Sudden Overheating Problem

The more things you rule out, the more it is sounding like a head gasket.

One other thing Dave, it's REALLY hot outside, and you may be able to hold more consistent temperatures with a higher 195 thermostat. It will allow coolant to stay in the radiator longer, getting it cooler, and allowing the engine to maintain a consistent temperature better. Most of our old cars have a really small radiator and there is a chance that the water never gets to cool off before going back into the engine. Good luck man.

Danny

 

Another thing to consider is crap in the radiator. My 64 Comet needed pretty much an entirely new cooling system. The pump was shot, the radiator leaked, etc. I fixed everything else and put a new radiator in and immediately it ran better, but still got way hot. The engine filled up the radiator with crap, and plugged it all up. I removed it, had it and the cooling system flushed. Put it back in, and it did it again, just not as bad. I had the radiator flushed AGAIN, and bought this little thing called a "Gano Filter" It's a clear plastic strainer type device for your upper rad hose that catches all the crap in your system before your radiator does. Check your radiator to see if it might have become all plugged up? If yes, flush it and get a "Gano Filter" Those little things are a great idea!
Other than that, I'd say a head gasket problem....
-GothY-

 

Is this car loosing fluids when it gets hot, or does the gauge just read HOT.


I few years ago I chased a problem like this for months turned out I had a bad wire going to the sending unit. Changed the bad wire and everything was better.

 

How often should he do that? I'm guessing every 2 months of 2400 miles.




(sorry, had to)

 

Lets back up and keep it simple. Maybe you had 2 thermostats go bad or not opening all the way.. Pull the thermostat out and run it without one, and see if this solves your problem, its been pretty hot in texas and they dont make stuff like they used too...

 

How about the headbolts? Some 5.0's used torque-to-yield headbolts that cannot be reused. If you do reuse them, you run the risk of maybe bottoming one out before it reaches its true clamping torque giving a false reading on your torque wrench. They could also snap. Either of these could lead to a blown headgasket.

If no water in the oil, it might have blown between cylinders which will cause one to overheat.

What radiator are you running? There are 3 row Crown Vic radiators Mustang guys like to use that work well.

Since its sudden though, I think its more serious. Sorry to hear all your troubles. Hope it turns out to be something simple like that radiator cap.

 

I agree ....

 

That's possible. Exploder 4.0 engines are notorious for going through stats. I was told this by a Ford mechanic that they have to change them often. They get stuck open. We have a 95 model.

Well, mine was stuck open and I left it that way since it wasn't overheating. It just took a little longer for the heater to work in winter. Drove it for 3 years like that until one day, at the worst possible time at the worst possible place in the middle of summer rush hour, it decided to close completey. This was even a Ford stat. I replaced it with one from O'Rielly's and about a year later it is stuck open.

 

another option.

Years ago, I had a 5.0 come in that was overheating like crazy. geyser out of the radiator in a matter of minutes. I condemned a head gasket, and pulled the heads (sooo much fun.)

I was surprised to find out I had found the problem...but it wasn't a blown head gasket- it was a clogged one.

seems s.b.f. has some cute little holes toward the back of the head (similar to steam holes on a small block 400.) The owner had a Jiffy lube radiator flush done (it was creeping up in temp at that point.) and loosened up some crud in the block (or heads..either way, he shook it up) and it formed these little "plugs" of crap.

Someday I will tell You what happens if You put ford head gaskets on "backwards"...that was funny. vroom! geyser!

 

If your distributor clamp is loose and rotated a little and now you have really retarded ignition, that'll make it run it run hot.

Are you sure your radiator is full of fluid? Maybe you thought you filled it and some air bubbles were keeping you from completely filling it up.

Could you be mounting the thermostat upside down and/or something like the gasket or a bad casting in the intake or thermostat housing is restricting the opening of it. I think it would be an easy test to just pull the thermostat and see if it fixes the problem, then you'll at least know where the problem is. You can boil the thermostat in a pot of water on the stove to see if it works okay.

I like to drill a little hole in the thermostat to let air bubbles work up out of block more easily when it's cold so it's easier to fill the cooling system.

 

a Good Parts Store has the Block kit to check for Blown Head-gaskets <br> I got mine at NAPA and the water in the Radiator should Not be filled to the Top <br> about 1 1/2" down from the Rim for expansion <br> it sounds like a Blown Head-Gasket

 

I had a very small hairline crack in the cap seal which caused it to lose presure and the temp would rise slowly until it hit the red.
Only found it by chance when I went back to the car one day and could just hear it very quietly hissing.

 

It's fixed!

I wasn't terribly excited about replacing the head gaskets, so I decided to get a block test kit to confirm if this was the issue. FYI - Autozone has them as loaner tools, so all you have to buy is the blue dye. They are also only $20 at Autozone if you buy one. NAPA sells the exact same one for $50.

I ran the test per the directions and, sure enough, the dye stayed blue. If you have combustion gasses in the radiator the dye turns yellow.

So, I bought (another) new thermostat, a radiator cap, a Prestone flush kit, a bottle of their flushing fluid, and some coolant. I pulled the old thermostat and put the water neck back on so I could flush the system without any restrictions. Flushed it with the Prestone fluid and then pressure flushed it with the T-fitting and a garden hose.

