Hi all. I know this topic has been discussed at nauseam but I have tried to search here and google with every phrase I can think of and nothing. So forgive me if this has been discussed.
2002 Disco II. Total engine rebuild including block pressure tested, inline stat mod, new radiator, and water pump. Temps have been great since then. Running about 188-200 plus or minus in the summer according to OBD2 gauge. Gauge would show a little spike after start up and then stat opens and everything settled down.
Fast forward to this week. -10 weather and dash gauge, which I have never seen move above middle, creeps above middle towards 3/4 mark. Odd I think in weather like this. Coolant level is perfect and engine shows no signs of running hot. Parked it for 5 minutes and gauge returns to middle. Go home and get OBD2 gauge. This is when things get weird. Drive it and temps start to climb hitting 242 at one point. 1 min later as I am trying to pull over temps immediately drop to 165-170 range within like 30 seconds. 5 minutes later temps climb again and I check engine. I can wrap my hands around upper hose. Warm but definitely not hot. I use a IR thermometer and point at various places on engine. Highest reading I get right where sensor is was 165 degrees. I conclude I am getting false readings and keep driving. The same process happens again in 5 min or so intervals every time I have tested it. Temps climb from 170 to 242+ stay there for 1 min and drop back down to 17-ish within 30 seconds. Never do the high temps stay high. Again can touch hoses and stat housing which is metal without getting burned. Was even able to open reservoir cap without coolant boiling over or spurting out when gauge read 230 degrees.
I replaced temp sensor and same issue only slightly different numbers. Reached 240 and let truck sit for 5 min. Gauge says 170 when I start it back up and idled at 170 for 20 min until starting to drive again and then creeped up to 230 which was when I was able to open cap with no issues. Also hoses are not rock hard but firm and squeezable when at high temps which seems normal to my recollection. I find it hard to believe these engines can cool down and heat up that fast. Never have I seen that happen so the odds of the stat malfunctioning seems slim.
Any thoughts? Did the extreme cold mess with the ECU? Does the ecu control the temp gauge in vehicle as well? What could I be missing? Anyone else deal with this before? Is it truly overheating?
I appreciate any help in advance.
2002 Disco II. Total engine rebuild including block pressure tested, inline stat mod, new radiator, and water pump. Temps have been great since then. Running about 188-200 plus or minus in the summer according to OBD2 gauge. Gauge would show a little spike after start up and then stat opens and everything settled down.
Fast forward to this week. -10 weather and dash gauge, which I have never seen move above middle, creeps above middle towards 3/4 mark. Odd I think in weather like this. Coolant level is perfect and engine shows no signs of running hot. Parked it for 5 minutes and gauge returns to middle. Go home and get OBD2 gauge. This is when things get weird. Drive it and temps start to climb hitting 242 at one point. 1 min later as I am trying to pull over temps immediately drop to 165-170 range within like 30 seconds. 5 minutes later temps climb again and I check engine. I can wrap my hands around upper hose. Warm but definitely not hot. I use a IR thermometer and point at various places on engine. Highest reading I get right where sensor is was 165 degrees. I conclude I am getting false readings and keep driving. The same process happens again in 5 min or so intervals every time I have tested it. Temps climb from 170 to 242+ stay there for 1 min and drop back down to 17-ish within 30 seconds. Never do the high temps stay high. Again can touch hoses and stat housing which is metal without getting burned. Was even able to open reservoir cap without coolant boiling over or spurting out when gauge read 230 degrees.
I replaced temp sensor and same issue only slightly different numbers. Reached 240 and let truck sit for 5 min. Gauge says 170 when I start it back up and idled at 170 for 20 min until starting to drive again and then creeped up to 230 which was when I was able to open cap with no issues. Also hoses are not rock hard but firm and squeezable when at high temps which seems normal to my recollection. I find it hard to believe these engines can cool down and heat up that fast. Never have I seen that happen so the odds of the stat malfunctioning seems slim.
Any thoughts? Did the extreme cold mess with the ECU? Does the ecu control the temp gauge in vehicle as well? What could I be missing? Anyone else deal with this before? Is it truly overheating?
I appreciate any help in advance.