Temperature

[Gcelevator]

Hey guys, I got a temp tag and was driving around the neighborhood and my temperature gage is rising to the 230 mark and then the hydraulic fan kicks in, drops To around 220 and so on. When I was around the block it never raised above 200, of course it was a couple of laps and not more than 20 MPH.
It is worth to mention that I was not able to shift into 4th gear, after about 30-40 MPH the truck starts jumping uncontrollable (left front tire) but that is another issue I have to take care of, I have to remove the run flats for a better or so quality ride.

Going back to the temp issue, my plan is to:
1 - grab a thermometer gun I have in my office and compare real temperature against the gauge
2 - if both are similar. I guess replace the thermostat for a lower temperature one.
3 - ask this forum if that temp is normal on these trucks (actually should have been 1st)
4 - try to enjoy as much as I can.

 

[Mogman]

Yes shoot it with a infrared temp gauge as the factory gauge is notoriously inacurate, BUT "uncontrollably" is a huge red flag, I would get that addressed first.

 

[Gcelevator]

Yes shoot it with a infrared temp gauge as the factory gauge is notoriously inacurate, BUT "uncontrollably" is a huge red flag, I would get that addressed first.

Yes, I am going to pull out the tire and also check the hub and spindle. I also see the tire wiggle a bit while on the way.
On the temperature issue, I hope is the gauge as I don't smell over heating or hear crackling on the engine or anything unusual other than the gage reading.

 

[Action]

Check the tierods, ball joints, idler and pitman arm, etc. I cant see the runflat causing the hmmwv to be uncontrollable. I drove 65 mph on the interstate with a flat tire. I could barely tell i had a flat.

 

[Gcelevator]

Check the tierods, ball joints, idler and pitman arm, etc. I cant see the runflat causing the hmmwv to be uncontrollable. I drove 65 mph on the interstate with a flat tire. I could barely tell i had a flat.

Will fo that next. Thanks.

 

[Coug]

Hey guys, I got a temp tag and was driving around the neighborhood and my temperature gage is rising to the 230 mark and then the hydraulic fan kicks in, drops To around 220 and so on. When I was around the block it never raised above 200, of course it was a couple of laps and not more than 20 MPH.
It is worth to mention that I was not able to shift into 4th gear, after about 30-40 MPH the truck starts jumping uncontrollable (left front tire) but that is another issue I have to take care of, I have to remove the run flats for a better or so quality ride.

Going back to the temp issue, my plan is to:
1 - grab a thermometer gun I have in my office and compare real temperature against the gauge
2 - if both are similar. I guess replace the thermostat for a lower temperature one.
3 - ask this forum if that temp is normal on these trucks (actually should have been 1st)
4 - try to enjoy as much as I can.

So to answer question #3 first, yes, that's within the normal range for these trucks.

There is no reason to replace the thermostat with a lower one. The fan kicks in and the temp drops, which means the thermostat is open by this point.

These have diesel engines that like to run warmer than most people are used to compared to gasoline engines.

The thermostat doesn't really have anything to do with when the fan kicks in/out either. For that you would be looking for a thermal switch.

Definitely use the laser thermometer to check the temps to make sure it isn't drastically off, but to me it sounds like the system is functioning pretty normally.
(mine the fan kicks in 220-225ish, then back off 30 seconds or so later)

Worry about the runflats after you take care of everything else, as they are the least of your worries. You're more likely to have flat spots in the tires from the truck sitting in one place for years with low pressure if you just got the truck, and no amount of balancing will fix that.

 

[Gcelevator]

So to answer question #3 first, yes, that's within the normal range for these trucks.

There is no reason to replace the thermostat with a lower one. The fan kicks in and the temp drops, which means the thermostat is open by this point.

These have diesel engines that like to run warmer than most people are used to compared to gasoline engines.

The thermostat doesn't really have anything to do with when the fan kicks in/out either. For that you would be looking for a thermal switch.

Definitely use the laser thermometer to check the temps to make sure it isn't drastically off, but to me it sounds like the system is functioning pretty normally.
(mine the fan kicks in 220-225ish, then back off 30 seconds or so later)

Worry about the runflats after you take care of everything else, as they are the least of your worries. You're more likely to have flat spots in the tires from the truck sitting in one place for years with low pressure if you just got the truck, and no amount of balancing will fix that.

