Hi all,

I'm considering purchasing a GMC Suburban 2500 that has been recently upgraded from the 6.3 to the 6.5L diesel. As the old engine was naturally aspirated (non-turbo) the owner kept the same setup with the new engine. The transmission was updated to a 4sp automatic with OD at the same time. Everything under the hood was also upgraded (injection pump, radiator, etc). Is there anything I should be wary of with the 6.5L diesel? I've driven and worked on Ford diesels when I used to work for the fire department, but have no experience with the GMC. I'm partial to GM and have wanted a diesel suburban for a while as a tow vehicle for my sailboat. Any comments regarding the reliability of the 6.5 and anything I should watch out for?

Thanks,
Scott

Check out "Frequently Asked Questions" in the moderator section that TD put together. You should find most of your answers there. Undoubtedly, the PMD has done the most damage to the 6.5s reputation.

N/A mechanical 6.5, either 5088 or its twin brother 5436 injection pump, change fuel filters regularly and run lubricity additive every tank to protect the Head & Rotor from wear causing hard start hot and keep the rest of the fuel system working properly as well.