440 over heating problem

[Chryco Psycho]

so what was changed between when it was running cool & now , something you changed had to affect the cooling

[72cudamaan]

Lack of air flow judging from the amount of time it takes to overheat.

[Kevin71]

The one thing I keep wondering about is the build up of something on the inside of the block.  When I changed the freeze plugs there was a thick wax maybe like sludge behind the plugs.  Of course it was breaking loose when I pulled the plugs.  I got as much out of the block as possible but I am sure some of it fell down in the water passages.  I keep thinking this would restrict water flow.  How do you determine if it is the water flow.  Could the build up cause it to  over heat.  The car wasn't driven more than 30 minutes at a time prior to all this in the previous 2 years.

[mopar12372]

did you remove all the air from the system?    the puleys that where replaced are they stock size or are they under driven/over driven ? are you running a shroud? is the clutch fan good?
is the cooling system holding pressure ? what is the pressure of the radiator cap?  is you over flow tank filling up when you shut off the car alon with the hoses sucking  together ? if so replace the rad cap .

if you have lots of stufff comming from the block when cleaning i would recomend replaceing freeze pulgs on the side of block. i dont agree  with the 4row rad comment , to each his own . have run them for years with great results / i always had b/rb engines that where not bored too far run on the cool side with a healthy cooling system. just openions hope all goes well

[beekppr]

I just went through this with my 383 and many of the suggestions were right on. In the end, I removed the tranny cooler in front of the radiator and my problem completely disappeared. My guess is that your radiator needs no obstructions in front of it. I tried everything else including electric fans and it just wasn't working. I hate to say it, but I bet you will be plagued with overheating issues until you ditch the condensor and let the fresh air in.

[Kevin71]

All of the the pulleys are stock and new.  How do you determine the amount of air flow and how much is enough.  The problem started after I pulled the engine when painting the car.  At that time I added a Classic Air system.  Also while I had the engine out I noticed that one of the freeze plugs had been leaking.  I replaced all of the freeze plugs and on the inside of the block was buildup of some sort.  Some of it came out, pulled some out, and some fell down in the block.  If these was barrs stop leak could it be causing a problem could it have blocked some passages.  I put a 2 core radiator in when I put the engine back in along with new alum water pump and housing, new all stock pulleys, and thermostate.   I don't know the pressure of the thermostate, but what is recommended?  At that time a aftermarket flex fan and no shroud.  Anyway it starts overheating.   Then I replaced the radiator with a 4 core alum, put a stock thermostate controlled fan on, and a shroud.  Still over heating to 240 degrees whether the ac is on or off.  I have check the temps to verifiy the gauge.  Have checked to make sure the thermostate opened at 180'.  Nobody has mentioned the buildup in the block.  Could this be a problem.  Also I guess the only way to check the air flow would be to remove the condensor and run it, is that right? 

[72rtchallenger]

My 440 is a 75 vintage C-body unit out of an Imperial that has about 70-80k on it.  I used an original 340 3 core 26" radiator because the lower pickups matched the C-body water pump housing.  It overheated whenever I put any stress to the engine.  I decided to upgrade the whole cooling system and got pretty much the same stuff you got.  Mopar aluminum housing, aluminum pump, 180 stat and a new aluminum radiator.  When I pulled the old water pump housing off a TON of sludge and brown coolant came out.  I had no idea the engine was that bad.  I got a big tray and a hose and power flushed the block through each water pump port.  POUNDS of sludge, sediment and brown coolant came out.  I flushed for quite some time along with using a coat hanger to dig out some chunks.  Once the water ran clear I re assembled all the new parts, clean fresh antifreeze mix and purged the air bubbles.  Since then the temp gauge NEVER goes over 180.  No matter what I do, it refuses to overheat.  Maybe it's worth pulling everything off again and power flushing the block?  Unless it was a recent rebuild you may have a ton of sludge and rust yourself.  That will just circulate and clog up the new radiator.

well some of us have suggested flushing the block like this to help clean out that sludge your talking about,,i would do it before anything else 

[brads70]

For sure flush the engine.
 Just a though...? How close is the condenser to the rad? Is there a good sized gap between them? If it was fastened right close to the rad airflow would be effected?

[mopar12372]

theres your problem (2core radiator ) 440 needs at least a 3 core.

[Kevin71]

I replaced the 2 core radiator with a 4 core.  The condensor mounts flush on the front side of the radiator support.  That's how the instructions with the classic air showed it.  I am going to try to get the time to flush it out Wed or tomorrow and call classic air about the mounting and if they have seen similar problems.  Do you think running a radiator cleaning solution thru the system would break down this build up.  I guess at this point anything is worth trying.  I have just have had alot of work lately and haven't had the time to try out some of these ideas.  I am hoping to tomorrow and will put a update on the site.  Thanks so much everybody.

[mopar12372]

did some stuff get stuck behind the thermostat?  what does the inside of the waterpump look like?
heres what o would do .
#1 flush engine with cleaner
 #2 remove water pump/ thermostat check for debree
 #3 re mount condenser at least 2in off radiator (creative thinking will help)
#4 check clutch fan for looseness (cold)
#5 if you have a shroud good
#6 run a 30 /70 water mixture coolant. coolant makes temps hotter/disapates heat slower
MYOP

[beekppr]

Flushing everything will only help your problem. If you have time to remove the radiator, I would and backflush it out of the car just in case you have large chunks of stuff blocking the rows.

I would definitely put some space in between the condenser and the radiator. If you are creative enough, mock someting up and have your local welder make some nice metal brackets out of whatever you find works best. 50 bucks will probably get you some nice clean brackets to move the condenser forward 2-3 inches. This will let in all kinds of fresh cool air so the fan doesn't have to suck it through two radiators.

I have had overheating issues for years with my 383 and let me tell you I tried everything. Water pumps, thermostats, hoses, electric fans, thick aluminum radiator, etc. It wasn't until I had a post in here that the guys suggested moving or removing the tranny cooler. Once I did that, problem just disappeared. It was so simple I kick myself for not trying it much sooner. I have a feeling once you get some brackets and move the condenser forward, you will be happy and will have saved yourself alot of trouble. 

[01fun]

   I had the same problem with my 440 after I installed the HV water pump and finally after replacing everything else I solved the problem with a HV thermostat from Summit Racing - like an idiot I never realized you need this to hold the pressure.

Good luck

[Chryco Psycho]

I didn't re-read the whole thread but you said you installed an alum water pump , it wasn't a 440 source housing was it , they have caused overheating problems for almost everyone using one .

[msbaugh]

Ok a little confused about something mentioned earlier... maybe someone can clarify? How can a higher velocity water pump reduce heat transfer? I would think that the heat transfer would increase. Simply because whatever mass flow rate you have coming out, would create an equal mass flow coming in, always. I understand the logic, it doesn't have time to cool off, but that shouldn't matter, the same amount is coming into the system. I would think that velocity should always increase heat transfer? Maybe the higher velocity creates unwanted pressure changes? ...I guess That could cause a reduction in heat transfer. Or is my linear relationship assumption between velocity and heat transfer just wrong? Is there a saturation poin if you will? A speed that's just too much or impracticle?