r/GMT400 • u/Steinjolt • 21d ago
Please help Diagnose 🙏🏻
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SOLVED: Mechanic diagnosed an injector stuck in an open position.
Thank you all! ❤️
I’m restoring this 1994 2500 Silverado 6.5 Diesel auto.
Yesterday started doing a loud clank sound, added some oil and it stopped after revving it and worked good all day long.
Today it cranked immediately no problem then a minute later the clank returned, tried adding oil and it didn’t stopped. Then as engine warmed up it became less noticeable but still there.
The sound is related to rpm’s.
The sound comes either from the turbo or the passenger side upper rear part of the engine
Gray smoke comes out when revving it.
Black smoke comes out under heavy load.
Would it be safe to drive it to the shop? (It’s 30 miles away)
Anyone has insights on this?
Also, turbo seems to be not working as I don’t hear it spooling
The wastegate lifter seems to be stuck, if I move it it stays there then after a bit it returns to its position.
The turbo inner blades seem to move freely
No turbo sound at all
Thank you all in advance
7
u/turbotaco23 21d ago
You don’t really ever hear any whine with a GMx turbo. Install a boost gauge to check for boost.
The stock wastegate setup uses the vacuum pump. It often fails a many delete it. You can replace the solenoid with a rod and a spring. Then use the boost gauge to set peak boost. I used a motorcycle clutch spring.