Hey everyone so i am new to this forum and i mainly signed up because i am completely stumped by my issue. nothing is making sense to me. So i sprung a coolant leak which ended up being from the timing chain cover gasket. i went and replaced that gasket along with the timing chain and gears, water pump and gasket, thermostat (195), thermostat housing and gasket, bypass hose, upper rad hose, lower rad hose, fan clutch, and idler pulley. I filled and burped the system and the truck ran great for about a day and a half before it leaked again. i must not have used the right gasket maker on the water pump cause the gasket blew out. took it all apart and redid the gasket on the water pump. dropped the alternator on the coolant temp sender and broke it so i then replaced that as well. rebled the whole system and now after doing it again my truck keeps reading between 220-240 degrees. I just changed the radiator cap, that didnt fix the problem. i pressure tested the system at 16psi. no leaks anywhere. truck runs great but its just hot. I also should note that i had the heat on high when i bled the system both times. im sure there are no more bubbles or air pockets in the system. the upper rad hose is hot, while the lower rad hose is at a warm temp. im lost at what else to do. ive run out of things to try. i can try flushing the system but i dont understand why it wasnt over heating before the water pump gasket blew out and after i fixed it, it now runs hot. any help or opinions would be appreciated cause im lost on this one.

 

If you replaced the temp sensor, that may be the entire issue. They weren't the most accurate things to begin with, and an aftermarket unit is likely worse. The sensor behind your alternator is for the gauge in the dash, so, make sure you have a good connection there, and the sensor gets a good ground to the intake manifold.

 

it was a cheap autozone one cause i needed it at the time. and i get a reading on the dash so i guess there is a good connection. i used some liquid thread sealant on the threads. you think that might be the issue?

 

Yep. It should have come with some sealant on the threads, that's really all you need. Its NPT thread as well, so, if it leaks, just tighten it up a bit more.

 

the sensor comes with sealant on the threads. the sender does not. i bought the sensor by mistake the first time and then went back and got the sender. although looking at the old one it looked like it had some sort of sealant on that one as well. i can try replacing it and see what happens. i dont know what else to try.

 

I did similar repairs to by 95 dodge ram 361 also about 40,000 miles ago. I broke the coolant sensor getting it out. replaced it with an advance auto sensor. from then on the temp gauge ran higher than 200 degrees. I replaced the thermostat but it did not change the gauge reading. there is no signs of coolant overheating. I have just lived with it.

 

im assuming it something along the lines of the sensor not reading correctly because there are no other signs of an overheating motor. everything is flowing properly. is there anywhere specific on the block i can get a temp reading with an infrared laser so i can double check the gauge. thatll tell me for sure if im running hot or not.

 

Right above the thermostat, on the housing. You need to practice some yoga to get a good shot at it, but, it's possible.

 

haha. i might need to clean it if i can. Not sure ill get an accurate reading with some crud build up over there. it was not an expensive truck when i bought it lol. now should the reading on the block be the exact same as the gauge or will the block be slightly warmer in comparison to the coolant running through there?

 

Let the thermostat open, and coolant cycle at least once before testing temp. It should be pretty close to 195, (thermostat full-open temp.) Then see what the gauge has to say. (best to test WHILE the thermostat is open, but, kinda hard to tell just when that is. )