Possible cooling issue and/or water pump problem?

[tremmert]

Driving a 1987 M998 w/ 6.2 with stock gauges.

During the summer, the vehicle always seems to run hot (100 deg outside) and my temp gauge will flirt with 220deg. During the winter, the gauge seems to stay at about 200-210 max.

Today I decided to do a coolant flush, but I dont think the coolant is completely being pumped throughout the system. I drained 100% via the valve under the vehicle, then began refilling via the coolant reservoir on passenger side. With the vehicle off, I filled to the "Cold Full" line. I used a water hose (because I am trying to flush the system) so I am not exactly sure how much entered the system. I then started the vehicle and allowed it to reach temperature, and expected it to suck the reservoir dry, but it didnt. Took the vehicle for a spin, and 220-230deg today.

I waited for the vehicle to cool down, then opened the reservoir cap, and water is still at the full line. I squeezed the upper radiator hose, and it should like it just has air in it, no fluid. Same with the lower hose. I expected to see water return to the reservoir when squeezed, but it did not.


Any thoughts if this is normal or not?

 

[Thecaptain]

I had something like this happen to me when I exchanged my coolant. You could have an air pocket in the system or could be a failed thermostat. When it gets up to temp, feel the upper and lower hoses - if they’re not equally hot - that can indicate your thermostat may not be doing it’s job. You may also want to investigate a new radiator cap if you haven’t replaced it.

My issue was fixed when I swapped out the newly replaced thermostat.

 

[gstirling]

one easy check is to just remove the thermostat and see where it runs.

 

[lowell66dart]

Go buy a cheap temp gun at a tool place then do some checking. When shooting the radiator hoses there should be a difference which indicates that the radiator is doing it's job. I am in Louisiana and it's hot too. I am running a 160 degree thermostat which a lot of folks will tell you is too cool. My truck runs at 185. I found this at Rock Auto for all of $5. You will need to buy or make a gasket.

 

[Sintorion]

I have never understood the value of a fail-safe thermostat. The only thing they seem to be good for is letting you know that you overheated and then you have to pull the t-stat out to unlock it. All of my t-stat failures have been from it not opening and the fail-safe contration is no value if it doesn't open.

 

[911joeblow]

Make sure you run your heater when you are refilling your system as that can hold a lot of air and you will not get a good flush with the heater valve closed either. I do not recommend running a thermostat less than 190deg as these diesels need to run around 190-210 to get proper burn. Make sure the fitting and hose on the top center of the crossover that runs to the overflow tank is not clogged by blowing compressed air in it.

Lastly is our selfless plug for our Cooling System Upgrade Kit which will balance the temps across the block and self bleed air out of the system. These trucks aerate the coolant due to pump cavitation and these really help with that too.

Here is a link to our blog that goes over all of this in detail: https://paradoxbydesign.com/blogs/news/the-humvee-diesel-engine-cooling-paradox

Here is a link to the kit for your truck: https://paradoxbydesign.com/collect...oducts/hmmwv-humvee-cooling-upgrade-system-v3

 

[ken]

The 3/8 hose mounted at the thermostat going to the overflow tank will bleed the air from the block. As long as it is not plugged up. When you added water the air should have been forced out. So long as you didn't over fill the tank and block off that hose with water. There could be a air pocket at the back of the block. The drive your took should have purged it if it was there. As joe stated make sure the heater valve is open also. I do disagree with Joe on one point. If you change the thermostat I would recommend a 180. When the 6.2 was introduced they came with 180's. This was the norm for diesels back then. As the EPA got involved they were increased to meet emissions. Even if the burn was better at 195. It's no where near as important as not cracking the block or blowing a head gasket. I'd rather get a little worse fuel mileage than have to change the engine. The coolant can indeed boil at the back of the block. But if you reduce the coolant temp below the boiling point the problem is solved.

 

[tremmert]

Thanks for all the good feedback! So I took the vehicle for a spin today (about 30 miles)... Once I returned, I grabbed my infrared temperature gun, but go figure, it was broken. By feeling the upper and lower radiator hose, I noticed that the upper is MUCH hotter than the lower. I assume this is a good sign, or a sign that fluid is not flowing?

Next, when I filled the system, I did have the heater core valve open. And lastly, the coolant level is not too high where it would block the other lines. I guess I need to open her up and replace that t-stat.

Thanks!

 

[Thecaptain]

That’s a sign the fluid isn’t flowing. With thermostat open, both should be pretty hot at that point.

 

[lowell66dart]

If you ran it for 30 minutes in this heat without overheating nothing is stuck closed. You WILL have a difference in temps on the hoses. Sounds like your radiator is working. The coolant level should be above any openings so it sucks coolant when needed and not air. It would probably be a good idea to replace your cap if you haven't done so.

 

[cwajciec]

That’s a sign the fluid isn’t flowing. With thermostat open, both should be pretty hot at that point.

Plugged radiator would have this symptom. I once had the same on my Jeep and I backflushed the radiator with a garden hose. All manner of brown junk came out and solved the problem. I stuck the garden hose with a rag to seal it on the bottom hose connection to fill the radiator. Then I turned the radiator upside down to flush everything out of the top hose connection.

