Weekend maintenance on the '01

[GW208]

Where is a good place to get the Cummins thermostats? I've gotten them from Geno's in the past but they don't seem to carry them anymore.

 

[Joe Mc]

Could it be that one time you used the red stuff the system wasn't air burped? You're a long standing member, I won't even ask if you used red Toyota coolant or Dex-Cool by mistake ;-)

Not sure what red stuff I used? I doubt there was any air in the system since we drove from Levittown, PA to Yellowstone. We made many stops along the way, even drove out in the desert for hours in 100+ degrees before we got there. I check everything at every fuel stop when traveling. Anyhow, entered Yellowstone on the old entrance, very narrow and steep if I recall correctly, it was slow going and I had the A/C on. Shouldn't have been an issue with the A/C being on as it never was in any other condition? Who knows for sure, anyway I'll never wander from the good old green again, at least in this truck.

NIsaacs, I'm almost certain there's something different (other than high price) about the Cummins Water Pump and T-Stats that makes them far superior than aftermarket parts store ones. I seem to recall there's a small hole in the outer edge of the T-Stat that needs to be up when installed, I believe it helps get air out and allows for slight by-pass when stat is closed. I just know I've had great luck using Cummins cooling parts over parts store stuff.

 

[Joe Mc]

Where is a good place to get the Cummins thermostats? I've gotten them from Geno's in the past but they don't seem to carry them anymore.

GW208 - here's an address to the Cummins locator - https://salesandservice.cummins.com/locations, you should be able to enter your zip code and locate one near you. Call to see if they have your part. They'll ask for engine model and serial number, which is located on a plate attached to the timing gear cover left (driver) side.

 

[Joe Mc]

Nick, I just remembered some years back (3 or 4???) I installed a new fan clutch only because I read on the TDR that as they age they can lose 2-5 degrees cooling per year. Like I said I only replaced because it was 10+ years at the time. BTW I purchased mine (Mopar #52028615) at Geno's. I think I still have the original if you'd like it just for a try of something different. PM me if interested and for cost of shipping it's yours.

 

[GW208]

GW208 - here's an address to the Cummins locator - https://salesandservice.cummins.com/locations, you should be able to enter your zip code and locate one near you. Call to see if they have your part. They'll ask for engine model and serial number, which is located on a plate attached to the timing gear cover left (driver) side.

Thanks Joe.

 

[NIsaacs]

[QUOTE="Joe Mc, post: 2568448, member: 8327"

NIsaacs, I'm almost certain there's something different (other than high price) about the Cummins Water Pump and T-Stats that makes them far superior than aftermarket parts store ones. I seem to recall there's a small hole in the outer edge of the T-Stat that needs to be up when installed, I believe it helps get air out and allows for slight by-pass when stat is closed. I just know I've had great luck using Cummins cooling parts over parts store stuff.[/QUOTE]

I have seen this time and time again about the Cummins t-stat, I need to order one (5292742). Here is a picture of my Napa 180 and 190. As far as water pump, I would think the impellers would be the same, Cummins v/s aftermarket but maybe not. I do know there are two types, here are some pictures.

Joe, do you still have your OEM radiator and if so is it 2 or 3 core? The OEM 12 valves used 3 core but the OEM Mopar replacement and aftermarket are 2 core. My '01 OEM was 2 core, the new one is 2 core.

Since the new Hayden clutch is no better than the old one, I am going to take it off and put my newest old Mopar back on. When I installed the 180 stat I only used the truck a few days before I changed to the Hayden clutch. I didn't give the Mopar clutch enough time for a good test. I wonder if my Napa stat is not opening enough when hot to give the radiator enough hot coolant to get it hot. Maybe my radiator is not hot, maybe it is just the engine that is hot. If so, that would explain why the Mopar clutch is slow to engage.

Ordered a thermostat from Rocky Mountain Cummins, Phoenix, should be here tomorrow.

