jcolman
Well-Known Member
My temp gauge (brand new autometer) indicates that my engine rarely gets above 150. Only on the hottest days does my motor show a temperature of 180 or higher. I'm guessing I should look to replace the thermostat?
My motor runs cool....maybe too cool?
- Thread starter jcolman
- Start date
-
No, you should verify first, before you turn a wrench or you're just guessing. Infrared temp guns are cheap. You should already have one.
jcolman
Well-Known Member
Thanks. I'll pick one up.
Thermostat only controls the temperature that coolant is allowed to begin flow out of the emgine to the radiator. Radiator capacity and cooling fans will have more to do with how hot or cool the engine actually runs.
jcolman
Well-Known Member
I thought that if the thermostat was faulty and open all the time, the engine would run too cool. Maybe I'm wrong?
By the time you get a temp gun, you will have driven yourself insane trying to figure this out. The car will still be THERE when you get the temp gun. Relax until you can verify something and then start diagnosing. You have nothing concrete to go on right now.
Absolutely that's a good idea if he has one. Dang you are cheap. Them temp guns are well under 20 bucks now. lol I'm right there with you. I'm cheap as hell too, but I do have a temp gun. lol
Scody21
Just send it
What radiator, fan, water pump setup on what motor we talking about? I’m running 175-180 with BeCool rad, high flow pump, dual electric fans, no thermostat... if I leave both fans on during a 60mph Run, car will be running 160 or so...
PRH
Well-Known Member
Where in the system is the temp sender located?
jcolman
Well-Known Member
340 .30 over. TRW flat top pistons. Mopar steel crank, Mopar performance rods. ARP fastners. Holley Sniper EFI with Hyperspark distributor. Edlebrock Aluminum Heads. Weiand Aluminum Intake. hydraulic roller cam. 490/490 lift, 262 duration. 10.5-1 CR. MSD Blaster SS Coil. 8mm Plug Wires. Aluminum Radiator. 6-Blade Aluminum Cooling Fan. Hooker Ceramic Coated Long Tube Headers.
I have no idea what the water pump set up is other than it appears to be stock. My engine use to run around 160-170, sometimes reaching 190 on a hot day. Now that the weather is cooler, I haven't seen temps over 150 even after running for 20 minutes.
jcolman
Well-Known Member
MopaR&D
Nerd Member
Definitely sounds like faulty thermostat but I agree with @RustyRatRod, verify temps FIRST with another method before messing with anything.
Scody21
Just send it
What’s being used for coolent?
jcolman
Well-Known Member
I just changed the coolant to Prestone 50/50 prediluted. I don't know what was in the system before. But the car started running cool as soon as the colder weather set in before I changed the coolant. After changing the coolant, I think it's running even a bit cooler now.
Well, it's not your problem, but I never buy 50/50. It's a ripoff. You're paying for HALF water. Think about that.
jcolman
Well-Known Member
Yeah I know but I was in a bit of a hurry.
mopowers
Well-Known Member
Are you certain that there is a thermostat currently installed?
jcolman
Well-Known Member
No I don't.
Once you have verified that your gauge is accurate & your temp is low, then you need to remove the stat & check it. There are some 140* marine stats, pretty rare. Make sure it closes fully.
If you have a high flow stat & the three bars across the top are s/steel [ not brass], you have a Chinese version. I have found that these open at the rated temp, but if the coolant temp drops, they are slow to close. I had a 160 stat after fully opening, didn't close fully till about 130*. Result was engine ran too cool. I now use Stant super stats, open/closes bang on the rated temp.
If you have a high flow stat & the three bars across the top are s/steel [ not brass], you have a Chinese version. I have found that these open at the rated temp, but if the coolant temp drops, they are slow to close. I had a 160 stat after fully opening, didn't close fully till about 130*. Result was engine ran too cool. I now use Stant super stats, open/closes bang on the rated temp.
