I'm at my absolute wits end- truck still overheating despite best efforts (1 Viewer)

[NLXTACY]

It's pretty much a (angle) straight shot to get to the tstat on a SC 80. Not bad at all.
I can see that it would be a pain with second battery on that side.

Is a pain in the ass with an SC and a second battery

 

[UnderDawg]

Crazy your still having problems with this, sorry to hear man.

 

[NLXTACY]

Crazy your still having problems with this, sorry to hear man.

Well at this point its kind of my own fault because I've been pulled into different directions right now so I don't have time to focus on it.

 

[UnderDawg]

Its happens, you'll figure it out no question about that.

 

[george_tlc]

Is a pain in the ass with an SC and a second battery

I just replaced my thermostat a few weeks ago (stuck open and definitely over-cooling a LOT) and it was quite an easy job (with S/C and 2nd battery). Took longer to drain/catch the coolant and undo the hardline hose coupler below than to access and R&R the thermostat. 1/4 drive ratchet/extension/socket make it easy to access the one partially crowded bolt head.

From reading some of this thread, you spend way the Fxxx too much time thinking about things versus just doing them

cheers,
george.

 

[NLXTACY]

Well obviously I wasn't using the right tool :flipoff:

The access is awkward and not using a long sleeved shirt sucked ass with all the fiberglass getting embedded in my forearm.

 

[george_tlc]

Huh? I worked on mine in a teeshirt - not sure where your fibreglass is coming from. The top of the battery tray SHOULD have a rubber seal just like the main battery and if not a few seconds overwrapping the top edge with some duct tape would have taken care of that.

Too many excuses man

cheers,
george.

 

[etarasoff]

#bumptothetop #joeysheat

 

[muddonkey]

I don't think the radiator or the water pump are the cause of the restricted flow or lack of flow. I think the thermostat is making the coolant sit in the block too long, it restricts the flow too much. I increased the flow through my thermostat and now it stays at much lower temps in +100* days. It hit 194 right after getting off the freeway, while on the freeway it was running at 190. 2 miles later when I pulled into my driveway it was sitting at 192, and after I let it idle for about 2 mins it dropped down to 188. Thermostats are cheap, and for us N/A guys they're easy to change out. It may be a pain to change one on a S/C engine but it couldn't hurt to try it.

NEAL, where did you drill your holes? 3 and 9 o'clock ??

 

[NLXTACY]

Ok guys so I've been seriously busy with two new business endeavors so my available time has been dropping dramatically. Apologies for that since I know you guys want to see closure just as much as I need a solution.

I got in the ringed fan from @DSRTRDR , smaller water pump pulley from @Photoman and @artech made me a fan clutch proxy . I really really love this community!!!

 

[NLXTACY]

Here is the fan clutch proxy

 

[NLXTACY]

First order of business was to take of the fan clutch, easy enough, and replace the water pump pulley. Why change out the water pump pulley? Well, it gets the water pump moving quicker at lower RPMs and by extension even faster at higher RPMs. I wanna move some coolant

Doing this meant getting the belts to be tighter since I needed to adjust for about an additional inch of play in the belts. After moving the adjuster I bunch I thought I hit the maximum extension. I was bummed. It meant I needed shorter belts. But after getting my head down there so I could see better it seemed as though the adjuster block arm was just barely touching the alternator bracket so I loosened up everything and gave the alt a big tug, there it went. Now I could adjust to my heart's content without any further headache. For the uninitiated, I am rocking @Photoman 's alternator upgrade using the Sequoia 150A alternator: https://forum.ih8mud.com/threads/upgrading-stock-alternator-to-130-150-amp.206807/

But before the pulley, I was checking out the water pump itself. No leaking or anything but I don't recall for the life of me, how the resistance should be on the pump and how much, if any, play there should be. When rocking the hub side to side I do a get about a few thou of play. Its not much, as seen in the video, but its there. Also, the hub frees awfully easily. Of course I could be reading into nothing but I just don't recall of hand how much resistance there was or wasn't. Just a data point.

 

[NLXTACY]

I re-used my original blue hub @landtank fan clutch which has 12k CST. This clutch is a few years old but still working condition. I added the ringed fan and mounted everything back together. With the ringed fan in place I have just TOUCH over 1/2" between the ringed fan blade and the top part of the cores of the radiator. Ugh, this makes me nervous BUT at least its the ringed fan and I don't need to worry about it flexing very much, just imploding

 

[jcardona1]

What has happened here?!

 

[NLXTACY]

The ringed fan could definitely be moved back about 1/2" or so. I could take better measurements later.

So, diving it around, the roar is completely gone. Temps here have been 105º to 109º yesterday. Now, it does get hot still. But oddly enough its not getting crazy hot. driving around town and mainly stop and go I will get into the 203-205º range. I did manage a 217º while letting it idle for a few minutes. So measureable change especially since its been the hottest days I've been testing thus far.

This round I:

• Change from the 3FE fan to the 19" ringed fan
• Changed the stock water pump pulley to a smaller machined pulley
• Changed my brand new Aisin blue hub 30kCST fan clutch to my older LT blue hub 12k CST

I have not tried out the new fan clutch proxy but that is next on my list as I get a few minutes. That will DEFINITELY rule out fan clutch if there is no change.

 

[NLXTACY]

Here is the point where I believe the thermostat was starting to open. The coolant went from red tinted but totally clear, to red and cloudy and "moving", It wasn't moving very much. Churning I'd call it.

 

[NLXTACY]

Here you can see how hot the temps are outside, what temperature the coolant sensor says the head is at, and what temperature the coolant at the top of the radiator is at. Notice the variation between the radiator temp and the head temp. Of course since the coolant is still clear and the there is no churning, I can safely assume the thermostat is not open. But this got me thinking. The thermostat is rated at 179.6º. So the head sees 181º which is one side of the thermostat but it will see 168º (actually less at the lower hose) pushing on the other side of the thermostat. There could be a temperature variance of 20º or more. So when is the thermostat opening...truly opening?

 

[scottryana]

New, custom made, one off parts, and still a 17 year old exhaust..... The other thing that has me thinking is are you sure it isn't timing related? This would be almost impossible to test, unless you had a stock 80 driving along with you and 2-way comms to compare ignition advance, but with your extra heat and high IAT's the computer could be retarding timing increasing the temp further increasing the problem, kind of like a positive re-enforcement system.

I do hope you find a way to keep the truck from overheating, but it sure seems to me like you are "buying bigger pants".

 

[CJF]

The coolant went from red tinted but totally clear, to red and cloudy

Is that normal??

I guess I've never watched mine closely, but that sure sounds odd.

 

[CJF]

I do hope you find a way to keep the truck from overheating, but it sure seems to me like you are "buying bigger pants".

Agreed. All the latest effort is, if anything, just a bigger band-aid.