going to take it all apart and check it out.

[Peter Badore]

if its not keyed, then how would you know it's aligned with the cam? I'm going to take it all apart and check it out.

There are no keyways in the camshaft sprockets that is why the special timing bar is really needed to properly set the timing belt tension and alignment. Yes, I know the belt can be changed without the bar and without the cam sprockets loose on the exhaust camshafts but the belt tension and alignment will not be 100%.

[Slimjimmn]

check for fuel when cranking. Fuel pumps do go bad, and cause no start and faster cranking.
compression test will tell if it has anything timing belt related broken

[taylorgang.]

so I got it all taken apart and it all looks to be in-time.





^ this is a picture that I just took, after all the problems.

v this is a picture that I took when I first did the t-belt 2 months ago. cams and sprockets look to be in the same exact place.

[taylorgang.]

check for fuel when cranking. Fuel pumps do go bad, and cause no start and faster cranking.
compression test will tell if it has anything timing belt related broken

fuel pump is working but have yet to perform a compression test.

[Slimjimmn]

fuel pump is working but have yet to perform a compression test.

dude, whats the title of this thread....

[taylorgang.]

dude, whats the title of this thread....

did you not read the description? I said it sounds like it has no compression. never said I did a test.

anyways, yesterday I poured oil in the cylinders, cranked right up. something caused the rings to wash out. anyone ever have this happen?

[Slimjimmn]

its common on V6 passats. Lots of cold start/turn off and it will flood it out.
I usually just hold my foot to the floor and crank for 20sec and it usually starts.
Sometimes in colder climates, you have to pull the plugs, crank it over to blow the fuel out and clean the plugs off, and then it will start.

[O_o]

just pulled hooked the scanner up to it and retrieved 4 codes.

P0118: engine coolant temperature sensor - circuit high input

P0171: system too lean (bank 1)

P0174: system too lean (bank 2)

P0507: idle control system - rpm higher than expected

I'm stumped and in desperate need for help here.

Your coolant temperature sensor has failed. Check that it is getting 5V and replace it. It's a $20 part, and you can replace it in less than 1/2 hour, although it's kind of awkward, especially if you have big hands. There could be other problems, but if the ECU does not know the coolant temperature, it will not know how to set the idle and mixture. Usually, this results in a rich condition, but I'd start there anyway. If you still have the lean codes after that, then you probably have a vacuum leak.