Volkswagen Passat Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
77 Posts
Discussion Starter #1
I have narrowed my low to no-boost situation down on my 98 AEB (81,500 mi) to what I believe is a bad wastegate actuator but need some final convincing before replacement. Here's what I have done and the results so far:

- checked boost gauge connections, all O.K.
- checked N75 for resistance, within VW specs
- replaced DV
- pressure tested from turbo outlet to intake, holds 15psi
- wastegate pivot is free to move

Still getting no more than 1 to 3 psi on my boost gauge. I believe the actuator rod has parted company with the metal diaphragm inside the actuator so the wastegate flapper doesn't close and build up boost.

Can I test this theory by attaching a weak spring to put some force on the the wastegate pivot and see if the boost goes up? (I won't drive it hard.) If so, would I want to place the spring so it holds the flapper forward (towards the actuator) or back towards the firewall?
 

·
Registered
Joined
·
3,216 Posts
White98_1.8t said:
- checked boost gauge connections, all O.K.
- checked N75 for resistance, within VW specs
- replaced DV
- pressure tested from turbo outlet to intake, holds 15psi
- wastegate pivot is free to move
Well, gee, I'm out of ideas. Can you manually move the wastegate rod while the car is off (and cool)?

White98_1.8t said:
Can I test this theory by attaching a weak spring to put some force on the the wastegate pivot and see if the boost goes up? (I won't drive it hard.) If so, would I want to place the spring so it holds the flapper forward (towards the actuator) or back towards the firewall?
Thats a novell approach (at least to me). I have no idea which way it would go.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #3
The wastegate rod and the wastegate pivot move freely, in fact too freely, that's why I suspect the rod end has separated from the metal diaphragm inside the actuator. I think I need to move the pivot toward the actuator to close the wastegate and build pressure.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #5
Well, it sounds like a visit to the local recycler ($100 for turbo core including actuator) or $150 for rebuildable Forge actuator is in my future. Anyone have experience with the Forge actuator?
 

·
Registered
Joined
·
77 Posts
Discussion Starter #6
Low Boost Resolved

I tracked down an OEM wastegae actuator through a Borg-Warner diesel turbo repair shop in Cleveland. They got the part from Borg-Warner Engine Group in N.C. and drop-shipped to me. Total cost $85. I installed the wastegate actuator this weekend. A bit of a pain to install since the entire turbo had to be removed to get the part free and hook the new one to the wastegate pivot. I used Hermann's K04-15 urbocharger upgrade writeup in the "How-to" section. (Thanks Hermann) It took about 8 hours taking my time and with breaks. Going slow gave me a chance to inspect and clean everything. On the difficulty scale it is about the same as timing belt change. The wastegate flap valve and linkage were in good shape. Bottom line is my car is running like new, even with 84,600 miles. Boost is back. Now I'm wondering how many K03's have been trashed because of a bad wastegate actuator.
 

·
Registered
Joined
·
3,946 Posts
White98_1.8t
Make sure that you have new oil line and the new heatshield installed on the oil line. It was a silent recall for 97/98/very early 99 cars. The old style heatshield did not sufficiently shielded the oil line and the oil had tendency to coke inside of the line. After awhile there was not enough flow to cool the turbo which then ran very hot. This heat cycling caused metal fatigue with subsequent wastegate rod failure. The famous rattle and free movement of the wastegate rod same as you had. If your oil line has coked oil inside you will have the same failure again.
The silent recall instructed the dealer to replace failed turbo, install the new heatshield, and replace the oil line with new design that has bigger inner diameter to prevent coking. If you do not have it installed the rod will fail again.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #8
I have a part number 058-148-778 for the turbo oil supply line...about $67 from Impex. Is this the revised part number?
 

·
Registered
Joined
·
14 Posts
Please clarify what a "silent recall" is

Boris said:
The silent recall instructed the dealer to replace failed turbo, install the new heatshield, and replace the oil line with new design that has bigger inner diameter to prevent coking. If you do not have it installed the rod will fail again.
I have a failed wastegate and the dealer is saying they won't replace it under the 98's 10 year/100,000 mile warranty. I'm pretty sure they won't admit that there was a "silent recall" unless I have pretty firm evidence.
 
1 - 9 of 9 Posts
About this Discussion
8 Replies
5 Participants
timswan
Volkswagen Passat Forum
Passatworld is a forum dedicated to Volkswagen Passat enthusiasts to discuss mods, Quattro, Turbo Diesel, reviews and more!
Full Forum Listing
Top