Competition Diesel.Com -  Bringing The BEST Together

Competition Diesel.Com - Bringing The BEST Together (http://www.competitiondiesel.com/forums/index.php)
-   94-98 2nd Gen. 12V (http://www.competitiondiesel.com/forums/forumdisplay.php?f=87)
-   -   Thermostat Fluctuation? (http://www.competitiondiesel.com/forums/showthread.php?t=147024)

CorneliusRox 12-27-2012 03:32 PM

Thermostat Fluctuation?
 
Alright, so I just read this:
http://www.cumminsforum.com/forum/94...mperature.html

But... When the truck was on it's original thermostat, it didnt do this.
Then I swapped the radiator and I dont remember it doing that after, then I swapped thermostats to a 24V Napa 190Deg one and it worked with fluctuation. This was over a year ago.

Two weeks ago I went to Cummins and paid $40 for a legit 12V thermostat and it wanted to operate between here (160) and here (170):
http://img.photobucket.com/albums/v7...436366AA2C.jpg
http://img.photobucket.com/albums/v7...436CF1454F.jpg

They are supposed to operate at 181deg and I wasnt seeing that. I even swapped the two seals.

I ended up getting my money back from Cummins, and tossing in a new AutoZone one from a 24V (looks the exact same as my old Napa one btw), but now I am getting the same fluctuation.

I feel like I have been in other 12V's that dont fluctuate.


Does anyone have any insight or a solution? I want to get a 24V Cummins Tstat, but if that is a waste of money, I might not. I just want my truck to warm up quickly, and then stay at temp (Ideally 190deg). Regardless of your coolant setup, (assuming your tstat isnt broken and that your coolant system can handle it) the tstat should keep the temperature at a single spot. It shouldnt dump, it should slowly open more and more to keep the engien at the correct temp.


or am I crazy?

captain_stabbin 12-27-2012 03:52 PM

mines does this bs too, change t-stats an can get it to stop either.

zstroken 12-27-2012 04:32 PM

I think it is where the sensor is located. It heats up and then gets cooler water when it opens.

BRE 12-27-2012 04:40 PM

My 12v did the exact same thing. Just never thought much of it. Block the radiator off completely in cold weather and it fixed it. Summer time, never noticed it.

CorneliusRox 12-27-2012 07:02 PM

Quote:

Originally Posted by zstroken (Post 1970336)
I think it is where the sensor is located. It heats up and then gets cooler water when it opens.

Where is it located? I have never looked for it.

Quote:

Originally Posted by BRE (Post 1970343)
My 12v did the exact same thing. Just never thought much of it. Block the radiator off completely in cold weather and it fixed it. Summer time, never noticed it.

What do you mean by blocking it off completely? I would definitely overheat.


Hmm, this is lame. I have now tried a 12V and an early 24V Tstat, Does anyone have any specs on common rail ones? I dont know if they have better thermostats, the sensor in a better place, or if they just program the gauge to average readings or something?

BRE 12-27-2012 08:00 PM

Mine never once started to get hot. I put cardboard in front of the radiator...

CorneliusRox 12-27-2012 08:03 PM

Quote:

Originally Posted by BRE (Post 1970511)
Mine never once started to get hot. I put cardboard in front of the radiator...

ahh, that's not the same as completely blocking it off. I have tried that before with insulation board inbetween teh radiator and intercooler. I didnt like it.

JSaat 12-27-2012 08:04 PM

Quote:

Originally Posted by BRE (Post 1970511)
Mine never once started to get hot. I put cardboard in front of the radiator...

I just take mine out when its cold Rick why dont you do that? works well!

BRE 12-27-2012 08:07 PM

Well it seems to same to me when none of it is uncovered. I block the entire face off.

Jesse your a tard lol

little6cylinder 12-27-2012 08:34 PM

Quote:

Originally Posted by CorneliusRox (Post 1970441)
Where is it located? I have never looked for it.



What do you mean by blocking it off completely? I would definitely overheat.


Hmm, this is lame. I have now tried a 12V and an early 24V Tstat, Does anyone have any specs on common rail ones? I dont know if they have better thermostats, the sensor in a better place, or if they just program the gauge to average readings or something?

The sender is located in the back of the head on the driver side. It's in a fine place. That doesn't matter for when the thermostat opens anyway though(I know you understand that, just for anyone that searches for this later). We should check your fan hub and throw the good flowing cummins t-stat back in.

307diesel 12-27-2012 08:34 PM

My 12v does the same thing and has for the last 200,000 miles. The heater is always hot and it doesn't overheat so I don't worry about it. Who's to say that your guage is correct, such a new truck and all. The sensor is in the driver side rear of the head.

Chris Mallett 12-27-2012 08:42 PM

I use a winter front on mine and leave it completely blocked off under 30*. Will open the center flaps if temps over 45*, have to remove completely if over 60*. It won't get hot just truck alone, but dislikes towing over 6k with the centers open and over 40*.


Back to the OP, almost every 12ver I have encountered has your same issue. Cover it and let it keep heat.

madmikeismad 12-27-2012 08:51 PM

I run without the fan must of the year, and cardboard in the winter, still never see over 170.

Sent from my DROID RAZR using Tapatalk 2

9612vinva 12-28-2012 11:54 AM

From what I have read the only reason the newer trucks don't do it is because dodge programmed them not to since there were so many complaints about it...

I have had 3 12v and they all have done it...

RockinRam96 12-28-2012 12:39 PM

I put a new radiator in my 12 valve last fall and noticed this to happen with my gauge. My gauge fluctuates from 190 to about 150 though. However, the water temperature never gets over 190, even in the summer pulling a 4,000 lb horse trailer. I dont' know when the last time the t-stat was changed, I dont remember if I changed it with the radiator. I'd have to check my book. Mine takes a little bit to warm up on cold mornings but when it does you know it! It has never really bothered me much.

My 24 valve has new NAPA 180* t-stat and original radiator and does not do this.

If your worried about heat just plug it in over night and start it 5 to 10 minutes early.

CorneliusRox 12-28-2012 01:24 PM

I am not worried about heat. I just want my truck to get up to temp quickly, and then stay exactly where it should.

Also, 12v thermostats are 181deg, and 24v are 190deg. At 190deg, your engine should be slightly happier, and seals will last just as long. The 24v thermostats are about 1m smaller in diameter than the 12v but they fit without leaking. Just some useful info for you guys.

f6jbob 12-28-2012 01:38 PM

Anytime you power wash your radiator or install a new one you will get this fluctuation. Like others have said get cardboard the size of the radiator and cut a 8" to 10" hole in the middle. Problem solved.

Tate 12-28-2012 02:00 PM

Quote:

Originally Posted by 307diesel (Post 1970542)
Who's to say that your guage is correct,

This.

My 12v gauge always says its running cold. The previous owner installed a separate water temp gauge under the dash. When I first bought the truck, it would run from 170-190 for hours on end, always up and down. A big rad will do that. That t-stat died on me about 2 years ago, got another one from Cummins, this one hold temp real steady, usually cools down when I'm coming off the highway slowing down in the winter.

I wouldn't worry about it. Your truck isn't the first to do it, and it won't be the last.

haloman 12-28-2012 02:22 PM

What Tate said. Got to keep in mind these truck were designed to keep cool in 100deg heat while at max capacity.

Custom cardboard insert with a hole cut in the middle always did the trick for me.


All times are GMT -5. The time now is 06:16 PM.

Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2006 - 2024, CompetitionDiesel.com
all information found on this site is property of www.competitiondiesel.com