Something that got my attention also is that the gauge does not have red or warning zone , so I figured the temp was about normal however not 100% sure hence my question.
I had to replace 1 tire that was new but flat in the front, probably this is the same issue.
If everything else checks out, I will move this one to the back just to make sure if the issue goes away.

 

[Bulldogger]

Don't forget to check the control arm ball joints too. I've seen some very bad ones (guy was in front of me at a trail ride, his control arm was visibly wonky going over obstacles). Loose control arm bearings let the arm waggle, which might explain your instability. The other advice is also worth pursuing.
Another item I didn't see mentioned is flat spots on tires or chunks of missing tread. If your HMMWV sat a long time or you haven't inspected the tires' surfaces, also worth looking at.
BDGR

 

[Mainsail]

... after about 30-40 MPH the truck starts jumping uncontrollable (left front tire)

Silly question I know, but the transfer case lever is in H (not H/L) right?

 

[Gcelevator]

Yes, the TC is in H. The wiggle is coming from the front left tire. Starts jumping at about 25-30 mph and wiggling after that.

 

[papakb]

Are you running bias ply or radial tires? Bias ply's will take a set after sitting for extended parioed.

 

[Mogman]

25-30 sounds pretty slow for such a large issue to be caused only by a flat spot on a tire.
Move the tire to the rear, same side and see if the problem moves with the tire.

 

[Gcelevator]

Are you running bias ply or radial tires? Bias ply's will take a set after sitting for extended parioed.

I am running Radials.

 

[Gcelevator]

25-30 sounds pretty slow for such a large issue to be caused only by a flat spot on a tire.
Move the tire to the rear, same side and see if the problem moves with the tire.

I will try a couple of other tires I have on the trailer. Will try to figure out the issue and report back.

 

[Gcelevator]

Well guys i am happy to report that no parts are damaged. Out of 8 tires i have only 2 are new and the other 2 are decent (not perfect). 1 blown and 3 with flat spots. So i am in the market for new tires, if anyone can point me in the right direction of a not so pricy supplier.. I have been chasing the auctions but thought it wouldn't be needed, know i know i need them as i also want to make a camper out of my military trailer.

In regards to the temp, i used an infrared thermometer and the highest temp any place in the engine is 200 degrees while other spots such as hoses, reservoir tank, and radiator was about 191 degrees.

Thanks all who chimed in.

 

[Gcelevator]

One thing i noticed though, my left upper rubber boot for the half shaft is cracked. I guess i have to replace sooner than later. I have read on this forum that the way to go is replacing the whole assembly in lieu of replacing just the boot. Also, if i were to replace the half shaft how do i know which one to buy. I guess my truck will take the 12k for the armored truck?

 

[Mogman]

One thing i noticed though, my left upper rubber boot for the half shaft is cracked. I guess i have to replace sooner than later. I have read on this forum that the way to go is replacing the whole assembly in lieu of replacing just the boot. Also, if i were to replace the half shaft how do i know which one to buy. I guess my truck will take the 12k for the armored truck?

Well one way is to look at your GVWR on the data plate, should give you clue as to which half shafts you need, over 10.3K?
If it is leaking it is not a sooner or later deal, it is a right now deal.

 

[Gcelevator]

Well one way is to look at your GVWR on the data plate, should give you clue as to which half shafts you need, over 10.3K?
If it is leaking it is not a sooner or later deal, it is a right now deal.

Yeah, meant sooner than later.

 

[Gcelevator]

Well one way is to look at your GVWR on the data plate, should give you clue as to which half shafts you need, over 10.3K?
If it is leaking it is not a sooner or later deal, it is a right now deal.

Any recomendation of a good seller/part? There are tons of options ranging from very cheap to expensive. I wouldn't like to buy a part that is going to leave me stranded.

 

[williamh]

I will try a couple of other tires I have on the trailer. Will try to figure out the issue and report back.

I got mine and the tires with the run flats shook so badly , I thought I owed it money. got some tires from csm tires , very happy with the quality.