Stumped With Cooling System Problem

[KennethS]

I only brought it up because I'm personally aware of an instance 10 or so years ago where a friend (that did ZERO preventative maintenance, and barely did required maintenance/repairs) was having an overheating issue. Ended up everything in his cooling system checked out fine or was replaced, but his heater core was so corroded & obstructed, it was still allowing coolant through but majorly limited the flow.

I would have halfway expected the heater core to bust/spring a leak under those conditions, but halfway wonder if the buildup didn't actually add some structural integrity to keep that from happening.

If reduced flow through the heater core causes overheating, then it seems bypassing a leaky core would also result in overheating.

 

[JKP]

Bypassing the heater core means connecting the two heater hoses together, increasing flow.

You don't block off the heater circuit.

 

[KennethS]

The reason for my comment above is my heater core is mostly blocked off due to all the stop leak I put in to, well stop the leak. I get around 90 degrees out the heater in the winter, which tells me flow through it it is mostly blocked, yet the engine cools well during 115+ degree summer temperatures. That indicates to me flow through the heater core has little to do with cooling the engine.

 

[MikeE024]

The reason for my comment above is my heater core is mostly blocked off due to all the stop leak I put in to, well stop the leak. I get around 90 degrees out the heater in the winter, which tells me flow through it it is mostly blocked, yet the engine cools well during 115+ degree summer temperatures. That indicates to me flow through the heater core has little to do with cooling the engine.

If it was mostly blocked off I believe you would be getting closer to ambient temps blowing out of the heater in the winter. The lack of heat is very noticeable when the heater core stops working, especially when a fan is blowing cold air on you.

 

[Slipstreak]

Alright I’ve ordered most of the materials to perform a heater core flush from Gregbelliville’s guide as well as resupplied on a large QTY of Prestone and distilled water to re-flush the system hard

Also picked up a new Stant 195 thermostat for peace of mind and will hold on to my old one just to rule out a defective thermostat

Even though my fan clutch is new (USMW 22159) I may post a video here of the resistance fully warmed up and shut off to see what people think. Read numerous times that fan clutches have a high failure rate right out of the box.

I’ll post my results of the deep flushing some time next week.

 

[Slipstreak]

Here’s the flush follow up; potentially several bad fan clutches?

Flushed the system with distilled water and Prestone radiator flush and there was a small amount of sediment that came out of the system but not enough for me to believe there was casting sand or rust scaling inside the engine causing overheating. HOWEVER, I do want to explore the possibility of my current fan clutch (as well as others) being defective which I captured in this video link:

Potentially Defective Fan Clutch?

I took a video under the hood at 226.4*F engine coolant temp and noted that the fan clutch was rather silent, almost making no noise with the only audible sound being the valve train running despite ECT being near maximum safe operating temperature and ambient temperature being 103*F. Because this is a USMW 22159 Severe Duty Unit, I was under the assumption under this much heat that the clutch should be roaring, almost like a school bus or a Freightliner but it’s not audible at idle OR under load while driving.

While the odds of it seem rather low, is it possible that I’ve just recieved a handful of bad fan clutches that were dead on arrival? Curious to know everyone’s thoughts on the video I made linked above.

I also picked up at Shaw 330-195 brass thermostat and will be installing it later this weekend or early next week, but the current thermostat in the system appeared to be operating normally.

 

[JKP]

You should be able to feel quite a bit of airflow through the grill and it def should be roaring if you rev the engine.

 

[Slipstreak]

Here’s the flush follow up; potentially several bad fan clutches?

Flushed the system with distilled water and Prestone radiator flush and there was a small amount of sediment that came out of the system but not enough for me to believe there was casting sand or rust scaling inside the engine causing overheating. HOWEVER, I do want to explore the possibility of my current fan clutch (as well as others) being defective which I captured in this video link:

Potentially Defective Fan Clutch?

I took a video under the hood at 226.4*F engine coolant temp and noted that the fan clutch was rather silent, almost making no noise with the only audible sound being the valve train running despite ECT being near maximum safe operating temperature and ambient temperature being 103*F. Because this is a USMW 22159 Severe Duty Unit, I was under the assumption under this much heat that the clutch should be roaring, almost like a school bus or a Freightliner but it’s not audible at idle OR under load while driving.

While the odds of it seem rather low, is it possible that I’ve just recieved a handful of bad fan clutches that were dead on arrival? Curious to know everyone’s thoughts on the video I made linked above.

I also picked up at Shaw 330-195 brass thermostat and will be installing it later this weekend or early next week, but the current thermostat in the system appeared to be operating normally.

*Bumping the thread*, any additional input on this?

 

[GoldenGorilla]

I took a video under the hood at 226.4*F engine coolant temp and noted that the fan clutch was rather silent, almost making no noise with the only audible sound being the valve train running despite ECT being near maximum safe operating temperature and ambient temperature being 103*F. Because this is a USMW 22159 Severe Duty Unit, I was under the assumption under this much heat that the clutch should be roaring, almost like a school bus or a Freightliner but it’s not audible at idle OR under load while driving.

The fan is based on the temp it sees on the coil on the front of the fan, right behind the radiator. Unlocked, my OE one was spinning and the fan was quite loud, certainly louder than the drivetrain. Locked, it was extremely loud.

Assuming the 4 bolts holding the pulley to the water pump/ fan clutch are installed and the pulley is spinning them, this really sound like you keep getting dead fan clutches. But your link circles back to this thread, so I don't see any video evidence.

 

[Slipstreak]

The fan is based on the temp it sees on the coil on the front of the fan, right behind the radiator. Unlocked, my OE one was spinning and the fan was quite loud, certainly louder than the drivetrain. Locked, it was extremely loud.

Assuming the 4 bolts holding the pulley to the water pump/ fan clutch are installed and the pulley is spinning them, this really sound like you keep getting dead fan clutches. But your link circles back to this thread, so I don't see any video evidence.

You’re totally right, the link was broken. I’ve re-embedded the link for the forum to view here:

Potentially Defective Fan Clutch?

 

[B.E. Coyote]

This video and ordering a cheap anemometer is what finally showed me that my brand new Hayden HD fan clutch was bad. Replacing a bad part in a system with a bad part that you assume is good, can be tricky to trouble shoot. The anemometer showed me my fan was pulling about 1/3 of what his was. I also ordered a laser tachonmeter.


View: %5BURL%5D%5BURL%5Dhttps://www.youtube.com/watch?v=OI8P8gu2My8&t=344s[/URL][/URL]

https://www.amazon.com/gp/aw/d/B09THDJX23?tag=wranglerorg-20