Under hood temps and hood heat extractor install

[poontanghooligan]

In an effort to reduce under hood operating temperatures on my ST, I'm going to install a hood heat extractor from a 2010-2014 Mustang GT500. Seems like it will look good with the Edge's hood lines (and hopefully very functional!).

 

I'm not having any overheating problems save for the occasional "AWD Disabled" message when towing my trailer in hot temps (90+) up long grades. My thinking is that since the PTU is water cooled and my ST is under quite a bit of boost going uphill with a big load (with A/C on), I can reduce the load of the cooling systems by extracting the ridiculously hot air under hood. Instead of the hot air from after the radiator trying to find a way to escape,  some of it will just go straight out of the extractor, hopefully reducing the heat load of the engine and trans enough to let the PTU operate within a safe range. That's the theory anyway.

 

So a couple of questions:

 

1. Anyone measured under hood temperatures with the 2.7? I would like to have before and after numbers to see if this mod is effective at heat extraction. I can always measure myself (unloaded and loaded) but am interested in anyone else's experiences too.

2. I am going to mount the extractor with the front edge of it lined up with the back of the radiator, basically in the gap between the radiator and the engine. This should provide the best low pressure area for extraction and, because of the angle of the extractor holes, allow for the most air to exit. Does this sound effective both in placement and best efficiency?

[Cerberus]

On 9/6/2021 at 8:00 PM, poontanghooligan said:

since the PTU is water cooled..

wait.. wut?

i will say that I have seen the temp sensor in the PTU on mine read well into the 2-teens, but never sampled under hood ambient temps

Forscan will let you see trans fluid temp, "transfer case fluid temp" (PTU) etc

but you might have better results by replacing the OEM grill with the honeycomb aftermarket one to improve flow, and maybe a meth fogger in front of the condenser or CAC

[poontanghooligan]

15 hours ago, Cerberus said:

wait.. wut?

Going off of this PDF for the 2019 ST, it shows a PTU cooler: 2019 ST PTU Oil Change. To be honest, I haven't verified my 20 has it but I would think there wouldn't be any change from the 19 to the 20. I'll crawl under there and check though.

 

I have some temp probes coming in a few days and will get some data on under hood temps. I also have the ODB adapter coming so I can Forscan. Good suggestion on the grill but the ST does have a honeycomb grill which is substantially more open than a non-ST grill. Now the meth fogger could be something to tinker with!

 

I have learned that the AWD disabled message is a result (at least in my case) of the PTU starting to reach it's max temp limit so the RDU is disconnected to avoid overheating the PTU. The PTU never gets the chance to overheat because of this protection. Once I'm done climbing a  long hill towing and boost levels are lower, the AWD is re-enabled and all is good. Will be interesting to see the PTU temp when this happens.

Edited September 8, 2021 by poontanghooligan
spelling, more context

[Cerberus]

My mind is blown

[Cerberus]

If you like the fogger idea, you might also consider the nitrous fogger option. A bit expensive and limited usability really, but a fun idea that was used to get a stock Mitsu 3000 GT VR4(?) over 200mph back in the day.

 

Id be wondering why the PTU is reaching its safety disable temp, even with a cooler.

[poontanghooligan]

5 hours ago, Cerberus said:

Id be wondering why the PTU is reaching its safety disable temp, even with a cooler.

 

Likely because I was pushing a lot of boost, around 12-14, for a long time at maximum GVWR and GCWR in 90+ temps. That's probably not a normal use case. Even tracking the ST doesn't generate the same continuous load. The good thing is that the protection measures kicked in. There were no other issues and I was able to continue along with the same load without overheating. Good thing it's an ST because it has the larger radiator.

 

In reading other Ford forums (Explorer, Bronco), the AWD disabled issue seems to happen on occasion, like going up long steep muddy hills and flogging in sand. This can generate a lot of PTU heat, or heat in general. Again, probably not the most common use cases for these vehicles so they don't get tested this way. Or maybe they do but those results aren't "public".

[Cerberus]

Just a side thought, but you said it is water cooled, which im wondering if it using the same coolant circuit tapped off the engine, which then begs the question if lowering the thermostat temp might lower the running temp of the PTU.

