Was it overheating in idle, or while driving? Worn engine bearings (more friction) could also cause the temp. to go up. I'm suspecting lots of sludge in the cooling passages in the engine block. How long does it take for the car to overheat? Thermostat stuck?
It wasn't over heating at idle.I took her down the highway a few miles and started getting real hot.I only put one summer on this water pump ,but maybe its a dud ?Its weird because when I drove to work the other day didn't start to get a little hot until I pulled into work which is about 18 miles from my house. I had a friend help me check compression and vacuum and they were fine and he said the timing "seemed" fine too.
is the coolant flowing through the radiator when it overheats? is the upper and lower hose tmep the same or diff when it gets hot? i have seen may impellors come loose from pumps and they tend to catch only on high rpm and somewhat pump coolant through the block. i also have seen many "NEW" pumps be bad also.
The hoses all feel the same .The upper hose is boiling hot. I'm thinking my "new" pump may have shit the bed.I bought it from Mcvey's.It's early here after this cup of coffee I'm going to try and figure this out...
Lack of coolant pressure can cause overheating at speeds. Rad cap good? Does coolant pass through the overflow pipe? Check everywhere for minor coolant leaks.
Get a new cap. Could be as dumb as that. Check your blades and make sure they are drawing the air from the rad, and not pushing.
Ok just turned the fan around and topped off coolant. I'm going to take her up the highway and see what she does. I'll check to see if it's drawing air too.
Well i just had it running and blew cigarette smoke and it sucked in!!!! So that means the fan was on backwards before this.....ok to the Highway I go.
You have me confused (and probably others). You say in your first post, that the car overheats when idling, but when the car goes down the road it cools down. Now you are saying the opposite. Please straighten out what it is really doing. If the car heats while idling, it may be head gasket or heads themselves that are the problem. (I had a 54 Cadillac with 331, and it started heating, only to find out both heads had good size cracks in them.) If it heats going down the road, it may be radiator is plugged up. The first thing I would do is a block test. This will show exhaust gases in the coolant. If they show up, then head/head gasket issues. If no gases, then radiator (or something else) may be faulty. Take the car to a radiator shop and have them run a block test for exhaust gases.
You got me thinking there for a minute. Look at the way the blades are pitched on your fan. Now turn the fan over and look at the pitch again. It stays the same! It may not flow as much air but it won't change the direction of airflow. Now if you reverse the rotation of the fan, it's a whole 'nother story!
Make sure you're not running too lean. Old timer taught me that, said you could melt the tailpipes off.
I think you are mixing me up with Ratfins56 who said "My '56 Cadillac has a little problem. When I drive, her temperature is fine, stays at 160 degrees. But if it stays in idle for more than a few minutes after driving for a while, the temp. starts creeping up,up,up...and it won't come down until I'm moving at a good speed. I said : "It wasn't over heating at idle.I took her down the highway a few miles and started getting real hot" ....
Lol it's my fault for jumping into his thread about over heating ..We have the same year Cadillacs too. Easy to get mixed up.
Hi everyone. I'm running into a similar problem where my 56 cad runs at 190 degrees when on the road, but temp rises to 230 degree range when idle or in stop and go traffic. The car eventually shuts off - no spewing of radiator fluids - just shuts off. Details: Rebuild 365 block Rebuild radiator with new water pump thermostat etc. I checked temp on radiator, and it appears to be doing well with cooling incoming water before sending back out. My issue is specific to vapor lock where the block gets so hot that I can see the fuel in the filter bubble and eventually gas before reaching the carb. My question: what temp should the block run at? Is my issue with the fuel lines being too close to the block? Or is there and underline issue with my the block is getting so hot? What engine oil is recommended 30w , 10w-30 etc? How can I reduce the heat on the block itself? Posted using the Full Custom H.A.M.B. App!
I have a 56 coupe and it does the same thing, I have tried everything even putting some heat shrink shield on the fuel lines, rebuilt radiator, new water pump etc same as you. Put electric fans on the radiator and nothing can keep the car from getting hot and boiling off the fuel and getting vapor lock. It only happens when I get stuck in traffic or sit at a red light for too long. My advice to you is put a sbc 350 in it. Im currently putting an Lt1 in mine because I got tired of trying to figure it out. The one thing that did help for me is putting an electric fuel pump down by the tank and flipping a switch when I sit at a light for too long so it won't stall out when I try and take off. If you could have someone fabricate a fan shroud it may help when at idle. Good Luck and if you figure it out let me know.
I'm going to suggest this again.....just in case there is someone who actually listens to advice. I think it has been ignored in all the other overheating threads in the past. Get it up to operating temp and shut it off. Place your hand on the center of the radiator core.....front or backside.....whichever is easiest. Just touch it quickly to see if it's hot. If it is.....no need to touch it again. If it's cold....you found the problem. Radiators tend to start clogging in the center and it progresses out toward the edges from there. Continue feeling toward the edges and you will notice it getting warmer until it's hot around the perimeter. If this describes what you feel....it's time for a new radiator. I've been in this exact same situation several times and swapping the motor won't help if you use the same clogged radiator. Doing this simple test will prevent lots of headaches and save lots of time and money. Someone else said that it's always an airflow problem....but not always......could also be a partially clogged core giving the same symptoms.
My experience over last few years (51 merc, SBC + cam, headers, TH350) 2008: Was 4 blade mechanical fan, no shroud, 2 crossed plug wires. Overheated in 15 minutes. Added 160 stat, played with carb, still would overheat to where it would puke. Eventually replaced the carburetor which helped it run better, and then went to very slim electric fan as puller. This was not bad. But would still over heat in mid summer, and wouldn't come back down. New radiator installed, better fit, no gaps around it. The new radiator is a mid 70's Doge truck application, so no fancy mega dollar setup. In fact the radiator was <$200. Now a 6 blade mechanical fan, still no shroud. Electric fan moved to front and set up as back up pusher. Runs at 180F on highway at any speed. In very slow bumper to bumper traffic would get to 205 and backup fan would come on. But it will cool down and not creep up fast, would take a long time to get back up to 205. I am adding universal 1/2 shroud soon, and I should be all good. Backup electric should come on only rarely then, friend believes that the car will not go over 195F once that is on. Pics: OLD: Adding:
I've always wondered why Cadillac designed their engines throughout the '50s, with the fuel pump on top of the engine...Bad design, if you ask me...