I'm trying to work out a cooling issue. I put in a new 180deg thermostat and when moving temps are around 184 or where they're supposed to be. When I stop (at a light for example) though, temps can go up to 204 in just 30 seconds or so. As soon as I start moving again they drop way back down.

I let the temps get to 195 then felt the radiator. the inlet corner is too hot to touch, the bottom on the inlet side feels warm but not anywhere near burning or even uncomfortable to touch. The outlet side is the same temp top and bottom and is just barely warm.

The fan seemed pretty easy to turn when hot (maybe a little less than 1/4 turn spinning it and letting go) I swapped it with another one I had to see if that would make a difference.

Is the radiator supposed to vary by that much or am I looking at putting in a new radiator?

 

your factory temperature range is 190-212f, which is when your aux. fan should kick on

 

I just put in a brand new radiator, lower temp thermo, hd fan clutch, im im getting pretty much your same numbers, so i dont think thats the issue. 204 is the hottest ive been getting letting it idle before the temps plummet again with the fans kicking in.

 

As long as I'm going 30+ mph it seems I stay around 185 (with new 180deg therm)...as soon as I stop temps climb pretty quick to 200+ and feeling the radiator the only place that is too hot to touch is right near the inlet...the inlet side bottom is warm and the entire outlet side is cool that's why i wonder if a shot radiator is causing the temps to rise.

I would think that idling at a light it would go up only a few degrees...not ~20 degrees

 

sayreville eh? i'm at the middlesex fire academy every mon+wen night come bring me coffee one night haha. certainly need good working suspension and cooling system for the roads in that area, damn... i thought the roads around here were bad. and what a lovely smell there too hahaha

 

Probably the cloud coming over from Staten Island causing the smell....and yeah the roads under the parkway there are awful, much better when you get into town more and out of the industrial center.

Probably putting a radiator in this weekend, that hopefully will even things out. My guess is a piece (or pieces) of my old 190 deg thermostat is stuck in the radiator seeing as it was disintegrating in my hand when I swapped it for the new one. I just hope it didnt make it to my heater core...

 

I would say that those temps are right in line with mine and I have new 180 tstat and brand new radiator. I hit just about 202-204 at a light, above 30 I am around 184-186. I think the issue is coolant flow at idle, the water pump is not moving as fast. Someone on this board was installing an electric water pump that would pump at a constant rate no matter the engine RPM. Unless your radiator was leaking I personally would not replace it.

 

^^ yep, was me. no more temp climbs, here. constant flow rate= constant temps.
to test....when your temps rise at a stop, raise the rpms and watch them drop.

 

Dusty,
How much pressure do you think the electric pump adds to the system? You suspected it may have caused your HG leak. Just curious if you discovered anything else after tearing it down.

 

not cause it.just made it noticeable, like an early warning system. same as if you pressure tested.
its has the ability for an extra 115lt/per minute or 1822gl/per hr.

I am sure the teeny tiny leak was there, just not enough pressure/flow to notice it with the stock system, yet. it would have eventually showed up, by itself. I just sped up the ability to notice it.

just old deteriorating gasket. I couldn't, clearly, pinpoint the crack. but It was coming from the #8 area.