water temp.. how much is too much and how much is normal?

[hesutton]

I've got a 7.3 head laying on the shop floor next the DT466. I'll have a good look at it and see if I can snap a photo or two and post up the differences. I have some good shots of the 6.9 heads after they got back from the machine shop.

Come to think of it........ I have a lot of photos I need to post of the crew cab project.

Heath.

 

[nyteshades]

I just climbed the rockies with my 94 250 with a 2300lb cab over camper + or - 500lb to 800lb of ppl and gear, and went over a few passes as high if not higher than 10,000ft elevation and I've been struggling with my wafer temp, I saw 250 at the highest, I never ever let it get this high, it scares the crap outa me , but on the long up hill pulls the wafer temp gets very high. Usually I've been seeing 220 to 240 on the long pulls, I jusf baby it in 2nd or 3rd. how high is way to high and what causes damage( I did a search, just couldn't find a straight answer)? I have not boiled over this frip. I know my fan clutch is good and I'm shure that my rad is not clogged because af idling, 190*f, I put my hand behind the fan and it feels Very hot, so there is heat exchange. My theory is that my t-stat isn't opening far enough to let enough coolant through on the long pulls, which could explain the overheating

For the serpentine belt type it isn't to bad of a job right? Easy enough to do in a parking lot? I've done some digging with fhe search and found that tstats arnt to expensive and that stant makes one now that is comparable to oe?




What do you guys think? Thanks

Don't forget it's been hot up there. At altitude the air is thinner. So between the warm ambient air and the thin air...you're working that motor. You could have a massive 20 row radiator...and you'd still run warm. In addition, you're also trying to cool the trans fluid in the same location. That's a lot of heat to disperse.

How hot was it coming down the mountain? I'm assuming that since you are in Boulder you came over Trail Ridge. So that would also add to your heat build up seeing as your not pushing as much air over the rad due to the slow nature of that road.

 

[1994Diesel]

It runs pretfy damn cool now, hottest I ever saw was 215. It seems like I dove up hill all day today with a miserable head wind going from colorado to arizona . I averaged 950egts, but never got it close to 1200. I was also in 3rd gear for what seems like half of the drive. The cabover is not aeodynamic!!! .

But for how windy, hilly, and hot it was today I was very impessed with the water temps.

Thanks again for all the input and advice!

 

[Agnem]

Nice thing about this issue, is that if you do open up the 7.3 head coolant passages, then all you need is both the 7.3 and 6.9 head gasket. The coolant passages for the 6.9 are actually rubber inserts in the gasket. All that will be needed to do is to cut out the 7.3 gasket, using the 6.9 gasket as a template, and just drop the rubber inserts into place.

 

[1994Diesel]

It been a while since the over heating fiasco and the truck is still running great.

I have a dirty little secret though.... Im running a Stant T-stat.

But to be honest with you guys i was in a pinch so i had to use it.

It performed perfectly while towing through the 112 degree desert heat. I dont see anything wrong with running it. IT WORKS GREAT.

Only time will tell though, that T-stat may fail on me tomorrow. But i think i may be one of the lucky ones that got a good one.

 

[icanfixall]

Well I'm glad you got the overheating issues worked out... A well running rig sure makes cross country drives a pleasure doesn't it.... Guys, I think this is the rig I went up into our local mountains to help with an overheating issue... Turns out the fan clutch was shot. The front of it was leaking the material out and had completely covered the thermostatic spring. So I installed a spare MS Tech clutch I had. Rig ran great on the homeward trip. Now finding out the radiator was finally giving up on another road trip makes me feel kinda bad. I did look into the radiator for any plugged tubes but didn't see any.... About that "dirty little secret"... I feel the thermostat should be changed for the real thing. As posted many times here... Other stats will fit but. They just can't flow enough coolant to maintain a cool engine.

 

[1994Diesel]

Well I'm glad you got the overheating issues worked out... A well running rig sure makes cross country drives a pleasure doesn't it.... Guys, I think this is the rig I went up into our local mountains to help with an overheating issue... Turns out the fan clutch was shot. The front of it was leaking the material out and had completely covered the thermostatic spring. So I installed a spare MS Tech clutch I had. Rig ran great on the homeward trip. Now finding out the radiator was finally giving up on another road trip makes me feel kinda bad. I did look into the radiator for any plugged tubes but didn't see any.... About that "dirty little secret"... I feel the thermostat should be changed for the real thing. As posted many times here... Other stats will fit but. They just can't flow enough coolant to maintain a cool engine.

Thanks gary

I know i should be looking into getting a motorcraft T-stat in there.

I compared the "stock" T-stat to the Stant and it appeared that the Stant T-stat has better flow capabilities.

I took a picture to compare i will post it later.

 

[1994Diesel]

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The Stant is the one with four openings.

BTW i did take the rubber o ring off of the Stant T-stat.

 

[1994Diesel]

What do ya'll think?

 

[icanfixall]

My feelings are the factory will flow better than any other thermostat. They have another seldom talked about design... That copper pellet under them blocks off the bypass in the block when the thermostat is open. I'm not thinking the stant can do that....

 

[Black dawg]

the problem with the stant stat is that it is taller and cannot open as far as the oem because it hits the block. in my "testing", neither one flows enough to keep my truck cool. also that style t stat is not exclusive to our engines, they are just a basic "high flow" stat.

 

[typ4]

I want the stant number, I cannot keep my truckcool whhen loaded even with the fan clutch modded. I think my bypass hole is not being closed by the factory stat and is recirculating too much hot bypass coolant through the system.
If the water flows too fast through the system it cannot carry away the heat, bigger is not always better.
\

I like the head gasket idea, wish it would have come up when the engine was down

 

[Black dawg]

I have run both stats, and the oem does cool better. It cools much better with the bypass blocked. the best setup for highway towing with mine has been no stat and the bypass blocked. on flat ground at 18k total temp wont go over 190. on the big hill run to the wood for many miles temp wont go over 230.