Engine Running Cold

[MJGenay]

My engine was running colder than normal, but erratically. The temp gauge would move around more than normal ranging from the N to the hash mark by cold. It used to sit at N once up to temperature and only go above that if climbing a long grade under load.

At any rate I replaced the thermostat (appeared to be some off brand one) with a new Motorcraft one, now the engine is running even colder, topping out at the end of cold end of the bar and often less than that. While replacing the thermostat I removed the ball bearing, which I still have. Someone previously RTV'd the previous housing to the block and also RTV'd the ball bearing in place.

I'm planning to replace the thermostat again, because I'm assuming my thermostat is stuck open. I don't have a GOOD temp gauge yet, however, I did a simple hand test. After about 5 minutes of idling and a good 15-20 minutes of driving which included highway speeds, I shut the truck off and the radiator was warm but not overly hot to the touch, I could leave my hand on it without discomfort.

I'm wondering if removing that ball bearing may be my issue, potentially allowing more coolant to flow and keeping the truck from warming up sufficiently? Temperatures have been 32*F or below.

Any opinions or knowledge is appreciated.

 

[KansasIDI]

Maybe try replacing temp sensor, they can go kinda wonky and usually read cold when they do… in my experience.

But if the touch test is saying that it is cold, then I don’t rightly know. My 86 does the same thing in below freezing conditions, it has an entirely new cooling system…

 

[MJGenay]

Maybe try replacing temp sensor, they can go kinda wonky and usually read cold when they do… in my experience.

But if the touch test is saying that it is cold, then I don’t rightly know. My 86 does the same thing in below freezing conditions, it has an entirely new cooling system…

Thanks. Yeah, I was kinda hoping for the sensor to be bad, but I just took the truck to town and back (15 minutes and about 10 minutes at high idle to warm up). Drove the **** out of it, pulled it in the garage, shut it off, popped the hood, and the upper radiator hose is closer to warm than hot. Temp gauge was at the low end of the line that is above NORMAL if that makes sense.

Would you say yours stays that cool during below freezing temps as well?

 

[Clb]

My .02 thoughts
1 easy test
ice cold h2o stat should be closed
Boiling h20o
Stat should rapidly open from room temperature.

2
The check ball is nothing but an air bleed, and left out its another bypass for cold circulation


Eta
I just hunted the tech 101 in my watched threads, nogo.
It must be buried in a cooling thread.
Cliffnotes
Go get a blankig/galley plug of comparable size as the hole in the stat housing ( bigger not smaller, ,make a clean and centered hole 1/3-1/2 the size of checkball in it, debur both sides, make the housing hole an interface fit,put in check ball,lightly apply sealant/glue agent ( hi-tac permatex for example) drift cap into the housing to trap the ball.
You did clean out the port good first right...

 

[Kdo58]

I have aftermarket gauges can't trust the old gauges.

 

[Kdo58]

You must be registered for see images attach

 

[MJGenay]

Yeah, I have boost and pyrometer. Could use coolant temp and oil pressure.

 

[MJGenay]

My .02 thoughts
1 easy test
ice cold h2o stat should be closed
Boiling h20o
Stat should rapidly open from room temperature.

2
The check ball is nothing but an air bleed, and left out its another bypass for cold circulation

1.) Yeah, I'm going to test this thermostat when I pull it out. I'll probably wait for the new one to show up so I don't have the truck in pieces again.

2.) I'm wondering if that cold circulation could be sufficient to keep the engine from reaching temperature?

 

[Clb]

No

 

[KansasIDI]

Thanks. Yeah, I was kinda hoping for the sensor to be bad, but I just took the truck to town and back (15 minutes and about 10 minutes at high idle to warm up). Drove the **** out of it, pulled it in the garage, shut it off, popped the hood, and the upper radiator hose is closer to warm than hot. Temp gauge was at the low end of the line that is above NORMAL if that makes sense.

Would you say yours stays that cool during below freezing temps as well?

One of my 2 trucks doesn’t really get up to temp in anything below 20*, my 86, which has an entirely new coolant system that I put in last fall. Still has the ball in the thermostat housing.

My 91 gets up to temp in very cold temps, but doesn’t overheat in hot weather, only has a new radiator, and temp sensor, after the old one went wonky. So it is working properly.

 

[franklin2]

Like someone alluded to in a post above, you can waste a lot of time and money looking at the factory gauges. One thing I can tell you, if you see one move quickly, you know it's a problem with the sensor or the gauge or the wiring. Factory gauges don't move quickly, another reason to get some aftermarket gauges on your truck.

 

[Clb]

On the checkball, there's a tech101 thread somewhere on how to make a new cap/holder.
At sub freezing temps it's likely going to struggle to get up to temp.
How'd it do in summer?
There's a lot of guy's running radiator reducing cardboard in the rustbelt .
If the stat is open and the top tank aint hot, it's just not up to temp yet.
How hit are the heads,in comparison?
Try leaving the radcap loose/open so you can check the flow when hot/been running and gauge says not cold...

 

[DaveBen]

I remember my '92 F-350 7.3 NA running cold. I was running over Donner Summit many years back. I took some cardboard and shoved it in front of the radiator, for something like 70% coverage. This got it much warmer but not hot, as I recall. Don't depend on factory Gauges!

 

[MJGenay]

On the checkball, there's a tech101 thread somewhere on how to make a new cap/holder.
At sub freezing temps it's likely going to struggle to get up to temp.
How'd it do in summer?
There's a lot of guy's running radiator reducing cardboard in the rustbelt .
If the stat is open and the top tank aint hot, it's just not up to temp yet.
How hit are the heads,in comparison?
Try leaving the radcap loose/open so you can check the flow when hot/been running and gauge says not cold...

It was usually fine last summer however I think the thermostat was stuck open for about a month as there was a little while there is was running cooler than normal (both on the gauge, by feel, and I think by power).

Mind clarifying the whole leaving the radiator cap loose thing for me? Always learning. So I want to take the cap off when it's cold and just leave it idle for awhile? Or do I need to drive it and then pop the cap off? How do I do that safely?

I remember my '92 F-350 7.3 NA running cold. I was running over Donner Summit many years back. I took some cardboard and shoved it in front of the radiator, for something like 70% coverage. This got it much warmer but not hot, as I recall. Don't depend on factory Gauges!

I ordered some aftermarket gauges. I have some sheet metal sitting around and might put some in front of the radiator that I can easily take on and off; the truck has an aftermarket bumper which really increases the amount of open space and allows more airflow. Plus I could use a guard so I don't put a stick through it when I'm driving through the woods.

 

[MJGenay]

Like someone alluded to in a post above, you can waste a lot of time and money looking at the factory gauges. One thing I can tell you, if you see one move quickly, you know it's a problem with the sensor or the gauge or the wiring. Factory gauges don't move quickly, another reason to get some aftermarket gauges on your truck.

thanks for the clarification. Yeah, I'm going to get a coolant temp and oil pressure gauge on it.