Acquired a 6.5 with Heath upgrades, a few questions

[97-6.5TD-F]

Hi all, back after a 2 year hiatus from 6.5's, but have acquired a 1996 K3500 extended cab long box dually equipped with a Heath diesel stage one performance combo (computer, manual wastegate, hd lift pump). The truck also has a fresh engine (under 10k), 0.030" over, stock compression, high flow injectors, 3.5" strait pipe, warm air intake, dsg gear drive/phaser, stainless oil cooler lines, and main girdles.

First off I bought the truck for a decent price from my uncle and know its history as I assisted with the engine overhaul and installed the Heath products myself.

The price was decent because it has a few issues. The first one being the temperature spikes up to about 220 every time it is warmed up. It seems like the thermostat is sticking, but he put used heads on it and I am concerned they may be bad. What is the best way to check them?

The second issue is a no brainer, the front pump seal on the trans is leaking pretty good, not a big deal for me as I have a fully equipped shop to use.

Lastly I am curious how much of a performance difference should be noticed with the heath setup I have? It doesn't seem that significant, maybe due to the size of this truck. Any input is greatly appreciated!

[suburbanK-2500HD]

My experience is that the exhaust, witch was the 1. thing i did with my truck helped a noticable bit. And the temp when towing was lower.
I also have Marine injectors, it was a noticeable different, but as Robin says, stock injectors would also make a difference. Resistor no:9, dont know if this does anything, could not tell....
i cleaned up the upper intake webbing, to get max airflow..i have No EGR.
I am about to install a Intercooler, hope to be done in 3-4 weeks..

:)

[Robyn]

If the heads have issues (cracks) the cooling system will over pressure and puke coolant out the overflow.

If this is not happening then the issue certainly could be a sticky stat.

If the temp comes back down to normal, I doubt that the problem is the heads.

Give this a check over and keep us posted.


Missy

[97-6.5TD-F]

It spikes up once when it first heats up, then stays at 190 all day, as long as it isn't cooled right down. The coolant doesn't come out but I also didn't look for it either.

I cant really drive it until I do the front seal because it leaks pretty good, but should be on it as soon as I get the time to bring it in to the shop.

Thanks for the replies, I am excited to be driving an oil burner again!

[6.5TDTahoe]

A few degree spike is normal as the thermostats pop open.Normal event on mine.. Install a direct read capillary tube gauge for accuracy. Two reliablethermostat choices are Genuine AC delco at 192 degree rating or Robert Shaw @180 degree.If all the 1999/2000 cooling upgrades are on board it will be OK with either stats. personally I would go with the 192 Delco stats. There will be less temp fluctionation with the 192 AC delco. Better for the cast iron ,IMO ! Go into the Page & read about JIM's experience with fan clutches,ETC.

[97-6.5TD-F]

So the temp spike is alot more drastic then was explained to me, it will peg the gauge for a good 2 minutes before it pukes a bunch of coolant and finally opens the stats (dual thermostats). After that it seems ok. I was then informed that the heads that were put on it were on an engine that had water in it and froze to the point of splitting the block open (:eek:).

I told him not to cheap out on the heads after spending that kind of money on the rebuild.....:o

[JohnC]

So the temp spike is alot more drastic then was explained to me, it will peg the gauge for a good 2 minutes before it pukes a bunch of coolant and finally opens the stats (dual thermostats).

This happens when the system is air bound. The thermostats won't open because they aren't in water. When it gets hot enough to blow, the steam in the housing opens the stats and allows water to flow.

If you bleed the air out and it continues to get air bound, there must be a compression leak into the cooling system...