Engine Help diagnose random overheating??

chrlsful

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Mar 6, 2021
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used to use thread treatment (had copper in it) just got cached up & added to the problem. Changed to a newer type (CRC or some other name brand, 'permatex'?) not much better but some. Just started using the new (1, 2 yrs?) caliper grease. None back for nxt change but I think it'll B da best...
Again...alu to steel aint good~
 
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7991LXnSHO

wanna catch the space herp
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used to use thread treatment (had copper in it) just got cached up & added to the problem. Changed to a newer type (CRC or some other name brand, 'permatex'?) not much better but some. Just started using the new (1, 2 yrs?) caliper grease. None back for nxt change but I think it'll B da best...
Again...alu to steel aint good~
What I have been using is like a big, silver crayon. It’s not as messy as the more liquid stuff with a brush in the lid. It’s also slower to get all the threads coated to my satisfaction.
Is anyone else using caliper grease or is really sold on a certain brand and type of anti seize?
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Is this similar to the modular ford engine spark plug problems I read about?
from hang'n around that shop for several years I noticed it was two spark plug problems, I think it was the 5.4 mod engine, blowing spark plugs out, and crud build up around the end of the plug that made them nearly impossible to remove.
I only remember twice when the head had to be removed
 
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TomOsiris

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May 19, 2019
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from hang'n around that shop for several years I noticed it was two spark plug problems, I think it was the 5.4 mod engine, blowing spark plugs out, and crud build up around the end of the plug that made them nearly impossible to remove.
I only remember twice when the head had to be removed
Funny enough, I had a 5.4 2v that also blew a head gasket.
The earlier 2v engines did not have enough threads in the head where the spark plug threads in, over time with enough vibration they would wiggle loose and start to vibrate, this vibration would eventually weaken the threads to a point where BANG we have liftoff and send a plug up through the hood.
When fomoco changed to a 3 valve 5.4 a few years later, they overcompensated and the plugs would actually get stuck in the head and be nearly impossible to remove without damaging the threads, similar to the situation I am in now.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Steel used against aluminium with liquid flowing through it has a corrosive effect (electrolysis), you know, all that scientific crap I did pay any attention to in school.
I just have trouble remembering now.
 
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manicmechanic007

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Sep 26, 2017
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You have the ones where the plug breaks in two and you have to go in with the Lisle 65600 tool to remove the bottom portion limp?
Do Tune it up more often 75k miles max
Do Clean the injectors (thru the rail using the special chit) and clean the plate / upper intake first with carb foam and then the plugs come out easier
Last one I did like that only one broke off
 

manicmechanic007

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Sep 26, 2017
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broken plugs.jpg
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
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You have the ones where the plug breaks in two and you have to go in with the Lisle 65600 tool to remove the bottom portion limp?
Do Tune it up more often 75k miles max
Do Clean the injectors (thru the rail using the special chit) and clean the plate / upper intake first with carb foam and then the plugs come out easier
Last one I did like that only one broke off
No, I have a real truck
DSCF0803.JPG
 
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limp

wrap a little cheese around it and its a done
Oct 4, 2020
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I’d give you flack for having a Chevy truck, but with the Ford HD trucks having crunchy axle tubes and driveshafts lately, I won’t bother.
I do not fit in fords... Not sure why, but they just are not built for my chubby little frame... Arm rests are the wrong height, seats don't every feel comfortable, pedals and steering wheel are out of whack ( for me)..... Chevy trucks are like the few times I have driven a 911.. OH MY, does this feel good...LOL
The verdict is out on my new truck... I rolled the dice and got the 3 liter straight six diesel chevy came out with in 2019. ( My truck is a 2020) While I love my truck, I REALLY love this engine, and I am the LAST person to ever think I would have a diesel.. My concern is this engine is an Engineers nightmare and if it turns up problematic, it will be ugly.....
 

manicmechanic007

5 Year Member
Sep 26, 2017
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Your Chev Limp, can't be much worse than a new Ford even with some trouble down the road
Hell, Fords got trouble now
Our old still applies joke at ford for the GM boys was
"they just lease the new GM products because they cant afford to sell you one" (with all the recalls and problems)
Ford has so many problems now with sticking turbo vanes and ecoboost turbo lines failure et al. I do not blame anyone evermore for buying whatever
Hate to say it but IMO Tesla makes a good product these days
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
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"they just lease the new BMW and Mercedes products because they cant afford to sell you one" (with all the recalls and problems)
Fixed it for you.... I found out why German cars that sell for over 100K are for sale for 10K not too many years later...... TOO expensive to fix, and they need LOTS of fixin as they age.....
DSCF0119.JPG
 

chrlsful

Active Member
Mar 6, 2021
259
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"...using caliper grease..."
as is in evidence 'I aint a gud writer'.
"...Just started using the new (1, 2 yrs?) caliper grease. None back for nxt change but I think it'll B da best..."

