Overheating at freeway speed

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charliecurrie
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Overheating at freeway speed

Post #1 by charliecurrie » Sun Sep 16, 2018 1:06 pm

My '66 stock 200 (except for Weber two barrel and DSII) has developed a new quirk. At freeway speed, the temp gets up to 204+ range (temp gun pointed at thermostat housing) and 154+/- where the bottom hose is attached to the block. it also starts belching a little coolant. This is something that has developed in the last 4 to 6 weeks. When I get off the freeway and drive at 40-45 mph, it cools right down - even in stop and go traffic. The only thing I've changed in that time is switch from 91 to 87 octane, which has made no difference in performance.

What do you think?

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bubba22349
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Re: Overheating at freeway speed

Post #2 by bubba22349 » Sun Sep 16, 2018 1:24 pm

The difference between the upper and lower radiator hoses shows the radiator is doing its job. If the radiator cap is still good (it might be a bit weak), also the hoses are in good condition (i.e. Not soft and or is collapsing) plus you have a properly rated T Stat installed of at least 180 to 194. The 204 isn't all that hot these engines they were designed to run in the 190 to 210 range so it should show it just a little above the mid range on the gauge. If the above parts check out as good then what you should do is install a coolant recovery system / overflow tank for the radiator overflow tube (If you don't already have one) to catch that belching coolant. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

charliecurrie
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Re: Overheating at freeway speed

Post #3 by charliecurrie » Sun Sep 16, 2018 1:59 pm

Thank you for your quick response. Everything you mentioned is in good order. It's just that this condition is a change from it's passed performance - always ran cool - 165-180 range - freeway or stop and go. So I'm just curious as to what happened to cause this change.

This is an original, unopened '66 engine with 75k +/- miles on it.

My friend who built and ran dragsters and sprint cars would tell me, they always run best right before they blow...and, this little engine runs real good. Ha

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chad
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Overheating at freeway speed Only

Post #4 by chad » Sun Sep 16, 2018 3:20 pm

last flush'n fill?

May B wanna drain it and get something caustic in there, flush, assure a 50/50% coolant replace (w/o adding air)?

IDK, may B a chunk broke off in there, or it's just gettin sludgy?
"Hi way speed" 2 me means stress but also plenty of wind blowin by the fins...

The 'overflow' is normal (@ stress). The temp U report not extravagant...
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Overheating at freeway speed

Post #5 by charliecurrie » Sun Sep 16, 2018 4:38 pm

Thanks for responding. I kinda have the same suspicion - something suddenly is partially blocking the flow in the block.

I'll give the flush n fill a shot.

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chad
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a 'decent' flush

Post #6 by chad » Sun Sep 16, 2018 6:18 pm

try a double flush (chem treatment 2X) and the "2 way" (i.e. in each direction).
Just get the "bad stuff" (Chemicals/slough) into a container (for environmental protection) 1st.
U may B surprised by what U C. Esp if you don't do the every-3-to-5-yr maintenance.
:thumbup:
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

charliecurrie
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Re: Overheating at freeway speed

Post #7 by charliecurrie » Sun Sep 16, 2018 7:00 pm

Thanks again, Chad.

I'm not familiar with the "two way" / "both directions" flush. Can you explain it so a six year old can understand it. Thanks.

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chad
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not overheating at freeway speed

Post #8 by chad » Sun Sep 16, 2018 7:43 pm

no, it's nother search function thread.
But use a hose for 'each way': 1st in typical place (up top) then dwn below. Some 1 w/better key board and english lang skills can explain if U don't C it in the search.
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Overheating at freeway speed

Post #9 by charliecurrie » Sun Sep 16, 2018 8:06 pm

Ok. Thanks. You've been very helpful.

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Re: Overheating at freeway speed

Post #10 by 65coupei6 » Sun Sep 16, 2018 10:37 pm

Usually overheating at freeway speeds is the lower hose collapsing.
...Marco

'65 Mustang Inline 200. VI (CI) Aluminum Head, Holley 350, Schneider 264/274 cam,
Headers, DSII, MSD 6A, and a whole lotta other stuff!

Build That Six With Parts From VintageInlines.com

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Re: Overheating at freeway speed

Post #11 by charliecurrie » Sun Sep 16, 2018 11:37 pm

Marco - thank you for that bit of information. Easy fix...messy, but easy.

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Re: Overheating at freeway speed

Post #12 by B RON CO » Mon Sep 17, 2018 2:09 pm

Hi, you may as well change the thermostat while you are working on it. Maybe the old thermostat is not opening all the way.
If you can feel the front of the radiator, or shoot it with the temp gun look for cold spots which indicates a blockage. Good luck
B RON CO. Still workin' on it!