Random thoughts. Ignore if useless

[poontanghooligan]

IIRC, the PTU cooler get its coolant AFTER the coolant has been run through the engine. If this is the case, then running at constant higher boost levels is going to add more heat than normal to the cooling system and that hotter coolant is then going to the PTU cooler before going back to the radiator to be cooled. Even with a lower temp thermostat, the temp at which the coolant is at higher boost levels is going to always be above the t-stat opening temp. A lower temp opening might delay PTU max temp but only for a short time I suspect.

 

I guess it's a matter of priority by Ford engineers as to what gets cooled first. Cooling the PTU first wouldn't add much heat to the overall cooling system before coolant goes through the engine. But sadly it's the opposite.

[Cerberus]

When you have Forscan set up you will be able to directly monitor coolant temp and see if the coolant is in fact going above the wide open temperature while on the long hard pull. Its a reasonable assumption but data acquisition removes all question.

[Special_K]

On 9/8/2021 at 4:16 PM, poontanghooligan said:

IIRC, the PTU cooler get its coolant AFTER the coolant has been run through the engine. If this is the case, then running at constant higher boost levels is going to add more heat than normal to the cooling system and that hotter coolant is then going to the PTU cooler before going back to the radiator to be cooled. Even with a lower temp thermostat, the temp at which the coolant is at higher boost levels is going to always be above the t-stat opening temp. A lower temp opening might delay PTU max temp but only for a short time I suspect.

 

I guess it's a matter of priority by Ford engineers as to what gets cooled first. Cooling the PTU first wouldn't add much heat to the overall cooling system before coolant goes through the engine. But sadly it's the opposite.

 

awd disabled can also be triggered from the following: coupler over heat, ptu overheat, transmission 245F+.  im willing to be the transmission is tripping the sensors before anything else is.  we had the issue towing up long grades.  The edge isnt mean for real towing like that sadly.  but two additional trans coolers and the trans couldn't be happier and havent had the warning since

[poontanghooligan]

On 9/16/2021 at 9:09 AM, Special_K said:

 

awd disabled can also be triggered from the following: coupler over heat, ptu overheat, transmission 245F+.  im willing to be the transmission is tripping the sensors before anything else is.  we had the issue towing up long grades.  The edge isnt mean for real towing like that sadly.  but two additional trans coolers and the trans couldn't be happier and havent had the warning since

 

Thanks for your input! In my case, data showed the PTU sump temp was fry high. I was able to get some data on the way to the campground yesterday. "AWD disabled" message only triggered once and that was at the top of a long grade (4700 to 7400) passing a slower truck and trailer. Otherwise no issues.

Ambient air temp: 82F

Air inlet temp: 102F to 105F

CAC temp: 145 F to 152F
Boost level: 7-12 PSI (during climb)
PTU disconnect temp: 265F (yikes)
PTU reconnect temp: 255F
Engine coolant temp max: 225F (not during AWD disabled)
Transmission temp max: 220F
Under hood temp near air intake snorkel (just to the left)  max: 204F
Under hood temp near battery max: 198F
Under hood temp near intake idling: 179F
Under hood temp near battery idling: 168F

The PTU just heat soaks and never recovers much until load is reduced. So I'm also looking at an oil pump to circulate the PTU oil through a small oil cooler and temp-activated fan. Also looking to install a 2014 GT500 hood heat extractor. Body shop says they can shape it to match the hood lines so I can place it nearest the front for best low pressure heat extraction. Pushing the Edge limits!

[Perblue]

I hope I'm proven wrong but I don't think the extractor will help much. You would be better off removing the active shutters and figuring out how to hook up a small front mount cooler for it. The ptu holds a whopping 500ml of fluid, this takes no time to heat up.

 

Ford rated it for towing but unfortunately I don't think they imagined towing a large grade while passing. Hate to say this too but sounds like you should have bought a full size suv or a truck. Just my opinion.

[Special_K]

13 hours ago, poontanghooligan said:

 

Thanks for your input! In my case, data showed the PTU sump temp was fry high. I was able to get some data on the way to the campground yesterday. "AWD disabled" message only triggered once and that was at the top of a long grade (4700 to 7400) passing a slower truck and trailer. Otherwise no issues.