But "Yes" I am happy spreadin CRC black caliper grease (silly cone I think?) all
around (as never-seize).
 

Mindseye007

Active Member
Oct 21, 2020
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I find that using the wrong antifreeze is bad....Using anything other than green isnt good,,

On a 351w I bought for a core on my 408 project the guy removed the engine and cleaned it up pretty good then reassembled it and put it back in he used Orange Antifreeze and only put a few thousand miles on the truck before letting it sit for 4 months due to issues with thetransmssion...When I took the engine apart to do my 408 I took the heads off and a couple of the lil steamholes were clogged with a thick orange gel..

Theres a huge difference between orange and green antifreeze...The orange stuff is acidic and doesnt mix with green well or like being in engines that have green antifreeze residue inside the block and radiator and starts a chemical reaction....

The seal between the timing cover and block develops places for air to enter and water to escape.I find proper torque,indianhead shellac and a retorque after a few heat cycles helps but I also have a fix for that ..

When you get antifreeze in the oil it gets filtered out and eventually clogs the oil filter fast and can be detrimental to your engine..

I took 3/4" copper couplers and epoxied them into the waterpump cover then when I installed the cover I used MotoSeal to seal the tubes where they go into the engine block

IMG_20220409_230657.jpg


The 4 long screws that attaches the waterpump to the engine needs thread sealer as this is another way for air to enter and antifreeze/water to escape..

Another thing I find is that intake manifolds need to be retorqued plus I put a lil Indian Head Shellac around the water ports on the intake gasket to prevent any possible leaks..

Another thing I find is if youre running MLS gaskets is the way you initially treat the engine..I do my initial startups on plain water and even though it says its not needed I do a retorque anyway as my 351w didnt come with aluminum heads from the factory.

Then theres the matter of buying the right headgaskets too...Some manufacturers list if the gasket is for a steel to steel,,aluminum to aluminum or an aluminum to steel application too..........

Usually renting a cooling system pressure tester helps find the leaks fast if there are any..I pump it up to the max pressure my radiator can produce and let it sit overnight with a sheet of cardboard underneath..

If you run the car with plain water or antifreeze thats less than the 50/50 mix and you didnt remove it all during the winter ice could of started a crack in a waterjacket too depending on how cold your winters get.............

I hope you get to the bottom of the problem..
What happens when the water jacket gets a crack?
 

7991LXnSHO

wanna catch the space herp
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It sends coolant into a cylinder, and also pressurizes the cooling system.
Maybe not at first, but either the crack will head to a bolt that will not stay torqued so the head gasket leaks, or it cracks to the cylinder area. another possibility is a leak to an oil pressure or oil return area. Those fluids do not do well when mixed. A cast iron block is strong, but remember it is also brittle and cracks are are hard to repair well in cast iron.
Flathead blocks that cracked in common places often could be run at least until the next rebuild using a boiler repair product plumbers also used for not water and steam heat systems. if a block is already apart, it's not worth putting new parts and mechanic in a can into a broken 5.0 block at this time.
 
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96pushrod

I think they're a little easier to get off
May 15, 2018
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Maybe not at first, but either the crack will head to a bolt that will not stay torqued so the head gasket leaks, or it cracks to the cylinder area. another possibility is a leak to an oil pressure or oil return area. Those fluids do not do well when mixed. A cast iron block is strong, but remember it is also brittle and cracks are are hard to repair well in cast iron.
Flathead blocks that cracked in common places often could be run at least until the next rebuild using a boiler repair product plumbers also used for not water and steam heat systems. if a block is already apart, it's not worth putting new parts and mechanic in a can into a broken 5.0 block at this time.
No matter where it starts or ends, a cracked water jacket pretty much spells the end of most stock block sbfs.
 
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