My stock 73 318 runs between 150 and 160 per the aftermarket gauge and verified with an IR thermometer.
Note those IR thermometers are notoriously inaccurate.
If mine is off, it's off the exact amount that my gauge is.
This is a 65,000 original mile motor and runs just fine.
Warms up "as expected" with the OEM choke.
I was having an issue using the AC where it would get up over 200 and boil over.
Since then I have evacuated the AC and replaced the dryer.
Now it does much better, running about 190-195 with the AC on.
Haven't really had the 100* weather to thoroughly test it, though.
Note those IR thermometers are notoriously inaccurate.
If mine is off, it's off the exact amount that my gauge is.
This is a 65,000 original mile motor and runs just fine.
Warms up "as expected" with the OEM choke.
I was having an issue using the AC where it would get up over 200 and boil over.
Since then I have evacuated the AC and replaced the dryer.
Now it does much better, running about 190-195 with the AC on.
Haven't really had the 100* weather to thoroughly test it, though.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
- Messages
- 24,898
- Reaction score
- 12,247
The stat sets the minimum operating temp, by closing ..... to get the temperature up. Once it is wide open, it cannot do anything more, it has done all that it can do.
The maximum temperature of your system will be governed by the efficiency of your system.
If your system has say a 180 stat in it, that is known to be in good working order, and it won't come up to temp; here are some possibilities;
1) the engine is running pig-rich and/or with retarded timing and a lot of the heat is going into the exhaust, or
2) you have a high-efficiency fan, running full time. or
3) the hood is open
4) the alloy heads do suck a lotta heat out of the water; I painted mine several coats of engine enamel
5) at idle the engine only has to produce enough power to idle! no surprise there. That might be FIVE horsepower So how hot can it get? It wouldn't surprise me at all if the stat closed up most of the way, and the water was mostly going thru the bypass. But if the stat is defective or missing, well the water is gonna go thru the rad instead of shortcutting back to the inlet via the bypass.
6) don't forget, your temp sensor has to not only be in the water, but in flowing water, NOT in a stagnant pocket created by two or more adapters, with the adapters radiating their heat into the airflow of the fan.
The maximum temperature of your system will be governed by the efficiency of your system.
If your system has say a 180 stat in it, that is known to be in good working order, and it won't come up to temp; here are some possibilities;
1) the engine is running pig-rich and/or with retarded timing and a lot of the heat is going into the exhaust, or
2) you have a high-efficiency fan, running full time. or
3) the hood is open
4) the alloy heads do suck a lotta heat out of the water; I painted mine several coats of engine enamel
5) at idle the engine only has to produce enough power to idle! no surprise there. That might be FIVE horsepower So how hot can it get? It wouldn't surprise me at all if the stat closed up most of the way, and the water was mostly going thru the bypass. But if the stat is defective or missing, well the water is gonna go thru the rad instead of shortcutting back to the inlet via the bypass.
6) don't forget, your temp sensor has to not only be in the water, but in flowing water, NOT in a stagnant pocket created by two or more adapters, with the adapters radiating their heat into the airflow of the fan.
If Noone said it yet, the sniper has and needs its own temp probe. Where is that installed, and what temp does the sniper say on the handheld???
The sniper will give a temp readout on the handheld!! So you have 2 sources to compare already!!!
Where is your temp probe for your gauge installed?
The sniper won't even go in open loop under 180 degrees.
Have you compared both Temps? Sniper and gauge?
The sniper will give a temp readout on the handheld!! So you have 2 sources to compare already!!!
Where is your temp probe for your gauge installed?
The sniper won't even go in open loop under 180 degrees.
Have you compared both Temps? Sniper and gauge?
512Stroker
We are all here because we are not all there.
I would not worry about it.
A lot of forum members would kill for those coolant temps.
Except he is efi, and the efi system doesn't even "learn" until it hits 180. So he is basically driving around with the "choke on" 90% of the time if the Temps he is claiming are correct.
-
