Engine running warm/hot...stumped

347notch89 · Sep 19, 2021

just picked up a 89 w/ a 347 stroker. afr heads and a c4 trans 3400/3500 stall cars been sitting a while, went thru changed fluids etc etc...after driving for 20 or so minutes water temp creeps up to 200 and keeps rising, idle/ stop and go iv seen 230 hwy is a little cooler but seems to keep creeping up 220. weather yesterday was 75-80 and higher humidity, auto meter gauges, car came with a beat 180 mr gasket tstat.
has a summit 2 core alum radiator and meziere electric water pump 35gpm pump is probably 15 years old i called them they said its probably fine it does pump good with the upper rad hose off but who know what it does under pressure and heat, flex lite black magic fan with controller and shroud, engine was built a while ago 04 and gone thru in 09, was a street/strip car but im thinking mostly strip. i called meziere they advised me to run no thermostat tried that same result, then I tried a new 160 with 5 bypass holes drilled same result. doesn't lose coolant when it gets warm, never seen anything come out over flow or even steam, when it cools down coolant level is right where i initially filled it but iv seen on the gauge 220-230 which worries me. if i shut the car down and run the fan and water pump it'll cool to 140 in 5 or so minutes. pretty stumped on this one...

OldManRiver · Sep 19, 2021

What temp is the fan start set to?
Does it kick on around 200-210 when idling in the driveway?

347notch89 · Sep 19, 2021

i have it set to come on at 140 and it still runs warm, i checked all the spark plugs for signs of hg today nothing they all look good

OldManRiver · Sep 19, 2021

So the fan pretty much runs all the time and the temp still climbs to 230?
Is the fan pulling air through the radiator or pushing,in other words spinning the right direction?
Someone who's had one may chime in,could be wrong but I think I've heard those Black Magic fans aren't worth a sh*t.

nickyb · Sep 19, 2021

I'd put a new 180 thermos back in . Then double check temp with a know gauge.

90sickfox · Sep 19, 2021

Ditch the black magic fan. Use a dual Contour fan and it'll cool the car better. I don't like running electric water pumps on street cars. I've seen plenty that would be fine for a 1/4 mile romp but would creap hot on the street. The thermostat doesn't monitor the engine temperature. A lower degree thermostat just let's it open up fully faster. The fan, radiator, and pump flow control the temps. I should clarify that, the thermostat does keep the engine from going below the thermostat temperature. However, it will not keep the car from running hot. If you run a thermostat that is too cool it can cause hot spots in the engine cooling passages. Well...wider temp variations.

Also, make sure the air dam is below the core support and the air deflectors are on the sides of the front of the radiator. I had a car that would spike hot coming off the highway because the air would go around the radiator instead of through it.

347notch89 · Sep 20, 2021

ill order the lmr ford contour fan kit, and air dams. i will report back thank you all

7991LXnSHO · Sep 20, 2021

@90sickfox
Too cool of thermostat can cause hot spots? I’ve never heard that before. I’m not sure how that would work.

Things I have heard or seen -
Water (blow by) never boiling off from your oil, the car running rich from the choke or computer staying in warm up or open loop mode, poor mileage, excessive engine wear.
All are good reasons to use the right thermostat.

90sickfox · Sep 20, 2021

7991LXnSHO said:
@90sickfox
Too cool of thermostat can cause hot spots? I’ve never heard that before. I’m not sure how that would work.

It's got to do with thermal dynamics. If you throw cold water on a hot manifold it will crack. It's the same theory with engine coolant temps and the metal it contacts. Not all areas cool at the same rate. If one area cools too fast it causes a greater temperature difference from the surrounding areas. The theory is to keep the engine as similar in temp as it can be, within reason.

90sickfox · Sep 20, 2021

7991LXnSHO said:
@90sickfox
Too cool of thermostat can cause hot spots? I’ve never heard that before. I’m not sure how that would work.

It's got to do with thermal dynamics. If you throw cold water on a hot manifold it will crack. It's the same theory with engine coolant temps and the metal it contacts. Not all areas cool at the same rate. If one area cools too fast it causes a greater temperature difference from the surrounding areas. The theory is to keep the engine as similar in temp as it can be, within reason.

2000xp8 · Sep 20, 2021

90sickfox said:
Ditch the black magic fan. Use a dual Contour fan and it'll cool the car better. I don't like running electric water pumps on street cars. I've seen plenty that would be fine for a 1/4 mile romp but would creap hot on the street. The thermostat doesn't monitor the engine temperature. A lower degree thermostat just let's it open up fully faster. The fan, radiator, and pump flow control the temps. I should clarify that, the thermostat does keep the engine from going below the thermostat temperature. However, it will not keep the car from running hot. If you run a thermostat that is too cool it can cause hot spots in the engine cooling passages. Well...wider temp variations.

Also, make sure the air dam is below the core support and the air deflectors are on the sides of the front of the radiator. I had a car that would spike hot coming off the highway because the air would go around the radiator instead of through it.

I don't know anyone that has successfully ran an electric water pump on a foxbody street car.
Even if a fan replacement solves the issue (i would think not, if the car still heats up on the highway), i'd still replace the water pump with the ford racing version (not some fancy high flo unit).

KRUISR · Sep 20, 2021

2000xp8 said:
i'd still replace the water pump with the ford racing version (not some fancy high flo unit).

Agreed. Stock replacement style.

A question for OP. Does the fan come on at idle sitting in the driveway? If so, what is the air flow like that is being pulled through rad? Where is your temperature sensor for the fan(s) located?

I would agree if you don't have the air dams in place, potential air flow will be lost. I know with my set up (Contour fans set up running dual speed through thermoresistor on Contour fan shroud), fans don't come on while driving (moving). Low speed will come on if in stop and go long enough.

347notch89 said:
ill order the lmr ford contour fan kit, and air dams.

347notch89 - do yourself a favor, buy a Contour fan from rockauto and save yourself $40 ($145 at LMR vs $105 at rockauto). Both come with the thermoresistor if you want to run dual speed (Contour style).

2000xp8 · Sep 21, 2021

Believe it or not, on the highway you can actually get away with no fan at all.
That's why i don't have much confidence in replacing the fan solving this issue.

If you were to have a stock fan/clutch and shroud available, i'd most likely say return the entire cooling system to stock then go from there. Then when it operates 100% you can start modifying it.

Engine running warm/hot...stumped

347notch89

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OldManRiver

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347notch89

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nickyb

I gotta say i never painted my nuts, Never Ever

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Wasn't a pretty sight...and I've got big hands

347notch89

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7991LXnSHO

wanna catch the space herp

90sickfox

Wasn't a pretty sight...and I've got big hands

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Wasn't a pretty sight...and I've got big hands

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