Thread: mercury 312 3 speed manual cooling issue

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when im crusing up the expressway at around 70 mph the temp starts to rise above where im comfortable to run it at, the vehical is a 1959 mercury monterey and its all stock and i dont want to modify it. so i was wandering about additives for the coolant that accualy work. water wetter or something like that. does anyone have any suggestions or ideas. it would realy help, as im going on a trip and want to drive it but i dont want to overheat it.

In your signature, it says "all original". I assume that means original radiator. I would think that instead of crutching it with wonder products, you would want to remove it and have it reconditioned at a radiator shop. Also, check the lower radiator hose for sucking flat at higher engine speeds. If it doesn't have a spiral wire in it, replace it or find a wire that will fit. Replace any sheet metal panels that you may have removed. Maybe the air is going around the radiator instead of through it.

Yep, a stock cooling system in good shape should not run warm. Ford made a lot of cars in this era and they had no overheat problems, so something has gotten plugged up or otherwise not working well in your system.

Like Richard said, either have your radiator redone or put in a new one. That would be a place to start. Check and replace any other worn parts, like hoses (they can suck down under high speed running) and also your water pump. Maybe your block has a build up of scale in it too.

Those other things you mention are just bandaids .

Don

These monsters date back to the time that I was doing a lot of garage work on a part time basis. First of all, the 'Y' block was not a hot running engine with a good cooling system. But, the main source of problem that I, personally invariably found was someone installed the thermostat with the pellet facing out towards the radiator. Also, you do need a good 180* thermostat. Most of the new ones seem to be 190*/200* for newer cars. A 160* will run nicely, but will also cause sludge build up.

(Then, there was that '57 Ford that I owned with a 312 - that @#$% car would just for spite would blow the anti freeze out - and that's with new hoses, thermostat and radiator cap - then it wouldn't do it again for months)

PS: Make sure you have the correct thermostat that fits the machined groove in the housing and don't crack that housing either - it's easy to crack and my guess, replacements are hard to find these days

well i know i have not removed any metal shroud as i dont think it came with one stock.
the hoses i think are original, as the plug wires and coil and well basicly everything else is original. i have not checked the thermostat or anything like that. i know the left side of the radiator shows some corrosion but is not leaking. the bottom hose does have the wire in it and the top hose looks to be i good condition. i did drain the radiator fluid and put in new coolent but thats all ive done. now i could be over reacting in the temp gauge it starts with a L then the word temp then H. when im driving on the expressway the temp needle gets to the edge of the p in temp. i havent checked the temp of the hose with a lazer thermometer yet but to me thats to high. am i wrong?


ps. thanks for all the help and addvice i sure dont want to hurt this car. me and my wife love it!!

You say it is all original and the hoses look good. Looks can be decieving.
Do you know how old the hoses are. They should be changed every 5 years in my book.
I would not want to take a trip and blow an old hose because they looked good. If in doubt change em. Look at the freeze plugs to see if they need changing. Change the hoses. Reverse flush the engine . Have the rad recored, put on new heater hoses and bypass hose if it has one.
While your at it put on some new belts .
Now you have a starting point .
So far you haven't spent a lot of money and probably will make the trip ok.
How old are the tires? Don't run on tires that are old or showing signs of cracking. 5 years should be changed and 10 years difinitly.
Happy travels. Bob

update!!! i flushed out the cooling system and i looked as far in the top tank as i could and the tubes in the radiator look to have alot of sediment buildup and it is pluging the tubes. the only thing i can think of doing is sending it to a radiator shop and having the tanks pulled and the tubes cleaned out then put the tanks back on. does anyone have any ideas or suggestions. if so let me know.

Any competent radiator shop can do it. If this doesn't work or the tubes will not clean out, then have it recored. Just had a radiator built for a car. The shop used the original upper and lower tanks, relocated the hose connections, and installed a new core.

hey dave should i do anything to maby try and clean out the motor. if the radiator had that much stuff in it wouldent the motor also have a bunch of sediment in it also. just wandering. and you gave me such great advice and info on my 66 cadillac i figure you would know. thanks again.

Don't see a problem, the "P" is just a bit over halfway, maybe 190? If it never goes any higher, just drive it. As long as it never blows coolant, it's OK.
For peace of mind, there are lots of rad flush compounds available.

I'm of the age that I had done much mechanic work (including racing) with the 312cid engines - and sludge build up in the rad was common. I do recall changing several sets of head gaskets from water seepage - and usually what you end up with is milky/cloudy looking oil and sludge. It isn't usually really bad enough to notice except for those two indicators. When you finally pull the heads, you usually only see a dark band where water and/or exhaust gases have passed - and those that I saw, it usually, and it might only be coincidence, wa between cyls 7 and 8 (left side rear)

Oh yeah - these engines have tender main webs, 5K rpm and higher

Probably wouldn't hurt a thing to run a can of flush through the entire system....I'd be doing it BEFORE I got the radiator repairs done for sure.....

after a good colling system flush, the heater core and radiator might spring leaks.. as being so old, the crud may be holding it all togther, which should be fixed anyway

Originally Posted by Dave Severson

Probably wouldn't hurt a thing to run a can of flush through the entire system....I'd be doing it BEFORE I got the radiator repairs done for sure.....

yeh ive ran a coolent system flush through it just last week. im going to be pulling the rad. tonight and dropping it off monday so well see what they say after that.

Well, hope it's good news on the recore! Nothing more frustrating then a good cruizin' day spent on the side of the road waiting for the temp to come down!!!! Hope you get it cooling good when you're all done!