Still running hot

[Kyle.malone]

So... Two weeks ago, I got the bronco started for the first time in two years.. Had a heating issue. This past weekend, I went ahead and changed the water pump and the thermostat (180 degrees) It was a quick and easy change. With a little bit of success, but its still running hot (210). When we got on it to see if it would hold temp, more white/light gray smoke filled the barn (It is a fresh rebuilt 302 with a .030 bore, new cam, rebuilt heads, and new intake) and the temp went up. I now have the idea to buy a cheap mechanical gauge and see if my new electrical gauge is working correctly. (my electric fan does not come on at 180 like it is suppose to and I had to hardwire it to the battery for testing. I know that it has power on the keyed on position becasue my fuel pump relay is on the same power line. Does anyone have any other ideas that it could be?

I do recall someone mentioning a fan shroud, but since I am running an electric fan, I didn't think I should need one. The fan I am using is rated at 1610 cfm. It's setup as a puller and we can feel the air being moved.

 

[Viperwolf1]

Not many electric fans do well in a Bronco. Might consider a mechanical fan and shroud until the bugs are worked out.

Keep a close eye on the coolant level. Any leak will let air in. Air in the intake, around the temp sender, will show a higher temp than coolant. A working coolant recovery system will eliminate air.

 

[ransil]

210 is not over heating.
180 fan on is too low it will never turn off.

 

[jalapeño]

210 is not over heating.

Oh, Thank GAWD!

 

[joshd1971bronco]

A couple more things to consider or try:

White smoke out of a fresh engine could be a problem - does it smell like burning oil or antifreeze? Could be a head gasket issue which would attribute to overheating. I might suggest running a compression check as well.

Also, did you try really flushing the cooling system out real well? That includes the radiator. After two years of setting, no telling what kind of sludge or rust or sediment has collected at the bottom and in all the passage ways.

Take the radiator out, and either have it professionally cleaned or try it your self with the garden hose. You can also flush out the engine by taking the thermostat out and undoing the top hose to the radiator and letting it pour on the ground. Just keep filling the radiator with fresh clean water.

Of course, always dispose of used antifreeze properly. Don't want a bunch of dead cats in the neighborhood......do you?

 

[Kyle.malone]

When I said two years, I was meaning from the start of my frame off. I picked the motor up back in November from rebuild. The radiator is a new BeCool aluminum. When putting this back together, I wanted everything to be new so I wouldn't have these kinds of problems.

I was unaware of the fan not kicking on until later, I guess I will check my realy to see where it kicks on.
EDIT:: just looked it up and its a 195/175 relay.

I will do a compression check as well.

IF I pull the spark plugs, can I tell if anything is wrong by the looks of them?

 

[joshd1971bronco]

Gotcha- my bad. I didn't realize the radiator and rest was brand new. That eliminates THAT!

Stupid thought - make sure the thermostat is installed correctly (not backwards).

Stupid thought 2 - did you get the correct rotation water pump (clockwise vs counterclockwise)?

Are you running underdrive pulleys or anything unusual there?

If all of the above is normal, I'd work on the fan.

Oooohh....one more thing. How much timing are you running? Too advanced of timing will cause the engine to run hot. Anudder thought there for you.....

 

[joshd1971bronco]

Crap - one more thought:

Did you get the head gaskets and intake gaskets on the right way? There is definitely a right way and wrong way with regards to the water passages through the heads.

 

[00gyrhed]

If you are not boiling water out of the radiator you are not overheating. Every degree under that point that your engine will run is nothing but safety factor. There is no temperature between where a 16 lbs cap with a 50/50 mix will boil out normal operation that will hurt anything in your engine. Period.

Always verify your gauges are acurate before chasing problems by using a known point, like water boils at 212 at sea level. Adjust it for you elevation and throw your senor in the boiling water. Your gauge should read 212.

electric fans introduce a lot of unknowns and can actually reduce total airflow when used in conjuction with a mechanical fan.

Your best bet for long term use is a mechanical fan with a shroud.

My EFI 302 runs 208 under most conditions and will sometimes climg higher. I had a CJ5 that ran 246 almost all of the time. Hard mudding would send it up to 258 and strat boiling it out of the raditator. But as long as you move liquid coolant through the engine you will not hurt the engine.

