My friend has an 89 RS 305 TBI that is overheating bad. I can't check it out till next week, since I won't be back till then. Here's what he's checked:
Fans ARE coming on at the correct times.
No leaks and coolant is relatively new and proper mix.
Air Dam is fine.
Radiator is two years old.

What else to check. How can I check to see if the water pump is going out? Anyhting else? Thanks

 

I have a few suggestions:

1) thermostat. they make these motors run hot from the factory for "emissions" reduction. Put a new thermostat and see if that solves it.

2) waterpump. they don't last forever and sometimes the impeller blades can corrode away and thus reduce its pumping ability

3)lower radiator hose. slight possibility but you can check by revving the engine (when the car is warm) and seeing if the lower radiator hose collapses

Other things to look would be the timing (is it too retarded?), lean a/f mixtures (has to be pretty lean to do this), clogged cat, bad egr valve, or bad gas.

 

Define "overheating".

Most of the time, when people say their car is "overheating", it's running perfectly normally, they just need a radiator cap to keep it from spewing; or they mean that they would like it to run cooler than it does in stock trim. Stock, the electric fan doesn't even turn on until 230° or so; therefore, anything up to that temp at least cannot possibly be considered as truly "overheating".

 

Overheating as in temperature climbs to 250* in 50* weather after about 30 minutes of driving highway or city and shows no sign of stopping unless the car is pulled over and parked until it's cool. I'll check those things that were suggested. Any way to tell if the water pump is bad without changing it? That's a last resort.

 

So is it in fact "overheating"? Could it just be that it needs a new gauge sending unit?

 

I'm assuming it is actually overheating. Like I said, i won't be able to check it out until next week. I'm going by what my friend said was happening and from what he told me when i told him to check a few things.

 

Check to see that the radiator is full(burp it good) and that the radiator is really hot when it overheats--that will verify the pump is at least moving the coolant and the thermostat is open.

 

easy way to tell if its circulating is to take the radiator cap off (while car is cool of course) and then start the car and watch inside the radiator should be awhirlpool in there if its not then the pump may be going out