Discussion in 'Engine Performance + Maintenance' started by Kobo_Dyger, Sep 16, 2019.
About 50% of forum posts world-wide if not more...
I think I'm going to tell the guy I'm not Interested in the 6.5 truck and hopefully they can fix my truck. Once I get my new truck then I'll be into doing a 6.0 ls or possibley a duramax swap as it wouldn't be a daily driver anymore so if it takes a year to do the swap it takes a year. I'm just hoping it's not expensive don't want to dig In to my new truck fund to fix my old truck.
I enjoy the 8.1 in my Tahoe, fwiw. Was a cheaper swap than a 6.0L. I found the 8.1 out of an Express van party bus for $800, half of what people want for the 6.0L around here and it only had 80K miles on it. The 8.1 bolts to the 350s mounts and big blocks came from the factory making headers and radiator hoses easy to find.
I'll have to remember this. It's ironic you said this cause I was offered a 8.1 the other day with wirring harness no trans and no serpentine belt stuff he wanted $1700. Then seen a guy selling a 6.0 vortec and 4l80 and transfer case he wanted $5000 I can find find a decent wrecked LLY duramax donors at the SGI insurance salvage sales for around $2500-$3000. My biggest fear with swaps like that are stuff like getting the gauges cruise control pushbutton 4x4 to work but iguess when the time comes I'll figure it out. Also thought about a 5.7 Iforce swap as am not only a 88-98 c/k fan but I'm also a Tundra fan would be cool to combine them and get weird looks at car shows. But I've definitely thought about that 8.1 I was offered if only it was more comlcomp he probably would of had a deal.
I copied this from a previous post.
The 6.5 was based on the 6.2 which didn't have enough power to do much of anything but The fine folks at General Moturds decided to "compete" with the 5.9 Cummins powered Dog and the upcoming 7.3 Powersmoke. To do that they slapped an inefficient turbo on a larger displacement engine with crappy metallurgy. Then they used a cooling system that wasn't up to the task. They also rushed the electronic injection pump using, in my opinion, an underdeveloped control module (PMD). There are notorious for PMS failures (was that really a typo?...), cracked blocks in the main webs, cracked heads, overheating cylinder #8, injection pump issues, failed oil pressure sensors, complete cooling system failures, harmonic balancer failures resulting in sheared crankshafts, a crappy rubber balancer pulley, the wastegate system consists of failed vacuum pump, cracked plastic lines and solenoid failures, the turbos used were really undersized for their application resulting in high drive pressures causing excessive heat leading to cracking in the heads and valve failures plus additional heat to the already overtaxed cooling system. Oh, I almost forgot that oil cooler lines like to fail in dramatic fashion. Don't believe me? Just Google 6.5 and everything that I mentioned.
I personally have owned 4 6.5 powered trucks. One I immediately sold. Two came to me with low mileage, 79k and 124k and both of those had valve failures. The 79k one had meticulous records including the additive and fuel mileage of every tank of fuel since new, every light bulb, oil change and truck wash. The fourth truck was my own personal truck and the #3 exhaust valve failed taking out the head, piston and possibly the rod as well. May it rest in pieces at 104k...
I'm stupid enough to put a 6.5 back in my truck because I don't have Cummins swapping cash and I had already bought new hoses, glow plugs, injectors, upgraded turbo, mandrel bent crossover and more prior to the engine failure. Not too long ago I came across an Optimizer for a reasonable price. Do I trust it? NOPE! I've addressed every single issue mentioned above but prior to it getting back on the road I will renew my AAA membership.
My dad has a buddy who bought a K3500 with the 6.5 back when they first came out. He destroyed two brand new engines in something like 10K miles. I don't remember the details of the transactions but I believe the GM dealership ended up buying it back and he went and bought a Ford which he ran until the Duramax trucks came out. He runs a concrete business and does a ton of heavy towing so he definitely used them hard, but that story pretty much cemented my opinion of the 6.5s.
I think in the right application with an owner who doesn't beat on them regularly (and knows their weaknesses) they're probably fine, and I still want a HMMWV so I can't say I'd never own one... But I think a 6.5 would be pretty much dead last on my list of engines I'd spend time and money swapping into one of these trucks.
A 6.5 is best driven at half throttle shifting at 2600 rpm. AND LESS!!! I towed with my 6.2 around 7200 pounds and the truck close to the same. Steep grades. Slow and steady won that race. I got 17 mpg towing. If you know what your driving and adjust to that it's a fine motor. Not nearly as much a dog as most think.
But it is not a cummins or dmax. But I have done every bolt on possible beside meth injection and the truck keeps pace with my buddies 300/700 cummins. Unless we are towing. But my chevy rides way smoother than that 95 ram. What I won't try and do is hook up 17k trailer and pull. I know something would fail. His cummins does that often and 9 to 11k weekly on top of the 2,000 pounds in the bed daily. My truck carried 4k daily but I rarely towed and babied her BIG TIME every time I did. And the most I towed was under 10k. Closer to 8 I'm sure. The military mechanic put in the Pistons rotated so the Pistons are cracked. Hoping to yank the motor this weekend take it to my machine shop and hoping it's new Pistons and head gasket and I'll stud it and call it a day. If not I'll cummins swap it. Done
I remember some dude years ago, I think was on Chevytalk? He defended the 6.5td at every possible chance, regardless of the horrible experiences being posted by others. Only his "good" experiences seemed to matter and allowed him to deny that others were suffering failure after failure, some minor but annoying, many catastrophic, of their 6.5td's. His was built, he did this, he did that.
Then his blew up. Catastrophically. He got rid of it and we pretty much never heard from him again, at least not defending 6.5td's, anyway.
Those that defend the 6.5td kinda remind me of that Mike Tyson quote. "Everyone has a plan until they get punched in the mouth." Everyone defends their 6.5td while it behaves, until it explodes...
I think I remember that. Except I think it was on Fullsizechevy. From what I remember the guy previously had a 95 TBI 350 truck that he constantly dogged as well talking the 6.5 up. In the end I remember him trying to get the most out of that truck.
Hey hey hey my 6.5 is perfect
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