02 Eng cooling sys questions

[Hooper]

My 02 7.3L seems to be doing a couple weird things. Over Memorial Day weekend, we made as trip up north on the 5 and when we came back south over the Grapevine my coolant temp gauge went up just a hair short of the red and the fan clutch didn't appear to kick in. I changed the fan clutch and added gauges (ISSPRO) including engine coolant temp. Then took it for a test drive pulling my 8K toy box. Now the fan clutch engages but not until the engine temp is about 235 on my new gauge but at this point the stock gauge is back up to HOT and the check gauges light is on.
Have you guys seen these fan clutches engauge what seems alittle late and this stock gauge register HOT like this. By the way I ordered a replacent Temp sender for the gauge. Any thoughts, I don't want this to spoil our vacation at Convict Lake next week.

 

[JLDickmon]

what was/is the ambient temp?

 

[Hooper]

My onboard outside temp read 106, pretty warm.

 

[JLDickmon]

106!!!
man, that's just plum HOT.

I'd say you've done about all that can be done, aside from running beside it with a garden hose and spraying the radiator..

You are easily running 235 degrees in the engine.. but 250 - 260 is the limit.
260 is the ABSOLUTE limit, and only for a brief moment..

 

[BIG JOE]

My 02 7.3L seems to be doing a couple weird things. Over Memorial Day weekend, we made as trip up north on the 5 and when we came back south over the Grapevine my coolant temp gauge went up just a hair short of the red and the fan clutch didn't appear to kick in. I changed the fan clutch and added gauges (ISSPRO) including engine coolant temp. Then took it for a test drive pulling my 8K toy box. Now the fan clutch engages but not until the engine temp is about 235 on my new gauge but at this point the stock gauge is back up to HOT and the check gauges light is on.
Have you guys seen these fan clutches engauge what seems alittle late and this stock gauge register HOT like this. By the way I ordered a replacent Temp sender for the gauge. Any thoughts, I don't want this to spoil our vacation at Convict Lake next week.

My onboard outside temp read 106, pretty warm.

Seems you've dun what needed to be Mechanically dun.. BUT.. It might also be a Real Good idea to Brush and Back=flush your A/C condenser, and Radiator.. to get rid of (if you haven't dun it before) 10 years of California BUGS & CRAP.. to restore better Air Flow.

I live up here in the San Joaquin valley, and do that deed.. at least.. once a year. (guna be 103 today, 108 Monday)

Makes a subtle, but noticeable difference.

Joe

 

[Hooper]

Well, on the way out of Bishop, going up the Sherwin grade with Toybox in tow, we hit 250 and blew abouit 1 1/2 qts. of coolant out the radiator cap or in this case the coolant recovery tank. Didn't appear to do any other damage.
Made it home (closely watching gauges). I hate these types of things where you just can't find what's wrong. But,,, now I have a new radiator. I'll run a test tomorrow and see what happens going back up Lamb Canyon. I also did a "block test" looking for compression gases in the cooling system and didn't
find anything.

 

[DaveBen]

Is your water pump good? Any water coming out of the holes around the pump shaft?

Dave

 

[dpantazis]

do you also have a tans temp gauge too? what was it doing?

the engine cooling system crosses over to cool the engine oil AND the trans fluid too:
- the oil cooler is part of the oil filter head
- the trans line out of the tranny goes into the bottom of the radiator. there was a change of some kind i think in 99.5 or 200o on this. you might not have it.
- consider switching the 7.3 with the 6.0 trans cooler to improve trans fluid cooling.

have you ever changed the thermostat on the truck?

 

[Hooper]

Dave, I checked for fluid leaks and nothing so far except the loss from the coolant recovery tank I mentioned.

Dpantazis, yes I do have a trans temp gauge and it seems to be registering an appropriate lower temp than the coolant even while towing. And yes I did replace the thermostat. The stat came from NAPA and has the Navistar part number stamped in it, so I'm sure it's correct and seems to be working properly.

Going for my test run later when it warms up abit. I'll keep you posted.

 

[iracemine]

wow! how fast are you pulling this trailer down the road?