Over heating
 

My 97 runs great but has always had an over heating issue under heavy loads towing up the mountains and/or in high summer heat so I have to drive carefully and sometimes turn on the heater, which is not much fun when it's 95+. I had the radiator checked and it is fine, so is the fan clutch. Is this a common issue? What are the remidies?

Thanks,

My ol 97 would get hot only if I had it really heavy in the mountains in 95+ temps. Really heavy I mean 30,000+, otherwise it was fine. My 02 never gets over 204 no matter how heavy and hot the temps.

Have you changed the T-Stat?

The shop changed the stat two years ago; I had the heater core replaced last year which required another draining. By the way, I checked the ph today which read near 3; for the engine this may not be aproblem as there are no sleeves but this could be an issue for the heater core as aluminum is most suceptible (sp?) to corrosion. What do you think?

I would add a little more water. I run a 50/50 mix and have never had any problems. In our dirt track car we use straight water because it cools better. Just have to remember to drain it for the winter time so it don't freeze and crack the block. My buddy found that out the hard way and ruined a $5500 race engine.:argh:

I will try your suggestion. What do you use to correct PH? I understand this is not a real issue with this Cummins since there are not liners but it is important with the heater core which nowadaze is aluminum which corrodes quite EZ. Mine coolant is PH 3 and needs balancing. I have heard this can be accomplished by adding borax until the PH i near 7. Any experience here?

Thanks,

odnob

i have heard cummins came out with a new/better stat for out trucks. the average thermostats from auto parts stores are terrible. new ones hardly ever open for a day or two and they are never right on.

:tu: Yup I agree.

As for using borax, I have no idea never used the stuff. Oh and the raidators are also aluminum.

mine has never overheated, even pulling 12k, mabey take it to a shop and have the coolant system flushed, there could be some prime building up in the passage ways

Straight water does not cool better.

Yes actually it does. The race engine in our dirt track car runs 10 degrees cooler with just water instead of coolant. Its a common misconception that coolant cools better. Coolant keeps it from freezing and prevents rusting.