I am currently running a 304 with a 3 core factory style radiator and a 190 degree thermostat (new) and a clutch fan that I think may need replacing. Driving around or wheelin it heats up and dosn't stop, the only way to keep it under control is to keep the rpms at 1500 or below, then it will hover around 200, otherwise it keeps going up!

Anyone else have similar problems? Solutions? Advice? etc.....



Thanks,
Justin

has the radiator been rodded/is it clean? is the thermostat clear? are the hoses in good shape and clear not pinched? How many times has the motor been over heated? (and to what temp) how many miles are on the motor? does it run lean? what is the coolant/water mixture? any foreign material like gasket material in the coolant? does the oil come out clean? (black okay...light brown or whiteish obviously head gasket)

basically I asked all these ???'s because the motor might be cooked 240+ degrees too many times can do some serious damage.

it could be as bad as a headgasket blown air to water if the oil is clean. you might just be running lean and could just richen it up and done deal. maybe the heat expanded everything too many times and now the tolerances are too tight causeing more friction adn less room for lubrication. it could be anything.

Sillyneck pretty much covered it all but is the new thermostat working? Take the fan clutch and giggle it is the moving back and forth(bad). Does it kick on and off? Start from the easiest crap to check and go from there. Our question to you is how long has this been happening and what change did you make when it started?

has the radiator been rodded/is it clean? is the thermostat clear? are the hoses in good shape and clear not pinched? How many times has the motor been over heated? (and to what temp) how many miles are on the motor? does it run lean? what is the coolant/water mixture? any foreign material like gasket material in the coolant? does the oil come out clean? (black okay...light brown or whiteish obviously head gasket)

here goes..... the motor is from cj-7 I got in a trade, it was not the origonal motor in the jeep, it was a running a driving jeep, none of the guages worked so I don't know what temp it ran at, but the only time I drove it was home, however it did run good and smooth. The 360 I had in my scrambler had worn out the timing cover and had no oil preasure and a few other probs, so out comes 360 and two core radiator, in goes 304 and new looking clean 3 core radiator from cj-7. the only thing I used off the 360 was the distributor so that I coud keep the current motorcraft ignition. After the motor went in it ran fine,and if anything the carb ran slightly rich, and had 50/50 mix and good looking hoses. When the motor was out, we inspected it as best we could through the exhaust ports and the pistons and cylinders apeared clean. I drove around on the road probably 50 miles or so with small tires and had no problems with overheating (also installed new maual guage with motor). Then I put the 42's back on and go wheelin, play around a little and it gets warm, we head back to camp and let it cool down, removed the thermostat, replaced lost coolant/water and went back out for another try, again gets hot, this time I didn't get off the trail intime and it puked over at about 250, let it cool and it fired back up and made it back to camp, onto the trailer, and back home. I installed a new 190 degree thermostat and checked to make sure it was the coolant was flowing which it was. Went back out on the road and found that I could keep it around 200, but only if I kept the rpms at or below 1500. Checked the oil today and is still black (since the pistons were so clean I filled it with mobil 1 when I droped it in the scrambler) and the coolant is still a bright green color. It has no fan shroud and a clutch fan, the clutch fan seems to be a little worn, but seemed to keep the 360 with a 2 core radiator fairly cool. Also, the radiator fins are still in good shape and I can see the front of the motor when looking straight forward at the front of my jeep. It has only overheated one time since I have owned the motor....I think that covered all your thorogh questions which I thank you for.

Current plan is to replace fan with either a manual or a new clutch fan and/or install electric pusher fan....but this is up to suggestions???

10-4,
Justin

What about the shroud can you make one?

Sounds like the clutch fan is gone. I replace it and see whats happens after that. Then go from there. Eric

I'm going to pick up a new clutch fan tomarrow at work and possibly a new 160 degree thermostat, if that dosn't work I'll probably try a shroud.

Thanks for the replys, keep them coming.


10-4,
Justin

Originally posted by TNScrambler
I'm going to pick up a new clutch fan tomarrow at work and possibly a new 160 degree thermostat, if that dosn't work I'll probably try a shroud.

Thanks for the replys, keep them coming.


10-4,
Justin

clutch fan 101. it should spin 1/2 turn when cool and motor is off. however when it is HOT and running roll up a news paper or magazine (not 4x4 or porn) :D and stick it a little bit in the path of the fan...if the fan stops then the clutch is done....of it destroys the magazine (preferably martha stewart) then you're good to go.

Originally posted by Sillyneck


clutch fan 101. it should spin 1/2 turn when cool and motor is off. however when it is HOT and running roll up a news paper or magazine (not 4x4 or porn) :D and stick it a little bit in the path of the fan...if the fan stops then the clutch is done....of it destroys the magazine (preferably martha stewart) then you're good to go.

hahahahahaha :D

(preferably martha stewart)

:laughing: HAHAHAHAHAHAHAHA
Sorry, don't have any martha stewart, how but some notes from statics class?


