Overheating on the freeway

[CobraSix]

hmmm...check the prices. Another chemical clean won't do the trick on a radiator that is clogged with rust. If it's from the block, another chemical flush may help. Where is the brown coming from, the block side or the radiator side?

You'll need the tubes punched more then likely. Ask the price of having the tubes punched. Just FYI for comparison, a new 3-row radiator for a 65 mustang (stock is 2 row) is $180, so if punching is going to run that much, you may want to buy a new one. That's what I did, punching my tubes was going to run about $150, so I'd rather spend another $30 and get a new improved version. Haven't had an issue since. But then again, my cooling system is 100% new. All new hoses, Tstat, pump, heater core and radiator by the time I was done with it.

Slade

 

[KustomSkylark]

im pretty sure the brown rusty water is a result of using the smae radiator I ran with my old 170. That engine was rusting away from the inside pretty bad. I didn't change the radiator becuase it was only about a year old. I took it to the shop and they "rodded it out" I put everything back together but didn't have time for a freeway test last night.

 

[Anonymous]

I guess I should have prefaced my answer with "assuming your radiator is in good shape and has clean fluid in it,".
Doug

 

[mugsy]

I had overheating at freeway speeds in my *other* project car. I finally took the radiator out and had a shop flow tested it. They did the test for free so I bought a new radiator from them when they told me it was only flowing 60% of stock.

Personally I would set the timing, then change the t/stat to a 180 and see if that cools things off. If you don't have any luck I would then have the radiator flow tested.

The other issue is that you have is the radiator was sized for 170 cu in engine and now you are running a 200. The larger engine will generate more heat. If I was a betting man I would place my money on either a restricted radiator or too small of a radiator. Either way its time to buy a new one sized for the larger engine.

Let us know what you find out!

 

[KustomSkylark]

OK I just went on my test drive. The damn thing still heats up but it took it longer, about 15 miles. It runs at like 210 normally around town and gets close to 240 on the freeway before I pull off. The rad. shop told me it was only flowing 30% when I took it in to get cleared out. So here is the list of things I have done so far:
1. Put the hood back on
2. Set the timing good
3. New bottom hose
4. Radiator pro. cleaned

Maybe the vacume advance isn't working right...I'm not sure if it would cause a prob like this. Maybe the head gasket is shot(unlikly because I just put the engine together after having the head milled) Maybe I just need a bigger radiator, 3-row maybe. Whats the best place to get a good deal on one? My other thought is that my gear ratio is bad. It hits top end at like 55 I think(my speedo says about 85 but it feels like 55). And I'm almost flooring it on the freeway. I don't know anything about gears or what gears are in the car. The rear is a stock '63 Comet station wagon and the trans. is from a '79 fairmont wagon. Is that a concern maybe? I think I will post a question on the gears in the drivetain section too. Thanks in advance for your comments.

 

[PLP6400]

Being it took longer to heat up this time it sounds like your radiator got plugged up again. I had the same problem until I installed a Gano filter in the upper radiator hose after I had the radiator cleaned for a second time. I had to cean the filter about once month for about 6 months before all the rust and crud was out of the engine.

 

[65coupei6]

It does not look like you back flushed the system. Did you? I like to do the heater core seperately also.

 

[MustangSix]

An inop advance could cause overheating. That was a common killer on Jag V12 engines. On the early six, the only advance is the vacuum diaphragm. When it goes bad, there is zero ignition advance, causing a loss of power at higher speeds and increased heat load on the engine.

Check that cooling system again. The two row is more than adequate for the 200 if the rest of the cooling system is working and not clogged. You may have alot of sediment clogging it up.

 

[KustomSkylark]

So I should backflush it again, or do I need to do that and get the radiator cleaned out again? I did notice the coolent was looking a little merky again. Where can I get one of those Gano filters, I looked around but nobody had them at the parts stores or the radiator shop.

 

[PLP6400]

Most of the vintage Mustang vendors carry them. I went through a lot of time and expense before I realized the radiator was just getting cloged every time. What I did before I had the radiator cleaned the second time was to run some flush treatment through the cooling system. NAPA has one that you add and drive a couple hundred miles before draining and flushing. I did that 3 times before I had the radiator cleaned again. Then I installed the Gano Filter. I still had rust and sediment in the engine, but the filter did it's job. When the car would start to run warmer than normal I new it was time to clean the filter.

I bought mine from Mustangs Plus.




http://www.mustangsplus.com/Merchant2/m ... _Code=gano

 

[MustangSix]

When I rebuilt the last 200, I took a coat hanger, a steel rod, and a stick to dislodge the crap that was in the block. This is what I got:

Every 200/250 I have ever rebuilt had at least this much garbage in it. If you don't get it out or filter it out, it will continue to clog your radiator. overheat, flush, clog, overheat, flush, clog.......a viscious cycle....

 

[WhitePony]

Good Lord! I hope that when the reman folks hot tank the block it will get all that stuff out!

 

[MustangSix]

Most of it goes away when the blocks are cleaned, but some of it remains, especially at the rear of the block around #6. It's best to chip away at it first, then send it out.

On this block, the bores were good so we didn't send it to the shop. We chipped all this out, then we pressure washed it to get out even more. There was a lot of rust at the base of the cylinders. After the pressure washing, I poured in some undiluted muriatic acid and that dissolved the remaining flakes.

If you can't get to the block to scrape this out, a chemical treatment may help, but keep in mind that you may have thin core plugs that will also be eaten away. Also, some of that stuff is hard on the heater core and radiator.

