Have an 87 YJ with the 2.5 . The temp gauge is saying that it's running at 220 degress. I've replaced the radiator and thermastat twice and all new hoses. The hoses will be hot but the cap will not be. The water pump is not leaking It's also leaking some where at the bottom but can see where. When i take the shroud off there is no leak. I'm at the end of my rope with this. Any ideas would be very help full . Thanks,
Later Mike
The first thought is that the gauge is not reading correctly. Does the temp move much from the indicated 220 degrees when sitting in traffic after going down the freeway? Or start climbing steadily on a hot day on the freeway? If not, I'm not too worried.
With a proper 192 degree thermostat, the engine should be running at around 200 to 210 degrees. They used some fairly cheap and inaccurate gauges in those years. (The oil sender is the worst by far.)You can buy a cheap meat thermometer, tape it to the thermostat housing, and wrap it with mutiple layers of rags to insulate it as a quick and dirty test. Expect it to read about 10 degrees lower than the liquid inside.
If it really is runn> Have an 87 YJ with the 2.5 .
Thanks for the help.It does just go to 220 and just stops . No going over and drops down a little. We have lazer thermator at work i'm going to try tonight. I went and retighted every thing and it no leaks. I'll just drive it till it breaks . I am going to pick up an after market gauge to see if thats the reproublem. Just had my fill of working on it for the last month. Thanks again for the help.
Later Mike
Have you checked or changed the engine drive clutch fan? If it is bad it can cause it to run hot.
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No i have not. But i will. That could be it. Thanks!
Later Mike
How would i go about checking the clutch fan. What am i looking for?
Later Mike
Better yet when it is running hot it should be engaged and pulling air agressively. If it is not it has either lost its fluid or the bimetal coil on it has aged to the point that the engagement temp it too high to do any good (as the coil ages it raises engagement tempature). One more thing, it should have no wobble or play in it. If you are of the mind to tweak it I wrote a article some time ago on how to adjust or tweak the bi metal coils on them. If is for a GM fan in pictures but the theory is the same. I have done this many times over the years.
Thanks for the help . I'll try it on Saturday and see what happens.
Later Mike
I'll check for wobble. I have a fan from my old 2.5 i'm going to swap over to see if there is any diffrence. Thanks for all the help. This group is the best.
Later Mike
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