90 renix suddenly running hotter than normal.
06-11-2017, 11:35 AM
#1
Newbie
Thread Starter
Join Date: May 2016
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
90 renix suddenly running hotter than normal.
Ok so here's the problem I've been having for the past few days.
I have a 90 cherokee with a renix 4.0. About a year ago I swapped to the newer "open" style cooling system. I got a brand new radiator (spectra cu1193), all new hoses, a new 195* stant thermostat, and a universal coolant overflow bottle and I built my own bracket to hold it. the water pump is less than two years old. The system performs flawlessly and normal operating temperature is about 195 degrees and barely ever hits 210 even in summer weather.
However, about 3 days ago I was driving home from work and I noticed my temp gauge was reading about 225*. The outside air temp was only about 65* so I figured something must be going on. I got home and checked for leaks and found nothing. The next morning before going to work I unplugged the connector for the temp sensor at the rear of the head and simply plugged it back in and my temperature was back to normal. The connector and stud were free of any grime or grease. Then on the way home from work the same day the temp was back up to 225-230. The outside air temp that day never got over 80* also, when the temperature occasionally got to 210 ish the electric fan would come on. Even when the gauge reads 225-230 now, no sign of the fan. I know the fan does indeed work and the switch that goes into the rad is also good. I also noticed that the temperature climbs a bit quicker now from cold. The thermostat must be opening because the gauge climbs, drops a bit when it opens, then continues to climb.
So I am wondering if my temp sensor is bad and my gauge is lying to me because absolutely no signs of it actually overheating are present. Or if it's a weak water pump or something else. Thanks in advance.
I have a 90 cherokee with a renix 4.0. About a year ago I swapped to the newer "open" style cooling system. I got a brand new radiator (spectra cu1193), all new hoses, a new 195* stant thermostat, and a universal coolant overflow bottle and I built my own bracket to hold it. the water pump is less than two years old. The system performs flawlessly and normal operating temperature is about 195 degrees and barely ever hits 210 even in summer weather.
However, about 3 days ago I was driving home from work and I noticed my temp gauge was reading about 225*. The outside air temp was only about 65* so I figured something must be going on. I got home and checked for leaks and found nothing. The next morning before going to work I unplugged the connector for the temp sensor at the rear of the head and simply plugged it back in and my temperature was back to normal. The connector and stud were free of any grime or grease. Then on the way home from work the same day the temp was back up to 225-230. The outside air temp that day never got over 80* also, when the temperature occasionally got to 210 ish the electric fan would come on. Even when the gauge reads 225-230 now, no sign of the fan. I know the fan does indeed work and the switch that goes into the rad is also good. I also noticed that the temperature climbs a bit quicker now from cold. The thermostat must be opening because the gauge climbs, drops a bit when it opens, then continues to climb.
So I am wondering if my temp sensor is bad and my gauge is lying to me because absolutely no signs of it actually overheating are present. Or if it's a weak water pump or something else. Thanks in advance.
Last edited by 90Limited; 06-11-2017 at 11:57 AM. Reason: Mistake
06-13-2017, 08:13 AM
#4
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,876
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Radiator cap not holding pressure?
