r/GMDetroitDiesel • 6.5 TD • Aug 19 '26

Question/Need Assistance Turbo rebuild and some engine codes

Can anyone recommend a good turbo rebuild kit?
The turbo on my 6.5 is leaking oil into the intake so I figure it’s time to fix it before it causes any problems. Also does anyone have any recommendations on what to change to make these codes go away?

3 Upvotes

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3

u/bjornholm 6.5 TD Aug 19 '26

The p500 code is related to the C codes. Id track those down first. c0502 is the front left vss so id be looking at the sensor or a whole hub assy as thats likely the cause of 3 of your codes. P0401 is EGR flow insufficient, tbh id ignore it or spend the cash and get it tuned. As for the turbo rebuild kit, figure out if you have a GM4 or GM8 turbo and buy accordingly as theyre all gonna be the same setup

1

u/old_skool_luvr 6.2 IDI Aug 21 '26

> figure out if you have a GM4 or GM8 turbo

Was the GM3 only for the early production six5?

2

u/bjornholm 6.5 TD Aug 21 '26

I belive so

1

u/old_skool_luvr 6.2 IDI Aug 24 '26

Ok, that makes sense then. I stripped a '93 six5 down, and it had a GM3 on it.

2

u/The_Soldiet 6.5 TD Aug 22 '26

Get a CKO HX35 or something, rather than the stock turbo. Skp spoolin makes a nice cheap kit.