Hi guys, let me pick your brain. I had a re-man water pump installed to replace my stock one. The water pump comes from our napa dealer and they sell good quality stuff. I get the truck back and take it for a drive. My truck allways ran below the word normal on the gage with no load on the truck(empty). If I were to giver down a road etc and stop at a light the gage would rise abit but drop back down to just below the word normal super quik. Now with the new re-man pump my truck runs hot well into the word normal, hanging around the O and when I boot it abit she climbs even higher then I have ever seen it do before. Even at idle it wont cool down below the word normal like it did before I changed the pump. I don't like what I am seeing. I figure the pump is a dud or the factory one was a high output and the re-man is not. I have not changed the thermostat as it worked fine the day before I had the pump changed. If the mechanic put the thermostat in upside down would that cause it to run hotter now? This one has me scratching my head as it ran cooler before the pump change and now it runs so much hotter. It's not the rad as it was checked out by a rad shop and it is fine. Any suggestions will be appreciated. Thanks.....

Ed

 

I replaced my waterpump a couple months ago and I didn't see the difference in temp's as you are seeing. Not sure about the stock pump being a high output or not but that could be the difference. I would say as long as the gauge doesn't read into the red, then you should be fine. As many other people on this site have said, the stock temp gauge is pretty much useless. That will be my 1st mod when I get the money. Keep us posted if you figure anything else out. There's lot's of experts on this site and someone will have some good idea why this happens.

 

This is Ed again. It cant be the gauge as it worked fine on a monday and was dufferent on a tuesday. Only thing that changed was the water pump. My guts tell me its the pump.

 

Is the fan clutch engaging? My truck was running hotter then normal and I tried all sorts of things to fix it. I finally replaced the clutch and it was back to normal. I know, it shouldn't have anything to do with replacing the water pump, but they still have to remove it to get to the pump. I'd find it hard to believe that there would be much difference between water pumps for the 7.3???

 

Is this a shop that specializes in diesels?

Gee, you don't suppose they put somebody else's clutch back on your truck, do you?

One of their employees doesn't have a 7.3, does he?

Just a thought.....

Pop

 

I can tell you its a general mechanics shop. The mechanic is a friend of mine and he does not drive a psd diesel truck. The clutch fan is blowing lots of air back into the engine as well. I dont think its the sending unit but they would have had to swap it to the replacement part. Anyway keep your ideas coming and I will keep watching for them. Once I figure it out I will post the answer. Thanks for the replys...


Ed

 

The only thing I can think of, is maybe it didn't get bled enough. Fords can be a pain in the rear to get bled. Try bleeding the system.

 

Hey nodakford, thanks but are you talking the same thing as vapor lock and if so whats the best way to bleed the coolant sytem. I had it down the highway for a half hour going through different speeds. Low and high. Let me know how to bleed a system and I will try it. Thanks.

Ed

 

I don't mean to keep harp'n on the subject of the fan clutch. The truck I replaced it on was a 93 F-250 gasser, so it had a fair amount of miles/time on it. The big tell tale sign that it was the culprit (besides lower temps) was the first time I drove it after replacing it. It'll make a loud turbo-prop noise when accelerating or if there's a load on the engine if it's working properly. My PSD clutch will kick in on a hot day just cruise'n down the highway. It's very noticeable! So if you hear it on occasion, then I'd say it's o.k. Before I replaced it, I had tried just about everything to get the temp back to normal, thermostat, radiator flush, tune-up, etc.

 

ok here one possible cause. i am a mechanic and use napa parts all the time. i did the water pump on my truck (a 95 PSD) and napa's listing for the pumps was incorrect. 94 and 95 maybe 96 use a long (or short, i can't remember which one is which) stem thermostat which is a 203 degree stat which if you read much on here the superduty guys are installing a 203 stat for a performance upgrade (but sorry the 203 from napa and the 203 from the diesel site are NOT the same!!!!) so any way i got the water pump and it wasn't the right one but it was the only one they listed new so i got a reman (ok so i can't remember if the right was the new or the reman but they were listed differently) one of them was the right one!

so moral of the story take it back to them and compare the old one with the new one. you have to take the thermostat housing off to see the difference. you may have the water pump with the 203 stat in it. in which case i would leave it as long as it really is not over heating.

hope that help as confusing as it was. i wish i could remember which was which. by the way i didn't use either because for another $50 the carquest store had a lifetime warrantee pump. (no brainer!)

 

One question Ed, when you have the heat on, and revving the motor, does hotter air come out, is so then it still needs to be bled. If not the more then likely it is bled. This is how I got my 2000 to bleed. Started the truck, crawled underneath, and squeezed the large hose to waterpump a couple time, kinda like priming the pump, then I ran it at 1500 to 2000 rpm till I got hot air out of the vents. Sounds goofy, but it worked for my F-150 also. tjbeggs could be right on wrong part from NAPA. I got a co-worker who used to work the parts counter at NAPA and some of their parts listings were incorrect. Carquest has been really good for correct parts.

 

This is why I love this site. Ok, I get only one listing for water pumps at napa. They only make one style for 1997 psd's. This is right from their parts book. I assume I recived the proper pump as it bolted right up and looks identical to the old one. Not sure about the thermostat area but the stock extention pipe bolted right up to it. I am getting good heat out of the vents, typical ford sweat you out of the truck heat. As far as the clutch fan, I do get the roar sound when its hot out or when Im towing. I have not towed anything since the pump change. I belive the clutch fan is working. I stopped in at napa today, they tell me it is probably not the pump, just the gauge, I keep saying how can the gauge work on a tuesday like nomal with no hint of it starting to go and now read way hotter on wednesday with the only difference is the water pump has been changed. Napa did tell me to use a external temp gauge to see how hot the antifreeze is at running temps. I will do that and then go to my buddy who has a fleet of psd's, two are 97's like mine. I will gauge their trucks and compare. If the two seperate trucks run the same temps I will give in to the idea of the gauge or sending unit went crazy on me. I tell you, this water pump mystery is making me want to have a rum or two. Thank you, Thank you guys for your ideas. I will keep trying your suggestions until I figure out WHAT THE HECK is going on. In the back of my mind a voice is telling me if I put the ford one back on my gauge will work where it allways did. I love how a simple water pump change at a repair shop can snowball into a trouble shooting journey. Chow for now.

Ed

 

ed the two water pumps i was talking about will bolt right up and the housing will fit perfect also but the thermostat housing is the key. if you can have them show you a new and the reman pump that fits your truck and see if the thermostat housing in the pump is the same. i agree that unless the shop did something wrong with the tmep sensor then you have an issue here. typically air in the system will cause over heating. did the shop use a vacum filler to refill the cooling system. That is really the only way to properly fill the system. it is very difficult to just pour the coolant in and hope it bleeds out.