2000 4.7 Running HOT
07-07-2017, 05:44 PM
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Model: Cherokee
2000 4.7 Running HOT
2000 Grand Cherokee
I replaced the thermostat and water pump a few weeks back after my 4.7 was running a bit warm/hot. Ran warmer than it used to, but reasonable (tad over 1/2 way on the gauge).
Couple hundred mile trip earlier last week and on my return it started to get hot.
Replaced thermostat again, clutch fan, and radiator. Radiator had some scale, not super bad but I thought for sure that it would be fine.
Just drove about 5 miles through town, HVAC off and sure enough it started to get pretty warm and not very far from the red. About 80 out here/now.
Not sure the clutch fan is working, electric fan was working.
Coolant was flushed in the shop a few years ago (2 1/2-3), didn't look bad previous to all this recently.
So radiator is new, water pump is new, thermostat is new (x2), clutch fan is new.
I want nothing to do with this at this point, but don't want to take a bath trading it in and don't want to stick someone else with my problems.
Ideas/thoughts?
ps: Upper hose is hot, lower hose is quite a bit cooler and the thermostat is in the correct direction.
Thank you...
I replaced the thermostat and water pump a few weeks back after my 4.7 was running a bit warm/hot. Ran warmer than it used to, but reasonable (tad over 1/2 way on the gauge).
Couple hundred mile trip earlier last week and on my return it started to get hot.
Replaced thermostat again, clutch fan, and radiator. Radiator had some scale, not super bad but I thought for sure that it would be fine.
Just drove about 5 miles through town, HVAC off and sure enough it started to get pretty warm and not very far from the red. About 80 out here/now.
Not sure the clutch fan is working, electric fan was working.
Coolant was flushed in the shop a few years ago (2 1/2-3), didn't look bad previous to all this recently.
So radiator is new, water pump is new, thermostat is new (x2), clutch fan is new.
I want nothing to do with this at this point, but don't want to take a bath trading it in and don't want to stick someone else with my problems.
Ideas/thoughts?
ps: Upper hose is hot, lower hose is quite a bit cooler and the thermostat is in the correct direction.
Thank you...
07-07-2017, 05:59 PM
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It was/is full (only have distilled water in it now). Ran it last night until it was about 170-180 and had it on stands (didn't have the bleeder open) so the filler was the highest point. Burped quite a bit of air out of it, ran it for a bit before driving it tonight and topped it off.
07-09-2017, 05:30 AM
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Sorry, fan clutch was replaced and I'm going to try another one on it today. One I replaced it with is engaging when I first start it, but not coming on when it's getting hot.
I've drained the water out and used HOAT & distilled water, bled it out with the bleeder screw (2-3x now). I've got a spill free funnel on order and I'll use that this coming week.
No signs of a head gasket going out, and continues to run just fine. Regardless, the temps were climbing on a 4-5 mile drive yesterday before I parked it again.
I've drained the water out and used HOAT & distilled water, bled it out with the bleeder screw (2-3x now). I've got a spill free funnel on order and I'll use that this coming week.
No signs of a head gasket going out, and continues to run just fine. Regardless, the temps were climbing on a 4-5 mile drive yesterday before I parked it again.
07-11-2017, 06:29 PM
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ARGH.......
Last night - Received a no spill funnel, jacked the front end up and ran it until the thermostat opened.
Took it for a drive - Same thing (indicating hot)
Borrowed a pressure tester today-
Did a radiator pressure test, have an 18 lb cap on presently.
Put 18-19 lbs in it, lost a touch at first and than stable at about 17 lbs for 3-5 minutes.
Replaced the temp sensor following that, thinking sure enough all along its just that simple.
Temp gauge still climbed while under load.
Temp gun readings, which all should be about normal. Slim chance I got a bad sensor or between it and the gauge???
Readings
Top Hose - 180-185 (same as the top of the radiator)
Bottom Hose - 120-125 (same as bottom of the radiator)
Temp at base of sensor - 170-180 -On the brass part of the sensor 200
Thermostat housing - 215-220
Water pump - 200-225 depending on what part of the housing
Throttle body (both sides) 210-215
Valve Covers - 180-185
Everything points to a normal running engine, but I honestly don't trust it.
I'll probably throw another sensor at it, but ???
Any other ideas?
Last night - Received a no spill funnel, jacked the front end up and ran it until the thermostat opened.
Took it for a drive - Same thing (indicating hot)
Borrowed a pressure tester today-
Did a radiator pressure test, have an 18 lb cap on presently.
Put 18-19 lbs in it, lost a touch at first and than stable at about 17 lbs for 3-5 minutes.
Replaced the temp sensor following that, thinking sure enough all along its just that simple.
Temp gauge still climbed while under load.
Temp gun readings, which all should be about normal. Slim chance I got a bad sensor or between it and the gauge???
Readings
Top Hose - 180-185 (same as the top of the radiator)
Bottom Hose - 120-125 (same as bottom of the radiator)
Temp at base of sensor - 170-180 -On the brass part of the sensor 200
Thermostat housing - 215-220
Water pump - 200-225 depending on what part of the housing
Throttle body (both sides) 210-215
Valve Covers - 180-185
Everything points to a normal running engine, but I honestly don't trust it.
I'll probably throw another sensor at it, but ???
Any other ideas?
Last edited by gellatly; 07-11-2017 at 06:35 PM.
07-11-2017, 06:38 PM
#7
Caracticus Potts The Mod
when you are putting coolant in, are you opening the bleeder screw on the upper hose first? quickest way to overheat a 4.7 and blow the headgasket is to get these engines air bound
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07-11-2017, 07:03 PM
#9
Caracticus Potts The Mod
head gasket is my bet, there are test kits you can try, or take to someone who has a 5 gas analyzer and have them "sniff" the top of the rad for exhaust gases
07-11-2017, 08:16 PM
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I'm not saying a gasket might not be bad, but there's absolutely no signs of a bad gasket or cracked head.
Normal amount of condensation in the exhaust, probably less than either of my other two vehicles. One of which I replaced the heads this past winter due to a bad gasket (Ford Ranger 4.0).
Nothing in the oil, so signs of gas in the coolent, not leaking a drop. Pressure test seemed to hold fine.
Every cylinder is within 5 degrees of one another (haven't pulled the plugs yet) but it's running as well as it ever has been.
And if it was really 240-250 degrees, wouldn't some area of the engine be registering that when checking with the heat gun? Not saying the gun is perfectly accurate, but all temps are very similar to my other engines when I've checked them at operating temp.
Dread the thought of pulling the heads, I can do a 4.0 OHV without a second thought, but this one is intimidating me for some reason. Maybe because of the timing chains?
Normal amount of condensation in the exhaust, probably less than either of my other two vehicles. One of which I replaced the heads this past winter due to a bad gasket (Ford Ranger 4.0).
Nothing in the oil, so signs of gas in the coolent, not leaking a drop. Pressure test seemed to hold fine.
Every cylinder is within 5 degrees of one another (haven't pulled the plugs yet) but it's running as well as it ever has been.
And if it was really 240-250 degrees, wouldn't some area of the engine be registering that when checking with the heat gun? Not saying the gun is perfectly accurate, but all temps are very similar to my other engines when I've checked them at operating temp.
Dread the thought of pulling the heads, I can do a 4.0 OHV without a second thought, but this one is intimidating me for some reason. Maybe because of the timing chains?