Justin

Dont run a 160 thermo on your 304, ITs too cool..

I ran a 160 for about 2 months the motor never ran quite right, When I switch to a 190 it ran like a champ.

I am betting clutch fan.

Steve

Agree with previous posts- sounds like the fan clutch. The addition of a fan shroud will also dramatically help the cooling efficiency.

I have been through all of this with my 304. Tryed 3 different thermostats, 4 core radiator, huge electric puller fan, then with pusher fan, different fan blades with and without a clutch. Then I finally spent the $100 for a fan shroud. That did it after I spent all that money. You MUST have a fan shroud. I now run a 401 with a huge Warn 8274 up front in front of the radiator and the temp never reaches 200 F.

Fan shroud, fan shroud, fan shroud.

I'm sure I'll get flamed for asking this, but where can I buy a fan shroud for my 304? It runs a little hot, and I've got a new 3-core radiator, a new 180 degree thermostat, and all new houses with a flex fan. Does anybody make a fan shroud for the 304? Thanks.

Flame suit on.

Originally posted by Steven_Mc
I'm sure I'll get flamed for asking this, but where can I buy a fan shroud for my 304? It runs a little hot, and I've got a new 3-core radiator, a new 180 degree thermostat, and all new houses with a flex fan. Does anybody make a fan shroud for the 304? Thanks.

Flame suit on.

maybe try jeepparts.com or whatever. otherwise jeep auto wreckers might have some or if I were you I'd either get a universal shroud and make it fit or you can go to your local metal fab shop and have one formed up for you which would be the best bet.

Originally posted by Steven_Mc
I'm sure I'll get flamed for asking this, but where can I buy a fan shroud for my 304? It runs a little hot, and I've got a new 3-core radiator, a new 180 degree thermostat, and all new houses with a flex fan. Does anybody make a fan shroud for the 304? Thanks.

Flame suit on.

What Silly said, or you can check with specialtyparts.com or your local stealership can still order them.

My 304 has low miles, the mechanical fan, no shroud, and no thermostat (in the summer). It hits 90 around here and mine started to run hot one day (about 220). I put a pusher fan in and it keeps it at 190 no problem.

I had a shroud and it worked well. I had to remove it when I relocated my radiator to install PS (early CJ), and I've been to lazy to reinstall it.

Fan shroud, fan shroud, fan shroud.

Well, I've got a fan shroud and a new clutch in the truck....I'm about to go put it on, I'll let yall know how it goes.


10-4,
Justin

AAAAAARRRRRRGGGGGGHHHHHHHHH!!!!!!!!!!!

Sorry, had to get that out of my system, but anyway, I put the new clutch on the fan, however the shroud could not go on, becuase it hits the top of the fan. Thre reason being that my transfer case is too low (which I've been meaning to raise up since my driveline angles are more than fine). So I guess I'll have to raise it up sooner than expected. The new clutch worked, and was able to keep it much cooler, but it only prolonged the motor to heat up. So I guess tomarow I'll try to raise the tcase and put the shroud on.

10-4,
Justin

I checked the timing, it was at 26 degrees advanced....no wonder it started so easy! So I set it at 10 degrees advanced. I noticed I could hear a slight hissing from the radiator cap, so I put a new 16 pound cap on. And I checked and I'm getting good flow. Took it for a drive and again, it was getting hot, but now the heating up even more prolonged and it was more controlable. It got no hotter than 220 while I was driving, and it seemed to jump up the most when I had to stop and then get going again. I'm going to try to play with the carb tomarrow and see if it makes any difference.

Thanks for all the help so far,
Justin

well finally after a new 190 thermostat, a new fan clutch, resetting the timing, re-adjusting the carb, and finally a 14" electric pusher fan it will idle at 165 and while driving stays in the 190-195 range, the only time it hit 200 was on a prolonged hill with me keeping it above 2 grand!!

Thanks to everyone for there advice and input on the subject....and yes I do plan to install the shroud I bought soon....just have to make a new crossmember to raise my tcase up some to alow the fan to not hit the shroud.

10-4,
Justin

:D the shroud is good for 30 degrees usually :D

try putting a restriction in the bypass hose. from the factory, there is a 3/4" rubber hose (u-shape) that goes fromt he intake manifold to the waterpump. the water pump pulls the water from the intake manifold (hot) and pumps it back into the engine, bypassing the radiator. i put a restriction in mine that takes the i.d. of the hose down to 1/4". its a round piece of brass with a hole thru it, each end is chamfered to help reduce turbulence. it seems to work fine.

and i have a shroud.

matt