The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1960 - 1966 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 04-11-2020, 12:27 AM   #26
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

Quote:
Originally Posted by Steeveedee View Post
If it is running smoothly and not overheating, it just may be coolant in the exhaust. Run it until it clears up. That may take awhile. I had it happen on a car of mine and I drove it about 30 miles before the water vapor calmed down.
I might try to do that and see what happens. Just afraid something is wrong and running it like that hurting it worse. I'll check compression tomorrow and see what that says. If ys all good I might just run it for a while
LuckyRabbit4 is offline   Reply With Quote
Old 04-11-2020, 12:15 PM   #27
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,577
Re: **cooling system issue**

Smart move!
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 04-11-2020, 03:31 PM   #28
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

I found that compression should be about 150psi in a 250 chevy.

Mine is: 130/120/150/120/120/120

I did see antifreeze on the 1st and 2nd plugs and unfortunately a little discoloration on the oil dipstick. I'm not sure why there is such a variation in the compression PSI if it's all suppose to be 150 like I've read.
LuckyRabbit4 is offline   Reply With Quote
Old 04-11-2020, 03:39 PM   #29
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

Could bad timing or setting the valves cause the compression to be off? I'm doing as much as I can on my own but starting to look like I need someone to take a look and diagnose this thing before I waste time on a warped head or something unfixable.

Timing and setting the valves are the only other things that I'm not 100% I've done right. Or maybe not close enough to perfect to make everything relatively smooth for now.
LuckyRabbit4 is offline   Reply With Quote
Old 04-11-2020, 03:41 PM   #30
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

Quote:
Originally Posted by LuckyRabbit4 View Post
I found that compression should be about 150psi in a 250 chevy.

Mine is: 130/120/150/120/120/120

I did see antifreeze on the 1st and 2nd plugs and unfortunately a little discoloration on the oil dipstick. I'm not sure why there is such a variation in the compression PSI if it's all suppose to be 150 like I've read.
I just found another forum saying that the compression should about 130 from the manual. So why is the 3rd piston at 150? clog? valves too tight and can't escape the cylinder? just bad timing?
LuckyRabbit4 is offline   Reply With Quote
Old 04-11-2020, 04:05 PM   #31
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,577
Re: **cooling system issue**

Could be carbon buildup. Your compression numbers aren't the greatest, but about what I'd expect to see in an old engine. I'd expect to see something like 150 psi on a new/rebuilt engine. It looks like at least the head is going to have to come off for either a gasket replacement or possibly a valve job, plus draining the contaminated oil.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 04-11-2020, 04:08 PM   #32
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

well... I've had the truck 2 years and hasn't seen the road for more than about 30 minutes. I'll look into getting a new gasket and probably intake while i'm at it. Valves are terrible to set. Not sure I've even done that right yet. I'll drop the oil out this weekend and start the gasket replacement all over again.
LuckyRabbit4 is offline   Reply With Quote
Old 04-15-2020, 02:14 PM   #33
Ken Cook
Registered User
 
Ken Cook's Avatar
 
Join Date: Apr 2017
Location: Ragley, La.
Posts: 137
Re: **cooling system issue**

Quote:
Originally Posted by LuckyRabbit4 View Post
I finally got the 4.1 250 back together after blowing a head gasket.
Did you bring the head to a machine shop to have it checked?
If you pull it back off, you should have it checked before you re-install it.
Ken Cook is offline   Reply With Quote
Old 04-15-2020, 02:56 PM   #34
LuckyRabbit4
Registered User
 
Join Date: Sep 2018
Location: Hartford Kentucky
Posts: 54
Re: **cooling system issue**

Quote:
Originally Posted by Ken Cook View Post
Did you bring the head to a machine shop to have it checked?
If you pull it back off, you should have it checked before you re-install it.
My dad is an engineer with all that stuff. Said the head checked out. Maybe the block has some issues. Torqued the head bolts to specific but maybe I missed something? Hard to believe it's broke before running it.
LuckyRabbit4 is offline   Reply With Quote
Reply

Bookmarks

Tags
cooling, overheating, pressure


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:46 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com