Overheating… again

[GregO]

Interesting, look how the former MMR hose is routed…… lower than the cylinder head coolant outlet ports.

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[tdstuart]

51. Start the engine, and allow it to idle with the cap off. Turn the
heater control valve on the vehicle’s HVAC unit to full hot, and
put the fan on low. Monitor the engine temperature and
coolant level in the reservoir. Add coolant as needed to
maintain proper level in the reservoir, and check your
connections for leaks. If the vehicle begins to overheat or
coolant starts to overflow from the reservoir, shut off the
engine and allow it to cool before continuing. Once the vehicle
is fully warmed up and the coolant level has stabilized, allow
the vehicle to cool off completely, and then top off the coolant
level. Coolant level should be checked once more after putting
in some miles.

Where is this information from?

 

[tdstuart]

Interesting, look how the former MMR hose is routed…… lower than the cylinder head coolant outlet ports.

Mine is probably that low. I can check tomorrow.

 

[GregO]

Mine is probably that low. I can check tomorrow.

I hope it is as low as the second illustration for your sake.
It would be good to know the flow bias of left and right cylinder cooling port outlets. I think it’s nearly impossible that the bias is a perfect 50/50 split.

 

[WildHorse]

Where is this information from?

Griffin coyote radiator PDF

 

[tdstuart]

Im calling it early but so far I think it's a success!

Haven't driven it yet but idle temperatures are so much better.
Idling at 181 CHT and 180 Coolant temp (normally CHT has been 15-20*F higher).

Im going to wait until the car cools down then top it off and go for a test drive.
I'll report back and maybe make a separate post about this if it works.

I used the vacuum bleeder mentioned here:

https://www.harborfreight.com/cooling-system-test-and-refill-kit-64985.html
Worked like a charm. However I only paid $40 for it a year ago. Might check Amazon

And used this method to help bleed the system further:

51. Start the engine, and allow it to idle with the cap off. Turn the
heater control valve on the vehicle’s HVAC unit to full hot, and
put the fan on low. Monitor the engine temperature and
coolant level in the reservoir. Add coolant as needed to
maintain proper level in the reservoir, and check your
connections for leaks. If the vehicle begins to overheat or
coolant starts to overflow from the reservoir, shut off the
engine and allow it to cool before continuing. Once the vehicle
is fully warmed up and the coolant level has stabilized, allow
the vehicle to cool off completely, and then top off the coolant
level. Coolant level should be checked once more after putting
in some miles.

The full method I used:
First I jacked the car up so the rear was higher than the front. I had the car in accessory mode with the heat set to high and fan on 1. Then I let the coolant drain and used my pressure tester to force some pressure in which seemed to get more coolant out. Then I jacked the car up so the front was higher than the rear. Then I put about 21 psi of vacuum on the system and let the coolant fill up the system. I then removed the vacuum and started the car for a bit (again had the heat on high and fan on 1) but had to stop because the expansion tank started overflowing. I then put the car back to level ground and started it up again. When the thermostat started opening I could see air coming through one of the return lines. To help the air I put the vacuum system back on and would add a little vacuum (1-5 psi) until the air stopped coming out. The coolant level dropped to just under the maximum and temps stabilized. I then turned off the car to wait for it to cool.

 

[80FoxCoupe]

I don't see the mmr crossover deal doing anything productive.

 

[tdstuart]

I don't see the mmr crossover deal doing anything productive.

I’m not sure. It’s hard for an independent person to do testing to back up their claims.

 

[WildHorse]

I don't see the mmr crossover deal doing anything productive.

It doesn't. Another gimmick IMO.

 

[80FoxCoupe]

I’m not sure. It’s hard for an independent person to do testing to back up their claims.

Have they backed up their claims?

 

[Cory S]

I’m not sure. It’s hard for an independent person to do testing to back up their claims.

I believe if Ford engineers found a crossover was NEEDED, and had any significant benefit, they would have put one there. With all the rigorous durability testing they did on the Coyote, I think it’s a useless mod IMHO.

 

[tdstuart]

Have they backed up their claims?

They just make statements:
"MMR's cooling head mod ( HCM ) for the 2011-2023 5.0 / 5.2 Coyote is designed to help eliminate hotspots in the #8 cylinder by promoting coolant flow around cylinder # 8 - the cylinder long known to be the first to detonate with aggressive naturally aspirated tunes and forced induction. Dont fall victim to this failure, protect your investment with this simple, professional kit. Installation requires tapping out the factory freeze plugs and simply installing the MMR kit. Kit seals with high grade DOUBLE* Viton Brand Aerospace O rings. NHRA Approved Socketless hose does not require hose clamps for simple push on installation. Includes all parts shown, no other parts required. Fits all Mustang, BOSS and F150 with 5.0 & 5.2 TiVCT engine. Billet Alloy construction. 100% USA MADE by MMR - Patent Pending"

Someone would have to call and ask what testing they did.

 

[tdstuart]

I believe if Ford engineers found a crossover was NEEDED, and had any significant benefit, they would have put one there. With all the rigorous durability testing they did on the Coyote, I think it’s a useless mod IMHO.

To be fair Ford also has kept the same oil pump gears. I have also seen people crack their engine blocks where it mates with the transmission (another product mmr sells).

I think it's not a need on stock cars, just like oil pump gears aren't. But I think there is a possibility of it being a benefit on modified cars.

 

[80FoxCoupe]

They just make statements:
"MMR's cooling head mod ( HCM ) for the 2011-2023 5.0 / 5.2 Coyote is designed to help eliminate hotspots in the #8 cylinder by promoting coolant flow around cylinder # 8 - the cylinder long known to be the first to detonate with aggressive naturally aspirated tunes and forced induction. Dont fall victim to this failure, protect your investment with this simple, professional kit. Installation requires tapping out the factory freeze plugs and simply installing the MMR kit. Kit seals with high grade DOUBLE* Viton Brand Aerospace O rings. NHRA Approved Socketless hose does not require hose clamps for simple push on installation. Includes all parts shown, no other parts required. Fits all Mustang, BOSS and F150 with 5.0 & 5.2 TiVCT engine. Billet Alloy construction. 100% USA MADE by MMR - Patent Pending"

Someone would have to call and ask what testing they did.

If data was available, it would be present in the product info.

 

[tdstuart]

If data was available, it would be present in the product info.

MMR doesn't even include installation instructions for any of its products. You kinda have to call and ask, they are pretty helpful on the phone.

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