why does my motor cool off so quick?

[BrettM]

My motor seems to be a bit slow getting up to operating temp (new 195* t-stat), but what's worse is that I can get it up to 210, go in a store for 30 minutes, and when I come back out the temp is hardly even registering anymore, then I freeze until it warms back up again... very annoying in the winter.

any ideas why it cools off faster than lots of other vehicles? any ideas to keep it warm longer, short of running a block heater off my battery?

'88 4.0 w/ closed system

 

[Voluster]

Mine seems to cool off pretty quick also.

Only thing I could say to keep warm it back up before you get out there is a remote start.

I have one in mine very easy to do.

I do them for a living so the cherokee is candy to do when it comes to some other cars


Good Luck

 

[BrettM]

I know remote starters often have safety features built in, but how complicated is the hookup if I were to make my own simple one?

 

[bcmaxx]

I really don't recommend using your battery to run a block heater, you will have a cold truck and a very dead battery. If it is cold enough outside it will cool your heater core ,lines, rad, so the engine temp must rise enough to cycle the thermostat thus cylcling hot water to your heater core before you get warm.

 

[badron]

===========================
short of running a block heater off my battery?
===========================
I have never seen a block heater that worked off of 12V DC?

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any ideas to keep it warm longer,
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Try covering 3/4 of the rad with cardboard. It can be a pain to get in and out. Don't forget about it come spring or you will over heat.

Shop faster, dress warmer etc

 

[BrettM]

I really don't recommend using your battery to run a block heater, you will have a cold truck and a very dead battery. If it is cold enough outside it will cool your heater core ,lines, rad, so the engine temp must rise enough to cycle the thermostat thus cylcling hot water to your heater core before you get warm.

exactly why i said something besides a block heater.

with my room-mates car the heater will blow warm immediately even after it's been sitting for 2+ hours, and it makes me jealous.

 

[rsliman]

man... i wish i had that problem, i live in phoenix and still have to use the a/c durring the day.

 

[badron]

You could also power flush the heater core. By removing the heater hoses from the block and holding a garden hose to one and let the other drain. Flush from both hoses until water runs clear.

 

[RichP]

Either check or replace the pressure cap. Usually if it takes forever to warm up it's because the thermostat may be partially open, it's supposed to stay closed till the block gets warm. I had one on my trooper get stuck open and it NEVER reached above 0 on the gauge. Fournd part of a wire tye stuck in it, in a parts store parking lot at 8am in freezing temps...not fun..

 

[87manche]

my renix takes about 5 minutes before useable heat. 10 minutes to open the thermostat fully and register 195 on the guage.
This in the 15* temps we've had in the last few days.
It does however stay warm far longer than the wife's camry.
I can park it at operating temp and come out an hour later and it still registers on the guage.
I second rich's suggestion of looking at the pressure cap/bottle. When my pressure cap wasn't holding properly the motor took forever to heat up, and never fully reached operating temp. I've since replaced it, and with a new t-stat it works properly.