 

[Sintorion]

Make sure you run your heater when you are refilling your system as that can hold a lot of air and you will not get a good flush with the heater valve closed either. I do not recommend running a thermostat less than 190deg as these diesels need to run around 190-210 to get proper burn. Make sure the fitting and hose on the top center of the crossover that runs to the overflow tank is not clogged by blowing compressed air in it.

Lastly is our selfless plug for our Cooling System Upgrade Kit which will balance the temps across the block and self bleed air out of the system. These trucks aerate the coolant due to pump cavitation and these really help with that too.

Here is a link to our blog that goes over all of this in detail: https://paradoxbydesign.com/blogs/news/the-humvee-diesel-engine-cooling-paradox

Here is a link to the kit for your truck: https://paradoxbydesign.com/collect...oducts/hmmwv-humvee-cooling-upgrade-system-v3

Still more claims and zero proof. Are you ever going to test your products so you can actually support the claims that you are making?

 

[911joeblow]

Still more claims and zero proof. Are you ever going to test your products so you can actually support the claims that you are making?

We have been over this with you time and time again. The kits are fully tested and proven and are in mass use now in hundreds of trucks around the world. There is no proving this to you at any cost and that is fine by us. Good luck as always Sintorion.

 

[Sintorion]

We have been over this with you time and time again. The kits are fully tested and proven and are in mass use now in hundreds of trucks around the world. There is no proving this to you at any cost and that is fine by us. Good luck as always Sintorion.

Haaa, so you still have not done any testing as promised, yet you continue to keep up with your claims. The fact that your product doesn't cause additional problems does not mean that it is actually doing anything. Maybe you can design a kit that runs a section of hose from the front of the fuel tank to the rear and claim that you get better mileage? I mean it won't hurt your mileage so why not just put it on.

 

[911joeblow]

Sintorion,

We spent months developing, testing, tuning, adjusting and then even after production started, continued to upgrade these kits. The only thing we have not done is spend time on a dynomometer which we would like to do when it works logistically to do so. You just dont like that we have stated the results without 'laboratory' testing, which I have said time and time again is just not in the budget for such a low production product. That does not mean we have not tested, we used multi-channel analog to digital data acquisition to get live data and from that data developed our solution over many months. But this has all been gone over with you to nausea. You will not be convinced and that is fine. Those who have kits are convinced and that ultimately is what counts for us. Have a nice day.

 

[Bighorn]

I can't believe that after months and months, this Sintorion idiot is still trolling.
This is allowed to continue why?
Makes the site unfriendly.
How about a moderator just boot this guy.
He doesn't contribute anything useful.

 

[Sintorion]

I can't believe that after months and months, this Sintorion idiot is still trolling.
This is allowed to continue why?
Makes the site unfriendly.
How about a moderator just boot this guy.
He doesn't contribute anything useful.

Bighorn, Why is it that you are so hurt by me holding Joe accountable for his statements? Seems odd that you are upset with me, but I am not the one that made promises and not delivered as well as made statements that appear to be total fabrications in the interest of selling his product. He still won't answer the question about how his product improves performance and increases longevity nor has he been able to substantiate his claim that coolant stagnates. Then he completely contradicts his statement claiming that he did all this testing and tuning, but then turns around and says that he can't justify testing his "low volume" product. I am just the messenger here.

 

[Bighorn]

So, Don't buy it.
You've said your peace.

I guess it is your own personal crusade to protect the world from this product.
I think all the threads about people putting junk oils into their multifuel engines "just cause" are stupid.
But I Don't spend months bashing them on the forum.
Hey, how about you put Joe's kit on your CUCV and test it out.
Expose the supposed fraud.
Prove to us it is a sham.
Otherwise, you got nothing but hot air.

 

[ken]

Let me see if I can help you understand. It's because we have all read your posts. WE GET IT! we completely understand your position. As a matter of fact I agree with you. I have shared this in other posts where I posted pics of the never style head gaskets and the coolant passages in the heads. I am in the lower the engines temp to 180 column. But enough already. Joe knows how you feel. We all do. Since we all know where you stand. And have been reminded many times We don't need to hear it over and over. Each owner of a 6.2/6.5 can clearly read and see both trains of thought. Then make a decision them self. Any search on the topic will show what both you have to say. So if a newbie comes along and searches the topic he will see what you have to say. At this point you are not helping anybody. Just casting yourself in a not so flattering light. That being said, the horse you are beating is already dead. Please move on!

 

[Sintorion]

So, Don't buy it.
You've said your peace.

I guess it is your own personal crusade to protect the world from this product.
I think all the threads about people putting junk oils into their multifuel engines "just cause" are stupid.
But I Don't spend months bashing them on the forum.
Hey, how about you put Joe's kit on your CUCV and test it out.
Expose the supposed fraud.
Prove to us it is a sham.
Otherwise, you got nothing but hot air.

So my hot air is not worthy, but he can continue to come here and make false claims? I am sorry, but I really don't see you point. You would rather someone post lies and not be called out on it?

I don't see Joe's BS any different than someone coming on here touting Amsoil as the greatest then turning around and promoting it at every opportunity. Joe is a fraud. He can't support his claims and hides behind people like you.