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charliecurrie
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Re: Overheating at freeway speed

Post #13 by charliecurrie » Mon Sep 17, 2018 5:20 pm

Thanks, B Ron Co - It appears, after a going over, it may be air in the system. I ran it for a bit with the cap off - ran the rpm up around 3k (just a guess-timate) while watching the temp gauge. When it slid past it's usual stopping point, I got out to check to see if the thermostat had opened and coolant was moving passed the fill spout. I had lots of frothy coolant with some bubbles trying to escape. I started rocking the car back and forth, working the air out. Ran the rpm back up for a bit and repeated the rocking. Did this 3 times before the coolant was clear and moving across the radiator. Repeat the process 3 more times until the froth/bubbles stopped appearing. During this whole episode, the temp gauge stayed put and the temp gun consistently read 177+/- at the thermostat and 143+/- at the return hose.

I'll have to take it for a freeway run to see if that made a difference. Hoping.

I noticed after reving it up and then gooseing it, I would get white smoke from the tailpipe. I changed the oil about a week ago and there was no signs of water in the oil. I've also been checking the level daily since then and there's still no signs of water. What do you think?

Thanks again for your response and suggestions.

Charlie

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Re: Overheating at freeway speed

Post #14 by Lazy JW » Mon Sep 17, 2018 6:10 pm

charliecurrie wrote:
... I had lots of frothy coolant with some bubbles trying to escape...

I would get white smoke from the tailpipe...


Sounds like it's time for a compression test on all cylinders
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Re: Overheating at freeway speed

Post #15 by charliecurrie » Mon Sep 17, 2018 6:22 pm

Lazy JW, Thanks for the input. Compression is low - low - but even across all cylinders. It's going to get torn down eventually, but it just runs too good as is, and I have a garage full of parts to play with in the mean time. Well, my wife says it's full, anyway. But, at the moment, my 99 year old mother needs 24/7 care, and I'm it.

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Re: Overheating at freeway speed

Post #16 by Lazy JW » Wed Sep 19, 2018 11:25 am

When I see bubbles in the radiator, it rings a warning bell in my head; possible head gasket issues or cracked head.

I fully understand how the "cares of life" can get in the way of our hobbies. Do take care your Mother :thumbup: :nod:
Best wishes,
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Re: Overheating at freeway speed

Post #17 by charliecurrie » Wed Sep 19, 2018 11:33 am

Thank you, Joe for your comment.

I think I've figured it out. I'll report back later.

Charlie

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Re: Overheating at freeway speed

Post #18 by 65coupei6 » Wed Sep 19, 2018 3:03 pm

Thanks for posting an update. I hope that solved your overheating. Usually I bleed the air out of the system with the front of the car jacked up, on ramps, or anything that raises the front of the car. Then just run the engine with the cap off.

Hopefully, it is not the head gasket. If you are going to do a rebuild soon. Then BlueDevil makes some nice "BandAid" products to get you by. https://store.gobdp.com/products/
...Marco

'65 Mustang Inline 200. VI (CI) Aluminum Head, Holley 350, Schneider 264/274 cam,
Headers, DSII, MSD 6A, and a whole lotta other stuff!

Build That Six With Parts From VintageInlines.com

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chad
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Re: Overheating at freeway speed

Post #19 by chad » Wed Sep 19, 2018 4:00 pm

65coupei6 wrote: Then BlueDevil makes some nice... https://store.gobdp.com/products/

Hope those gud ol boys frm Sou Carlinie did OK in this storm!
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Overheating at freeway speed

Post #20 by charliecurrie » Wed Sep 19, 2018 8:29 pm

Never discount the simplest causes and easiest solutions.

I have to go back to the first responder Bubba 22349 because the cause and the solution was in his response.

Yesterday, after bleeding the system the day before, I went to the store and it started heating up quickly - city streets, light traffic, 8 miles +/-. When I parked the temp gun was reading 154 and it was puking coolant. I thought this ain't right. So on the way home I stopped and picked up a new cap.

Later when it cooled down, I went to see how much coolant I lost and check the cap. 4-5 oz is all. I got out the new cap to compare it with the old - the spring on the old seemed a pound or two lighter. I turned the caps over and lo and behold the rubber gasket at the bottom/top - depending on how you look at it - of the cap was gone - metal to metal does not make a great seal under pressure. It must have loosened and fell off, unbeknownst to me when I did a fluid check last week when I changed the oil. That's why the change in how it operated happened so suddenly an out of the blue.

Radiator Cap!

Simple, cheap and easy.

Don't over think the problem - I'm the worst offender.

Thanks to all who commented and all the good advise. Learned a few things I didn't know, and that, I'm sure, will come in handy in the future.

Charlie

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chad
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Re: Overheating at freeway speed

Post #21 by chad » Wed Sep 19, 2018 8:47 pm

good on ya mate!
Let's C frm here...
Last edited by chad on Thu Sep 20, 2018 12:35 am, edited 1 time in total.
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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bubba22349
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Re: Overheating at freeway speed

Post #22 by bubba22349 » Wed Sep 19, 2018 11:54 pm

:beer: congrats on finding the bad part. :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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