No water flow=overheating 83' I6

[duke94]

As part of the restoration on my 83' with AMC 258 i6 / 4.2l , I replaced the water pump, radiator, heater core, all hoses plus T-stat. When I started it up, after a few minutes idling, the temp got almost to the hot mark. Temp at the back of the head where the sensor is was 200 F. I've been through all the suggestions on getting the air out, but I don't seem to be getting any noticeable water flow in the rad tank. Shouldn't I see lots of water movement with the cap off? Pulled and checked the T-stat and it was OK (even drilled a small hole in it). Lower hose is not collapsed. Where do I look next?

 

[Old Dog]

are you sure you have the right pump? I believe there is a reg. rotation and a reverse rotation pump depending on if you have v belts or serp. belts.

 

[CJ]

1st thing that comes to mind is make sure you have the correct pump. I have seen it many times that a serp belt pump was installed instead of a v-belt pump and vis-versa (the pumps turn opposite from each other.) A pump turning backwards has almost no flow.

 

[CJ]

LOL - thinking alike!

 

[Petescj]

No Snoozeling.

LOL - thinking alike!

 

[duke94]

Of course I couldn't find the receipt for the water pump (found every other receipt!!). The one I have is aluminum, and I'm thinking I have the wrong one as you all suspect. I should see lots of water action in the upper tank correct?

 

[CJ]

You should, do you have the old pump? Pull the new one and compare the impellers.

 

[duke94]

You should, do you have the old pump? Pull the new one and compare the impellers.

Pitched the old one long ago. Can anyone tell me if this is the correct pump?

 

[Tin Medic]

 

[duke94]

The rotors are so different in shape, it's not clear if I have the right pump or not. What do you think?

 

[BrockGrimes]

My first thought was the t-stat was in backwards.
What's the part # on your current water pump?

 

[duke94]

My first thought was the t-stat was in backwards.
What's the part # on your current water pump?

Unfortunately there is no part number on the pump. Pretty sure I got it at O'rielys but I couldn't find the receipt. It seemed like the pump wasn't doing anything because there was never any noticeable water movement in the tank with the engine running.

 

[Trujeepr]

if not the pump, try removing the t-stat and put the cover back on with out it and run it and see if it heats up.

 

[duke94]

if not the pump, try removing the t-stat and put the cover back on with out it and run it and see if it heats up.

I ordered a new pump today. Will try that first and if it still doesn't cool down will remove the T-stat.

 

[johnnyreb]

I have heard of thermostats that don't open up at all.

 

[BrockGrimes]

Water boils at 212 so if your tstat is a 195 drop it in a cup of boiling water and see if it opens. easy test

 

[duke94]

Just a quick follow up. I replaced the water pump and the temp was still heading toward hot. Decided to just let it run and see what happens while monitoring the temp at the temp sender (rear of the head) with an infrared thermometer. The temp never got over 175 after idling in the garage for 15 minutes. It seems that the either the gauge or sensor are not right. Both are new (made in China!). Which is the most likely to be off?

Thanks

 

[alpha6]

Looks like you have the one posted on the right.