 

[KustomSkylark]

I'm going to have to put more tests on hold untill I get paid again. So it will be a about next week before updates on the problem. Which size of those filters do i need? They have small medium or large. Thanks again for all the tips.

 

[Guest]

Check your head gasket, heres how:

You can buy a compression tester for around 30 or 40 dollars at any parts store. Disconnect the battery, take off the dist cap, take out the plugs, number the plug wires, push the thing in the plug hole, and have someone crank it over about 3 to 5 full revolutions while you hold the compression tester/guage. Continue on each cylinder until you get 6 readings. Make sure ALL plugs are out, because you can get a misreading if even on is in (for head gasket leaks between two cylinders).

Write each reading down from 1 to six from front to back (not sequentially). They should be around 100 psi or a bit more, and not vary more than 5 to 10%. If you have even one that reads below 80 or 90 psi(Ive gotten 25 psi, and another time 50 psi), you have a head gasket leak or cracked head.

I wouldnt drive it uless testing, by God, youre going to crack the head (or even the block!!!!) if its not already cracked. I delayed on my head gasket on my Falcon, neglected to test it, and it got hot out last spring, and I cracked the head too. I hate to get stuff Magnafluxed!!!! GRRRRRRRR!

Whatever it is, youre going to do more damage, alot more, just by driving it. Use it only on tests, until you figure out whats wrong. I think you should focus on other aspects of the problem other than the radiator (and the radiator as well). Try spending 20 minutes changing the thermostat, they go bad all the time, even new, and put a 180 in there. I think you said you had a 210 in there...way too hot for summer, and proned to stick shut even easier.

Good Luck.

 

[KustomSkylark]

OK it's update time. I backflushed again, then used a chem. flush and backflushed anothertime......It still gets hot. I also put in a 160 thermostat. I think I'm just going to get a 3-row radiator from Falconparts.com since I do live in the extreme heat of Phoenix. Has any one put a 3-row in a 60-63 Comet? The falcon parts website says that you have to modify the radiator support to get it to fit. I'm going to do this and install one of those filter things at the same time so I don't contaminate the new rad. I also checked my compresion and I got 145, 150, 150, 145, 150, 150, so the head gasket seems good but do those readings seem high? I think I'm going to go ahead and get a new vacume advance too. Anybody else have any ideas? It still only gets too hot on the freeway.

 

[addo]

Which distributor are you running? Did you see Montego Man's notes about rebuilt ones being "wrong"?

Setting initial timing is one thing - it can surely influence what the car does at idle - but what happens under load and higher RPM is more critical. The engine's more stressed then, it's burning more fuel and the results of mis-setting more apparent.

The balancer should be verified for TDC, also.

A new close-finned 3-row radiator will work (especially with a more efficient than stock fan) but it's probably not the total answer. Cheapskates use a stocking over the top radiator hose fitting, in place of a filter.

Regards, Adam.

 

[KustomSkylark]

The distributer is 1968 mustang 200, new from the parts store, but with my old vacume advance. I used the old one because the vacume fitting was different on the new one.

What do you mean when you say the balancer needs to be verified for TDC?

What kinda stocking? Like the ones business type women ware?

 

[Guest]

Your tempature sender might be putting out the wrong impedence, casusing it to misread. Check this...does the radiator cap bubble over, or the overfill tank have alot of coolant, and is it boining, when you get it that hot? Try getting it up to the temperature that makes it hotter (please, not too hot), and pull over, check the overfill tank. If its not full and boiling, or the radiator isnt too hot, your temp sender might be bad. They go bad on modern cars all the time, and thats what causes them to run too lean or rich. Tempeture variant sensors play a way bigger role in EFI cars, but hopefully, and not usually in our oldies. It tells the guage what to read (though theres another factor beyond that).

Also get a really big beach towel, and open the cap, slowly, to half open. When its hot. Kind of ball it up over the cap, and be ready to either close the cap or move the hell back. Very dangerous, be careful... Do you get pressure at a high amount, when it first cracks half open? If so, You may also want to drill a 1/8 hole into the housing of the thermostat to constantly dissipate air pressure in the cooling system.

So see if its actually that hot, and that its not a misreading, also you can get a high temp thermometer and place it in the top hole of the radiator inlet, run it at idle for awhile, see what the guage reads, and if it matches what the thermometer reads. Thats another great way to see if its the sensor. The sensor is located on the drivers side, on the block, at the corner back of it.

Your water pump impeller may not be spinning right, or theres damage. Sometimes the impeller cracks off completely, causing absolutely no flow in the radiator and back to the engine. Check the belt tension on the water pump...push against the fan and see if it slips real bad...a bit of slippage is ok, but extreme slipping only makes the pump not spin properly, or slip and slide on the pulley to belt connection with abrupt rpm variations. It also makes the fan not respond as well, and doesnt move and spin properly.

Good luck. Hope you figure it out. All those are things I experienced, and Ive blown head gaskets, cracked heads or punched a hole in a piston when I was younger, before wising up to how to avoid that kind of stuff.

If it IS the temp sensor, be glad its reading HIGH. I once had one read way too low, and the summer hit...I was out of comission for 4 months with that car, head gasket.

Joe

 

[KustomSkylark]

The sender is a new mechanical type temp gauge, very unlikely that it is reading wrong and the rad. blows through the cap at high temp. Also the water pump is brand new. Thanks for the suggestions.