2nd Gen Non-Engine/Transmission no heat

[mwilson]

Sean,

Did you try the flush last night and if so, any improvement??????

 

[SRath]

My heater box and ductwork have special internal insulation. I removed it several months ago but it has grown back all on its own. And my heater will roast ya!

Since this bait didn't get any bites, I'll voluntarily confess that my "special internal ductwork/heaterbox insulation" is from pesky mice who just will not stop building nests in there. Nice fluffy ones that blow paper towel confetti out the vents. Its gotta be pretty good insulation.



I think once they leave their pheromone trail that no matter how many I erradicate and how many times I clean out the box and ducts, more mice just follow. All I have to do is let the truck sit for a week or more and the little buggers come back. If you ever ride in my truck, be careful about where you stick your fingers (under the seats for example) since I leave the traps armed.

 

[mwilson]

I was going to nibble but unsure if I really wanted to know what your "Special Insulation" was. :-laf:-laf

 

[The patriot]

Oh yea, I should mention my old heat coil and a/c evap coil were so clean they'd almost pass for new.

I do clean leaves & pine needles from the intake frequently, and in the summer I take it off AC and run it on vent for about 1/2 mile before I'm home.

I also spray lysol/oust or something like it in the intake about 1x a month.

 

[SeanM]

Well I'm impressed. I went and got some radiator flush from napa and filled the heater core with it. I did this 3 times throughout the day and then blew it out with about 15 psi of air. Then I filled the heater core with distilled water a few times and blew that out as well.



I topped her off with coolant and its now like a inferno coming from the vents. I can't believe it, I didn't even get anything out of the heater core. All the coolant, water and flush I took out I put in gallon water containers. I then filtered it through paint filters and I may have had a few small pieces of crap but nothing really to write home about. Anyways I am really glad I tried that instead of what I was going to do. Thanks

 

[mwilson]

Glad to hear it!!!



We got very little debris out of mine, you don't think it was even worth doing until you turn the heat on after flushing.

I guess that will be part of my annual fall vehicle prep from now on.



Be warm and prosper... ... .....



Mike.

 

[SeanM]

Well here I go again. I have no heat. When I was working on the truck its was in a heated shop for about 5 hours. After I finshed flushing the heater core I let it warm up outside and then took it for a 6 mile ride and the heat was great. I even let the windows down to let the heat out and it warmed right up again. (outside temp was 28) Tonight on the way home it was about the same outside and my heat was like it was before I flushed it.



When I got home I tried to"burp" the engine and the heater core again thinking maybe I had a air bubble stuck and still nothing. I am really perplexed now.



Whiskey Tango Foxtrot!!!!!

 

[mwilson]

Maybe it is air, that is some strange behavior.



Something else that I just thought of that you see in big trucks from time to time,



Could your water pump impeller be slipping??? In cold weather the engine wouldn't really reflect it as the cooling system is so big but there would be very little flow thru the heater.



How far do you commute??



When the truck was shop warm maybe it took a hold of the shaft for a while until you shut it down and let it get cold. Then the coolant would be slightly thicker and harder to push.



Just a thought, it can be a b**** to diagnose one especially in the winter.

 

[SeanM]

My commute is about 20 miles. I normally let her warm up 5-10 mins before I leave work and my thermostat opens up right as I hit the on ramp for the interstate. My water pump isn't slipping either. This is really wierd. I really don't know what could be the problem at this point.

 

[SeanM]

hey mike do you think you you could shoot your heater hoses with you IR thermometer and let me know what the temps are. I am just going to buy a new thermometer tomorrow and will use your temps as a baseline.

 

[mwilson]

Sure, I am going on a 400 mile round trip tomorrow chasing a snowmobile. I will check them a couple times during the day and let you know either in the evening or if it is late I will post it Sunday.





Mike.

 

[mwilson]

Sean,

Had 20" of snow here yesterday afternoon so let the truck run while snowblowing and shoveling this morning.



Truck showed 150-160 on temp gauge, shot the lines and got 160 inbound and 150 outbound from the heater core. Outside air temp was 5 degrees.



Found the easiest place to do so was st the end of the steel pipes at the clamp that holds them steady. You can brace your hand against the valve cover because if you are not careful you will pick up exhaust manifold heat.



So if your line closest to the valve cover is not the same temp as the motor you have a flow problem.



Will try to grab some more readings thru the day, getting ready to head out now.



Mike.

