Of fan clutches and mileage

[Tominator223]

A fan clutch takes away 10-17hp. So they will affect mpg. Run a 190 T-stat in that 5.7. If the new fan has a different pitch that could be a noise issue. If want better mpg go electric fan(s). But they’ll probably be even louder.

 

[bcja]

A fan clutch takes away 10-17hp. So they will affect mpg. Run a 190 T-stat in that 5.7. If the new fan has a different pitch that could be a noise issue. If want better mpg go electric fan(s). But they’ll probably be even louder.

Thanks. I went with the stock 203 Tstat. Fan had the same pitch. I did think about electric, but between the new cowling and not wanting to deal with a mod I decided against it. Maybe I will revisit down the road.

I started on the intake the other day, then realized I didn't have enough time. I did a smoke test (homemade), which did not show any leaks. I suppose there could be one underneath and the smoke blocked by the foam, but feeling like that route may be a dead end. Also tested that evap hose I made during the header replacement, and it was ok.

Going to wait for the new clutch before I do anything else, should be here this week.

 

[bcja]

Map sensors rarely fail in reality, it isn't unheard of but much rarer than people think.
Usually when they fail, it is the baro read side - which throws it all out of whach - easy to see on a scanner.

Yeah, I figured. Data seemed fine, didn't look to close though. I was more concerned with a brittle o-ring and plastic, so for the price a new one seemed like less hassle.

 

[Pokealong 42]

I maybe in the wrong spot to ask this, but why not go electric ???

 

[Ken226]

An electric only fan has some advantages, but it's disadvantage is that the stock programming doesn't start turning the electric fan on until the coolant temp reaches 225° -230°.

To get an electric fan setup to work right, you have to deal with sending your PCM in to be unlocked, then buying and using a tuner to edit the PCM and lower the fan on/off threshold values.

Or, wiring in some kind of relay/toggle switch bypass and a separate sensor>controller, or toggle switch and trying to manually control it.

 

[bcja]

An electric only fan has some advantages, but it's disadvantage is that the stock programming doesn't start turning the electric fan on until the coolant temp reaches 225° -230°.

To get an electric fan setup to work right, you have to deal with sending your PCM in to be unlocked, then buying and using a tuner to edit the PCM and lower the fan on/off threshold values.

Or, wiring in some kind of relay/toggle switch bypass and a separate sensor>controller, or toggle switch and trying to manually control it.

Oh geez. I figured there would be more fiddling than just plugging it in, but all of that is far beyond what I suspected. And much more than I would want to deal with.

( @Pokealong 42 )

 

[Bigskyroadglide]

An electric only fan has some advantages, but it's disadvantage is that the stock programming doesn't start turning the electric fan on until the coolant temp reaches 225° -230°.

To get an electric fan setup to work right, you have to deal with sending your PCM in to be unlocked, then buying and using a tuner to edit the PCM and lower the fan on/off threshold values.

Or, wiring in some kind of relay/toggle switch bypass and a separate sensor>controller, or toggle switch and trying to manually control

Put the electric fan in, change nothing, cut auto climate on and leave it on or turn the air conditioner on.

The e fan is commanded to on when the ac is on.

Everything works. No need to do anything else.

If you can't use the ac, then it will go up to 226 as described.

226 is not overheated.

 

[Ken226]

Put the electric fan in, change nothing, cut auto climate on and leave it on or turn the air conditioner on.

The e fan is commanded to on when the ac is on.

Everything works. No need to do anything else.

If you can't use the ac, then it will go up to 226 as described.

226 is not overheated.

Does that still work if you live somewhere where you run the heater most months of the year? I guess, maybe if you leave the defroster on?

 

[Bigskyroadglide]

Absolutely, I live in Montana, my 24 1500 classic has an electric fan conversion at 20k miles, stock thermostat. I run in auto climate, temp set at 69. Winter or summer. Fan works great, cycling on an off as needed. 203 temp, once warmed up.

I never touch it.

If you don't have auto climate, yes defrost works.

When compressor kicks on fan turns on.

I've used this fan on 6 different 1500s, 11 to 24 model years (DS)

https://a.co/d/0efaErX0

 

[samsdad02]

Have the same issue. Stock fan clutch started locking up on cold starts and then after sitting for half hour. Replaced with Hayden replacement. Did the same thing. Warrantied it and the new one does the same thing. Hayden tech says its normal. I disagree. Clutch stays locked up on cold starts to 4500 rpms. If it sits for more than half hour or less it will lock up for about 30 seconds. Took the fan and clutch off yesterday. Fan has black rub marks from being sucked into the ac electric fan shroud. Fan and clutch are in the back seat now. Don't see any difference in temps but it's a lot quieter.

 

[mdc1990zr1]

Have the same issue. Stock fan clutch started locking up on cold starts and then after sitting for half hour. Replaced with Hayden replacement. Did the same thing. Warrantied it and the new one does the same thing. Hayden tech says its normal. I disagree. Clutch stays locked up on cold starts to 4500 rpms. If it sits for more than half hour or less it will lock up for about 30 seconds. Took the fan and clutch off yesterday. Fan has black rub marks from being sucked into the ac electric fan shroud. Fan and clutch are in the back seat now. Don't see any difference in temps but it's a lot quieter.

