Please help identify this issue 1.9 alh


New member
Apr 29, 2022
New York
Golf mk4 ALH
I have a 2000 golf with a 1.9 alh. I left my girlfriends house one night and was driving home and accelerated up a hill then I felt a sudden loss of power. My car usually goes into limp mode if I push it past 3000rpm and if I turn it off and on limp mode goes away but this issue is constant since that night. The turbo spool is significantly quieter and when I give it about half throttle or try to accelerate up a hill there’s a weird sound coming from the engine bay it sounds just like air escaping the engine bay. I’m hoping it’s just a vacuum leak but it’s really loud and my car makes a lot more soot now. This is my first tdi so I’m new to diesel motors. Can someone identify this issue?


TDIClub Enthusiast, Principal IDParts, Vendor , w/
Aug 16, 2004
South of Boston
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Boost hose is split or came off its attachment, or the intercooler is leaking. Look at the hose system from the turbo exit up to the intercooler and back to the intake. Trace oil escaping is a good sign of a leak, especially on the intercooler. The ends of the intercooler are plastic and can break free if you hit a curb. Also, the hose that goes into the intake (90 degree turn) can split on the inside and not be visible unless you squeeze it.

If all the hoses look OK you may have a broken EGR cooler pipe, if you still have that system in place. However, you usually will smell diesel in the cabin if one of those pipes is broken.