 

[Joe Mc]

Nick, I wouldn't go out and replace the water pump, but I did notice the vanes on the Cummins pump are different than the parts store one that failed every year. Forgot to mention = the parts store honored their warranty and refunded me current price in full + tax when I returned their pump and said I was purchasing one from Cummins! Rare! I didn't notice any difference in cooling ability tho. I did replace the OEM radiator with like and kind (from Advance) back in 01/2012 (just went out and checked) it measures 2-¼" deep (across the top) so whether it's a 2 or 3 row??? Been thinking a bit about your dilemma... a few questions (don't be offended) 1- do you have a shroud, 2- have you checked the front of rad (between A/C condenser and rad) to see if it's clogged/restricted with oil/dust build up (not sure if you have extended the breather tube from the gear case or not, 3- are you running stock turbo and have increased power? Not sure but, does a 90CTD have intercooler? Are you fully gaged up = fuel psi/boost/egt? Seems like you shouldn't have cooling issues unless there's a restriction somewhere = internal, external, or lack of flow. I'd try the Cummins T-Stat and check radiator for cleanliness. If no shroud that makes me think the rad isn't able to cool like it should...

 

[NIsaacs]

Joe, Yes, my oem shroud is in place, the system is clean, radiator is new 5 years ago. I installed an Edge Juice 4 years ago, still using the stock turbo, this is when I started having heating issues. Prior too, is had an Edge EZ/RV275 injectors for 12 years, never really had an overheat issue then. However, part of my concern is I now have a digital temp gauge, so now I can see exact temps that were only vague before, oem gauge. It really didn't send up any red flags. All gauges are scattered all over the truck Vent tube is installed.

The 1st gen intercooler arrived in '91.5, mine has it. I don't have an issue with it or the Ford/Cummins but they have less power. I run my '01 on 2-5, 5 seems to get the best mileage, max boost is 34 psi, max EGT's are set for 1350* On a cold day, (40*) it will barely hit 1250 wot, pulling hard. In the summer it will hit 1350 in about a 1/2 mile, wot, pulling hard.

I just installed the Cummins 180* t-stat and installed my oem Mopar fan clutch. I just did a quick shake down run to burp the system and the t-stat seems way more stable than the Napa. This was just a light duty cruise, I will know more as soon as I can load it up.

The new Cummins stat is on the left, center is 190*, no clue on the brand but looks like the Cummins style, right is 180 Napa.

 

[NIsaacs]

This time of year I don't have a problem so I will be fine until summer. I am almost certain I will need to upgrade the radiator or fan or both. Turning down the Juice is not an option nor is turning off the A/C.

I have looked at all the E-bay sellers of the all aluminum 3 and 4 core radiators. The price is good but am not convinced of quality. I will most likely go with a 3 core from Radiator Express, they have a 50 year track record with great reviews.

http://radiatorexpress.com/product/all/dodge/2001/ram 2500 pickup/quad cab/59l-l6/221747/1400072

 

[ofelas]

Some FSM testing if you haven't already -

 

[NIsaacs]

Thanks of, if this t-stat and clutch don't work together, I will do the test. I would have liked to do that with the Napa t-stat to compare.

 

[Joe Mc]

Nick, Just thought I’d give you some info as comparison from mine: As it begins to come up to full operating temp the (stock) temp gage approaches 190* (sometimes it will go a bit over 190*) then temp drops to about 170-ish and gradually works back up to 190-ish and the cycle continues. I’m pretty certain I installed a 190* stat and but the temps (even tho on the stock gage) I’d say my recollection is spot on. Hope things work out for you. BTW I’m taking a 2.5 hr trip this coming week, if you’d like I can observe and try to time the stat opens to close/reopen at like 75MPH. Let me know

 

[Mikey-KE7LBB]

There are differences in the water pump designs that affect flow rates. The newer trucks have the lowest flow rate with the open fin impeller, and the the 1st gens used the highest flow rate closed vane design... It seems the higher the HP goes, the slower the flow rate?? This leaves me scratching my head, but Cummins QuickServe still shows different pumps for the '92 vs. '09, while NAPA has the same PN for both.

Not sure which is best, but I'm sure it has something to do with past customer complaints about "wild gauge movements"...

