Teardown and Rebuild

[CSM]

same sound here.  big rig fan.

[Me78569]

mine too, but mine doesn't kick on until above 200*f

[CSM]

9 minutes ago, Me78569 said:

mine too, but mine doesn't kick on until above 200*f

 

mine doesnt kick at a set coolant temp, but when the fan heat soaks enough.  like stop and go after a pull on a hot day.... when just towing, it rarely comes on.  

[Me78569]

I wouldn't call mine a set temp either, but it never kicks on unless a good bit above 200*f

[TFaoro]

Mine is kicking on driving around town without anything hooked to it in 75-80 deg weather.

[CSM]

17 minutes ago, TFaoro said:

Mine is kicking on driving around town without anything hooked to it in 75-80 deg weather.

 

that isnt necessarily a bad thing.  as long as the ac stays cold you know you're getting airflow.  

[TFaoro]

6 minutes ago, CSM said:

 

that isnt necessarily a bad thing.  as long as the ac stays cold you know you're getting airflow.  

More annoying than anything. Plus, it does use some amount of fuel when it's locked.

[AH64ID]

5 hours ago, TFaoro said:

That I would get, but these were small short hills. The one longer one I only had it pinned for 15 seconds or so. The rest of the  time is was maybe 50% throttle.

I feel like if it was a long hard pull the temps would have easily kept climbing, even though the fan kicked on at 197 (seems low for the fan to be on????)

 

I would suspect thermostat before radiator. At flat cruise, even with a trailer, the radiator shouldn't be really even all that warm. 

 

IIRC you replaced the thermostat recently. What brand did you go with?

 

50% throttle is still about 100% of stock :-) 400-450 rwhp is about the limit of the cooling system (oil and coolant) for sustained use on a ISB. 

 

Did you pull/clean the radiator with the rebuild?

 

 

No clue on the fan... 3rd gens are electronically controlled. 

Edited June 13, 2016 by AH64ID

[TFaoro]

5 minutes ago, AH64ID said:

 

I would suspect thermostat before radiator. At flat cruise, even with a trailer, the radiator shouldn't be really even all that warm. 

 

IIRC you replaced the thermostat recently. What brand did you go with?

 

50% throttle is still about 100% of stock :-) 400-450 rwhp is about the limit of the cooling system (oil and coolant) for sustained use on a ISB. 

 

Did you pull/clean the radiator with the rebuild?

 

 

No clue on the fan... 3rd gens are electronically controlled. 

The thermostat was replaced last week with a Napa. It acts nearly the same as the one that was in it before.

 

I doubt it's making 400+ with the settings I had it on. Stock fueling with some timing. Even if it was making 300hp to keep going (I don't think it was on the rolling hills) the cooling system should have been able to keep up easier.

 

Yes, the radiator was power washed on the outside and rinsed on the inside.

 

I wish I could stuff one of those fan clutches in mine! Too bad they turn opposite directions.

[AH64ID]

Was the previous thermostat a NAPA one too? There are plenty of complaints on non-Cummins thermostats. 

 

Lets go lower and say you were making 250 rwhp on the hill. I still would have expected to see 207° out of that much power since 207° is full open. In my experience getting to 207° isn't all that hard above 16K GCW and it should climb slower once it's full open. 

 

It's been a few years but the last time I towed with stock software and stock injectors I would go to 100% load at 65-70 in 6th on very small hills at ~16-17K GCW. The rpms and stock power curve put me at ±200 rwhp. Coolant temps would go to 205-207° on short 1/2 mile shallow grades. So you may have been making more power than you think. 

 

I assume that the 10-11K was the trailer, so you were at 17-18K combined? 206° on a small hill is where I would expect to see the coolant at. 

 

 

Edited June 13, 2016 by AH64ID

[TFaoro]

2 hours ago, AH64ID said:

Was the previous thermostat a NAPA one too? There are plenty of complaints on non-Cummins thermostats. 

