Overheat 289

New thermostat??

Brandon

Bad thermostat or installed backwards. Plugged water passages. Radiator hoses that collapse. Radiator cap that does not hold to the correct pressure.

Obviously the first thing to look at is the thermostat. Also, what kind fan are you using? Stock, electric, flexacrap? When did you install the water pump and did it start overheating after installing it? I'm not sure if its even possible to get the wrong water pump for your car but another possibility (on some cars) is that you got a reverse rotation water pump. Mike MuscularMustangs.com

I took the termostat out, could it be head gasket

its not original fan . its one that i bought after market aluminun

Also, are you sure you got all the air pockets out of the system??

With the car running, squeeze the hoses to get the air out. Then fill the radiator again. Keep squeezing till it quits burping air out.

Just a thought.

Brandon

From bitter experience - a blown head gasket. Also, if the engine has been recently rebuilt and it was taken .060 overbore, then you may be hosed with the overheating problem.

IMHO, the only way we could get all the air out of these cooling systems back when they were new was to just about cook them........ have premixed coolant at the ready, run the motor without the rad cap until the thermostat opens and add what you need with the motor running. It can be disconcerting, but it works.

Be aware that the water pump from the 302 will fit.... also be aware that some 302 water pumps turn the 'wrong' direction...... if you had to furble any which way with pulleys or bolt spacing with the water pump, you need to take a hard look at what you have.

Can I ask why this is?..... I'd have thought that as 0.060" overbore being an 'approved' rebore size, wouldn't have any adverse effects on the engine. Why would it cause overheating more than any other overbore size? I ask this because I have two blocks that need rebored....one will need to go up to 0.060"....

Looking forward to your answer...

Thanks

"Ralph Snart" a écrit dans le message de news:0Mctc.1084$eY2.479@attbi_s02...

Thers 80 000 mile , on idle for a long time it will over heat and if i drive it when i get back and shut it offf, it will drain itself from the presure

About the headgasket if it was blown , would i have prestone in my oil , and would the engine smoke

Well, with my blown gasket, I nver had oil/water mix - I did have some white smoke when the engine got hot.

.060 is the max that a smallblock ford engine can be overbored, but heat disapation problems are common at that stage of overbore.

IF you've tried everything that you've said, how about replacing the temp gauge sender? They're only about 10 bucks, and like other pieces of equipment, have been known to become inaccuate.

Hmm, from what I can understand the engine starts overheating at long periods of idle, apparently when you drive the engine it cools down? Then when you shut the engine off pressure decreases from the heads and hoses? If this is true your head gasket has compressed to the point that your heads are allowing fluids into the combustion chamber which will cause pressure in the heads to increase and thus cause over heating. Also you may see wisps of white smoke coming from the tail pipes.

Yves, if this was my car I would have an engine shop or certified mech. do a compression test on the engine. If you are a do it your self person you can replace the head gaskets your self. (Get the heads cleaned and ported and redo your springs and valves while you have the heads removed)

Hope this helps. I also would drive as least as possible so that you can aviod cracking the heads or block.

Good luck!

This may or may not apply, but 98 Mustang GT's stock fan has 2 speeds. Low & high. The CCRM normally determines when to kick the fan into high speed & this is what keeps the engine from overheating in my car. My CCRM no longer does its job & thanks to Tim (aka Mustangguy) who pointed me to a webpage guide.. I wired in a switch to let me determine when my fan goes into high speed. Since you have an aftermarket fan, I'd probably suspect that. Just my .02 cents though. IIRC, 43+mph is enough wind to keep the engine cool enough.. does it ever overheat on trips where you're on the highway for long enough for it to overheat during city driving (like 45 min drive on the highway where you're going 65-70mph)?

-Mike

Thru bitter experience I have learned a few things about overheating small block Fords.

Does the lower radiator hose have a coil spring wire inside it? If this spring is missing, the lower hose collapses and you get no flow thru the radiator.

Assuming the radiator is in good shape, overheating at idle is caused by not enough air flow thru the radiator. You need a good fan and a shroud. The mustang restoration shops sell a reproduction 6 blade fan and shroud. GET THEM.

If you suspect that you have a bad head gasket, take your car to a shop with a smog check machine. Have them stick the tailpipe sniffer in the radiator while the engine is running. If it detects unburned hydrocarbons, your gasket is history. When my Sunbeam Tiger had a bad head gasket, it would lose water slowly over a period of days. When it got low then it would overheat. On a cold start, the water temp would rise, it would go up to 210 F and then cool back down to the thermostat setting of 180F. The Tiger was nice because the gauge had numbers on it and I was able to check calibration and know it was accurate. Once the head gasket was repaired the temp would not overshoot the thermstat setting.

Another thing that old Ford engines do, is shed rusty metal chunks from the inside of the coolant passages. These chunks can and WILL clog up a brand new radiator in short order. You said, the engine has 80,000 miles since rebuild. How many years? Has the coolant been maintained or has it been allowed to get rusty? Did the car run cool right after the radiator replacement and then a week or two later start overheating? That is a good sign you have chunks blocking the radiator. Drain coolant until you can see the tops of the tubes thru the filler neck. If you see anything blocking any tubes, you need to have the radiator rodded out. The other check for blocked tubes is to let the car get warm and then stick your thumb on the radiator tubes on the GRILL side of the radiator. They should all be hot enough to make you pull your hand away after a few seconds. Cold tubes means no flow. Buy a GANO filter from the Mustang places and install it in the upper radiator hose. You will be shocked at the junk it will catch.

I had another problem with my Tiger. Everything was new (except water pump) and in good shape. The car ran cool at idle and at speeds up to 65 mph. The faster I drove, the hotter the car ran. at 80 the car would get up to

240 F. I replaced the water pump with an Edelbrock hi flow pump and the car runs 190 at 80 mph now. I don't think this is your problem, but keep the knowledge in your back pocket, it may be useful some day.

Good luck, you can beat these heating problems.

Erich