Cooling system question

[sixty6]

As my ignition/carb issues resolved now it's time for cooling system. I checked coolant for boiling point and it is very low, around 210 (looks fine, green, regular coolant smell), my truck is 265 so I know the measuring device works properly. So it's time for replacement. As I took hoses off I also found out it has 180F thermostat. OEM should be 195F but it seems like they sell from 160 all the way to 200. Should I go with 195? No rust inside radiator just some crud from silicone gaskets and scaling. Lower hose engine side is very rusty on inside and outside (is that a water pump?). Is that usual rust spot? Radiator has no leaks, should I clean and keep using it? Is there's a drain on the engine block? Just draining radiator I got about 1.5 gallons.

[bubba22349]

The Engine Operating Temp basics can be broken down like this up to a point a slightly cooler running engine will make a little more power. But an engine is much more efficient the warmer it is again this is up to a fine point and it will then also get its best very best economy. T Stats are rated for their opening Temp. so this is not always the engines operating Temp.
they help the engine warm up faster and reduce the coolest flow through the engine so it has enough time to be air cooled by the Radiators fins. Are you having some overheating? From what I can see the Rad looks fairly clean and is in decent condition, check the tubes for crude in them. There are cases of were a Rad looks real good but still won't cool I have had this experience a number of times then all you can do is replace it with a another Rad. If you happen to have an old time Rad shop in your area you can get it boiled out if you want. If you are planing to replace the Rad there are also new stock type (brass) 2 row's, the higher capacity 3 row's (sometimes called a desert cooler) and or also the Alum Rad with 2 and 3 row's for extra cooling. Yes that's your water pump were the lower hose was connected. I believe Ford used a 190-192 degree T Stat stock, but a 180 would also work well your stock Mustang I would not use a 160 except for a more hi performance type engine. These older Ford engines were designed to run at a much lower temp then the later model engines of today, and operated in about the 180 to 205 range so you also could try up to the 195 T Stat if you want to experiment some and or your goal is going for the very best in fuel economy otherwise I would stay with the 180 or up to a 192 Stat. There is small pipe plug on the side of the block about a 1/4 NPT that you could install a drain petcock there if you want or just pull the plug to drain and then replace it again. Good luck

Edited

[sixty6]

When it was hot outside (about 100F) and with city driving temp gauge went above (about 1/4 higher) then what I saw it before. With less stops temp went down and since then it didn't happen again nor was as hot outside. But it happened about 1 week before my voltage regulator behind instrument cluster died, so I'm not really sure i'f it was true reading.
Is that rust on water pump outlet common rust spot? Should I clean it up and put it all back together or something else needs to be done? Thanks!

[bubba22349]

The stock gauges are not real accurate they show a range of acceptable temps in between the normal range brackets, you only need be concerned if the needle starts heading towards the higher side above the normal range or if it starts boiling and dumping coolant on the ground. An old timers tip if you get in a situation driving or climbing a long grade and the temp starts riseing a little too high you can turn on your heater for awhile to help cool it down some. It's a good idea to add a coolant recovery tank kit if you live were its hotter. Yes that is common for rust to form there if you want to clean it up some use a wire brush on a drill. If the water pump otherwise looks good and there is no signs of any leaking out of the weap hole (it's under the pump shaft) craw under car t check it or use a mirror. If it's showing some leakage might be the time to replace with a new one otherwise put it back together. Good luck

[sixty6]

Thank you for your help!
Water pump shows some light leakage that I can see now. It looks brown/rust color. I don't see it leaking while engine running, looks more chronic. I have read that it's normal for water pump to drip small amount of coolant but not sure what's this stuff. Also there's little play in water pump. When I move fan blade back and forward on the farthest side from the middle it moves about 1/16 on an inch. Not sure if little play like this is ok. Does my fan needs to have a fan clutch or that's optional? Also still can't find that drain plug on the block, what side of engine is it located?

In the middle of the first photo you can see that brown crusty sludge coming out of WP. When I look through the WP coolant return it looks relatively clean inside.

