Engine knocking and runs like crap - Vintage Mustang Forums
 4Likes
Reply
 
Thread Tools
post #1 of 17 (permalink) Old 12-31-2018, 11:11 AM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
Engine knocking and runs like crap

Im starting yr 6 of a 2 yr build, and finally got the engine in and started. I pulled the engine and transmission from a '90 gt about 4 trs ago. It ran fine before it was pulled.

Its running and idles rough and has a knock. How kind i find the source or eliminate optoins? Since it hasnt run in yrs should i let it idle for 10-15 min and see what happens?
Thanks
Walter
https://youtu.be/3el6WK5eyF4
wscott00 is offline  
Sponsored Links
Advertisement
 
post #2 of 17 (permalink) Old 12-31-2018, 11:21 AM
Senior Member
 
happystang's Avatar
 
Join Date: Jan 2013
Location: San Jose, CA
Posts: 4,141
Garage
Definitely sounds like a header gasket/exhaust leak. I see you have EFI, my guess is that the exhaust leak is throwing off the O2 sensor readings and making it run like crap .
Huskinhano likes this.

1969 Convertible field find (450hp spaghetti noodle)
1968 Fastback (428 and a 4 speed)
www.SaveClassicCars.net

-Armon

happystang is offline  
post #3 of 17 (permalink) Old 12-31-2018, 11:23 AM
Senior Member
 
Join Date: Mar 2001
Location: Tunkhannock PA
Posts: 19,703
Ditto, definitely a exhaust leak

Tom

One thing great about getting older. A life in prison sentence is less of a deterrence

Huskinhano is offline  
 
post #4 of 17 (permalink) Old 12-31-2018, 11:29 AM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
Ive got a cheap header gasket from autozone. Should i buy specific kind or use some rtv?
wscott00 is offline  
post #5 of 17 (permalink) Old 12-31-2018, 11:38 AM
Senior Member
 
happystang's Avatar
 
Join Date: Jan 2013
Location: San Jose, CA
Posts: 4,141
Garage
Quote:
Originally Posted by wscott00 View Post
Ive got a cheap header gasket from autozone. Should i buy specific kind or use some rtv?
Opinions will vary, but I'm a big of Percy's Aluminum gaskets- they're blow-proof and reusable.

1969 Convertible field find (450hp spaghetti noodle)
1968 Fastback (428 and a 4 speed)
www.SaveClassicCars.net

-Armon

happystang is offline  
post #6 of 17 (permalink) Old 12-31-2018, 12:40 PM
Senior Member
 
Join Date: Jul 2013
Posts: 4,160
Ya, there definitely needs to be an audio sticky somewhere to teach the differences between a tick, a tap, a slap, a rattle, a knock and an exhaust leak

Any correct gasket should work, if they don't you have torqued them improperly or there's an imperfection on either surface. No type of sealer is gonna work there.
I think the biggest thing is having some sort of pressure twisting on the manifolds from the pipes or its hitting something so when you think its tight its really not. You should be able to press by hand tightly to the head or else you're fighting yourself.
Don't get all HeMan on those little bolts either!
1ofAMillion+ is online now  
post #7 of 17 (permalink) Old 12-31-2018, 12:42 PM
Senior Member
 
MrFlash's Avatar
 
Join Date: Apr 2018
Location: JAX
Posts: 641
Did you plug the thermactor “smog” holes at the back of the heads?
A threaded plug goes into each hole.
Huskinhano and 1ofAMillion+ like this.

1970 Mustang coupe
MrFlash is online now  
post #8 of 17 (permalink) Old 12-31-2018, 01:01 PM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
Ill check for the smog delete plugs. Should it be on the back of the heads
wscott00 is offline  
post #9 of 17 (permalink) Old 12-31-2018, 01:21 PM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
There is a threaded hole on both side. Should there be a plug in them?
So you know what size bolt
Attached Images
File Type: jpg 20181231_131312_1546280414536.jpg (323.4 KB, 10 views)
wscott00 is offline  
post #10 of 17 (permalink) Old 12-31-2018, 01:38 PM
Senior Member
 
MrFlash's Avatar
 
Join Date: Apr 2018
Location: JAX
Posts: 641
Quote:
Originally Posted by wscott00 View Post
Ill check for the smog delete plugs. Should it be on the back of the heads
When that engine came out of the 90 mustang, there was a crossover tube at the back of the heads that connected the smog holes to the smog pump.
Those holes need to be plugged.
1ofAMillion+ likes this.

1970 Mustang coupe
MrFlash is online now  
post #11 of 17 (permalink) Old 12-31-2018, 01:41 PM
Senior Member
 
MrFlash's Avatar
 
Join Date: Apr 2018
Location: JAX
Posts: 641
MrFlash is online now  
post #12 of 17 (permalink) Old 12-31-2018, 02:12 PM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
Will i be able to feel air coming from the holes when its running
wscott00 is offline  
post #13 of 17 (permalink) Old 12-31-2018, 02:28 PM
Senior Member
 
MrFlash's Avatar
 
Join Date: Apr 2018
Location: JAX
Posts: 641
Quote:
Originally Posted by wscott00 View Post
Will i be able to feel air coming from the holes when its running
Most likely.

1970 Mustang coupe
MrFlash is online now  
post #14 of 17 (permalink) Old 01-01-2019, 08:47 AM Thread Starter
Senior Member
 
wscott00's Avatar
 
Join Date: Nov 2012
Posts: 946
When i look into the holes on the back of the heads it blocked off and a straw only goes 1.5" or so inside. I also dont see any smome or feel any air coming out

Is it possible that theae heads dont have a thermactor port
Attached Images
File Type: jpg Screenshot_20190101-084211_Video Player_1546350338507.jpg (267.1 KB, 3 views)
wscott00 is offline  
post #15 of 17 (permalink) Old 01-01-2019, 09:16 AM
Senior Member
 
MrFlash's Avatar
 
Join Date: Apr 2018
Location: JAX
Posts: 641
Ok. It appears your heads do not have the holes. Those apparently are not factory ford E7 5.0 heads.

Just for reference, this is what a plugged smog hole looks like.
Attached Images
File Type: jpeg BFB2C60C-6C33-47EC-8003-5AE00E675408_1546352163883.jpeg (59.1 KB, 3 views)

1970 Mustang coupe
MrFlash is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 Off

 
For the best viewing experience please update your browser to Google Chrome