water pump on its way out?

[racsan]

my '93 4.0 with 130,000+ miles seems to be developing a overheating problem, but its intermitant. yesterday i pulled my 1,000 pound box trailer 25 miles, engine temp was a little higher than normal but not enough to worry much about. later i drove to work, was fine on the way there. when i got to work i waited for the shift ahead of me to leave from a meeting, i sat for about 20 min with the a/c on high, actually fell asleep. woke up and the temp guage was higher than when i pulled the trailer, not pegged out to the far right but over halfway of the needle sweep. i rolled down the windows, turned the climate controls to heat and ran the blower on high for 5 min until the temp guage dropped to normal. on the way home, it was fine, coolant level is normal, was last changed 3 years ago when i put in a thermostat. when iwas pulling the trailer i was only going 55 in 4rth, wasnt really working it hard, and it wasnt hot outside. im wondering if the fan clutch could be not working or if its something with the water pump. both are oringinal. if i get a new water pump is the "severe duty" worth it or just a extra 20 bucks? usually if i have something with a cooling system issue, its either working or running hot, not a intermittant issue.

 

[Big Jim M]

Ok so you sat there taking a nap in the august heat and when you woke up you noticed the temp was up 5 or 10*... What the hell is abnormal about that?
Look! These systems do vary a few degrees depending on how much heat the engine is putting out and the engine speed at the time.
EVEN A BRAND ONE WOULD DO THE EXACT SAME!
THE RULE is if it contains it's fluid..it IS OK! The engine can take 100* more temperature than the coolant can. So if the coolant is happy the engine sure is.
Down here in Texas our wives sometimes leave their engine running while they shop.. just to keep from entering a 160* vehicle with their grocerys. Ford has built that ability in to our rides.
So leave well enough alone. If it keeps it's coolant it is good.
Big JIm

 

[sholzy]

my '93 4.0 with 130,000+ miles seems to be developing a overheating problem, but its intermitant. yesterday i pulled my 1,000 pound box trailer 25 miles, engine temp was a little higher than normal but not enough to worry much about. later i drove to work, was fine on the way there. when i got to work i waited for the shift ahead of me to leave from a meeting, i sat for about 20 min with the a/c on high, actually fell asleep. woke up and the temp guage was higher than when i pulled the trailer, not pegged out to the far right but over halfway of the needle sweep. i rolled down the windows, turned the climate controls to heat and ran the blower on high for 5 min until the temp guage dropped to normal. on the way home, it was fine, coolant level is normal, was last changed 3 years ago when i put in a thermostat. when iwas pulling the trailer i was only going 55 in 4rth, wasnt really working it hard, and it wasnt hot outside. im wondering if the fan clutch could be not working or if its something with the water pump. both are oringinal. if i get a new water pump is the "severe duty" worth it or just a extra 20 bucks? usually if i have something with a cooling system issue, its either working or running hot, not a intermittant issue.

My 93 has the exact same problem. Mine has always run on the cold side (between the N & O in NORMAL) summer or winter (in Ohio and Florida) until the mileage hit about 130k (3~4 yrs ago, now 197k). It didn't matter how hot outside or whether I was pulling something or not it stayed on the cool side of the gage. If everything in the cooling system was functioning properly I would have to agree with Jim. But on days when it should normally run on the cool side and instead it's running on the hot side (near the A in NORMAL) of the gage there is a problem (or the start of a problem) and I want to know what the cause is so I can correct it before it starts puking coolant and stranding me somewhere. Sorry Jim, Florida is just as hot as the Houston area of Texas where I am now so it's not the outside temps causing this, but it could be aggravating it.

3 months ago I've replaced a bad fan clutch and a cracked fan. 2 weeks ago I replaced the water pump, thermostat and flushed the system. The new 198* thermostat replaced a 192* I put in about 5 yrs ago so it's running MUCH hotter all the time now and has puked twice this week after shutting off the engine after a 10 mile drive to work in the morning in 80* temp. Both times I had to add 2 quarts of coolant. I stopped at NAPA on the way home tonight and got a 180* thermostat. I'll change it out tomorrow and see how much that helps, if any. I'm also doing a tranny filter/fluid change since it's waaaay past due (I'm thinking the tranny is working harder and adding more heat than normal to the cooling system).

There is a definite problem somewhere. If it's a bad head gasket or cracked head it's not showing any obvious signs of it -- no smoke out the exhaust, no milky oil, no bubbles in the radiator or extra pressure pushing past the radiator cap.

 

[Big Jim M]

My 93 has the exact same problem. Mine has always run on the cold side (between the N & O in NORMAL) summer or winter (in Ohio and Florida) until the mileage hit about 130k (3~4 yrs ago, now 197k). It didn't matter how hot outside or whether I was pulling something or not it stayed on the cool side of the gage. If everything in the cooling system was functioning properly I would have to agree with Jim. But on days when it should normally run on the cool side and instead it's running on the hot side (near the A in NORMAL) of the gage there is a problem (or the start of a problem) and I want to know what the cause is so I can correct it before it starts puking coolant and stranding me somewhere. Sorry Jim, Florida is just as hot as the Houston area of Texas where I am now so it's not the outside temps causing this, but it could be aggravating it.

