Hi all,
Great list! Avid follower and contribute when I can!
I am having difficulty with our 2001 (B5) Passat with AUG engine. Runs well. But I noticed that the brakes barely work when you first start the car and it is cold. After a minute or two they are fine. First I thought it was a brake issue - replaced several questionable or unknown condition parts and saw no improvement.
Finally I moved onto the engine vacuum. When I first start the car, it gives a solid 14 inches of vacuum at idle. This lasts for about 3-4 seconds and then it drops considerably to about 7-8 inches vacuum. It slowly builds over the next minute or so. The funny thing is that you can watch it build, and the final "bump" happens exactly when the SAIP stops running. Once this happens and it hits about 15 inches and the brakes are great.
I am really struggling with this one. If anyone has any idea where to look, please let me know.
The following has been done to the engine: replaced head (due to timing belt failure), compression check (152-157 across all four cylinders cold), new timing belt and tensioner, replaced VVT, replaced vacuum lines, TBA.
I have a VAG-COM and I watch it when it warms up. One odd thing is the Throttle valve angle - it starts at 5.9 degrees - I would have guessed it started close to 0. When the vacuum drops, you can see the throttle valve angle increase to about 9.5-10 degrees. I know will cause the vacuum to drop - but I do not know WHAT is causing it to open.
There is no check engine light and no stored codes. Fuel trims look fine. I watch the coolant temp warm up as expected.
All help appreciated!
Z
Great list! Avid follower and contribute when I can!
I am having difficulty with our 2001 (B5) Passat with AUG engine. Runs well. But I noticed that the brakes barely work when you first start the car and it is cold. After a minute or two they are fine. First I thought it was a brake issue - replaced several questionable or unknown condition parts and saw no improvement.
Finally I moved onto the engine vacuum. When I first start the car, it gives a solid 14 inches of vacuum at idle. This lasts for about 3-4 seconds and then it drops considerably to about 7-8 inches vacuum. It slowly builds over the next minute or so. The funny thing is that you can watch it build, and the final "bump" happens exactly when the SAIP stops running. Once this happens and it hits about 15 inches and the brakes are great.
I am really struggling with this one. If anyone has any idea where to look, please let me know.
The following has been done to the engine: replaced head (due to timing belt failure), compression check (152-157 across all four cylinders cold), new timing belt and tensioner, replaced VVT, replaced vacuum lines, TBA.
I have a VAG-COM and I watch it when it warms up. One odd thing is the Throttle valve angle - it starts at 5.9 degrees - I would have guessed it started close to 0. When the vacuum drops, you can see the throttle valve angle increase to about 9.5-10 degrees. I know will cause the vacuum to drop - but I do not know WHAT is causing it to open.
There is no check engine light and no stored codes. Fuel trims look fine. I watch the coolant temp warm up as expected.
All help appreciated!
Z
