ssnick
Member
I've had a number of B4 Passats over the year and just bought my first B4V. Very excited to do some Mexico camping in the next week or so.
It has an interesting issue that I'm hoping someone might have seen/heard before. When starting cold, it will start right up but then sound like it's missing. There may be some smoke that occurs when it's missing but not always. It's irregular but will continue until the engine warms up a bit, then it will occur less until it's close to 190 degrees and will then run properly with no misses. Once warmed up, no problem to shut off and restart as long as the engine doesn't cool down too much and then it will happen again.
Here's the interesting thing, when it is missing, I can hear a noise like a valve opening and closing that sounds like it's from behind the passenger side dash. When colder and I'm raising the RPMs, it is surging and the missing perfectly corresponds to the noise.
I've tried listening from the engine compartment but the missing doesn't seem to happen at idle, and I can't hear the valve noise from the engine compartment. When inside though, I can still hear the valve noise behind the dash but it doesn't seem to effect the idle, only when I raise the rpms.
One possibility is that it's the turbo actuator and the missing is it loosing boost. However, I couldn't hear anything from the engine compartment and thought it was strange that it only happens when it's cold.
I also read another thread that something similar was caused by a bad idle control relay.
It's a 96 B4V with 360k, with what sounds like a tapping lifter or exhaust leak. I found 2 exhaust manifold nuts today that were finger tight and one that was holding a bit but was stripped. Tightened them up but didn't seem to change the tapping. The timing belt was changed 13k miles ago. I'm planning on checking the timing as soon as I find someone local with a Vagcom.
Once warm, it has good power and drives very well.
Anyone recognize the valve sounding noise behind the dash?
It has an interesting issue that I'm hoping someone might have seen/heard before. When starting cold, it will start right up but then sound like it's missing. There may be some smoke that occurs when it's missing but not always. It's irregular but will continue until the engine warms up a bit, then it will occur less until it's close to 190 degrees and will then run properly with no misses. Once warmed up, no problem to shut off and restart as long as the engine doesn't cool down too much and then it will happen again.
Here's the interesting thing, when it is missing, I can hear a noise like a valve opening and closing that sounds like it's from behind the passenger side dash. When colder and I'm raising the RPMs, it is surging and the missing perfectly corresponds to the noise.
I've tried listening from the engine compartment but the missing doesn't seem to happen at idle, and I can't hear the valve noise from the engine compartment. When inside though, I can still hear the valve noise behind the dash but it doesn't seem to effect the idle, only when I raise the rpms.
One possibility is that it's the turbo actuator and the missing is it loosing boost. However, I couldn't hear anything from the engine compartment and thought it was strange that it only happens when it's cold.
I also read another thread that something similar was caused by a bad idle control relay.
It's a 96 B4V with 360k, with what sounds like a tapping lifter or exhaust leak. I found 2 exhaust manifold nuts today that were finger tight and one that was holding a bit but was stripped. Tightened them up but didn't seem to change the tapping. The timing belt was changed 13k miles ago. I'm planning on checking the timing as soon as I find someone local with a Vagcom.
Once warm, it has good power and drives very well.
Anyone recognize the valve sounding noise behind the dash?