V6 Still Overheating!

I hate to be the guy who is asking for all the help all the time but I'm out of ideas. I thought I had it under control but riding into town today at lunch (5 miles) the gauge went to 250*!! slowly just crept up there the whole way. I was on the local state Hwy doing 50- 55 mph pretty much the whole way. On the way back to office I kept it a little slower doing about 45-50 and it was a little better but still way to hot at about 230*+

New radiator, new water pump, new hoses. I have taken the thermostat completely out to eliminate that possibility. The only thing I look at as being the problem is the heater hose I have from going from the pump directly to the intake manifold. (photo). I've been checking the oil for signs of coolant but none visible.

What do y'all think?

 

Still unclear. Is it boiling over?

 

Does not seem to be boiling over. It did previously. But I stopped as it reached 250* so it may have if I continued.

 

Personally I would say you need the thermostat because at speed your coolant will flow to fast to cool. The next issue is no fan shroud. You can get away with it if the fan is much closer to the radiator than yours is. Also it's a ridged fan which will have a negative effect at speed.

 

Do you know what psi your cap is?
250 degrees is the boiling limit for a 15psi cap with 50/50 antifreeze/water mix at sea level. Any chance the gauge is off a bit?

You say you stopped when it reached 250; it didn't boil over after you stopped? Did you happen to notice what the temp climbed to after you shut the engine down? (It will continue to climb due to heat transfer without water circulation.) If it was able to climb higher than a stated 250 without boiling over, the gauge can't be accurate unless the cap has an astronomical pressure release.

 

That can very well contribute to the problem as noted by RATTYFLATTY - "I would say you need the thermostat because at speed your coolant will flow to fast to cool."

 

I concur. Your fan is a good distance from the rad a shroud would help, def need a tstat, is the gauge accurate? Side note what do your plugs look like and how's the timing?

 

I would definitely double check the gauge. Spent 2 weeks trying to find the issue with my A1. After cleaning and/or replacing everything the only issue was a worn out gauge.

 

No shroud on the radiator! Your not pulling air through the radiator efficiently. The fan is pretty far away from the matrix, and there is no shroud to help pull the air through the radiator.
-Donny

 

I'm willing to bet that the lack of a thermostat is the cause of your overheating at highway speed. The thermostat is necessary to restrict the water flow and slow it down so it spends more time in the radiator cooling. On race cars you run a water restrictor in place of the thermostat for that very reason. The shroud wont do any good at highway speed. The shrouds purpose is to pull air through the radiator at idle and very low speed (stop and go traffic).

 

I agree that your hose that essentially is a by pass of the heater core appears flat or kinked. The small S shaped unger the upper radiator hose also looks kinked or something but hard to tell.

Is there a spring inside your lower radiator hose?

Maybe a dumb question but, does a shroud have that much affect at highway speeds?

edit: Thanks Kyle. You answered that question as I was typing it.

 

I think its related to your questionable distributor and apparently retarded timing. Your Jeep is badly out of tune. You are getting 10 mpg. Distributor not responding to vacuum advance or mechanical advance somehow. Tune it up. Fix ignition first. Get advance mechanisms working, set points, dwell. Then tune the carb. And change any service parts that have been getting you by for too long.

MY ERROR. The timing issue was another poster. Still, retarded timing will make it run hot. If timing is good then ignore everything I typed.

 

I had a problem like that. A shroud is what helped my problem. I tried no thermostat, but that did not help. Put thermostat back in and added shroud. Fixed my problem.