 

[SeanM]

Ok thanks a lot just got my thermometer today will let you know what I have tonight

 

[SeanM]

well heres the data

vents with blower on high 98 (best temp)

vents with blower one click less 123 (best) 117 (average)



heater hoses with engine temp barely below 190

inbound 173

out 160ish ( hard to get accurate reading with manifold and turbo right there)



outside temp was 25



all readings were taken about 1 inch from target



The heat felt a little bit better this afternoon then it did this morning. It was 12 this morning and I froze on the way to work at 5:30. I would've liked to get thos readings. I will take readings tomorrow when its 5 degrees outside.

 

[SeanM]

I am thinking that my heater hose temp were a little low when compared to the engine temp. I'm kinda starting to wonder if maybe it is my water pump after all. I will take that off tomorrow if I get chance.

 

[mwilson]

Sean,

How are you making out??

Checked temps yesterday and line closest to valve cover is always the same as engine coolant temp. Outbound line is 10-15 degrees cooler but heater is on so is dissapating it in the cab as it should.



My father called this morning and he is one of the best Diesel mechanics in the state. Told him if he was crazy enough to call he might as well dispense some advice. :-laf:-laf

Asked his opinion of your situation and he is agreeing with me on the possiblity of a slipping impeller.

We ran thru the scenarios and he also agrees that where this engine is in an unloaded pick-up truck that you will not get the other symptoms like overheating on a hill, etc. that you would if it were really working the engine. The coolant would take the path of least resistance, the heater would not have any or very little flow and the block would not overheat in low ambient air temps.

His only other question was if the belt was properly threaded, have seen skidder jockeys get them threaded so that the pump is turning in the wrong direction, but that would not explain why you had heat when you took it out of the shop the other day, just a thought.



I ran my truck back here last night and was -5 below when I got home. Had heater set on defrost-floor split flow, temp knob all the way up and fan on dead low, truck was comfortably warm to ride in. You could feel the chill on your left arm from the cold window glass but no drafts. No jacket on and I was comfy. That is the way I want to ride.



We are really hoping that you find the cause and get warm, happy feet again!!



Let us know what you find.



Mike.

 

[Hammer]

One of the single biggest issues with heat in our trucks is the incorrect thermostat. Too many times I see or hear of someone attempting to use a thermostat from another vendors other than a original Cummins part and they all complain about heat issues.



When my truck had the head done back in 08 they used a thermostat from Napa and while it would throw plenty of heat when sitting still the colder it was outside and you drove it the heat would disappear in very short order. I also went through all the things checking as many posted here and then I just replaced the thermostat with a proper one and have had no more issues at all. The truck has even been into the -30F temps in Northern Quebec when I took a trip there last winter to ride sled with a friend and had zero heat issues.



Just may be something your overlooking... ... . Andy

 

[mwilson]

Good Point Andy,

I don't think of the aftermarket stuff quickly as the Cummins stuff is affordable and readily available, why would anyone use anything else???



Could be letting coolant by. A tiny flow thru it when closed could be an issue.

 

[SeanM]

I was working all day today and didn't get a chance to pull the water pump. I replaced my thremostat with a cummins part back when I replaced my radiator last summer. So I don't think thats it but its still anybodys game rite now. Tomorrow I will pull the water pump and have a gander.



Its was -5 today and the best heat I could get from my floor ducts was 83!



I also took temp of the heater hoses again when I got to work this morning and they were 160 at the head and 149 at the return. I also shot the t-stat housing and it was at 160. The temp gauge in the truck said it was at 190. Very confused. I will let you know more tomorrow.

 

[SRath]

Sean, Are you restricting the air flow to your radiator? you should be in these temps. I use a thin, but tough and weatherproof, sheet of teflon cut from a pallet slip-sheet. I cut it to size to slip down beteen my radiator and intercooler and leave about 3 inches extra folded over at the top just to make it easy to grab hold of and remove.



I also cut a couple of flaps in it so I can adjust the airflow restriction as temps dictate. If I don't use a an airblock, my cummins has a terrible time even getting to 180* and cannot even begin to hold it. The thermostat cycles continuously as soon as it reaches 180 and then the engine struggles to get back to 180.



Based on what you say your heater hose temp readings are coming out of the block, it doesn't sound like you have the radiator blocked off effectively. If your thermostat is not open, you cannot get the flow through your heater core that you need in sub-zero.



It is best to not use a full winter front on intercooled trucks. Block the radiator, not the intercooler. Also, a cover over your grille or intercooler can still allow too much cold air to reach your radiator in sub-zero weather. The gap in between is the culprit. A slip sheet flat against the radiator itself solves that.