engine running hot, but not overheating! help
#21
Just a silly question, when you put the belt on any chance the water pump got routed wrong and is running backwards? ALso, do you have a laser temp gun? You could have a bad reference or sensor thats off a bit and its not getting hot enough to open the t stat even though the dash indicates its hot. Temp the thermostat housing while its warming up.
with the thermostat out and the truck warmed up, when the fan kicks on, it blows HOT air away from the because the radiator is actually warm.
with a thermostat in, and the fan turns on, it just blows cold air away from the radiator. because there isnt enough hot water flowing to even warm up the radiator
---AutoMerged DoublePost---
ok i messed with it some more today. the heater hoses seemed to be kind of kinking themselves, so i put some barbed 90's on em today to take care of that problem. it made a little difference but not enough, which thinks im on the right track.
i did notice one thing today though. i a heat exchanger in there when i had the auto trans. when i put the manual in it, i took everything off of it, except the hose that brings coolant into it.
would aking that line off, and plugging it (which would allow full flow to the heater core instead of half of it) maybe solve my problem?
Last edited by tltruckparts; 02-17-2010 at 06:20 PM. Reason: Automerged Doublepost
#25
ok everyone i have a new update.
i went ahead and replaced the radiator cap yesterday and took it for a drive. now it runs hot while driving, but the second i put it in neutral or coast not in gear, the temperature instantly drops drop to normal range within a minute or two. and when i turn the heater on, it also drops the temps right away. so kinda rules out the waterpump or fan issues.
what would cause it to run hot only while driving but not at idle?
i went ahead and replaced the radiator cap yesterday and took it for a drive. now it runs hot while driving, but the second i put it in neutral or coast not in gear, the temperature instantly drops drop to normal range within a minute or two. and when i turn the heater on, it also drops the temps right away. so kinda rules out the waterpump or fan issues.
what would cause it to run hot only while driving but not at idle?
#26
Normally when they are doing that it is either the fan not moving enough air or a partly clogged radiator. Since it sounds like you have an electric fan the first place to check is the radiator. The thermostat not opening all the way might also be a possibility. We used to have a Chevy 3500 with a 454 that always ran at about 235 degrees and when I took the radiator out and had it cleaned at a radiator shop the temp never went above 200 again.
Last edited by gradyc; 02-23-2010 at 06:35 PM.
#27
Normally when they are doing that it is either the fan not moving enough air or a partly clogged radiator. Since it sounds like you have an electric fan the first place to check is the radiator. The thermostat not opening all the way might also be a possibility. We used to have a Chevy 3500 with a 454 that always ran at about 235 degrees and when I took the radiator out and had it cleaned at a radiator shop the temp never went above 200 again.
#28
Normally when they are doing that it is either the fan not moving enough air or a partly clogged radiator. Since it sounds like you have an electric fan the first place to check is the radiator. The thermostat not opening all the way might also be a possibility. We used to have a Chevy 3500 with a 454 that always ran at about 235 degrees and when I took the radiator out and had it cleaned at a radiator shop the temp never went above 200 again.
the electric fan blows very hard so i dont believe its a problem moving air. but i am going to try gettin the radiator cleaned that seems like the only possibility left to fix this problem
#29
there are 2 types of thermostates.
1. is a universal or as cummins says, NEW STYLE
2. OLD STLYE
the new style thermo has like a rubber wrapped around the thermo and does not have a tang and do not require special positioning for proper venting, if you have the old style you will have to install the correct way for venting, this can cause over heating problems, or engine staying cold.
the best way to see if it is the thermo, take it out and run the truck up to operating temps and see if it stays on the lower end of the temps.
1. is a universal or as cummins says, NEW STYLE
2. OLD STLYE
the new style thermo has like a rubber wrapped around the thermo and does not have a tang and do not require special positioning for proper venting, if you have the old style you will have to install the correct way for venting, this can cause over heating problems, or engine staying cold.
the best way to see if it is the thermo, take it out and run the truck up to operating temps and see if it stays on the lower end of the temps.
#30
there are 2 types of thermostates.
1. is a universal or as cummins says, NEW STYLE
2. OLD STLYE
the new style thermo has like a rubber wrapped around the thermo and does not have a tang and do not require special positioning for proper venting, if you have the old style you will have to install the correct way for venting, this can cause over heating problems, or engine staying cold.
the best way to see if it is the thermo, take it out and run the truck up to operating temps and see if it stays on the lower end of the temps.
1. is a universal or as cummins says, NEW STYLE
2. OLD STLYE
the new style thermo has like a rubber wrapped around the thermo and does not have a tang and do not require special positioning for proper venting, if you have the old style you will have to install the correct way for venting, this can cause over heating problems, or engine staying cold.
the best way to see if it is the thermo, take it out and run the truck up to operating temps and see if it stays on the lower end of the temps.
how do i know which style it is or how to install it correctly? alldata doesnt give me any specs on it and neither did the thermostat have any directions or anything or it wasnt marked. but i know there was a rubber gasket around the edge of it.
when i took it out and ran it without it it ran at 210 on the mark, never even budged once.
the radiator shop just called and said my radiator is done, they said it was very dirty and partly clogged, but he also said if i was running 230* or 240* it wasnt enough to cause that. i gotta go get it tonight, so ill put it in tomorrow and update everyone