Misfire - Ranger-Forums - The Ultimate Ford Ranger Resource


4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 05-29-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
Misfire

I have been having a misfire on my truck recently. It is a 2000 Ranger 4X4 with the 4.0L OHV and auto tranny. I have a misfire on cylinder #4 for about ten seconds after I start the truck. I replaced the spark plug and it got better for a week or two and now it is doing it again. The plug looks fouled out. I replaced the rubber intake gasket inserts six months ago but I didn't touch the intake gaskets under the fuel rail. Compression check was 175-185 on all of the cylinders. Any suggestions would be helpful. Thanks
Reply With Quote
  #2  
Old 05-29-2008
99MazdaB4000's Avatar
Member
 
Join Date: Apr 2008
Location: Kutztown, PA
Posts: 1,980
brother, im in the same boat. i keep replacing the spark plug because idk what else to do. i have a 1999 Mazda B4000 4x4 4.0L automatic, pretty much the same thing as your truck, and its been doing it since this previous fall. i think it started in september. spark plug looks like its been charbroiled?
Reply With Quote
  #3  
Old 05-29-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
Yea exactly. I figured the compression check would let me know how serious it was, but im confused (and glad) that is was all ok.
Reply With Quote
  #4  
Old 05-29-2008
99MazdaB4000's Avatar
Member
 
Join Date: Apr 2008
Location: Kutztown, PA
Posts: 1,980
so the compression is "good" on your truck? idk if you've seen my other thread, but my frame cracked by the real shock mount, so once its welded up and i get her back on the road, i'll let you know how it goes and we can compare info. but if you get it fixed before then, def. let me know what the h3ll is up with this. all it did was **** me off all winter.
Reply With Quote
  #5  
Old 05-29-2008
Level I Supporter
 
Join Date: Aug 2006
Location: Durham, NC
Posts: 3,657
Try changing the plug wire.....or swapping it with another cylinder.
Reply With Quote
  #6  
Old 05-29-2008
04 EDGE
Unregistered User
 
Posts: n/a
not the plug wire.if a wire is bad then it would misfire all the time. have you been loosing coolant?

my guess is a blown head gasket or cracked head. ford has a TSB on this somewhere. what happens is this, when you shut the engine off as the engine cools the gap opens and coolant gets into the cylinder, once you start it, it misfires until the coolant is burned out.

try doing a pressure test on the cooling system when the engine is cold and remove the spark plug.
Reply With Quote
  #7  
Old 05-29-2008
Level I Supporter
 
Join Date: Aug 2006
Location: Durham, NC
Posts: 3,657
Quote:
Originally Posted by 04 EDGE View Post
not the plug wire.if a wire is bad then it would misfire all the time. have you been loosing coolant?

my guess is a blown head gasket or cracked head. ford has a TSB on this somewhere. what happens is this, when you shut the engine off as the engine cools the gap opens and coolant gets into the cylinder, once you start it, it misfires until the coolant is burned out.

try doing a pressure test on the cooling system when the engine is cold and remove the spark plug.
Sorry, A plug wire will cause this problem!!! I guess you missed the point that his compression is good, this rules out head gasket and/or cracked head!

But, you are in usual form, low reading comprehension again!!

The earlier vintage 4.0L's did have a problem with loose lower intake bolts, which would cause a vacuum leak.

Last edited by Takeda; 05-29-2008 at 06:54 AM.
Reply With Quote
  #8  
Old 05-29-2008
Redrocket's Avatar
Member
iTrader: (6)
 
Join Date: Jan 2007
Location: Waynesville n.c
Posts: 1,993
my truck does the same stuff good compressure runs great most of the time but when its cold it runs like crap mine is a head gasket cause im useing a but of water like a gallen once every 4 weeks
Reply With Quote
  #9  
Old 05-29-2008
Level I Supporter
 
Join Date: Aug 2006
Location: Durham, NC
Posts: 3,657
Quote:
Originally Posted by Redrocket View Post
my truck does the same stuff good compressure runs great most of the time but when its cold it runs like crap mine is a head gasket cause im useing a but of water like a gallen once every 4 weeks
If you are sure your compression is good (you may want to try a cylinder leak down test) then your problem isn't the head gasket, but the lower intake gasket will cause loss of coolant.
Reply With Quote
  #10  
Old 05-29-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
I forgot to mention I did replace the plug wires two weeks ago. What is involved with the leakdown test? I think that might be my next step. I did notice my coolant resivrior was empty but the radiator was still full. I'll keep a close eye on that. Thats a good idea on doing the pressure test, I'll try that. Also my truck only has 66 thousand miles on it. Thank you all for the info. I really like the truck and would like to get this figured out.
Reply With Quote
  #11  
Old 05-29-2008
99MazdaB4000's Avatar
Member
 
Join Date: Apr 2008
Location: Kutztown, PA
Posts: 1,980
Well, I was losing a ton of coolant every week back when the truck was still on the road, and like i said, it is the #4 cylinder.....and its the ONLY one that misfires. Problem is I have a 142,xxx on the truck, and its going in for the "cracked frame" repair. How much will all these tests run me?
Reply With Quote
  #12  
Old 05-29-2008
Level I Supporter
 
Join Date: Aug 2006
Location: Durham, NC
Posts: 3,657
Quote:
Originally Posted by Fiveologyjay View Post
I forgot to mention I did replace the plug wires two weeks ago. What is involved with the leakdown test? I think that might be my next step. I did notice my coolant resivrior was empty but the radiator was still full. I'll keep a close eye on that. Thats a good idea on doing the pressure test, I'll try that. Also my truck only has 66 thousand miles on it. Thank you all for the info. I really like the truck and would like to get this figured out.
With the leakdown test, you bring the piston to TDC on the compression stroke, pressurize the cylinder with compressed air, and watch how long it takes the pressure to drop off.....
Reply With Quote
  #13  
Old 05-29-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
Yea I'll try the leakdown test and keep you all updated. I just pulled the plug out again to look at it and there is definitely oil on it. Im just not sure exactly where its coming from. Thank you all for the input.
Reply With Quote
  #14  
Old 06-01-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
Name:  DSC03478.jpg
Views: 9
Size:  56.6 KB

This is the spark plug hole on the number 4 cylinder. Looks like oil there. How would oil get in front of the plug?
Reply With Quote
  #15  
Old 06-01-2008
Member
 
Join Date: Nov 2005
Location: canton,NC
Posts: 16
i had a 2.9 ford rander which the spark plugs was getting fouled once every couple weeks cause of the piston rings were shot i put some plug defoulers which is like a couple bucks at the auto part store you can try that if you dont know what it is i dont know but you screw the plug into it then put it in the plug hole like normal
Reply With Quote
  #16  
Old 06-10-2008
Member
Thread Starter
 
Join Date: May 2006
Location: Havre De Grace, MD
Posts: 113
Do you guys think the head is cracked?
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
cylinder 4 misfire skankinandy SOHC - 2.3L & 2.5L Lima Engines 20 10-15-2015 03:26 AM
Misfire 4,5,6 help. JDRead 2.9L & 3.0L V6 Tech 10 09-24-2008 02:10 AM
help misfire after i washed engine? vic 2.9L & 3.0L V6 Tech 3 08-13-2006 01:37 PM
Engine misfire???? phatspeed7x 4.0L OHV & SOHC V6 Tech 4 07-02-2006 09:08 AM
Misfire TBarCYa 4.0L OHV & SOHC V6 Tech 5 02-23-2005 11:14 AM


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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 05:14 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.