WHY? Engine temp runs cool in traffic, but overheats on highways?

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hoffa65

Master Mechanic
Mar 11, 2019
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416
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Atlanta GA
I live alone and the dog's leg won't reach the pedal........but I'll find a way..........maybe call for an UBER and just use the driver for a few minutes and
send him off with a tip.........
the 3k does not have to be exact, just grab the throttle at the carb and run up the RPMs to approx 2500-3k and look down at the lower hose
 

shoedoos

Master Mechanic
Jul 3, 2012
406
403
63
replacing parts or having a quick look at your timing? Which is cheaper? I know what I would be doing before spending any money....Get inside that distributor to confirm everything is moving freely, then slap a light on it and confirm what the timing is doing at various rpm levels....
 
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69hurstolds

Geezer
Supporting Member
Jan 2, 2006
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I assumed you've already checked out all your vacuum lines, timing, etc.?? As others' suggested, if you haven't checked to see if the distributor canister can still pull some advance (i.e., diaphragm doesn't leak) and your base timing is spot on as well as the mechanical advance weights are good, then go with it.

If your timing is retarded and/or vacuum/mech advance isn't working, I think you'd notice that at highway speeds. Good to check anyway to rule it out. The other part of this equation is...….does it still have the original timing chain in it? Just wondering. Those plastic teeth on the cam gear may not have given way yet, but they will. And your cam would be retarded as hell.

Pure speculation.
 

azmusclecar

G-Body Guru
Feb 13, 2018
601
306
63
replacing parts or having a quick look at your timing? Which is cheaper? I know what I would be doing before spending any money....Get inside that distributor to confirm everything is moving freely, then slap a light on it and confirm what the timing is doing at various rpm levels....

Good suggestion........this problem is taking me everywhere over the engine.
 

azmusclecar

G-Body Guru
Feb 13, 2018
601
306
63
I assumed you've already checked out all your vacuum lines, timing, etc.?? As others' suggested, if you haven't checked to see if the distributor canister can still pull some advance (i.e., diaphragm doesn't leak) and your base timing is spot on as well as the mechanical advance weights are good, then go with it.

If your timing is retarded and/or vacuum/mech advance isn't working, I think you'd notice that at highway speeds. Good to check anyway to rule it out. The other part of this equation is...….does it still have the original timing chain in it? Just wondering. Those plastic teeth on the cam gear may not have given way yet, but they will. And your cam would be retarded as hell.

Pure speculation.

I've replaced almost every vaccum line on the engine. Except the one in the other thread I posted and found out it is connected to the EGR valve above the water
pump But that's a whole other can of worms.

I didn't know about the plastic teeth. As far as I can tell, the engine has never been opened. When I installed the new water pump, usually you can see
evidence of something other than factory work.

Thanks for the speculation and calling it what it is..........I think I'll stay within the area of possible hose collapse, or radiator blockage, as my first two areas to address.

As far as the timing, I will throw a light on it....but it seems to run so well with no engine ping, knock, instant start, smooth idle, I actually stood there and remarked how well the carb rebuild has made this engine come to life. I owned a 1978 Pontiac Grand Am with the enemic 301 (sorry Pontiac fans) and this 350 really stood up where the 301 laid down. This is just opinionated observance.....unlike what Joe Friday wanted............JUST THE FACTS MAM...........JUST THE FACTS.
 
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azmusclecar

G-Body Guru
Feb 13, 2018
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If you can get Linda to sign your glovebox, don't pass up that chance. She is a true southern lady and she has a tremendous memory about what it was like doing all those events and people she's met along the way. If you ever get a chance to meet her, do it. She's a delight to talk to.

.


In honor of the help I've received from 69hurstolds...my cousin sent me this pic to brighten my day. He may have sent it saying:
Rob I know you can't own a 1969 Hurst Olds but here's an alternative to owning a true 1969 ............called the Hurst Hustler.:cool:
Is that a DUAL GATE shifter on that bike?

Not sure how many are aware these bikes were even made..........but now at least I know I am. Where do you have Lidna Vaughn sign on a bike.:unsure::LOL:
hursthustler.jpg
 
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azmusclecar

G-Body Guru
Feb 13, 2018
601
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the 3k does not have to be exact, just grab the throttle at the carb and run up the RPMs to approx 2500-3k and look down at the lower hose

That'll have to be the way it is, Uber doesn't even come to my remote area.............but I take your direction with full appreciation.
 

Huen79H/O

Apprentice
Jun 5, 2018
74
161
33
[QUOTE="azmusclecar, post: 702676, member: 27191]
But my cousin who knows Linda Vaughn told me to send him the glove compartment door and he will get her to sign it. [/QUOTE]


This is awesome will she do mine 2
 

azmusclecar

G-Body Guru
Feb 13, 2018
601
306
63
[QUOTE="azmusclecar, post: 702676, member: 27191]
But my cousin who knows Linda Vaughn told me to send him the glove compartment door and he will get her to sign it.


This is awesome will she do mine 2[/QUOTE]
I will ask him. I'll PM you some details.........
 
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