 

Lets go lower and say you were making 250 rwhp on the hill. I still would have expected to see 207° out of that much power since 207° is full open. In my experience getting to 207° isn't all that hard above 16K GCW and it should climb slower once it's full open. 

 

It's been a few years but the last time I towed with stock software and stock injectors I would go to 100% load at 65-70 in 6th on very small hills at ~16-17K GCW. The rpms and stock power curve put me at ±200 rwhp. Coolant temps would go to 205-207° on short 1/2 mile shallow grades. So you may have been making more power than you think. 

 

I assume that the 10-11K was the trailer, so you were at 17-18K combined? 206° on a small hill is where I would expect to see the coolant at. 

 

 

Thank you for the explanation. I believe what you're saying now.

As for the fan clutch, I still think it's shot. It's locking up before the coolant even circulates -__- So annoying!

[AH64ID]

Yes you could have an early lockup issue on top of it. 

[Mopar1973Man]

 

Take note of my high mark on the coolant. That is where the fan locked fully and sounded like a turbo prop.  As for the IAT I'm sure some are going to comment on that high mark. That is what happens when you exhaust braking for miles in 4th gear.  As for normal driving the needle typically sits right in the green band for IAT.  Also no MPG fooler was used also not required. Weather during this was 87*F outside and mild breeze.  Edge Comp on 1x3 just for fun too. Fun part of the IAT subtract 40 from that number your match my outside temperature... 87*F. I'll admit also I was towing faster than I normally do just to get some test data from high speed towing. All I can say I don't see any benefits to towing at high rate of speed.

Edited June 14, 2016 by Mopar1973Man

[notlimah]

My fan will do the same thing! How hard is a fan clutch replacement? If you end up doing yours take lots of pics please! 

[TFaoro]

12 hours ago, Mopar1973Man said:

 

Take note of my high mark on the coolant. That is where the fan locked fully and sounded like a turbo prop.  As for the IAT I'm sure some are going to comment on that high mark. That is what happens when you exhaust braking for miles in 4th gear.  As for normal driving the needle typically sits right in the green band for IAT.  Also no MPG fooler was used also not required. Weather during this was 87*F outside and mild breeze.  Edge Comp on 1x3 just for fun too. Fun part of the IAT subtract 40 from that number your match my outside temperature... 87*F. I'll admit also I was towing faster than I normally do just to get some test data from high speed towing. All I can say I don't see any benefits to towing at high rate of speed.

Interesting, with my mishimoto intercooler I always see 30* above OAT.

It looks like your coolant was right about 207-209?? I'd be fine with mine locking up right there.

 

11 hours ago, notlimah said:

My fan will do the same thing! How hard is a fan clutch replacement? If you end up doing yours take lots of pics please! 

Should be cake... big C clamp on the belt (around the fan pully) and a big crescent wrench. I'm pretty sure it's a 36mm.

[Mopar1973Man]

You might want to get a fan pulley tool. Fairly cheap at a NAPA store I bought one for $18 IIRC...  Basically hooks the pulley bolt giving you a way of hold it from turning without damaging the pulley.

55 minutes ago, TFaoro said:

Interesting, with my mishimoto intercooler I always see 30* above OAT.

 

As for the -10*F difference in IAT make little to no difference really. Might for racing where EGT have to stay in check but for daily driver there isn't enough to worry about.  Being the green band is most optimal for 24V MPG wise. I'm not sweating it at all.

[CUMMINSDIESELPWR]

the way i remove fan clutch, propane torch on the nut that threads onto the pulley to get it hot and expanded, put the fanclutch tool on and give it a good solid whack clockwise to release nut and it spins off. do it with belt on everytime 

[TFaoro]

Bought a trailer this weekend.... 6K axles and uses a 2 5/16 ball. Needs some TLC but I couldn't pass up the deal! 

Sure beats dragging the gooseneck around for 100 bales

[leathermaneod]

Looking good!

[Mopar1973Man]

I see someone has the Ford squat problem... LOL

Edited June 20, 2016 by Mopar1973Man