Cat 3126 Warm Up

[P51bombay]

The one in my T300 seems very cold blooded, even after running 15 minutes it takes another 3 miles driving before it gets up to 125F and produces any cab heat. The one in the M2 was a bit cold blooded as well but was blowing somewhat warm air after 10 or so minutes and the temp was up to 125F. I've also noticed that after when it finally does get up to 185F, just a few minutes idling has it back down at 155F.

Either it needs a cold front or I'm thinking maybe the thermostat is stuck open - anyone know if this engine has a fail safe (sticks open) type of thermostat?

 

[danthewolf00]

lol even my sprinter needed a cold front this year so i don't think it's the thermostat.

 

[P51bombay]

lol even my sprinter needed a cold front this year so i don't think it's the thermostat.

umm.........I'm not talking arctic conditions here, only talking about lows around 28-34F and its still taking quite a long while whereas the same engine in the M2 I had up till this month was producing heat after 10 minutes or so - maybe not HOT air but enough to defrost the windows..

 

[Refer Hauler]

I don't know the year of your 3126 but since you called it a 3126 and not a C7 it may be a pre-emission engine, but I've noticed the same slow heating on my detroit. The 02 would warm up like you said in 10 miles or so, The 08 is considerably longer. I think it is due to the increased cooling capacity on the 08 due to the more stringent emisissions.

Be carefull with winter fronts! if engine is working hard you can deflect the plastic (or whatever they are) fan blades enough to come in contact with the radiator. I've done it.

 

[P51bombay]

Truck is a 2003 although I think the engine is 2002 production. Obviously there's no DPF but strangely it does have a catalytic converter in the muffler(single vertical) complete with O2 sensor. Talked with the mechanic and he agrees that it probably has a bad thermostat and said they do stick open which would explain the long warm up. Taking it in next week for an oil change, and new belt anyway so even if only for the piece of mind of knowing it wont fail any time soon I think I'll get it changed.

 

[bluejaybee]

I have never had a 3126 that new, but had a 2001 and 2 2000's. All three of them had 2 thermostats in them. I think the C7's came out in 2004. When you first start them in cold weather, 135 is not going to warm the interior up very fast.
All of mine would cool way down idling in cold weather. Around 130 to 155. Idling at night for heat, they kept me warm. Of course, once I hit the road, they would come back up to around 185. Also, everyone of mine, if you watched the temp gauge, you would see it rise and fall a slight amount as you go down the road. Sorta scary, but, guess it is normal.
BTW: the thermostats look just like any other ones you have seen. Nothing out of the ordinary about them. They are easy to replace if you want to do it yourself, but I think you are going to find it of no help in warming you up any quicker. Dang diesels are cool runners and only get hot under load.