 

[Joe Mc]

Mikey, Good point! Now that I think of it the aftermarket ones I got (each "new" not reman pump lasted 1 year +/-) had open vanes the Cummins one (as well as the original one) had closed vanes.

 

[ofelas]

Has to do with emissions requirements on the newer trucks, hence the slowed down flow for higher temperatures.

I changed the shrouded water pump to one of the newer open vane Cummins pumps, as I barely tow/haul & live mostly in Canada.

The other way to use a slower flowing water pump is to clip the vanes on the existing pump.

There are differences in the water pump designs that affect flow rates. The newer trucks have the lowest flow rate with the open fin impeller, and the the 1st gens used the highest flow rate closed vane design... It seems the higher the HP goes, the slower the flow rate?? This leaves me scratching my head, but Cummins QuickServe still shows different pumps for the '92 vs. '09, while NAPA has the same PN for both.

Not sure which is best, but I'm sure it has something to do with past customer complaints about "wild gauge movements"...

 

[JR]

Has to do with emissions requirements on the newer trucks, hence the slowed down flow for higher temperatures.

I changed the shrouded water pump to one of the newer open vane Cummins pumps, as I barely tow/haul & live mostly in Canada.

The other way to use a slower flowing water pump is to clip the vanes on the existing pump.

Just thinking out loud here, but I think there's more to it than that, especially since final temperatures are largely controlled by thermostats. I actually ran a 6.7 stat in my 98 a couple of our colder winters. It ran hotter (200), but I found that any time I towed the fan ran significantly more so I went back to my 190.

A modern 6.7 compared to an early 12 valve - more displacement, more hp, EGR (think heat load). Not to mention post injection event, etc. etc. It could just be that when the 6.7 was designed it was done so with larger or maybe even better placed, coolant passages, and subsequently a lower flow pump.

 

[ofelas]

Not to mention a much better designed head & multiple injection events.

Just thinking out loud here, but I think there's more to it than that, especially since final temperatures are largely controlled by thermostats. I actually ran a 6.7 stat in my 98 a couple of our colder winters. It ran hotter (200), but I found that any time I towed the fan ran significantly more so I went back to my 190.

A modern 6.7 compared to an early 12 valve - more displacement, more hp, EGR (think heat load). Not to mention post injection event, etc. etc. It could just be that when the 6.7 was designed it was done so with larger or maybe even better placed, coolant passages, and subsequently a lower flow pump.

 

[NIsaacs]

A modern 6.7 compared to an early 12 valve - more displacement, more hp, EGR (think heat load). Not to mention post injection event, etc. etc. It could just be that when the 6.7 was designed it was done so with larger or maybe even better placed, coolant passages, and subsequently a lower flow pump.

The 6.7 has a 7 impellor water pump v/s 5 on a 5.9, so I think the 6.7 has a higher flow. I think a 6.7 pump will bolt on a 5.9 but I am not sure that would be a good idea/upgrade.

That is interesting that the open pump has less flow than the enclosed type, that looks/seems backwards. My oem was open, one replacement was closed and now my last one is open. I never really noticed a difference but I probably wasn't watching close enough. The closed one, Car Quest (GMB) only went 24k, I have a Napa open now.

 

[JR]

It does seem backwards to me as well. The extra heat load from the EGR alone would make you think there would be a need for a higher flowing pump. It may just be a byproduct of the efficiency of the newer engines, all the "new age" SCR equipped tractors on the farm have smaller cooling systems - radiator and coolant capacity - than the old stuff I grew up running.
This is also true in our trucks. My 98 coolant capacity - 6 gallons. My 14 coolant capacity - 5.7 gallons. A 1/3 gallon doesn't seem like much but when you factor in the differences you would think it would at least be the other way around.

 

[Joe Mc]

Nick, For what it's worth, during my 2.5 hour trip - @ 75 mph, outside temps in the low-mid-40's, pretty much flat road (from beginning of PA Tpk close to New Jersey onto the N/E ext and out to Pittston, PA) I saw the stat open at slightly over the 190* mark, once it opened it settled in at around 180-ish and stayed there the remainder of the trip.