Running hot under load!

[Stray Cat]

Ever since I put the Banks Turbo and 700R4 trans in my '83 4WD 3/4T 6.2L Suburban, the coolant runs hot under load. I have had the heads replaced, put in a High Efficiency radiator, High-flow 7-blade flex fan, dual 14" electric puller fans, high-flow water pump, high-flow 180 degree thermostat. All of that made it much better, but on a long grade, it will overheat if I let it. The engine oil and transmission stay relatively cool, but the coolant will quickly increase. To stop it, I downshift and let off the accelerator. The overheating doesn't come with high EGTs, but with load on the engine. I can run 900-1,000 EGTs on level ground with no heating problem; when the engine is loadad on a grade, I have keep the EGTs at less than 700 (by downshifting & backing off accelerator) and the coolant climbs quickly. Once the load is removed (crested the grade), the coolant temp drops off quickly. The EGT will never go above 1,050, and boost max's at about 8psi. Does anyone have any solutions? I bought the Banks & 700R4 so I could travel from So. Cal. to Eastern AZ regularly. I have all the power, but can't use it because of the overheating problem! HELP!!! :confused:

[jbell]

best guess I have is the obvious -- stuff between the ac coil and radiator blocking airflow... try a good cleanout.
Other than that, the turbo adds under hood heat -- a jeep trick is to 'ventilate' the fenderwells to allow more heat / airflow out from under the hood.

[jcomp]

I have the penninsular diesel dual thermostat kit on my turbo 6.2. I have had no problems with overheating at all, the highest I've seen it was 210 and I've run it pretty hard going up some long hills.

Also, I avoid flex and electric fans when I can. I still use the factory fan with the original clutch.

[gmctd]

The flex fans are meant to cool in low-speed scenarios, such as traffic, but reduce pitch angle at hi-speeds to reduce power drain, when thru-radiator air flow from vehicle speed is sufficient.

Napa has the HD cw clutch for 6.2L, Chrysler has the 20" 7-blade GM fan to fit.

Engine oil cooler in cool tank is ok with external cooler first in series loop.

Trans cooler in hot tank is not good, even with ext cooler in series.

I have oem aux elect fan over external eng cooler, but seldom use it, even loaded. Mostly in low speed traffic.

Also, there was a small, dufus-looking plastic spoiler under the bumper on the 4-wd vehicles - that was to provide a low-pressure area just behind the front bulkhead, to pull air thru the radiator and get it past the straight front axle, which provides a hi-pressure area if the spoiler is not there.

[Stray Cat]

[QUOTE]Originally posted by gmctd:
Thanks for the reply! Do you know part numbers for the Napa clutch and Chrysler fan? Why does Chrysler carry a GM fan? Does GM carry the fan too?

"Napa has the HD cw clutch for 6.2L, Chrysler has the 20" 7-blade GM fan to fit.

Engine oil cooler in cool tank is ok with external cooler first in series loop."
:cool:

[Stray Cat]

jcomp, Thanks for the reply. Where did you get the dual thermostat kit?


Originally posted by jcomp:
I have the penninsular diesel dual thermostat kit on my turbo 6.2. I have had no problems with overheating at all, the highest I've seen it was 210 and I've run it pretty hard going up some long hills.

Also, I avoid flex and electric fans when I can. I still use the factory fan with the original clutch.

[gmctd]

GM never carried that 20" 7-blade - Chrysler used it, with Delco clutch, on the 413\440 vehicles with HD towing, also on the motorhomes.

Do a 'search' here for further info from Dieselboy.

'Search' function is excellent - name your poison, get immediate multiple response.

Just ask for '87 6.2L HD clutch.
Ask for '88, you'll get ccw clutch, for serpentine service.

[jcomp]

Penninsular Diesel sells the Dual T-stat kit here...

http://www.peninsulardiesel.com/parts.htm

I had to modify my throttle bracket and lose my cruise control to make it fit, something penninsular failed to mention when I ordered it.

[ropinfool]

i would try taking the tranny cooler out of the tranny. Add one up front and bypass the radiator all together. Good Luck. John

[Salemone]

StrayCat--I live in Corona too. I have 4 diesel
vehicals. Got a 6.5-and 3 6.2 .Like to talk to you
have some unique idea's--have a dyno. Phone # is 737-9192. Call me.

[Fumes]

Has anyone tried a Hayden fan clutch?

[Stray Cat]

Thanks for all the great responses! I have tried pretty much all of them previously. I believe that I have figured out the problem. I believe that, the high-volume water-pump I installed when I added the Turbo, was actually for a engine with serpentine drive (which turns the opposite direction). So, it is pumping the wrong direction. I have ordered the Penninsular dual thermostat system with high volume pump that definitely pumps the right direction! I will let you all know, after I get it installed, if that did it! Thanks again!