Don’t lay the fan down, it has to stay it the upright position as it sits in the vehicle or it will leak the silicone fluid. It won’t take long. Ask me how I know?

 

[bcja]

Absolutely, I live in Montana, my 24 1500 classic has an electric fan conversion at 20k miles, stock thermostat. I run in auto climate, temp set at 69. Winter or summer. Fan works great, cycling on an off as needed. 203 temp, once warmed up.

I never touch it.

If you don't have auto climate, yes defrost works.

Absolutely, I live in Montana, my 24 1500 classic has an electric fan conversion at 20k miles, stock thermostat. I run in auto climate, temp set at 69. Winter or summer. Fan works great, cycling on an off as needed. 203 temp, once warmed up.

I never touch it.

If you don't have auto climate, yes defrost works.

When compressor kicks on fan turns on.

I've used this fan on 6 different 1500s, 11 to 24 model years (DS)

https://a.co/d/0efaErX0

When compressor kicks on fan turns on.

I've used this fan on 6 different 1500s, 11 to 24 model years (DS)

https://a.co/d/0efaErX0

Thanks for that, if this clutch doesn't work out I will try that fan. Much cheaper than the clutch, but not much less for me when factoring in the recently purchased fan blades and cowling. This was all an afterthought to replacing the water pump, not a lot of research went into this ahead of time.

 

[bcja]

Have the same issue. Stock fan clutch started locking up on cold starts and then after sitting for half hour. Replaced with Hayden replacement. Did the same thing. Warrantied it and the new one does the same thing. Hayden tech says its normal. I disagree. Clutch stays locked up on cold starts to 4500 rpms. If it sits for more than half hour or less it will lock up for about 30 seconds. Took the fan and clutch off yesterday. Fan has black rub marks from being sucked into the ac electric fan shroud. Fan and clutch are in the back seat now. Don't see any difference in temps but it's a lot quieter.

I would return the clutch and get the electric fan recommended by @Bigskyroadglide if I were in your position.

 

[bcja]

Don’t lay the fan down, it has to stay it the upright position as it sits in the vehicle or it will leak the silicone fluid. It won’t take long. Ask me how I know?

Due to the snowstorms and weeks of ice this winter, I had a long time between receiving the replacement clutch and installing it. I put it upright on a shelf over a radiator, and it still doesn't work right.

If you had one that leaked, I would think it was (extra) faulty. Otherwise you could never ship or warehouse these at any scale.

 

[mdc1990zr1]

Due to the snowstorms and weeks of ice this winter, I had a long time between receiving the replacement clutch and installing it. I put it upright on a shelf over a radiator, and it still doesn't work right.

If you had one that leaked, I would think it was (extra) faulty. Otherwise you could never ship or warehouse these at any scale.

No, I layed it down to do a water pump. Took the pump off on a Saturday, put it together on Sunday. Had an oooy gooy substance seep out. Put it all back together and everything has been fine

 

[bcja]

Success!

New MOPAR clutch came today. Couldn’t wait, so it’s already installed. SO MUCH quieter than the GMB Severe Duty! Didn’t have to be embarrassed accelerating in the neighborhood anymore. Fuel mileage was almost instantly better. After a little warmup and retraining of the ECM, I was seeing 18-19 on the highway (taking it easy, no AC, mostly empty). Driving through city neighborhoods (stop sign on every block) it got down to around 14. I switched on the AC (which is currently not working) and got down to 13.5 before getting home. City mpg may come down a bit more with more driving, but far better than the 8-9 I was seeing before.

I did also find where the high pressure AC sensor housing had backed off/unscrewed from the tube and leaked, so maybe there is hope there - but that is another thread.

One other thing I noted was that the MOPAR clutch was much smaller and lighter than the GMB, which would likely have been a factor in the loss of fuel economy with the GMB.

 

[Ken226]

It's unfortunate that the aftermarket can't seem to make anything that works anymore.

 

[bcja]

It's unfortunate that the aftermarket can't seem to make anything that works anymore.

For most things I have not had an issue with OEM aftermarket. That said, this is definitely true in this case.

The catalogs all say you need a severe duty clutch, The MOPAR was smaller, and although it was not “duty graded”, I suspect it is what the aftermarket calls standard duty.

I am curious if an aftermarket regular duty would behave like the MOPAR, but I’m not running that experiment.

All this to say it may be a marketing specification. Either as CYA for overheat damage or appeal those who prefer something called severe duty rather than standard.

 

[Ken226]

I am curious if an aftermarket regular duty would behave like the MOPAR

Lots of folks on this forum have tried. I've never heard of one working yet. Not a single one, and i've been on this forum since 2017.

Same with the aftermarket EPS racks. Not one, ever.

And lifters.

 

[bcja]

Lots of folks on this forum have tried. I've never heard of one working yet. Not a single one, and i've been on this forum since 2017.

Same with the aftermarket EPS racks. Not one, ever.

And lifters.

Good to know, thanks!