Ambient air temp: 82F

Air inlet temp: 102F to 105F

CAC temp: 145 F to 152F
Boost level: 7-12 PSI (during climb)
PTU disconnect temp: 265F (yikes)
PTU reconnect temp: 255F
Engine coolant temp max: 225F (not during AWD disabled)
Transmission temp max: 220F
Under hood temp near air intake snorkel (just to the left)  max: 204F
Under hood temp near battery max: 198F
Under hood temp near intake idling: 179F
Under hood temp near battery idling: 168F

The PTU just heat soaks and never recovers much until load is reduced. So I'm also looking at an oil pump to circulate the PTU oil through a small oil cooler and temp-activated fan. Also looking to install a 2014 GT500 hood heat extractor. Body shop says they can shape it to match the hood lines so I can place it nearest the front for best low pressure heat extraction. Pushing the Edge limits!

 

seems like you have positive confirmation as to the problem along with a viable solution. GO FORTH AND PAVE THE WAY!

[poontanghooligan]

22 hours ago, Perblue said:

I hope I'm proven wrong but I don't think the extractor will help much. You would be better off removing the active shutters and figuring out how to hook up a small front mount cooler for it. The ptu holds a whopping 500ml of fluid, this takes no time to heat up.

 

Ford rated it for towing but unfortunately I don't think they imagined towing a large grade while passing. Hate to say this too but sounds like you should have bought a full size suv or a truck. Just my opinion.

 

My thought is that by combining the heat extractor and PTU cooler, I'll get the temps under control. Should be able to increase oil capacity a fair amount too between the lines and cooler.

 

The ST tows so well in almost all cases that I loath to give up so easily, especially because of the plans I have for it. Thought about a new Explorer but they aren't rated for much more. Only 5600 lbs with the most expensive trim and engine configuration (ST). Just not worth it. They are WAY overpriced. And I don't really want a truck. I suppose the Ranger could work but not nearly as roomy in the back seat. F150's are WAY overpriced as well.

[poontanghooligan]

11 hours ago, Special_K said:

 

seems like you have positive confirmation as to the problem along with a viable solution. GO FORTH AND PAVE THE WAY!

 

I shall endeavor to strive for greatness in all that is PTU cooling. BTW, I am also an engineer so these "problems" are just issues to solve. With a little ingenuity and testing (like you've done so much of!), thy will be done!

[poontanghooligan]

Just wanted to make a correction about me saying my '20 ST PTU being water cooled. Turns out mine is not. It has the mounting boss and bolted cap but no cooler. It's likely because it's US spec and not for hot climates. Now I wonder if I could source the parts to retrofit the cooler. Seems like it would be a better route than an aftermarket oil cooler and pump.

[Cerberus]

1 hour ago, poontanghooligan said:

Just wanted to make a correction about me saying my '20 ST PTU being water cooled. Turns out mine is not. It has the mounting boss and bolted cap but no cooler. It's likely because it's US spec and not for hot climates. Now I wonder if I could source the parts to retrofit the cooler. Seems like it would be a better route than an aftermarket oil cooler and pump.

I'd say that is your best first choice imho

[omar302]

5 hours ago, poontanghooligan said:

Just wanted to make a correction about me saying my '20 ST PTU being water cooled. Turns out mine is not. It has the mounting boss and bolted cap but no cooler. It's likely because it's US spec and not for hot climates. Now I wonder if I could source the parts to retrofit the cooler. Seems like it would be a better route than an aftermarket oil cooler and pump.

 

The 2019+ Edge has a different PTU than prior models, is there also a water cooled version of the new PTU?

 

The change in the 2019+ PTU is the ability to disconnect the driveshaft when AWD is not needed, so I am surprised it is heating up in your Edge ST when towing at highway speeds, I would have thought that the driveshaft would be disconnected and thus no load on the PTU.

[poontanghooligan]

9 hours ago, omar302 said:

 

The 2019+ Edge has a different PTU than prior models, is there also a water cooled version of the new PTU?

 

The change in the 2019+ PTU is the ability to disconnect the driveshaft when AWD is not needed, so I am surprised it is heating up in your Edge ST when towing at highway speeds, I would have thought that the driveshaft would be disconnected and thus no load on the PTU.

 

I'm not sure if there is a water-cooled version of the 2019+ PTU for the 8F57 transmission. Information about anything new from Ford is hard to find sometimes.

