Garrett Turbo Charger

[LeonKatz]

Need help to comfirm if there is a turbo charger problem on my first recondition task, 1987 300D Turbo (original part Garrett) what problem signs are to be consider and what steps should be taken to confirm before I spend

[psfred]

Leon:

First check the boost signal line and overboost protection switchover valve for proper operation. The line must hold pressure and the switchover must not blow out the top unless energized.

Basic turbo operation can be confirmed by a large increase in power at the rpm goes past 2000 under heavy throttle. If you don't get a big push, something is wrong.

If the boost signal line is OK and you still don't have noticable turbo power, take the air hose off the front of the turbo with the engine off (NEVER open up the air system on a running engine, please!!). Reach in and spin the turbo compressor wheel. It must turn freely. May not keep spinning if you flip it, but must turn easily and smoothly. If there are any rough spots in the rotation, or it binds under light sideways pressure, it's toast and must be rebuild.

More than very slight axial or lateral play means the bearings are shot, rebuild.

Check for a missing waste gate controller link -- they can come off, leaving the waste gate open all the time so you get no boost.

If you have access to a boost guage, you want 13.9 psi max boost.

Peter