Overheating leads to ....... ?

[Madmiles442]

I have this friend,
Okay, I know, just go with me on this one,
Let's say I have this friend with a Cobra who got stuck in accident backup traffic. His alternator's out so the fans were only running maybe 1/4 speed.
The oil temp got ot 110C (230F) and the water got to 125C (257F) Oil pressure never dropped.
He says it seems to running fine afterwards. No new leaks to speak of (they all run together anyway).
Are there any major engine components my friend may have damaged? If so, what's the diagnostic procedure?

[hey,littlecobra]

the friend should have waited on the shoulder for hours to let the wreck get cleared up and then he could have driven home trouble free.

anyway, i think overheating causes things to expand. you know, things like hoses and such. then they blow up all over the car and underside of the hood and what a mess! if nothing spewed, puked or otherwise exploded i'd say your friend may have gotten lucky.
no wonder his car got overheated!

[Madmiles442]

Lil Cobra, sometimes I just like the way you describe things.

Expanding, heated hoses exploding, spewing and overflowing.

And I thought we were going to have a boring discussion about bearings and the like....

[hey,littlecobra]

so.... and HOW IS Amy???

[Madmiles442]

Amy who?

Oh, you didn't hear about the bus accident?

Actually, she's fine. In Houston again for the whole week. Just me and the boys.

[Excaliber]

Water boils at 212. Under pressure of say a 15lb radiator cap and assuming some antifreeze (which raises boiling point) it would have to get well North of 250 or so before it would blow out the overflow. 18lb cap would be even higher temp, 20 lb cap, etc.

Again, assuming good hoses, tight connections, they should be able to handle the temp and the pressure.

Worse case scenario? Like HLC said, blowing a hose. If that didn't happen, no big deal. A well built engine should be able to take those temps in stride.

Seems to me I've heard engine oil temps in excess of 300 or so is not good, damages the oil in some way.

[hey,littlecobra]

hope the bus was ok....

you and the boys....hmmmmmmmmm

so. have you checked out the thermostat? Sam discovered his was busted. Not overheating at all, afterall.
If my Mustang didn't blow after that Labor Day parade it ain't ever gonna blow. wow! that gauge was sitting right below the "H". like a smidgeon below.
Why dontcha get wicked joe over to check your wiring on the alternator??

i think you love me. yup. you are just a h**** dude with AMY gone and you just home with da boys....
K

[hey,littlecobra]

thanks, Ernie. I'm feeling pretty smart. Or is that smart and pretty????
or..... whatever!!!
I'm outta here!
good luck, Milesy.

[Bob In Ct]

Tell your friend to try to run a 50/50 blend of water and antifreeze since, as it was earlier stated, this will raise the BP of the coolant mixture significantly. It will also lubricate the water pump and will slow down corrosion.

Synthetic oil also tends to tolerate heat better than does dyno oil.

What really amazes me is that your friend did not just pull over and turn it off.

Bob

[392cobra]

Miles,
I would tell that friend of yours to change out the thermostat.That high of heat can cause them to fail and most will fail in the closed position.

You might invite Kristen over to slap your friend around a little for not pulling over.

[Barnsnake]

It wouldn't be a bad idea for your friend to re-torque his heads and intake manifold. The aluminum components have a higher rate of thermal expansion than the steel fasteners holding them together. High temperatures tend to crush the gaskets to "make up the difference".

[SSSammy]

Miles, fan running 1/4 speed in heavy traffic = overheating. Fix alternator and re-check for overheating. Might also do a fast charge on the battery before setting out.

Did any of this start right after KCM fixed your busted rod from the Hallett episode? So engine has been opened up .. what got diddled with then? Did the intake manifold come off? If so, then a water passage may have been fouled/blocked.

Can you see water circulating if you let the engine idle with the radiator cap off? Start this with a cold engine and a known good t-stat. No water circulating = broken water pump impeller, or sheared pin and it's spinning freely.

How about the timing? Way off timing can cause engine to run hot.

Coolant mix is probably not causing this much overheating in the current mild autumn climate. Something is broken. Good thermostats sometimes go bad, easy to change. Can also test it by dropping it in a pan of 180 deg (or whatever temp is stamped on the plug) water (use meat thermometer) and see if it opens up. Pick it out of the pan with tongs, not fingers

My problem was a bad water temp gauge, not the t-stat. But I went through the entire menu of possibilities before I discovered that, including changing the thermostat and coolant.

Think .. when did the overheating problem start? What changes immediately preceded that?

Call anytime for in-person consult

Sam

[fsstnotch]

All of what has been said so far sounds like good info for your friend. You might want to change your oil a littel earlier this time as well. Once it's burned up it don't work as well.

I'va actually FIXED problems with one of my fox's by overheating it! It had a minor sticking lifter for a few months. one day I was on my way out to a friends house and the car seemed VERY sluggish. About 7 miles and she just shut off. No signs of overheating at all. I didn't run a thermostat in that car. Well, i get it fired back up but it knocking like crazy and smoking on acceleration. "Only a mile to my friends.. i can make it!" The last stop sign before his house she shuts down and won't even turn over. "wonderful, what have I destroyed now?!" Pop the radiator......... NO water. ZERO, ZILCH, NADA! Not good..... She took 12 gallons of water, most of which steamed away. I'm thinking.. "I've welded the whole rotating assembly into a pile of junk!" Let her cool down good, fired her up and got to my friends. topped the water off and listened to her run... no lifter tap... SWEET! lol

This is not the method I would recommend to fix anything! I'm sure it did more damage than good in the long run!

[Madmiles442]

Yes, Sam this all started when getting my car back from the bent rod work. I got it back with a burnt up alternator, 2 quarts low on oil and an idle at 1800 that I can't bring down. While 1800 sounds good in a rocks glass, not so good at a stoplight. The idle screw is all the way and no change. When I try and physically pull it lower, the secondaries open and it goes up again. And the last time I jacked with the carb, well, it took someone knowledgeable 2 hours to reset it.
Just hasn't been right since I got it back...
Hitting the alternator again this afternoon. Turning into quite a career move....

[Wayne Maybury]

442

Why are you playing with your friend's car? Sorry had to ask.

Some Holleys have an adjustment screw to stop the secondaries from shutting completely. Maybe the secondaries are open a bit which is allowing too much air to pass the carb at idle. It is a small screw that is not easy to see unless the carb is on the bench.

By the way, why didn't your friend pull onto the shoulder when his engine began to over heat?

Wayne

[Madmiles442]

Originally Posted by 392cobra

Miles,
I would tell that friend of yours to change out the thermostat.That high of heat can cause them to fail and most will fail in the closed position.

Great idea Smoke-Free-Fred. I'm dubious about this one anyway.

Originally Posted by Barnsnake

It wouldn't be a bad idea for your friend to re-torque his heads and intake manifold. The aluminum components have a higher rate of thermal expansion than the steel fasteners holding them together. High temperatures tend to crush the gaskets to "make up the difference".

Excellent idea.

Originally Posted by Wayne Maybury

.......By the way, why didn't your friend pull onto the shoulder when his engine began to over heat?
Wayne

He's a real stubborn ole coot!!