 

[Kyle.malone]

Answers for stupid thoughts:

1. thermostat is installed correctly.. Motor is etched in (so couldn't get that one wrong).
2. I have a standard rotation water pump
3. just alt and power steering pulleys
4. timing is set at (11 initial and 32 total)
5. Gaskets were put on by my engine builder. They rebuilt the whole motor and assembeld the long block with the intake on. I hope they would know what their doing. Its a reputable race and high HP marine shop.

I am using an electric fan only and it is set up as a puller (no fan shroud either).

 

[mdowner]

Seems like I went through this 10 or so years ago with my mostly stock 68, messed around with different thermostats, had the shroud on and off(huge difference), eventually had the radiator rebuilt and now as 00gyrhed said they do tend to run around 205, 210, and even warmer when idling or crawling. Definately put a shroud on, see how the electric fan works with that.

 

[kayakersteve]

I agree that 210 is not hot and mine commonly hits 210 when creeping along on the trail or idleing Agree should have shroud as we get into warmer months, however.

 

[ransil]

Answers for stupid thoughts:

1. thermostat is installed correctly.. Motor is etched in (so couldn't get that one wrong).
2. I have a standard rotation water pump
3. just alt and power steering pulleys
4. timing is set at (11 initial and 32 total)
5. Gaskets were put on by my engine builder. They rebuilt the whole motor and assembeld the long block with the intake on. I hope they would know what their doing. Its a reputable race and high HP marine shop.

I am using an electric fan only and it is set up as a puller (no fan shroud either).

put a mechanical fan with shroud on it..

 

[blubuckaroo]

While I'll agree that 210* isn't too hot, I don't think I'd be satisfied with that this time of year. I'd be a bit concerned about the white smoke filling the barn too. Ours has a warmed over and .040 overbored 302 that doesn't get that hot even on a 105* day idling in traffic with the A/C on! Sounds like you have a lot invested in it. I'd do a combustion gas check and install a good fan/shroud.

 

[broncnaz]

Need more fan 1600 cfm is not going to cut it and just figure your not even driving it yet its only idling in a barn. Where is the temp switch for the fan? if its in the radiator it will take a lot longer for the fan to kick on so the engine temp will probably be way higher. but overall it sounds like you may have a coolent leak somewhere. plugs may tell you could be wet and not firing or way to clean compared to other ones. I would suspect a intake manifold leak sometimes one of the corners will leak into one of the corner cylinders 1,4,5 or 8.

 

[Apogee]

...But as long as you move liquid coolant through the engine you will not hurt the engine.

I disagree with this statement somewhat...while temperatures above 240 F can be tolerated for short periods of time, your engine oil life drops dramatically above 240 F leading to other inherent lubrication issues. You can certainly add oil coolers to extend the safe operation under severe-duty conditions, but that should be for severe-duty use (like racing/towing/etc).

I tend to agree with most everybody here though that 210 F isn't that bad and that you more than likely have a combination of things contributing, including the undersized fan, no shroud and possible timing and/or vacuum issues. Would I be correct that that cam break-in went well? The only engines I've ever built tended to get well into the 220 to 230 F range breaking in the cam during the initial run(s), and that's with mechanical fans and shrouds.

Tobin

 

[bmc69]

The fan I am using is rated at 1610 cfm. It's setup as a puller and we can feel the air being moved.

About 1/3 the CFM that is required. If yr electric fan is not pulling 40 amps and more ..its not big enough.

My 408 just laughed at the 2600 cfm electric that I tried to use..briefly.

 

[dbevans2249]

JMO the correct fan shroud and the factory 7 blade flex fan should keep it at the thermostat temperature. I run that on a .030 over 302 at 16 degrees advance and it is fine.

 

[beaux312]

About 1/3 the CFM that is required. If yr electric fan is not pulling 40 amps and more ..its not big enough.

My 408 just laughed at the 2600 cfm electric that I tried to use..briefly.

agree Im running a 18" two speed off a 03 Heep Grand Cherokee mounted the my stock shroud