[bubba22349]

The brown sludge is dirt, mud, and rust that is in the blocks cooling passages. You should flush all of it out of the block until you see nothing but clean or clear water. The play in your water pump isn't a good sign sooner rather then later it will be time to replace it. The drain plug should be located on the passenger side of the block towards the rear just below the 2nd from the rear freeze plug. you could also remove the temperature sending unit from the drivers side rear of the block though it's not as low as the drain plug is. A clutch fan wasn't usually on the early Mustangs unless it was a fully loaded model with AC and Power Steering & Brakes etc. its a good item to upgrade too though because it will give you back some power and save you some on fuel since turning the fan really isn't needed after a car reaches a certain speed (roughly about 25-30 MPH) and it will then have enough air flow over the Rad. Good luck

ReEdited

[sixty6]

Should I try using any commercial flushes? On some Mustang V8 boards people use 2 pounds of citric acid. Also should I use Gano filters before radiator and heater core? My understanding is that don't replace anything yet until it's all cleaned out. Also when I drained coolant it looked clean without any sediment. Thanks!

http://www.american-mustang.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=gano&x=39&y=6

[bubba22349]

Yes you would need to reinstall the Rad and hoses (you can leave the T Stat out) first so don't replace anything with new parts until you have flushed it out good. After the coolant is drained out I will refill with water and use a commercial flush and run the engine until it's warmed up good then drain it. Next I do the same with just water running it and then drain and last continue to flush the engine with a water hose a number of times until it's clean. I have not used the filters or the critic acid before but it may work well. Good luck

[sixty6]

Thank you for your help. I was able to find drain plug but it's so stuck that I stripped the head and wasn't able to remove it, I just left it alone for now.
As far as flush goes I watched some Chris Fix YouTube videos on him using Prestone flush + cleaner and he was driving around for a few days and then he had nasty looking brown coolant to drain. Well, I did the same thing and after few days driving my coolant still was a transparent light iced tea color. After draining and flushing everything well I thought I'm ready and took that water pump out and found out this inside.


(this photo is sideways for some reason, there are no loose particles or rust, all that is stuck pretty hard to the block walls)
Not sure what else can I do. Is it normal for 50 year old engine to look inside like that? Should I just install new WP add 1 gallon of concentrated coolant and top it off with distilled water or should I do some more cleaning?

[bubba22349]

Yes that's fairly normal for these old blocks cooling passages to look like that. About the only thing left you can try is to use a screw driver or a coat hanger to reach back into the block cooling passages were you have the access and see if you can loosen up any more mud or lose rust to flush out etc. or if you happen to have the use of a pressure washer to flush it out with. Other then that not much more you can do unless you want to compleatly disassemble your engine then there are A few other ways to clean it like in a hot tank, a jet washer, and having it Chem Stripped or acid dipped. It's actually looking fairly clean right now and if water is running out clean then I would say you can call it good enough. Good luck

[bubba22349]

So did you get it all back together?

[sixty6]

Just put it back together but lower hose at WP seems to have weird angle. I used Gates water pump and it points more upward than stock one and creates passage that is more narrow. I used appropriate for year/model/engine WP and house by Gates and not sure why it ended up like this. I was told that my radiator is from Falcon but, maybe that's an issue along with Gates WP?

[bubba22349]

Try loosening that upper hose clamp and twisting the end of hose just a little bit, turning it in towards the engine (clockwise on the Water Pump outlet end) and you should be able to get most of that kink out. Then as the hose warms up with some use over time it will also reshape some. It should workout just fine. Good luck

[hotrodguy]

2 days ago I went thru the thermostat thing, my engine runs cool all the time, very slow to warm up. I had a somewhat rusted 196 thermostat and replaced it with a new Napa 195. When cold the engine warms up quicker now , the guage goes just past the middle for a very short time then the thermostat opens and the needle drops back to the 1 quarter deflection as usual. I believe it will run better now and hopefully the mileage will improve.