overheating last night

[treegump]

Of course it had to happen on the coldest evening so far. -20 windchills, 5 degrees outside. My blower motor is going out (1st setting doesn't really work, but 4th seemed to work ok) I cracked my hood open and ran like that for the rest of the way. My buddy came to rensselaer and took the thermostat out (he jumped into the engine compartment before i had a chance), and I drove it to work this morning w/o a thermostat with it being 5 degrees outside. (Never got above 160 degrees - had 4 layers of clothes and could still see my breath.)

My buddy, Chuck, said it was ok to run w/o a thermostat but then I read that its not good because its not pulling the heat as it should...is this correct? I'm getting an AC delco from a chevy dealership for 32 bucks (only place close by to sell it) I'm also ordering a pmd extension cord and heatsink to get the pmd off the intake.

With it being 5 degrees and me not pushing it hard - do I need to worry about the engine too much? It ran for 2 hrs highway, 1 hr sitting, and it never sounded like there were any problems.

 

[ak diesel driver]

mileage might suffer but you should be ok and btw the ac delco tstat is the one you want

 

[treegump]

mileage might suffer but you should be ok and btw the ac delco tstat is the one you want

yea -i specified that with the gm stealership. They want 32 bucks - but the number matches up - both the ACDelco & GM number match apparently, and that's the closest. Just gotta find a place to spill a little coolant.

 

[ak diesel driver]

throw some cardboard over the rad until you get it changed just keep an eye on the temp guage

 

[WarWagon]

Check the old t-stat in a pot heated on the stove with a thermometer. This makes sure it is the problem. Otherwise it is possible for snow to plug the condenser and overheat the engine. Or other issues...

 

[treegump]

temp gauge hasn't even twitched in the 3 hrs it ran. I shut the truck off immediately after coming across something about the truck not cooling due to the coolant not being able to absorb the heat

 

[treegump]

Check the old t-stat in a pot heated on the stove with a thermometer. This makes sure it is the problem. Otherwise it is possible for snow to plug the condenser and overheat the engine. Or other issues...

well, if that were the case - then with the t-stat removed, the engine would still be warming up, wouldn't it? And, I don't know if you suppose to be able to push the spring up by hand, but we couldn't last night when we tried.

 

[ak diesel driver]

I don't think I'd worry to much about the coolant not absorbing heat. Without the tstat in water is being cooled faster than your heating it up

 

[docdray]

yes it is true that coolant moving too fast cannot soak the heat from the metal, but you are not in 110 degree desert heat. being so cold outside makes the heat transfer not so critical- in summer you would need every bit of efficiency to cool the engine.

 

[treegump]

okay - thank you so much for the reassurance. I really hate to second guess Chuck (my best friend/bro) but he already doubts this 6.5 and the credit all you guys give it.

(He had a 6.2 and was not impressed at all, and I think he just gives the same mindset to the 6.5. After telling him I'm getting about 4-6 lbs of boost and 9 max he's scared i'm going to blow a gasket, and telling me not to do anything to it - that the motor can't take it. When I tried to explain that it could be a great truck, he offered to tie his 02 F250 with powerstroke and performance clutch onto it and do a pull off...I don't think so - not yet anyways )

 

[docdray]

i'm sure you know some of the 6.5's weaknesses, but to compare a NA to a turbo is faulty brain cells. the 6.2 was for mileage and it accomplished just that, 6.5 was slightly different goals.
on to the powerstrokes-most PS's I know (except 7.3) personally, have had major issues. 2- rods through block, 1- head failure, 1-chronic injection issues, and the duel-turbo's, extremely disappointing in my and the owners opinion.

pull-off-hahahaha- how about ride-off, or ergonomic-off. you buy the truck you got for overall reasons, If I wanted a truck to out pull my buddies I would have bought my friends Peterbuilt. I love the ride and look of chevy (bowtie on front too). GM, dodge, ford all have pro's and con's-thats why they (MFG) offer different engine packages.

 

[treegump]

so...i thought the acdelco 131103 was for my truck so that's what I ordered through the stealership. I get there and its the wrong size and wrong kind...or is it? The one I pulled out has 2 springs, but I only pulled 1 thermostat out. (I don't know if people can interchange them or not). attached is a picture of my thermostat housing. And also the line on the passenger side where I think coolant is leaking from (in very very small amounts).

The guy at the counter said he was showing 2 thermostats, and another customer who had a 99 said he changed 2 thermostats and insisted that I should have 2 as well. Am I missing something here?

Anyway - he (the gm parts guy) said he found the thermostat - did I want 1 or 2. I told him 1 because before I yanked the old one the engine was getting further and further to the right of 210, and now I have absolutely no heat in the cab and the engine temp hasn't moved...so I figure I only have 1. Again...am I an idiot here?

 

[WarWagon]

1997+ has dual t-stats. Yours does not.

The snow will melt when you stop and let the radiator heat melt it out. This is for blizzard conditions though. Or if you start up the day after and hit the freeway w/o a warmup.

Race cars run restrictor washers rather than thermostats. As the water spends 0.7 seconds in a Duramax radiator the restriction become important from the t-stat even wide open...

Again test yours boiling water it should open wide up - not open then it is bad. Otherwise you may have to look for other cooling system problems. T-stats usually stick open... But die both ways.

 

[treegump]

1997+ has dual t-stats. Yours does not.

The snow will melt when you stop and let the radiator heat melt it out. This is for blizzard conditions though. Or if you start up the day after and hit the freeway w/o a warmup.

Race cars run restrictor washers rather than thermostats. As the water spends 0.7 seconds in a Duramax radiator the restriction become important from the t-stat even wide open...

Again test yours boiling water it should open wide up - not open then it is bad. Otherwise you may have to look for other cooling system problems. T-stats usually stick open... But die both ways.

well, i ran my truck on high idle for about 1/2 hr or 45 minutes before driving in the blizzard. I would think that in that time it would have melted whatever. But even while sitting it didn't seem to do anything, and with the hood popped open and heater turned up all the way, there still didn't seem to be a difference in the temperature - only when i sped up or slowed down

 

[treegump]

new on the left [ac delco 131-91 (what is the opening degree on this?), old on the right. I don't see a secondary spring on the left - so if there is one - it must be inside.

 

[ak diesel driver]

Tstats changed mid year in 96 even the napa book asks which you have single or duals. I have duals on my 96

 

[docdray]

single tstat up to late 96, then gm went to duel tstat and ho water pump, pic shows single t stat on your truck. should be able to xreference number on tstat and see if it crosses to new one you have. keep single, if want to upgrade cooling, talk to heath who recommends the single.

 

[Brooklyn Tow]

There should be a part # in the Diesel Tech Reference Library.

 

[Pruittx2]

Thermostat Unknown – 12551496, AC Delco - 12559338
Thermostat (195 for dual) OEM – Thermostat Unknown – 12551496, AC Delco - 12559338


These are in the tech ref library,, but there doesn't seem to be one for single t-stat.
I just bought one of these on the bay for 14.95 total shipped 12559336
I hope it will work in my single 94 system. I bought it more as a deal, than that I needed it.

 

[Brooklyn Tow]

Call Heath...Maybe he'll give you a part#.