3 months ago I've replaced a bad fan clutch and a cracked fan. 2 weeks ago I replaced the water pump, thermostat and flushed the system. The new 198* thermostat replaced a 192* I put in about 5 yrs ago so it's running MUCH hotter all the time now and has puked twice this week after shutting off the engine after a 10 mile drive to work in the morning in 80* temp. Both times I had to add 2 quarts of coolant. I stopped at NAPA on the way home tonight and got a 180* thermostat. I'll change it out tomorrow and see how much that helps, if any. I'm also doing a tranny filter/fluid change since it's waaaay past due (I'm thinking the tranny is working harder and adding more heat than normal to the cooling system).
I suspect the coolant system of not being filled properly after the new 198* thermostat was installed. These vehicles must have the heater turned to the hot position and be filled continually while the engine is warming and until it reaches temperature and the thermostat opens and pushes the final air out of the system. If the original fill was done with the heater off and only till the radiator APPEARED to be full, the result is the heads have air pockets in them which overheat and cause the coolant to boil when the engine is turned off.
As a side note there is never a reason to use a 180* thermostat in our engines.


There is a definite problem somewhere. If it's a bad head gasket or cracked head it's not showing any obvious signs of it -- no smoke out the exhaust, no milky oil, no bubbles in the radiator or extra pressure pushing past the radiator cap.

The air pockets in the head as stated above cause almost all headgasket and head cracks. VERY few are caused by other than that air.

Big JIm

 

[sholzy]

The air pockets in the head as stated above cause almost all headgasket and head cracks. VERY few are caused by other than that air.

Big JIm

It was filled properly. Until I can find a t-stat closer to 190*, the 180* will have to do. I just hope it won't allow the coolant to cycle through the radiator too fast and cause overheating problems that way.

I didn't intend to hijack this thread...

 

[sholzy]

... so it's running MUCH hotter all the time now and has puked twice this week after shutting off the engine after a 10 mile drive to work in the morning in 80* temp. Both times I had to add 2 quarts of coolant.

Changing out the t-stat yesterday I found the source of my coolant leak and a possible reason why it only puked sometimes, and, why it ran so much hotter all the time. When I replace my water pump 2 weeks ago, I missed putting a hose clamp back on on the upper hose at the water outlet tube side. The hose was slid back about 1/2" from the pressure but because the hose was up against the oil filler tube and several other things it could not come off completely. Since the system was no longer sealed and pressurized, the boiling point was lowered.

 

[sholzy]

... im wondering if the fan clutch could be not working or if its something with the water pump. both are oringinal. if i get a new water pump is the "severe duty" worth it or just a extra 20 bucks? usually if i have something with a cooling system issue, its either working or running hot, not a intermittant issue.

You can test the fan clutch with the engine OFF by spinning it by hand. With the engine cool, spin the fan by hand. If it rotates more than 5 turns, it's bad.

If your pump is not leaking or making a noise, then it is probably still good. My original pump had thick metal impeller blades, so blade wear was not a problem. The new (not rebuilt) pump from AutoZone is identical looking to the original one.

I would just flush out the system really good and and put in a new t-stat and coolant. As Jim pointed out earlier, make sure you refill it properly.

 

[AllanD]

my '93 4.0 with 130,000+ miles seems to be developing a overheating problem, but its intermitant. yesterday i pulled my 1,000 pound box trailer 25 miles, engine temp was a little higher than normal but not enough to worry much about. later i drove to work, was fine on the way there. when i got to work i waited for the shift ahead of me to leave from a meeting, i sat for about 20 min with the a/c on high, actually fell asleep. woke up and the temp guage was higher than when i pulled the trailer, not pegged out to the far right but over halfway of the needle sweep. i rolled down the windows, turned the climate controls to heat and ran the blower on high for 5 min until the temp guage dropped to normal. on the way home, it was fine, coolant level is normal, was last changed 3 years ago when i put in a thermostat. when iwas pulling the trailer i was only going 55 in 4rth, wasnt really working it hard, and it wasnt hot outside. im wondering if the fan clutch could be not working or if its something with the water pump. both are oringinal. if i get a new water pump is the "severe duty" worth it or just a extra 20 bucks? usually if i have something with a cooling system issue, its either working or running hot, not a intermittant issue.

Generally speaking "shady" mechanics will blame a water pump for overheating because they make more money replacing a water pump (labor & markup on the pump) than they would replacing the radiator and/or thermostat.

And before you replkace anything you need to confirm that the "problem"
isn't either "normal operation" or chimera... and artifact of imagination created by "mechanical paranoia" or an even simpler "instrumentation" problem.

Even something so simple as a dirty ground can cause erratic high readings.

AD

 

[racsan]

you know, since that day it hasnt done anything unusual, it just seemed strange to me that a guage that normally doesnt barly register, suddenly goes halfway and then later while idleing with the a/c on, goes 3/4 of the way. i guess gremlins are bound to pop up with a truck of this age, id like to add a mechanical guage sometime so i have some actual idea of how warm the engine is or isnt. the electrical guage is more of a comparasion to what youve seen it register before.