getting hot

[adamk85]

2000 wagon 6.5 turbo diesel. Just installed aluminum radiator and made new
fan shroud with 14in fan and 12 in electric fans and fan controller. has new
thermostats in about 8k miles ago. it is getting up to 230 deg F after about
10-15 miles. it is about 95 deg outside right now. It can sit and idle and not
get above 180. also when idling after awhile it will hiccup and blow some black
smoke a couple of times. 2 times now on startup it has tried to rev really high
without touching throttle before i shut the key off. stumped?????

[ssgharkness020147]

First of all ditch the thermostats for new ones. They can fail at anytime regardless of mileage. Everyone I have ever heard of that replaced their OEM fan for electrics ran two fans, not one. Call Lynch I know they used to sell a kit, you may want to see if they still have a few laying around. The pushers should help, but not every truck does well with them, in fact some trucks run hotter with the pushers. Fix the temp issue before addressing the surging issue, HUMMER did have a re-flash for the PCM a while back, but your Y2K truck should have had it from the factory.

[adamk85]

I have 2 fans, one is 14in 1250 cfm and the other is 12in 800 cfm, I have 2 pcm's
one is factory and the other is one from predator, swapped pcm back to stock
and still does it. the fans are in an aluminum shroud bolted directly to the engine
side of radiator. It can idle all day and never get above 180. I am wondering if
they had any trouble with the water pumps. the engine was replaed in 2004. has
approx 50k on it.

[audiofetish]

Aluminum radiators do not help that much on H1s. There have been lots of discussions on this at humvee.net. Did you modify your existing shroud at all? I would not suggest any kind of a shroud that would limit air flow. Most electric fans that H1 owners do add have no shroud and do not restrict airflow when not in use. Personally, I would ditch the add on fans. As ssgharkness suggested check the t-stats. Make sure to get nice ones. Do not get cheap $3.00 ones from Napa. Those crap out like no other. AC Delco is the way to go. Have you checked your fan clutch? Those also fail quite a bit. When the motor is up around 230 or so, turn off the motor and see if you can turn the fan by hand. If you can it is bad. Lastly, are you going by the temp gauge on the dash or by a scan gauge or something similar? The gauges on the dash are almost always wrong. Mine latest H1 is off by about 10 to 15. Hope this helps...

[HUMTECH]

Check for air flow restrictions between rad, oil cooler and trans cooler. Common to get plugged up with road debris, leaves, etc.

[adamk85]

well i figured I would update a little bit, got it to stay somewhat cool, put some water wetter in coolant and made swiss cheese out of fan shroud with hole saw to let some air through at cruising speeds. staying around 210-215. I think that is good, also found out that if you watch a scanner and monitor temp its about 15-20 degs lower than the gauge.