I have a customer that has a 98 OBW. I recently replaced the engine with a low mileage 2.2 The car runs beautifully except for when he turns on the a/c the temp jumps up to 2/3. I haven't seen it happen yet but he says its full of anti freeze and that both cooling fans are running.

We put the engine in months ago and there have been no overheating issues until the past week when it got HOT and he turned the a/c on.

Any thoughts?

Ive seen this many times.

 

Check the simple first (the car is old enough) a bad radiator cap.

 

Check the AC system to make sure it has the proper pressures.

 

Next inspect the radiator for missing fins. If all those are OK check for a clogged radiator. This is the most likely issue if the radiator was not flushed at the time of the conversion. I am going to assume there was a HG issue. The oil+antifreeze+air can make a glue that clogs everything in the radiator.

 

Don't go so much by mileage, go buy age.

I'm leaning towards a radiator issue too...some kind of restriction in the flow.

Thanks

I'd confirm that both fans are running. Next is to find out what is meant by "full" of antifreeze. Is he just looking in the reservoir or the radiator as well?

 

I'll also second nipper with checking the fins of the radiator as well as the condenser for obstruction.

 

Internal obstruction is a possibility. A flush may be in order if a new radiator cap doesn't cure it.

he seems to know enough to check inside the radiator... I have a couple spare radiators from auto legacys ( no hg issues) i might throw one in just to eliminate several variables. You guys are soooo much help. C