Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
Sign in using an external account
Register Forgot Password?


Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 01-10-2012, 01:35 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
Exhaust manifold leak

Hey guys need a little help here,rebuilt the heads on my 81 460 and they have no war page,but the passenger side exhaust manifold haas an exhaust leak. Could the exhaust manifold be warped ? Is this a common problem?
Reply With Quote
  #2  
Old 01-10-2012, 05:31 PM
redmondjp's Avatar
redmondjp redmondjp is offline
Senior User
 
Join Date: Apr 2011
Location: Redmond, WA USA
Posts: 449
redmondjp is gaining momentum as a positive member of FTE.redmondjp is gaining momentum as a positive member of FTE.
I don't know about common, but it can definitely be warped. Are you using exhaust gaskets or bolting directly to the head? A machine shop can surface it to restore flatness of the sealing surface, if needed.

Another possibility, one which is more likely IMO, is a small crack. They can be really hard to see if on the engine side.
__________________
1990 F-350 XLT CCLB SRW 460 5spd 4x4 3.55LS, 98K miles, mostly stock

sent from my iKeyboard
Reply With Quote
  #3  
Old 01-10-2012, 05:55 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
I used brand new gaskets,I will check for cracks.thanks
Reply With Quote
  #4  
Old 01-12-2012, 07:59 AM
fasthauler's Avatar
fasthauler fasthauler is offline
Posting Guru
 
Join Date: Mar 2004
Location: Hesperia, CA
Posts: 1,182
fasthauler is starting off with a positive reputation.
Hopefully the shop that rebuilt the heads should have checked for any warpage at the exhaust ports. Shame on them if they didn’t. The exhaust manifold will usually pull up tight to the head if torqued properly unless it is major warped. My guess would be a crack somewhere. Start the thing up and, while still cold, just run you’re bare hand around the manifold. You should definitely feel it if it is leaking. I am guessing that this is happening on the right side manifold. That is the one that usually causes the problem.
__________________
Gary
1977 F250 460 Hauler.
Reply With Quote
  #5  
Old 01-12-2012, 07:24 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
Yea it's the right side, I will check for that thanks.
Reply With Quote
  #6  
Old 02-17-2012, 08:29 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
well the exhaust leak is all good now thanks for the help! the problem now is i had to pour a little gas in the carb to get it to run.it took a couple times repeating this then it stayed running and ran great for about 20 minutes then stalled,coudnt get it to start again.it was low on gas and had been sitting for awhile.today i added about 5gallons of premium gas and tried starting it again with no luck.when i put gas in the carb it would fire rite up untill the gas was used.will only start now when i add gas to carb but wont stay running!could it be the mechanical fuel pump?is there away to test the fuel pump?any advice would be appreciated
Reply With Quote
  #7  
Old 02-17-2012, 11:08 PM
Sevillian273's Avatar
Sevillian273 Sevillian273 is offline
Freshman User
 
Join Date: Nov 2010
Posts: 39
Sevillian273 is starting off with a positive reputation.
Fuel filter.
Reply With Quote
  #8  
Old 02-17-2012, 11:29 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
460 starved

I changed the inline filter going to the carb,do you know if there is another one inline somewhere?this motor is in an e350 motorhome.
Reply With Quote
  #9  
Old 02-18-2012, 07:49 AM
bigbluebronco43 bigbluebronco43 is offline
Elder User
 
Join Date: Nov 2002
Location: Norwood USA
Posts: 790
bigbluebronco43 is starting off with a positive reputation.
What was the fix on the exhaust manifold? I'm having the same leak on my 97 f250? I'd think your fuel pump is bad if you replaced the filter.
Reply With Quote
  #10  
Old 02-18-2012, 08:55 AM
fasthauler's Avatar
fasthauler fasthauler is offline
Posting Guru
 
Join Date: Mar 2004
Location: Hesperia, CA
Posts: 1,182
fasthauler is starting off with a positive reputation.
I have seen guys do major battle with their fuel pumps and find out the pickup screen in the tank is plugged. This happens a lot more than people think. The gas nowadays is really dirty and will eventually plug that little screen that is on the end of the pickup tube that is in the gas tank. The difficult fix is dropping the tank and removing the pickup tube and replacing the screen. The easy fix is to put a blow gun on the gas line to the tank and with as much pressure as the air compressor is able to put out, blow the darn thing off of the end of the pickup tube. Then put a filter in the gas line before the fuel pump. That way it will be easy to clean the filter next time without taking the gas tank down. The easiest check to see if this pickup tube filter is plugged is to pull the gas line loose where it comes from the tank to the fuel pump and suck on it. If you get a mouth full of gas then it is not plugged.

