My 1993 Isuzu Rodeo V6 is over-heating very quickly (within 2-3 miles of driving). I have replaced the thermostat and gasget and hoses. Once it has overheated, it begins to "whistle" from the engine compartment? The coolant and oil levels are fine. My next step is to flush the radiator, but I cannot locate the radiator drain valve? Any advice on where it may be hidden? Also, any advice on my next step if the flush does not solve this proble? Thanks!

Mark Cuillier, March 2007

Ask a garage how the pump could be checked, I would say it is unusual to overheat so quickly if the pump is OK.

If that's OK then suspect the thermostat (but you changed!!)

So then .......the sealer (Radweld or similar)
Radweld is a radiator sealer - really just intended to be temporary.
Try running engine until 'overheating' and feel your radiator. Is it hot across the full width? If so it's doing it's job (does the fan cut in?).
If not it is probably (or partly) clogged with the sealer and the water is not going thro' ALL of it therefore giving the rad chance to LOSE the heat it doesn't need.
I also asked does the heater work well, if that is poor then the mattrix MAY be partly clogged as well.

If the rad weld is at fault then any flush may not fully remove the clogs (including the leak area), but if they ARE removed then you MAY know for definate if that WAS causing the overheating, even if you get your old leak back!! So then replace radiator.

Steve, March 2007

Thank you for the input. I am not familiar with "Radweld?" I know last year, it was leaking radiator fluid slowly. My mechanic could not locate the leak, so he installed a sealer in the radiator temporarily stoping the leak. The Rodeo has sat most of the winter undriven.

The lower hose clamp is upside-down. I will probably need to cut it off when it needs to be replaced.

Thanks again Steve!

MCuillier, March 2007

Sorry - thought of another slim chance - has it ever had Radweld or similar in?

Steve, March 2007

Any chance the pump is defective?

Does the heater work?

Steve, March 2007

Can't speak for your vehicle but often it is as easy to remove the bottom hose.

Stops overtightening of plug or possibility ofneeding a new washer as well!

Steve, March 2007