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Hi everyone. I have posted on this before I have not been able to solve it though and wanted to start fresh. Thanks
i have a PCM 2004 ZR6 closed loop cooling system in my 2004 Tige 22v. Let me first tell you what the symptoms are. I at idle or low rpms I run right about 175 dead center on the guage. Checking the engine with an infrared thermometer confirms this. Some spots lower and some a little higher temps. If I run much above 30 mph or say 2500 to 300 rpm I begin to heat up. When I go wide open throttle within a minute I will over heat.
Now let me tell what I have done to trouble shoot this problem. I have been all the way through the raw water cooling side of the engine. The impeller is new, I have cleaned the Heat exchanger, and trans cooler. There is no debris or blockage. After that I started looking at the Closed loop side. First thing I did was change the t-stat and I also tested the old one in a pan of water with a temperature probe, it opened up right above 160 deg f. Any ways with the new t-stat I still experienced the same problem ans even logged an over temp fault and purged from the degas bottle which put me into low rpm mode until it cooled down. My next move was to completely remove the t-stat. After removing the new t-stat the engine would not get above about 140 deg f and even lower in cooler water no mater how hard I ran it. So from this I concluded the following. That there is no problem with my raw water cooling system. There does seem to be a problem with closed loop system and it appears to be a blockage with the thermostat. Afetr running with out the thermostat aI tested the new one again in a pan of water it as expected. I pulled the water pump off and checked it also. I put the new thermostat back in being very careful to make sure it did not slip during the install and reinstalled the water pump also. Yesterday I was at the lake and same old problem. As soon as I slow down or idle the temp comes back down.
It has been suggested that the engine coolant sensor could be bad but it seems to working correctly and confirming what the water temp sending unit is reading on the gauge.
Any help would be appreciated.
i have a PCM 2004 ZR6 closed loop cooling system in my 2004 Tige 22v. Let me first tell you what the symptoms are. I at idle or low rpms I run right about 175 dead center on the guage. Checking the engine with an infrared thermometer confirms this. Some spots lower and some a little higher temps. If I run much above 30 mph or say 2500 to 300 rpm I begin to heat up. When I go wide open throttle within a minute I will over heat.
Now let me tell what I have done to trouble shoot this problem. I have been all the way through the raw water cooling side of the engine. The impeller is new, I have cleaned the Heat exchanger, and trans cooler. There is no debris or blockage. After that I started looking at the Closed loop side. First thing I did was change the t-stat and I also tested the old one in a pan of water with a temperature probe, it opened up right above 160 deg f. Any ways with the new t-stat I still experienced the same problem ans even logged an over temp fault and purged from the degas bottle which put me into low rpm mode until it cooled down. My next move was to completely remove the t-stat. After removing the new t-stat the engine would not get above about 140 deg f and even lower in cooler water no mater how hard I ran it. So from this I concluded the following. That there is no problem with my raw water cooling system. There does seem to be a problem with closed loop system and it appears to be a blockage with the thermostat. Afetr running with out the thermostat aI tested the new one again in a pan of water it as expected. I pulled the water pump off and checked it also. I put the new thermostat back in being very careful to make sure it did not slip during the install and reinstalled the water pump also. Yesterday I was at the lake and same old problem. As soon as I slow down or idle the temp comes back down.
It has been suggested that the engine coolant sensor could be bad but it seems to working correctly and confirming what the water temp sending unit is reading on the gauge.
Any help would be appreciated.
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