Since it is not a good idea to get a mouthful of gas find an alternate way of providing suction on the line. One of the simplest ways would be to go to the hardware store and buy a length of clear vinyl tubing the size of the gas line. Put the vinyl tubing on the end of the gas line and then suck on the vinyl tubing. If you see gas coming up the vinyl tubing quit sucking. If gas is present in the tubing you should be able to lay the tubing on the ground, preferably in a container, and the gas should flow freely. If not then the filter is probably plugged. (Or nearly plugged) These kinds of problems can really plague you, so good luck.
__________________
Gary
1977 F250 460 Hauler.
Reply With Quote
  #11  
Old 02-18-2012, 12:59 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
460 starved

thanks for the advice i am going to try that before changing the pump!getting back to my exhaust manifold,i was going to switch out to headers since people were telling me thats how they got rid of there exhaust manifold leak.Before doing that as one last resort i went over the the bolts retorqueing them one last time when the engine was warm,so far knock on wood I have not had any more exhaust manifold leak!For now i will leave that alone!So close to having this motor done hopefully this fuel issue is the last problem.
Reply With Quote
  #12  
Old 02-19-2012, 06:30 PM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
starved 460

so I pulled the fuel line from the carb and turned over the motor got good fuel pressure out of fuel line so i guess the fuel pump must be ok .hooked line back up to carb and it still wont start? still starts when adding gas to top of carb but wont stay running.has anybody had this prob before ?
Reply With Quote
  #13  
Old 02-20-2012, 12:51 AM
redmondjp's Avatar
redmondjp redmondjp is offline
Senior User
 
Join Date: Apr 2011
Location: Redmond, WA USA
Posts: 449
redmondjp is gaining momentum as a positive member of FTE.redmondjp is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by foreverfordtrucks View Post
so I pulled the fuel line from the carb and turned over the motor got good fuel pressure out of fuel line so i guess the fuel pump must be ok .hooked line back up to carb and it still wont start? still starts when adding gas to top of carb but wont stay running.has anybody had this prob before ?
Your float in the carburetor may be stuck in the 'up' position. Is there any gas in the bowl of the carb? You can usually tell by operating the throttle - if the accelerator pump squirts fuel down the venturis when you do this, then there is fuel in there (unless your accelerator pump doesn't work).

When is the last time that the carb has been rebuilt? You may be due.
__________________
1990 F-350 XLT CCLB SRW 460 5spd 4x4 3.55LS, 98K miles, mostly stock

sent from my iKeyboard
Reply With Quote
  #14  
Old 02-22-2012, 11:34 AM
foreverfordtrucks foreverfordtrucks is offline
Freshman User
 
Join Date: Feb 2009
Posts: 36
foreverfordtrucks is starting off with a positive reputation.
starved 460

so guys looks like my accelerator pump doesnt work.dont think this carb has ever been rebuilt.before i rebuild this i found another holley the exact same as mine that has been rebuilt but it has an electric egr valve instead of vacum,would this be easy to adapt to my 81 460 or would it be to much work?I dont know what year this other carb is other than its identical to mine with electronic egr.any advice would be appreciated
Reply With Quote
  #15  
Old 02-22-2012, 05:34 PM
redmondjp's Avatar
redmondjp redmondjp is offline
Senior User
 
Join Date: Apr 2011
Location: Redmond, WA USA
Posts: 449
redmondjp is gaining momentum as a positive member of FTE.redmondjp is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by foreverfordtrucks View Post
so guys looks like my accelerator pump doesnt work.dont think this carb has ever been rebuilt.before i rebuild this i found another holley the exact same as mine that has been rebuilt but it has an electric egr valve instead of vacum,would this be easy to adapt to my 81 460 or would it be to much work?I dont know what year this other carb is other than its identical to mine with electronic egr.any advice would be appreciated
If it bolts in place and has the same throttle and transmission kickdown levers, I'd go for it. Nothing to lose at this point.

And I think you probably meant to say electronic choke instead of EGR - you will have to connect that to the stator output of the alternator (check a Ford wiring diagram to confirm this). Electric chokes are connected to the alternator so that they will only be powered up while the engine is running (as opposed to when the ignition is on).

You can connect the electric choke to a switched ignition source, but just remember NOT to leave the key on for very long w/o starting the engine, when the engine is cold (the choke will warm up and open too soon).
__________________
1990 F-350 XLT CCLB SRW 460 5spd 4x4 3.55LS, 98K miles, mostly stock

sent from my iKeyboard
Reply With Quote
Old 02-22-2012, 05:34 PM
 
 
 
Reply

Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)

Tags
77, enthusiasts, exhaust, f250, fe, ford, forums, leak, leaky, machine, manifold, manifolds, manifoldsnh, moter, shop, truck

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Exhaust Leak Jared32676 1997 - 2003 F150 8 04-16-2014 07:44 PM
passenger side exhaust manifold Jaaaaaaackman 1994.5 - 1997 7.3L Power Stroke Diesel 13 05-03-2012 10:59 PM
exhaust manifolds WALJON Expedition & Navigator 16 12-25-2009 06:56 PM
'96 F150 300-6cyl Exhaust Manifold Leak BobbyB Ford Inline Six, 200, 250, 4.9L / 300 2 07-25-2005 02:03 PM
Front Pipe/Manifold Exhaust Leak Racerguy 1987 - 1996 F150 & Larger F-Series Trucks 1 01-16-2003 11:19 AM



All times are GMT -5. The time now is 11:48 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup