Timing Belt Noise

captgravity

New member
Joined
May 22, 2012
Location
CA
TDI
1999.5 Jetta TDI MK4 ALH
I just replaced my timing belt and serpentine belt and noticed a noise when I get up to >2500 RPM. The noise increases in proportion to the RPM and I would describe it as a valve letting off pressure -- shhhhhhh. Has anyone else experienced this or know what could be causing this? Thanks.

Car: 1999.5 Jetta TDI ALH MK4
New TB & Serp Belt: Contitech
New idlers: INA
New tensioner: Litens
New water pump: Geba
 

audiphile

Vendor
Joined
Apr 20, 2008
Location
Irvington, NJ
TDI
shop full of swaps
I think the noise you're hearing is a boost leak - you probably didn't clip the intercooler hose on all the way.
 

captgravity

New member
Joined
May 22, 2012
Location
CA
TDI
1999.5 Jetta TDI MK4 ALH
I think the noise you're hearing is a boost leak - you probably didn't clip the intercooler hose on all the way.
You were right about the intercooler hose. I made sure it was seated correctly and the noise went away. Unfortunately, now I don't feel the turbo boost and can't rev past 3000 RPM. Any ideas?
 

audiphile

Vendor
Joined
Apr 20, 2008
Location
Irvington, NJ
TDI
shop full of swaps
well, it's possible that the other end of the hose is now completely off, thus not allowing boost to build up.

or your ECU is in limp mode. is the check engine light on?

Come to think of it, you probably got the timing off by a tooth or two... or the injection pump is out of time.. did you use a pin to lock the pump? did you spin the engine by hand after installing the timing kit to make sure it aligns after 2 turns?
 

vwjettadsl

Vendor , w/Business number
Joined
Feb 24, 2005
Location
Missouri
TDI
TDI’s
Make sure a vacuum hose did not come loose during the timing belt job. Its easy for a hose to come loose when you are raising or lowering the engine during the TB job.

I would look specifically at the vacuum hoses behind the intake manifold, those are the most common culprits.
 

captgravity

New member
Joined
May 22, 2012
Location
CA
TDI
1999.5 Jetta TDI MK4 ALH
@audiophile: there was no check engine light, and I made sure to lock the IP, manually crank 2x, and then fine tune with a Ross-tech cable.

@vwjettadsl: I went over all the vacuum hoses and found the hose leading into the vacuum pump was kinked from when I moved it out of the way during the timing belt procedure. Turbo is now back and I no longer feel impotent when I drive.

Thanks both for the help!
 
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