1999 6.5L Performance upgrades

[aquaman0001]

Mine runs closer to 190 year round but I am not for sure if there is an advantage or disadvantage to the lower temps. You would think for the summer or like you said towing, that a lower temp is better.
A

[AllThumbs]

This may sound stupidly simple (sometimes life is like that) but the thermostats may have been put in wrong. That does not sound right in this case since you have been running low temps all along. On my truck, I could not get it to warm up and when we pulled the thermostats, one had the rubber sealing ring stuck inside the throat and would not allow it to close.

[scot5146]

This may sound stupidly simple (sometimes life is like that) but the thermostats may have been put in wrong. That does not sound right in this case since you have been running low temps all along. On my truck, I could not get it to warm up and when we pulled the thermostats, one had the rubber sealing ring stuck inside the throat and would not allow it to close.

Hey everyone... Hope you all had a great holiday...

Ok so the update to date on my 1999 K2500 GMC Suburban 6.5 diesel...

I got the cooling figured out, you were right the shop put in one of the wrong thermostats in my rig, problem has been fixed and i am running a consistant ~185* (about)...

I ordered the 4" exhaust kit and I am saving up for the AFE intake and a set of Sunpro Diesel Guages from Summit that are a good price...

I will post pictures as i go...

Questions:

1) Is there or do I need to replace the exhaust crossover pipes from each side of the exhaust manifold? I have seen a kit that claims smooth bends more flow, power, etc... Any truth to this?

2) Is there an exhaust "header" for the 6.5 diesel that will make more power, lower EGT's, etc...?

3) I want to relocate the PMD... is this by a longer wiring harness atachment or is there a bracket of some kind, because what i am seeing online is a bracket, but they are all really expenssive...$ 140 ish...

Well I am at work playing on the computer, sitting up after a structure fire at 2 am in the morning and all my words are running together, so I guess those are my questions for now! bed time (i love my job job but the long nights can be brutal)

Ayway thanks everyone, I appreciate all the help so far! Pictures to come on my Suburban project!

Best Regards

Mike (New Guy)

[AllThumbs]

The information I gathered here was that if you wanted a different crossover pipe for performance purposes, you were wasting your time. Mine would have been very difficult to get out as the bolts were really rusty and the always terrible problem of breaking one off in the manifold was raising its ugly head. So, I simply left mine as it was and could still feel a terrific improvement. I don't think there is a lot there. The 4" exhaust is another issue. Mine was not difficult to put in and made an obvious, instant improvement.

[scot5146]

Ok so the 4" exhaust is a go... I think I wont bother with the crossover pipes from the exhaust manifolds...

As for the other parts I am still planning on:

Gauges
Exhaust
CPU upgrades
Duramax cooling fan blade
Air Intake
re locating the PMD

What other considerations should I look into? maybe water/meth or an inter-cooler?

Thanks


Mike

[6.5 Detroit Diesel]

it'a up to you really. with the stock turbo's, you really don't need an intercooler. it might make a little difference, but not much. if you were swapping to something different for the turbo, it could be a good upgrade.

as for the w/m injection. some say it works, some say it doesnt. others say it add's power and cools, some say it only cools.

from my own experience, it added power and resulted in dropping a couple hundred degrees on the pyro while at WOT. i was spraying to much, but the point is, it worked.

[scot5146]

Hey everyone-

My suburban project gave the service engine soon light yesterday...

I ran my OBD II scanner and got a code: P0251

(Injection Metering Control A- (cam/rotor/injector)

can anyone shead some light on this for me, I am confused and not sure what this means or what I need to repair...

thanks

Mike

[Kennedy]

Ok so the 4" exhaust is a go... I think I wont bother with the crossover pipes from the exhaust manifolds...

As for the other parts I am still planning on:

Gauges
Exhaust
CPU upgrades
Duramax cooling fan blade
Air Intake
re locating the PMD

What other considerations should I look into? maybe water/meth or an inter-cooler?

Thanks


Mike

The duramax blade will gain you nothing. If heat is an issue when things warm up then consider my Special Calibration fan clutch and keep the stock blade.

We have a very nuce FSD cooler setup that attaches cleanly and simply to a vacant bracket already in place on the 96+ vehicles.

CPU upgrades require exchange ECM for this model year. I tune these myself in house.