DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum

DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum (http://www.ramforumz.com/index.php)
-   5.2L V8 Specific Topics (http://www.ramforumz.com/forumdisplay.php?f=172)
-   -   Underheating (http://www.ramforumz.com/showthread.php?t=127137)

bholmes88 11-30-2012 12:23 AM

Underheating
 
I have searched everywhere and can not find the answer to why my truck is under heating. Even after running around town for a hour it does not pass 160 or so. I changed the thermostat to a 180 and nothing changed. Today I grabbed my temp gun and checked everything. The upper radiator hose heated to 130, the lower hose stayed at 83 and the heater core hoses hit 180. Any suggestions?

ramvan2500 11-30-2012 02:24 PM

Quote:

Originally Posted by bholmes88 (Post 949669)
I have searched everywhere and can not find the answer to why my truck is under heating. Even after running around town for a hour it does not pass 160 or so. I changed the thermostat to a 180 and nothing changed. Today I grabbed my temp gun and checked everything. The upper radiator hose heated to 130, the lower hose stayed at 83 and the heater core hoses hit 180. Any suggestions?

If it is taking a long time for the engine to reach temp, that is if you are going by the gauge in the cluster, then it is possible of two things I can think of one is the sending unit is faulty (happens and when they are faulty they usually report a lower then actual temp). The second thing is to keep the heater core valve closed until the vehicle reaches temp, if for instance I have turned my heat on and the vehicle hasn't already been warmed up, then sometimes the engine never reaches temp. So just make sure the valve is closing. The fact that the heater core reaches 180 tells me that is where all the coolant is going and 180, engine is practically warmed up. So check sensor, replace. Check to make sure the water valve is closing and not clogged.

Gen1dak 11-30-2012 03:38 PM

Yeah it does sound like a bad heater control valve.

bdodge445 12-11-2012 04:57 PM

Quote:

Originally Posted by Gen1dak (Post 950061)
Yeah it does sound like a bad heater control valve.

Correct me if I am wrong, but I don't believe these trucks have a heater control valve. I would lean towards a faulty t-stat even though it is new, I have had them bad right out of the box as well. I would also suggest replacing it with a 195 degree t-stat like it should have, the lower temp will tell the computer that it's cold outside and waste fuel.

ramvan2500 12-12-2012 12:39 PM

Quote:

Originally Posted by bdodge445 (Post 958247)
Correct me if I am wrong, but I don't believe these trucks have a heater control valve. I would lean towards a faulty t-stat even though it is new, I have had them bad right out of the box as well. I would also suggest replacing it with a 195 degree t-stat like it should have, the lower temp will tell the computer that it's cold outside and waste fuel.

Well if there isn't some sort of a valve the engine may actually never reach temperature because of the heater core cooling the coolant prematurely.

ramfam 12-12-2012 01:01 PM

They if I'm thinking right do have valve on pass side close to fire wall. On outlet hose. Also step up to the 196 temp. Only reason for a lower temp thermistat is if you spend a lot of time in desert or bilt eng up.

Goatboy 12-15-2012 09:52 PM

Wouldnt a lower running temp engine have the potential to last longer? My average running temp is about 160 with temps maybe getting up to 180 with alot of stop and go in town during the summer. When I first got my truck, it would reach up into the 200 range but when I changed over to full synthetic oil, I havent gotten anywhere near that. Truck heats up enough to turn heater on withing the a couple of miles. Not hot air by any means at that point, but warm enough to warrant turning it on.

ramvan2500 12-17-2012 10:50 AM

Quote:

Originally Posted by Goatboy (Post 961027)
Wouldnt a lower running temp engine have the potential to last longer? My average running temp is about 160 with temps maybe getting up to 180 with alot of stop and go in town during the summer. When I first got my truck, it would reach up into the 200 range but when I changed over to full synthetic oil, I havent gotten anywhere near that. Truck heats up enough to turn heater on withing the a couple of miles. Not hot air by any means at that point, but warm enough to warrant turning it on.

Well a cooler running engine wouldn't exactly have the potential to last longer, remember that engines are engineered around thermal expansion among other things. Overheating and underheating are both bad things, not only in the fact that one leads to detonation and pinging while the other leads to excessive unburned fuel. What engineers are do, have been doing, and will continue to do is engineer engines that can operate at there peak thermal efficiency but within the parameters of fuel type, fuel consumption, and avoiding overheating. This is very hard to do which is why many engineers recently have been spending more time with volumetric efficiency because it is much more effective, this is the reason for the increase in super chargers and well mostly turbo chargers, it's also cheaper to just throw a turbo, cheap horsepower. But for some instances like the mustang jet, they most likely threw a super charger on the engine for the horsepower because that engine is really designed around torque and it's at the low end of the spectrum so horsepower without a super for that engine wouldn't be very high. So throw a super on there and you increase torque and hp throughout the band where most of the top end power is being produced by a super charger. It is a very economical and effective way to build and engine, there engineers where very smart with designing that engine.

But anyways, the thermostat temperature is going to vary. If you are doing all out racing you are obviously going to want to keep a cooler stat because the engine will heat up rapidly. I always say keep the engine in the 180's-190's. If you build an engine with the idea of a 180F stat, then make sure the ECM is programmed for that temp and the A/F is corrected for that temp.

panhead 12-25-2012 02:00 PM

Quote:

Originally Posted by ramvan2500 (Post 958756)
Well if there isn't some sort of a valve the engine may actually never reach temperature because of the heater core cooling the coolant prematurely.

What? :LOL:


These Magnums have no valve except for a thermostat.

ramvan2500 12-25-2012 02:30 PM

Quote:

Originally Posted by panhead (Post 967546)
What? :LOL:


These Magnums have no valve except for a thermostat.

The engine has only the thermostat. But when you connect the heating system there is a heater valve. If the heater valve is open the hot coolant will get directed to the heater core. I have had instances where I left the temperature selector to heat and drove for hours and I never once reached temperature.


All times are GMT -4. The time now is 04:34 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
vB.Sponsors
= Copyright RamForumZ.com a Gigathreads.com Network Site =Ad Management by RedTyger