Thread: Auto Problem?

Originally Posted by trumpycam

Recently my ZF4HP22 (300tdi) has been making a high pitched whining noise, when you put the foot down to cause a kick down in gears. Also does it when going up hills and need to accelerate to maintain speed, or towing and trying to accelerate. Under normal circumstances sounds OK no unusual noise, and still shifts well. Thought it may have possibly been a turbo problem but symptoms seem to point to transmission. Has nearly 300k. Transfer box??
Thanks Joe

Apart from the noise, what are the symptoms? Sure it's not just an exhaust leak?

None really, still runs and shifts fine, definitely not an exhaust leak and whine is very loud, but stops when load is off. One more seems to be worse when cold not as bad when warmed up.

Originally Posted by trumpycam

Recently my ZF4HP22 (300tdi) has been making a high pitched whining noise, when you put the foot down to cause a kick down in gears. ......

I'm going to wild guess here probably a worn bearing in transfer case.

I've had two experiences of LT230 high pitched whining noises under power .. and both had a worn bearing.
Back off and high pitched noise can disappear.

Turbo does make a high pitched noise, but in my tdi way too hard to hear this over tdi rattle to be considered an issue.
But do check turbo hoses. The 180° bent one can come loose around the back at the turbo.
And intercooler hoses can get a small split in them and whistle/whine.
And don't forget to check pressure hose from turbo over and across to fuel injection pump too. small hose can split.

Problem solved, went over to local LR Indi, turns out only a loose intercooler hose, he diagnosed a leak somewhere in about 2min. He let me borrow his smoke machine, and I quickly found where leak was. Did a quick check of all other hoses and manifolds while had machine and all were OK. Turned out a lot cheaper than expected.
Thanks for input Joe