GQ rd28t engine overheating on LOW rpm's???

[Yahnz]

I've got a bit of an odd problem & would be grateful for ideas.

In a '95 Safari 2.8td, auto, stock-standard, engine temp goes way high on low RPM's, but seemingly only after the car has been in use for a while:

After a recent trip down some unpaved roads (90k+ of horrible shaking) I noticed the temp gauge going up when coasting down hills. Going back up the temp leveled off again. On arrival in town I found that I had to rev the engine up to keep it cool - the temp would shoot up waiting at lights, etc.

Had a look - fan spins fine, no coolant in oil or oil in coolant, exhaust is fine. It is not loosing coolant, nothing is leaking, no other apparent issues.

I replaced the radiator cap, topped off the coolant just in case, and next day, found the symptoms just went away. Drove around town for an hour or two, problem seemed to have gone away. Drove back home (460k's) - no problems. Hit the first street light off the motorway, and bang, the temp gauge shot up. Back to revving to keep it cool.

Since then, I have not seen the problem reappear BUT have not really driven hard out.

My best guess was that the thermostat is borked, but the mechanic says they only get stuck open. Any suggestions on what this might be? Don't want to replace the cooling system bit by bit just hunting...

Thanks!

J

[KIWI]

Water pump problem?

[84mksd33t]

Have you checked your clutch fan? The viscous hub might be stuffed!

With the motor running, wrap ur hand in cloth (enough to protect it) and try to stop the fan - gently gently lower your padded hand onto it.

If it stops, its shagged. - If it seems to slow easily, its shagged.

My advice is find someone with the same motor, and borrow his clutch fan.

If you are overheating @ idle then the fan is not doing its job and pulling enough air through the radiator to cool the motor.

Let us know how you go!

[msjc38]

the 2.8s are renowned for over heating as the cooling system is only just good enough so it only takes somthing minor to cause problems. as the last post said check the viscous coypling. also chech that the radiator is not part blocked have a look between the radiator & the a/c condencor. If you have driving lights in front of the radiator try removing them to see if there is some improvment. If there is you have an air flow problem. check water pump flow. If you hav to put a new water pump on it get a genuine one from nissan as they have a better impella. I have tested both for cavatation thae genuine one wins hands down. BUT before you do anything for peice of mind & not to get caught out with majorly expencive parts costs put a new genuine thermostat in it i have seen top mechanics get caught out with that in the past.
Hope this helps