Car is a 94 3.4 L. Just replaced water pump due to leak at the weep hole about a month and a half ago. Back story...i ordered a genuine GM water pump from pepboys. After a month long ordeal with them i ended up with a Bosch made pump.


So when i took out the old pump which was a GM pump the vanes on the back had larger openings. Dont know if this Bosh pump is more efficient or not. But installed it anyways.

So my issue is that the engine is having a hard time cooling down. I turn the ac on (which forces the fan to come on) and it struggles to cool the engine. It Also takes a long time to cool down when driving a 55 mph. Observation...with engine running, ac on and verified fan spinning i can actually feel a temperature difference of the air behind the fan. Its actually cooler on the bottom of the fan and hot on top quadrant. So do yall think the radiator is clogged, or my water pump is not flowing correct? My thoughts are the new pump with better flow (?) piled up some sediment in the radiator causing it to block some passages. Getting tired of messing with this car. Its not an every day driver. I have a colorado for that.

 

One thing I used to do was a feel test on the radiator. If the lower part of the rad was significantly cooler then the upper part there it is most likely plugged with sediment. Sometimes the sediment can be flushed out with a hose and some times the radiator can not be saved. These days I would confirm the temps with a infrared Thermometer.

12:1 Infrared Laser Thermometer (harborfreight.com)

 

Thanks for the reply Gorn. It ended up being the thermostat. I pulled it out and tested it in some hot water. Looked like it was not opening up all the way. Bought a new one and tested it also it opens up alot further. Water was 200 on a cooking thermometer both times. The old thermostat was a 195 deg the new is stock at 180. Dont know why i put a 195 in....Hummm?

Wife is mad now that i used her coffee mug.

 

Higher temperature for better emissions.