Cooling issue?

[P72Ford]

So I think I have a bit of an issue with the cooling system. I recently replaced the water pump, all the hoses, and the radiator. Before this, I'm not sure what the engine ran at (temp wise) on a hot day in the summer. However, I added a temp gauge about the same time I did everything else. The car runs at 150-165 in the winter time.

Now that its 90 degrees out, the engine is running a lot hotter. W/o the A/c it can run up to 195, and with the A/c it can approach 210. Its only gone over 210 like one time. Is this wrong? How hot should it run (ideally)? Am I causing too much excess wear and tear by letting it run hot?

What should I do to rectify this? I will be trying a coolant additive (someone recommended this, but I personally am skeptical) this afternoon. My dad said to switch it to a 160 t-stat. Good next step if the additive doesn't help?

I would add another fan... but this is a cop car and there is little room in front of the rad w/ the oil and power steering fluid coolers. Maybe I could squeeze a small fan in (10 in). Would this be a good idea?

I was thinking of converting it to an electric fan (taurus, etc), but I'm afraid that will draw too much juice. (I think I have an issue with my electrical system somewhere already. At night at an idle the headlights pulse with the engine. Also, the voltmeter jumps way down with the A/c on). I'm afraid that the complete electric fan set up would really cause a problem because the A/c compressor already drops my voltage, and the fan would be drawing alot of current as well.

Also, this rad it from ford (a retrofit though). Its identical to the rad my dad has on his 99. I think its inadequate at cooling another 70 cubic inches.

Any help/ thoughts are appreciated.

[LtMercDaddy]

I'd def switch to a pre-92 rad. the cores in the 92+ are smaller. since its a 351 id recommend going with a 3 core if ur going to be keeping ur factory belt driven fan along with switching out the fan clutch if u havent done so.

if swappin to electric, id still go with a pre-92 rad. dont really have to be a 3 core if ur going with an electric fan set up. a 3g alt conversion is gonna be nessisary to handle ur added amp draw.

the alternator swap might cure ur pulsating at idle aswell....

whatever u do, dont use any coolant additive. only thing u should add to your coolant is H20.

[1987cp]

Lights pulsing at idle is probably just a bad regulator. $10 at AutoZone solved that problem on the '79; the original alternator was still good.

[Nathan in MI]

210 ain't nothing to worry about. You most likely have a 190* t-stat, so it's going to run right around there, plus or minus 20 degrees or so. Mine normally runs right around 200 degrees, sometimes as high as 210 on a hot day.

Now if you get up to like 230-240, yeah, that's getting pretty steamy, but if you get it cooled down and fix whatever the problem is that's causing the overheating, then it shouldn't do any permanent damage.

One more thing--don't switch to the 160 degree t-stat. Having the engine run too cool isn't good either...efficiency will drop and it's not good from a longevity standpoint...just like never driving the car long enough to get it warmed up.

[turbo2256b]

The car should run 190 to 210 perty much all year round. Your thermostat migfht be the problem. IT COULD BE STUCK SLIGHTLY OPEN. Replace it with the factory recomended one 195* I believe wouldnt hurt to usse a high flow one.

[P72Ford]

Lights pulsing at idle is probably just a bad regulator. $10 at AutoZone solved that problem on the '79; the original alternator was still good.

Where is the regulator?

Also, shouldn't the police car have a different (bigger) alt to run all the accesories?

[P72Ford]

Okay, I'm a fool. I know where the regulator is. I swiped the one off of my 89 P72 parts car... but the voltage was way lower on the gauge. I'll go to Napa and grab one tomorrow morning.

the cop cars have a 100 amp alternator. (I think?)

[OVERKILL]

Just a couple of points:

1. The charging issue, if it DOES end up being the alternator, just switch to a 3G. They make more juice at a lower RPM and are overall, just a much better design.

2. I echo turbo's sentiments about a partially stuck thermostat. The car should run basically the same temp year round. If it's running cold in the winter and hot in the summer, the thermostat may very well be stuck half-open, allowing inadequate heat-up in the winter and cool-down in the summer.

3. I would NOT put a 160 degree t-stat in. The MINIMUM to go with would be a 180. The stock one is a 192. Regardless, the ONLY reason to really run a 180 is to allow the ECM (on computer controlled cars) to add more timing. The ECM on EEC-IV cars starts pulling timing after 188 degrees or something, so running a 180 will keep the timing "maxed" for whatever minuscule power gain there is from it........ Adding a cooler T-stat will NOT make the engine run cooler if it's overheating unless your other T-stat was completely buggered. If your engine is overheating and the T-stat is OK, then putting a colder T-stat in does nothingl Once your cooling system's ability to remove heat is maxed out, it will only be able to keep the engine at the temperature it's capacity allows. If for example, your cooling system is only adequate enough to keep your engine at 195 degrees on a hot day, putting in a 160 will NOT make it run at 160, it will continue to run at 195 because the cooling system is not large enough to run it any cooler than that.

[Lincolnmania]

replace your fan clutch
radiator also might be toast.....they clog internally

[gadget73]

If it stays under 210 I wouldn't get super concerned. The stock thermostat is 195, so 210 isn't unreasonable. Check the fan clutch if it starts getting hot in traffic.

[P72Ford]

replace your fan clutch
radiator also might be toast.....they clog internally

even if the radiator is only like 3 months old?

[Lincolnmania]

i'd suspect the fan clutch then

[P72Ford]

scott, is 195*, or higher too hot, considering it now has the smaller two row rad? I think the fan clutch is fine. I checked it our when I replaced the water pump, etc. The fan has never stuck on or anything like that.

Also, for those thinking the thermostat is partially stuck open. interesting idea, but couldn't the fact that the outside temp is 60 to 80 degrees colder have an effect on the running temp. The air passing through the rad cools the water, and if the air is cooler, then wouldn't this cool the water and result in lower engine temps. This is just my logical thought (who knows how logical it really is). Any reason why this is wrong?

[turbo2256b]

scott, is 195*, or higher too hot, considering it now has the smaller two row rad? I think the fan clutch is fine. I checked it our when I replaced the water pump, etc. The fan has never stuck on or anything like that.

Also, for those thinking the thermostat is partially stuck open. interesting idea, but couldn't the fact that the outside temp is 60 to 80 degrees colder have an effect on the running temp. The air passing through the rad cools the water, and if the air is cooler, then wouldn't this cool the water and result in lower engine temps. This is just my logical thought (who knows how logical it really is). Any reason why this is wrong?

A thermostat is there to keep the engine temp with in about 10* + or - or less for system design temp. For most FI cars itss around 195* the differance between inlet and outlet temperature according to fords design guide is 10*. Temps lower than 185 or higher than 205 start effecting the tune of the vehicle.

[P72Ford]

Ok, a few things.

Tonight I bought a new voltage regulator. Observations: The volt meter reads a constant 14.1/2, with the exception of at a few times (pulsates breifly). The headlights don't pulsate like they used to.

Also, drove about 25 miles tonight (50/50 highway, local). Water temp hovered around 180- 185 on the highway, and stayed around 195 for local driving (ambient temp 83). I guess this a good sign. Only the A/c makes it climb I guess. I may add an auxilary fan for that prupose.

Thank you to all who posted comments. Really appreciate 1987cp, and his suggestion that the lights pulsating was the regulator.