Truck takes forever to warm up

[high psi]

Even if I have had the block heater plugged in overnight my truck is not making heat by the time I get to work (about 15 mins). It is warm enough when I start it that the high idle doesn't kick on, but it never gets up to the n in normal if it is below 30 degrees out. I changed the thermostat and put cardboard in front of 75% of the rad, but it didn't seem to help. I started the truck and left it idle for about 10 minutes before I left work today. That was enought to get it off of high idle, but even with the 15 minute drive home the air coming out of the vents never got past being lukewarm. Am I overlooking something? I'm afraid I won't be able to keep my windshield clean when it snows/sleets. Should I try keeping it in a lower gear? I usually keep my RPM's around 12-1500 when cruising along. It takes alot of the fun out of driving this thing.

 

[devildog88]

letting these engines idle will not warm them up they really dont build alot of heat at idle. A 15 minute easy ride to work is never going to warm it up.

 

[fuzzy1626]

Is your fan clutch working? I agree with devildog88, they won't warm up at idle.

 

[high psi]

I realize that it won't warm up at idle, but it usually takes the edge off and at least gets it warm enough to disable the cold start and fast idle solenoids. Interestingly enough I believe I found my problem. I popped the glove box out to make sure the heater controls were working properly. I turned the air blend dial all the way hot and was then able to reach in and push the lever about 1/4" further. Right away i could feel a difference in the heat. I think what was going on is that it was just blending some cold air into the ducts which is why i never got good heat out of the vents. The coolant temp still isn't climbing up into the normal range, but I have heat and that's all I care about. I'll be interested to see how it works when it is about 15 degrees tomorrow morning. Thanks for your replies.

 

[jimraelee]

Im thinking there is another issue... my truck warms up and warm/hot air in 10min of driving... if you idle it, then drive 15 min you should get some hot air... have you checked both heater hose lines to make sure that there is coolant flow in and out of the heater core???? is the door opening as it should??? Maybe you have a dash control issue

what does the guage say on the dash???

 

[Mr_Roboto]

Yep if the blend door is not closed all the way you lose a lot of heat. The air flows a lot easier around the door rather than through the heater core.

I had the same thing on an E250, the blend door linkage had come out of adjustment over the years. It made a huge difference once it was adjusted properly.

 

[hheynow]

You need one of THESE . Don't laugh. It works. It's a glorified caulk gun that hooks on the steering wheel and can be adjusted to press the pedal as far as you like.

You must be registered for see images

 

[Andylad13]

take the cardboard off the rad. your using it to bandaid a problem, and its not even bandaiding it. theres a reason why your cooling system isn't working properly. did you put your thermostat in boiling water before installing it to make sure it works properly? has this always happened since you owned the truck? because if so then the owner before you could have put in additive's to lower operating temps. or....your guage is bad!

 

[rthomas]

both my trucks wont warm up much until they work a little, however blocking the rad.,and cranking up the high idle help some. but if your truck gets to the N (180)without added help thats probly pretty good, my idi spends most of the time at 160-180 and thats without a mechanical fan and a tested 195 tstat

 

[Diesel JD]

One thing those factory gauges may or may not tell you anything useful about your coolant temp. I use a mechanical gauge and I think it is about due for replacement as well since it has started giving me suspicious readings. Also, it takes a bit of driving to warm up. I have only about a 10-15 minute drive to work. As long as its warm I get to 190-195 before I get there but if its cold, say below 45 and I haven't plugged in the truck it may not get above 130 by the time I reach work. I don't think slow idle warms them up much at all, might even cool them down a bit. Now the fast idle/cold timing advance does warm up the motor, maybe not a lot but pretty quickly to 112 in Florida most of the time.

 

[f-two-fiddy]

Here's a couple of tricks I use.

When you start the engine. Let it high idle long enough to get running stable. Then hold the accelerator down so that it high idles around 1800 RPM's. Do this until you hear the fan clutch dis-engage. You don't need it sucking cold air over the rad while your trying to warm the engine.

I also made a wedge for getting the thing to idle higher, after the cold start solinoid kicks off. Just a piece of electrical conduit cut so I can wedge it between the seat, and the accelerator. I wedge it in so that the truck idles about 1100 RPM's. It'll take forever to warm up idleing @ 650 RPM's. But only takes about 5 Mins idleing @ 1100 RPM's

There's a wiring diagram,somewhere, that allows you to use the high idle solinoid on a switch. It'll fuction normally untill you flip the witch. Then it'll high idle untill you turn it off.

 

[Agnem]

I think most of the issues have been mentioned, but I'll sumarize.

Cardboard won't help. You won't reach operating temps on a 15 minute drive.
If the thermostat is bad, the engine will most likely get colder as you drive instead of warmer.

With the block heater on overnight, you should have some heat right away.

Do the high idle mod in our tech articles, so you can run the block heater, AND idle high.

Test your heater core to make sure it isn't plugged. If water isn't flowing through it, you can't tell unless you verify that it is.

Clean the vents and check operation of the doors. You won't get heat if the air isn't passing through it.

 

[Mr_Roboto]

I would disagree that an engine won't warm up in 15 minutes.

My truck is blessed with a gauge with numbers on it.

In 2 minutes the gauge comes off 100* and I can turn on the heat. In 5 or 6 minutes the gauge is up to 170*, about as hot as it gets when it's below freezing out.

Yes my truck is heavier but it's also geared much lower so while there is more load on the motor it probably isn't more than 25%.

I've had a number of the IDI's in light trucks and vans also. With the radiator partially blocked off heat was never more than a few minutes away.

 

[subway]

I would disagree that an engine won't warm up in 15 minutes.

My truck is blessed with a gauge with numbers on it.

In 2 minutes the gauge comes off 100* and I can turn on the heat. In 5 or 6 minutes the gauge is up to 170*, about as hot as it gets when it's below freezing out.

Yes my truck is heavier but it's also geared much lower so while there is more load on the motor it probably isn't more than 25%.

I've had a number of the IDI's in light trucks and vans also. With the radiator partially blocked off heat was never more than a few minutes away.

i agree my truck throws warm heat in just a few miles of driving and it will warm up idling in 5-10 mins enough to heat up the truck.

just hope my cylinder walls arent cavatated to dangerously thin to do that

dont trust that factory gage though, i put in an aftermarket one to really know whats going on.

 

[69oiler]

i agree my truck throws warm heat in just a few miles of driving and it will warm up idling in 5-10 mins enough to heat up the truck.

same here. my 6.9 will heat up the cab idling. heater gets hot hot in 5 miles or so.