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1998 TD: Sometimes the engine heats up going up the mountains

shazmo

Member
Messages
7
Location
Los Angeles
hello,

I have a 98TD. I have no heating issues at any speed, driving around town. Sometimes
when I go uphill in the mountains, the temp starts going into the 220 range. Usually it
hangs around 192-198 range.

Are there any tricks to managing temperature when going uphill?

I make sure my A/C is off.
I go up hill in low gear.

Someone mentioned I need to turn the heater on so the fan kicks in?

thanks
 

3Hummers

Super Moderator
Staff member
Messages
10,398
Location
Central Texas
I drive by the temp Gauge. Sometimes I might be doing 35-40 mph up long inclines. I assume you have flushed the radiator, good thermostat, fan is working and blades are all good.
 

shazmo

Member
Messages
7
Location
Los Angeles
I drive by the temp Gauge.....
By this you mean that you keep your eye on the temp gauge and what ever speed makes the temps
go into the normal range, that's gonna be your speed. Is that a correct interpretation?

..... I assume you have flushed the radiator, good thermostat, fan is working and blades are all good.
I have not flushed the radiator, since color is nice and green of the coolant. Thermostat, I am not sure about. Fan blades, well I have a fan
and it has its wings and none are missing ...
If thermostat was bad, the truck would be misbehaving at freeway speeds also, won't it? But my truck drives cool and I only see the heating
up once in a while and only on uphill climbs.
 

3Hummers

Super Moderator
Staff member
Messages
10,398
Location
Central Texas
Yep. Also Mike S at Tustin GMC is the best Hummer mechanic around. If your issue gets worse you might let him take a look at it. Sounds like your truck is completely normal.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
What 3Hummers said isn't unique to H1s. Lots of big vehicles drive by the temp gauge; I've done it in a Uhaul heading up the Grapevine in SoCal. But I've heard that from multiple H1 owners as well. Good thing is that you don't spend most of your time climbing mountain ranges on the highway.
 

Enter Hummer

Well-Known Member
Messages
244
Location
Southwest
Just dont go uphill.

Haha, no really even little cars get a little warmer doing something out of the ordinary like going up a hill. Its just the nature of the beast, but much more noticable in a really heavy truck like yours.

Too you're in a hot place. I dont know the elevation of hills that your doing but here in colorado most of the hills around me are over 10,000 high. The temperature is never over 60 even in summer. That dosn't eliminate heat issues either but it does help.
 
Last edited:

GreatDaneHummer

Well-Known Member
Messages
994
Location
Chicago
Thinking outside the box here, you could upgrade your cooling system with a Gryphon Radiator, Trans cooler etc and even add E-Fans but in the end you may have spent a good $2k and only returned 10% better cooling. As Enter Hummer said your area is also pretty hot in the summer.
 

Kurt

Well-Known Member
Messages
955
Location
Orange County, CA
By this you mean that you keep your eye on the temp gauge and what ever speed makes the temps
go into the normal range, that's gonna be your speed. Is that a correct interpretation?


I have not flushed the radiator, since color is nice and green of the coolant. Thermostat, I am not sure about. Fan blades, well I have a fan
and it has its wings and none are missing ...
If thermostat was bad, the truck would be misbehaving at freeway speeds also, won't it? But my truck drives cool and I only see the heating
up once in a while and only on uphill climbs.

Completely normal.

I just had a new engine and all new cooling system [radiator, trans/oil cooler, condenser, fan clutch, etc] installed and it didn't make that big a difference on steep grades at highway speeds. [All new components I did notice that I returned to normal cooling levels quicker after a climb, but other than that its still 55mph on certain climbs and if its a really steep climb, down to 45mph in D].

I'm planning to add an intercooler sometime in the next year and will see if that makes some improvement or not.

Cooling is a big issue on these trucks and as David said, drive to the temperature gauge, not the speedometer.

For the LA area:

-It's 55 mph for me up the I-15 in some spots. A/C off on Cajon pass, A/C can be on on some stretches of I-15 to Vegas depending on how hot it is outside.
-55 mph for the grapevine, I can do that 55mph with AC on and it doesn't get out of 220 [max I'm willing to go].
-45 mph in the steep hills in Death Valley in the eastern part of the park, and along Tioga pass from Monolake to Yosemite. That climb was a hoot, It was me and a old VW microbus going neck and neck up that pass :giggle:
 

shazmo

Member
Messages
7
Location
Los Angeles
Completely normal.

For the LA area:

-It's 55 mph for me up the I-15 in some spots. A/C off on Cajon pass, A/C can be on on some stretches of I-15 to Vegas depending on how hot it is outside.
-55 mph for the grapevine, I can do that 55mph with AC on and it doesn't get out of 220 [max I'm willing to go].
-45 mph in the steep hills in Death Valley in the eastern part of the park, and along Tioga pass from Monolake to Yosemite. That climb was a hoot, It was me and a old VW microbus going neck and neck up that pass :giggle:


Thanks Kurt. How about the speeds for going up to Big Bear?

thanks
 

Kurt

Well-Known Member
Messages
955
Location
Orange County, CA
Thanks Kurt. How about the speeds for going up to Big Bear?

thanks

Big bear I 'm fine at 55-60 in some sorts with HVAC on no problem, depending on road conditions... there's spots you really can't go much faster than that safely with two lanes in parts and switchback turns.
 

LagunaH1

Well-Known Member
Messages
3,703
Location
Lake Forest, CA
Sounds pretty normal... although.... 220 is in my opinion too high. I always stuck to no more than 200, maybe 205 in extremely rare situations.

Question: When you run hot like that, do you hear the fan? If not, then the fan clutch might be worth a second look
 

shaunkite

Active Member
Messages
28
Location
Las Vegas
Sounds pretty normal... although.... 220 is in my opinion too high. I always stuck to no more than 200, maybe 205 in extremely rare situations.

Question: When you run hot like that, do you hear the fan? If not, then the fan clutch might be worth a second look

The truck rarely goes over 195. It has gotten over 210 once going up a pretty steep and long incline, but dropped back below 200 the second I made it over the crest. I would be very uncomfortable at 220.
 

Green 1

Matty Patty Pookie Bear
Messages
1,149
Location
Ferris,Texas
I agree with the others. I had a dual electric cooling fans on my 95 but took them off. I could tell no difference from stock. Just watch the gauge it is the only way to drive these trucks in extreme conditions.
 
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