 

I'm not having any issues when just cruising at highway speed and I do see the RDU is not getting any power transferred to it in the AWD message display. It's only when AWD is fully engaged, i.e., 50/50 split of power, while going up a long grade under high boost. That's when the PTU temp gets too high and the RDU is disengaged. The driveshaft is still spinning but the RDU clutch is fully disengaged. I also see this in the AWD message display.

[omar302]

57 minutes ago, poontanghooligan said:

I'm not sure if there is a water-cooled version of the 2019+ PTU for the 8F57 transmission. Information about anything new from Ford is hard to find sometimes.

 

If you have access to the 2019/2020 service manual you should be able to see the engine cooling components. That's how I found it on the 2015 model.

[poontanghooligan]

Well folks, I did what I said I wouldn't and traded in the ST for a 2021 Explorer Limited 4WD with the 2.3 and 10 speed. After looking at the cost of installing the heat extractor and electric PTU pump and cooler, I was looking at $2K and that's without knowing if I could make the PTU live while towing at the limits.

 

I did a lot of research on the drivetrain of the Explorer. The RWD bias design, transaxle and FDU are in a much better arrangement in terms of heat generation and cooling. The RDU is a little beefier as well and the transmission (10R60) is rated at 442 foot pounds (600 nm), which it way more than the 310 foot pounds the 2.3 puts out. So towing longevity should be improved a lot.

 

Once I get passed the break in mileage, I'll do a towing test with underhood temps and Forscan as a comparison then report back.

[Cerberus]

16 hours ago, poontanghooligan said:

Well folks, I did what I said I wouldn't and traded in the ST for a 2021 Explorer Limited 4WD with the 2.3 and 10 speed. After looking at the cost of installing the heat extractor and electric PTU pump and cooler, I was looking at $2K and that's without knowing if I could make the PTU live while towing at the limits.

 

I did a lot of research on the drivetrain of the Explorer. The RWD bias design, transaxle and FDU are in a much better arrangement in terms of heat generation and cooling. The RDU is a little beefier as well and the transmission (10R60) is rated at 442 foot pounds (600 nm), which it way more than the 310 foot pounds the 2.3 puts out. So towing longevity should be improved a lot.

 

Once I get passed the break in mileage, I'll do a towing test with underhood temps and Forscan as a comparison then report back.

Soo.. you went to a larger vehicle with less power?

THAT'll be fun.

Just messing with you, good luck with the new ride

[Special_K]

On 9/25/2021 at 5:39 PM, poontanghooligan said:

Well folks, I did what I said I wouldn't and traded in the ST for a 2021 Explorer Limited 4WD with the 2.3 and 10 speed. After looking at the cost of installing the heat extractor and electric PTU pump and cooler, I was looking at $2K and that's without knowing if I could make the PTU live while towing at the limits.

 

I did a lot of research on the drivetrain of the Explorer. The RWD bias design, transaxle and FDU are in a much better arrangement in terms of heat generation and cooling. The RDU is a little beefier as well and the transmission (10R60) is rated at 442 foot pounds (600 nm), which it way more than the 310 foot pounds the 2.3 puts out. So towing longevity should be improved a lot.

 

Once I get passed the break in mileage, I'll do a towing test with underhood temps and Forscan as a comparison then report back.

 

BOOOOOO as us engineers would say .... YOU FOGEY.

Nah i kid, cost analysis makes sense for the expected risk.  but i will say this......should have done the ST, its a BEAST

[poontanghooligan]

5 hours ago, Special_K said:

 

BOOOOOO as us engineers would say .... YOU FOGEY.

Nah i kid, cost analysis makes sense for the expected risk.  but i will say this......should have done the ST, its a BEAST

Oh I'm owning it for sure! One of my favorite engineering quotes: "When you want to know how things really work, study them when they're coming apart."

 

I DID look at the ST but dang they were $10K more than the limited. But they are very quick! With just a tune they're running low 12's. Perfect for towing. I wonder what the ST would do in the 1/4 with a 5k trailer. 18-20?

 

I do wish I could have made the Edge work. I put a bit of work into it but I got $40k on trade in so it made sense for the deal overall. 

 

5-Star tune is on it's way for the 2.3. Gets close to the stock Edge ST crank numbers on 93 at the wheels.