Thermostat part #

[therabbittree]

man I'm kinda ******... I took out a napa 180 degree thermostat and replaced it with another 180 napa thermostat. ands still no heat. . It never gets over 110 degress driving around town here. I put in a autometer water temp too. . even driving 1 hr to seafood fest only saw 115 with a infrared gun on the head when we arrived. . I plow and its cold here. . I may just yank my '89's old thermostat and try that. . kinda sucks. .

I'd like it to run 170-180 . . please.

Thanks

Deo

 

[dpuckett]

Deo- sounds like more over-priced quality from CRAPA (can you say $17 for a Wix fuel filter? ). Try an el-cheapo from AutoZone. You have nothing to lose. I got one from O'Reilley's a few years ago. It didnt sit still, but at least I had heat.



DP

 

[bgilbert]

Oh the plot thickens. Just went to Cummins to get a new t-stat for the 91. 5. Gave them my engine serial number. Hmm guess what part number came up? 3802968. Gave em my ESN for my 90 engine (non-IC'd), guess what part number came up... 3802968. But wait. Open the 3802968 box and low and behold the t-stat is stamped 3972071[yuk]! Comes with the template, and o-ring/gasket which is part number 3923331. I tell him that I really want the 2968 t-stat. Then I have him go back and bring out a handful of them 2968 t-stat boxes so I can see what stat is in them, maybe I'd get lucky and find the 2968. Negatory.



The description on the 2968 box says THM, not kit. But you still get the needed o-ring with the stat. I dug out my old t-stat box from years ago, it's dated 12-2002. This new box is dated 10-2006. Looks as though my favorite 3802968 stat is no longer available, sure the box says that, but you get the 'btoscano' stat (3972071).



Then again, I could've gotten the 3972071 stat years ago, but my box said 3802968, hmmmm ... Oh well, hopefully I'll get some heater a little quicker with this stat. I will update yall when I get this installed this weekend. Plus will let ya know what stat was in there before, it's a swinger like Daniel. . or is that like Michael:-laf :-laf . .



Bottom line though, Deo wipe your blank with anything other than a Cummins t-stat.

 

[IRoss]

When I replaced mine last spring it was with a crappy napa one, and i'm thinking i'll replace it with the cummins one now... bounces around between the first third mark and under pretty often with all the hills around here, i always though that was on the hot side, so i'm relieved to know that it is normal operating temp. My question is about the fluid level in the rad after running it a bit on the hot side... my normal rad level cold, after taking it out for a good rip, is about 1-1. 5 Litres(you guys know what those are?) down... is this normal? It will basically fill the overflow container from min. to max... Also, i read on another tsat thread that a small hole can be drilled in the stat itself to reduce the cycling. . has anybody tried this?

 

[IRoss]

... . anybody?

 

[MMeier]

Radiator should be full, all the way to the top. Cummins T Stats have those lil' " wiggle" pins in them to help alleviate any air pockets... means you should n't have to stand there forever waiting for the system to burp itself.

 

[bgilbert]

Coolant expands as it's heated. This would explain why your overflow goes from min to max. I'm starting to feel the way Daniel feels, let it cycle, who cares as long as you have heat. Not sure about drilling the stat. I thought I read that it was to aid in high RPM competition form so as to not blow out freeze plugs.

 

[btoscano]

Hey Gilbert,



You should have kept your NAPA t-stat



You can have my 3802968 if you want it, I would like to put back the old 3917324 t-stat (p/n stamped on casing) as it kept the temp steady, no windshield wipers back and forth.



Brian

 

[bgilbert]

The wiper action, no heat t-stat that I removed from this truck was just that, 3917324. I have not driven the truck hardly any at all yet, but with this new stat 3972071 it 'seem's to be even slower to warm up, and cycle as much or more than the old 3917324 stat. At this rate, I'd probly be better off with a cheap parts house t-stat. I could care less about the cycling, I just want the engine to build heat at a decent rate and give me some heat like I get with my 89 truck.



What gets me is, in the Cummins book, it shows two types of t-stats, an 'OLD' one and a 'NEW one. The 'OLD' looking like the 3972071 stat with jiggle pins at the mounting surface. The 'NEW' looking like the 3917324 I removed. It's a different shape and doesn't have the jiggle pins exposed at the mounting surface.



I'll run this stat for awhile, then if still no heat, I'm gonna try an el cheapo. BTW I know all about the heater cores, engine fan/clutch, air across radiator and heater flow valve.

 

[JStokes]

Check out this thread!

http://www.frybrid.com/forum/showthread.php?t=5187



These guys are running coolant based heat exchangers for vegetable oil conversions and need the heat. It looks like the Napa part number thm291 may work for our first gens. It opens at 190 and the extra heat should help the vehicle get better fuel economy as well. I was told the Cummins T-stat opens in two stages. (I'm not sure if this is true on the first gens) The first opening ocurs at 140 degrees and the second comes on at 180. When I had my 98 12 valve it never seemed to ever hit 180 degrees on the gauge unless I was pulling and even then it fell right back down as soon as I hit the 180 mark. If I were working my vehicle hard every day and pulling big loads in hot weather then maybe this isn't a good t-stat to change to. But if you are using the truck as a daily driver and towing on ocassion I think it should be considered.

 

[GOTSOOT]

tell me what I have here P/N-3967195W/seal 180*?also3928499/190*?