STILL OVERHEATING! - Diesel Forum

FastDEW · 10-30-1999, 01:56 PM

Usually if a water pump fails it just starts leaking because the bearings or bushing goes bad. I have heard of water pumps not flowing very good after they are old, although I have never seen one fail this way myself. As for the fan clutch, if it is working you will know it. When my fan clutch engages on a hill it is very loud and I can hear it even with the radio cranked or kids screaming. If you don't hear it wine, it aint coming on. There is a spring that senses tempurature on the front of the fan clutch. I do not know if it can be replaced. I have always just changed the entire unit. They usually cost $50 - $75. I don't know if it would be more expensive for the diesel, seems like a lot of things are.

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99 PSD E350 VAN 3.55LS Club Wagon Chateau with Factory Rear Seat/Bed and Aluminum Wheels. Isspro Pyrometer, Boost, Trans Temp and Tach gauges. "Drive it like you stole it!"

C. Parent · 10-31-1999, 12:14 AM

MY 91 7.3 VAN STILL CREEPS UP PAST 210 WHEN I'M GOING 60+ AND HIT ANY KIND OF HILL OR GO OVER 75 ON THE INTERSTATE. I REPLACED THE STOCK TEMP GAUGE WITH AN ISSPRO MECHANICAL AND HAD THE RADIATOR FLUSHED AND FLOW TESTED. THE THERMOSTAT SEEMS TO BE WORKING FINE AS I CAN WATCH THE GAUGE GO TO 200 THEN STOP AND DROP A BIT. MY FRIEND AT A RADIATOR SHOP SAID THE RADIATOR IS FLOWING FINE AND THE FAN CLUTCH IS COMING ON WHEN IT SHOULD BE. I'VE READ SOME OLD POSTS ABOUT FAN CLUTCHES NOT COMING ON AT HIGHWAY SPEEDS. I CAN'T TELL IF MINE IS TURNING ON WHEN IT STARTS TO CREEP PAST 210. IT SEEMS TO BE IN PERFECT CONDITION. IS THERE SOME SORT OF TEMP SENSOR SWITCH MOUNTED ON THE FAN CLUTCH THAT CAN BE REPLACED OR COULD THE WATER PUMP BE WORKING BUT ONLY AT 80%? ANY COMMENTS WOULD BE GREAT.

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Rich · 11-09-1999, 10:57 AM

I had that problem with my chevy van. I found the following. The water pump was not leaking but when I replaced it the blades on the pump wer just about gone, and the faster it turned it would creat an air bubble around it and not pull the anitifreeze through it.

Also I went through 3 bad thermostates out of the box. The best one I found that cycled correctly was one that has a high flow rate. when it opened more fluid flowed through it faster and then it shut faster allowing the radiator to cool the fluid before the next cycle.

FastDEW · 11-09-1999, 11:25 AM

Rich,

I find your water pump failure interesting. I have heard of this happening, but always by third or forth removed from the actual failure. First time I have heard of this by the actual person that had the failure. This gives me something new to look for in the future if I ever have an over heating issue that I can't seem to solve.

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99 PSD E350 VAN 3.55LS Club Wagon Chateau with Factory Rear Seat/Bed and Aluminum Wheels. Isspro Pyrometer, Boost, Trans Temp and Tach gauges. "Drive it like you stole it!"

bjornar · 11-10-1999, 02:50 AM

There is of course the issue about the thermostat; if it has even been changed, make sure the new one is a Motorcraft for the diesel. There are supposedly thermostats w/out a bypass and with a lower flow rate offered by 3rd party vendors. My Clifford manual warned about this, I also seem to remember that someone else with an earlier IDI actually experienced problems because of this!

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Bjørnar
Ålesund, Norway
1990 E-250 7.3l E4OD 3.54
2000 Excursion Limited on order
Moms Antiques: <A HREF="http://www.bgnett.no/~bjornar/hitra/hitraeng.htm" TARGET=_blank>http://www.bgnett.no/~bjornar/hitra/hitraeng.htm

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