Once I got everything filled back up with water and coolant, I let it idle in the driveway and all looked well. We went for a drive and it's completely back to normal. I also switched back to a 192* thermostat instead of the 180*.

Just to ease my curiosity, I brought the thermostat that I replaced in the house and boiled it in a pot of water. It never friggin' opened! I just installed it on Sunday and the previous one (same model) was only in there for a month and did the same thing. Make sure you avoid the Mr. Gasket "High Performance" thermostats. Mine was model 4364. Two bad ones back-to-back.

So, this little adventure had me; replacing the thermostat 3 times, draining (and flushing) the radiator 4 times, replacing the water pump, replacing the radiator cap, and ALMOST replacing the head gaskets in a span of 3 days. Good times. Thanks a fuckin' lot, Mr Gasket!

 

Glad to hear it was the thermostat, I had suspisions it was as I stated earlier in your post. You may want to get yourself some 'water-restrictors' to have in the tool box when or if the thermostat goes bad again. Then you do not have to worry about them anymore.
See here: http://www.jegs.com/i/Moroso/710/63440/10002/-1/751807%7C10129

 

glad the fix was of little pain....

 

I was going to suggest changing the thermostat again. I had three of them in a row go bad on me years ago. After that, I started carrying two in the trunk. It seems like everything is junk anymore.

For what it's worth, i've heard of the water pump's impeller spinning on the shaft before.

 

Maybe fan belt or possibly fan clutch if you have one. Overheating from a bad fan clutch would be more evident around town than on highway.

Unhappier possibility would be a blown head gasket or cracked head. I had a cracked head last year that stumped me for a while. Only when it worsened and began to over-pressurize the cooling system did I figure it out. It would run fine and cool for a while but once it had quietly forced out enough coolant it would suddenly heat up and blow.

Good luck. Try to figure it out before you spend lots of money replacing parts.

 

D'oh! Should have read all the way through. Isn't it a pleasure to handle ethylene glycol?

 

Cool, Glad it was not something major

 

Well if it will make you feel any better..(probably not)..I have run into this thermostat problem with other manufactures..probably all foriegn made shit no doubt. but still a pain in the ass when you end up with the bad ones.
glad you got it figured out and it didnt end up costing you a pile of time and money.

 

yeah, when you come across this I recommend buying another brand from a different store. Shops usually get them a few at a time and they are usually from the same batch. So if you have 1 bad one chances are the rest are all bad.

Plus. I have this aversion to spending money to replace a brand new part with the same part. If a new part fails I go on to the next manufacturer.

Glad it wasn't head gaskets!

 

I'm just seeing this thread for the 1st time. My question is why didn't you try running it with no thermostat soon as the problem occurred? On "sudden" cooling issues, it's usually the 'stat or head gasket. Running no 'stat being the easiest to try 1st. I'm just curious. I read almost 2 whole pages before the 'stat even came up. I NEVER run thermostats for that very reason. I don't trust them. Yeah, I know what you all are thinking about me running no 'stat, and I don't care. In SoCal, motor's come up to temp soon enough, and I've seen too many a good motor ruined by a stuck, imported, POS 'stat

 

I think they now offer a lifetime warranty on thermostats now. I laughed when I first heard of it, but now I understand why. They know they sell crap

 

I had temp problems with my Truck, it also had the SBF/AOD set up. get a seperate tranny cooler and see if that corrects the problem. Just a thought.

 

I have had a similar problem with my truck, I am running a small block 302 and was having heating problems. I discovered a warped water-neck and had a hairline stream leak. I got rid of the chromed off the shelf water-neck and put an original neck that I painted to match the Edlebrock silver intake. I also put a Mr. Gasket Hi-Flow 160 degree thermostat and have been running cool with flex-fan and shroud. I was told by a Ford-Guy that if you are not running a heater a 160 degree will work fine.

 

I wish I had been on here in the past few days cause I would have told you the exact same thing about the "Mr. Shit" t-stats. I went through the same thing with my old Buick and I knew it was not the heads because I just had done them. A little stress every now and then will keep you on your toes

 

Yep, it was a learning experience for sure. I've heard stories about getting multiple bad parts right off the shelf, but this is the first time it's happened to me. Other than just pulling the thermostat right from the get-go (instead of replacing it twice), I think I pretty much followed a logical pattern.

I still think the water pump was a contributor, too. Nothing like having multiple piece of crap imported parts fail at the same time! ...and lifetime warranties suck if you still have to replace the parts every six months.

Thanks again to everyone for the ideas and suggestions. I think these kinds of threads are really valuable for the next person who runs into a similar situation and does a quick search.

 

An out-of-the-box defect...THAT's always nice! Just goes to show you that new doesn't always mean functioning. I'm glad it all worked out for you without having to do headgaskets. I think I might make a little noise about this at the auto parts store myself....

 

I've also had problems with new thermostats that do not open. You wonder how hard it is to make a reliable one.

 

You should write Mr. Gasket and tell them what happened and tell them you've posted about what happened to thousands of hot rodders, and hopefully they'll get the message that they can't stay in business long selling pieces of crap like that. Maybe they should sell toilet seat liners and change their name to "Mr. Ass Gasket".

I've had good luck with the Stant thermostats they sell at Kragens. The part that opens and closes is made of stainless steel. But I drill a little hole in it to get air bubbles up out of there for easier filling of the cooling system. The paper gaskets that come with the Stant gaskets are crap though.