Kurt
Well-Known Member
- Messages
- 958
- Location
- Orange County, CA
Engines are a crapshoot. Any GM '506 is susceptible [506 is the last 3 numbers of the 6.5 turbo van casting codes used in most h1's], My truck had mine replaced in 01 under warranty with a "fixed GM cast" and that got the #8 during my ownership after about 70k miles [first engine went at around 50k, the second went at around 125k] And I babied that engine during my ownership and it still cracked. I wound up replacing it a few months ago with a recent year military optimizer 6.5 [still 506 block but recast with slight redesigns by AMG/GEP].
They're not bad to reinstall if you are comfortable with doing that stuff, Bostic on the east coast does the remans for the military and you can get reman 6.5 optmizers with late model year blocks [forged in the past few years] for around 5 grand or so. I'd consider another turbo diesel H1 only if every other thing is in tip top shape.
I talked to a bunch of chevy/GMC guys with their 6.5 experiences and they had less issue since the 1990's GMC/Chevy ck2500/3500 series trucks had better cooling than the H1. Basically the temp probes are located at the front of the engine, on the driver front for the analog gauge, and near the thermostat for the ECM.
If you are running 210 on an H1, it's a safe bet the rear cylinders are close to 240-250, I'm going to look at putting a temperature probe around the #8 and see what the actual differential is on temps. That being said, the problem is forever solved with the 2004+ castings of the 6.5 GEP blocks.
They're not bad to reinstall if you are comfortable with doing that stuff, Bostic on the east coast does the remans for the military and you can get reman 6.5 optmizers with late model year blocks [forged in the past few years] for around 5 grand or so. I'd consider another turbo diesel H1 only if every other thing is in tip top shape.
I talked to a bunch of chevy/GMC guys with their 6.5 experiences and they had less issue since the 1990's GMC/Chevy ck2500/3500 series trucks had better cooling than the H1. Basically the temp probes are located at the front of the engine, on the driver front for the analog gauge, and near the thermostat for the ECM.
If you are running 210 on an H1, it's a safe bet the rear cylinders are close to 240-250, I'm going to look at putting a temperature probe around the #8 and see what the actual differential is on temps. That being said, the problem is forever solved with the 2004+ castings of the 6.5 GEP blocks.
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