Jeep runs hot (very hot)

[stevenf]

I own a custom built rock crawler with a CJ7 as the body all else is custom, frame, drive shafts, difs, trany etc. I use it on the ranch to haul heavy stuff around and toodle around the ranch in. It has a 327 under the hood that I fuel injected last year and I still can't get it to idle around the ranch at less than 210 it was at 250 but I just got thru putting a high volume edelbrock water pump, a HV 180 thermostat, new hoses, belts, radiator, 16lb pressure cap and a heavy duty stainless clutchless perma cool fan made specificly for low speed cooling. I still can't get it below 210. anybody got any suggestions I'm thinking about an electric fan next do you think that'll help. When I take it on the road all troubles go away it just isn't the type vehicle you want on the road from a dead stop it'll stand up on 2 wheels and walk across the pasture riding on the trailer hitch besides the open headers don't make it any less conspicuous for the police I only take it to town to get gas other than that it stays on the ranch.
Steve /forums/images/graemlins/confused.gif

 

[DUMBDOG]

Radiator?

 

[GerardC]

Maybe the gauge is faulty?

 

[RobertN]

What radiator do you have? Does it have a shroud? someone else mentioned... are you sure about the sending unit and guage? What antifreeze/water ratio are you using? 50/50? Is it a manual or auto? If auto, how is the tranny cooled, and have you checked that temp yet? How do the plugs look; is it lean at idle? are the head and intake gaskets correct, and aligned over the water ports properly? Saw that happen before...

Make sure you need the high-flow water pump... If the water passes through the radiator too fast, it does not have time for the necessary heat transfer to occur. It may run hotter with the high-flow pump...

Sounds dumb, but I did it once... It the thermostat in right side up?

Used to run the rocks around here. Grew up in a '42MB. We never ran open headers though... Illegal, too loud, and fire danger out on the trail...

 

[ByronBob]

Take the T-Stat out and see how warm it runs. Being in Texas do you need heat?

 

[stevenf]

Robert, I think your reply has the greatest amount of stuff that I don't know or don't know how to check so I'll reply to yours and try to answer everyone elses to. The radiator is custom built 4 core I just had it boiled out, rodded, pressure checked, and flow tested. It does have a shroud and the new fan is spaced per MFG at the back of the fan a 1/4" outside the shroud. Sending unit and gauge accurate it didn't boil out last night since I did get a 40 degree change for the better with the new pump and before I installed the pump I took a garden hose and put it in one side of the block and let it flow to wash out any possible stuff in block and it flows freely thru the block and out the other side. The antifreeze I used is the premixed 50/50 supertech from Wally World. The Tranny is a 3 speed auto with a seperate transmission cooler mounted in front of the radiator with 2" between them I don't know how or have the ability to check the tranny temp currently. Plugs are brand new platinum. The Holly injection system I had put on it has a closed loop I think its called system with the computer to auto adjust based on the various needs so its not running bad or lean no smoke no smell idles perfect after warmup. The Heads, intake gaskets and alignment are beyond my current background but I wasn't having this problem 2 years ago with no changes made to them it has gotten increasingly worse hence all my cooling system replacement parts yesterday. The High flow was recommended by numerous mechanics because most of our work is done at very low speeds and RPM's. The Thrmostat is installed with the round base with the 180 marking in the block and the cone with the point sticking up into the thermostat housing. Actually the Header aren't completely open I've got fire arrestor baffles before the tail pipe as fires and Texas don't go together well in the summer when its dry it can be like gasoline when the grass gets lit. If anyone can think of anything else for me to spend my hard earned money on chime in but I still figure a electric fan has some promise if I can find one to fit properly as like I say if I put this thing on the road all heating issues go away.
Steve

 

[stevenf]

Byron, I forgot to answer yours, I tried it it didn't help at all actually affected highway travel by heating up at high speed also as the water didn't spend enough time in the radiator to cool properly.
Steve

 

[EddieWalker]

I'm unsure of when this started happening. Was the temp on the engine always hot, or did it just start after you put in the fuel injection system?

I'm thinking you've done all the basics and everything sounds right, so the question is, what's the water doing inside the block?

Did you put on a new manifold with the injection system, or at least take it off? Sometimes you get the wrong gaskets and they will block the flow of water through the manifold. That happend on a 304 I had in a '73 CJ5 when I put an Edlebrock manifold on it. I had extreme overheating issues right away. There was no driving it, since it heated up so quickly.

Good luck,
Eddie

 

[SnowRidge]

If the problem goes away on the highway, it sounds like an air flow issue. The gradual deterioration of cooling at low speeds may be explained by a gradual build up of scale inside the cooling passages. Not much, but just enough to require additional air flow at low speeds.

I would try the electric fan. Here's a link to a guy that has them cheap. He sells SPAL fans.

I have a SPAL fan on my Power Trac to cool the hydraulics, and I have had a couple on cars over the years. They work well. SPAL's home page is here.

Assuming the problem exists at idle, you could test the airflow theory by getting her hot, and then sticking a big honker of a 115 volt electric fan right in front of the grille. If that doesn't drop the temperature, you need to look elsewhere.

 

[sneaky_pete]

Steven, What is the cam like in the 327, and what compression are you running? These can make a big difference in engine temps. A cam with modest intake duration and a longer exhaust duration will drop your temp by 15-20 degrees.