What is making my Ranger jerk and shake intermittantly? - 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.

LinkBack Thread Tools Search this Thread
Old 06-17-2015
Thread Starter
Join Date: Jun 2015
Location: Elkhorn, Ky
Posts: 1
What is making my Ranger jerk and shake intermittantly?

Hi; I have owned this 2009 Ranger Sport 4x4 with now 70K mi for a little over a year. i've placed approx. 12K on it. Up till approx. 2mo. ago it has driven flawless but now i have developed a very strange problem that has left 2 technitions sctratching their heads to resolve. I have this intermittant sudden "Shake' or "Faltering" that occurs somewhere in the drivetrain(either engine or further back) that occasionally occurs. Under the most severe occurrence the whole chassis will shake as if I have been driving over railroad ties, other times its more subtle. Been going on approx. 2 mo. but up till the other day the check engine light had not come on. Once it finally did, it indicated 'A misfire" in #3 cyl. Prior to the check engine illuminating I had this at a Ford dealership who could not reproduce the problem during limited drive time and sent me home!
Subsequently I drove it with my trusted mechanic for approx. 5 mi. and could not reproduce the problem however it continues to happen intermittently yet rather unpredictably. If there is a pattern to it then it may occur during light acceleration at lower slower speeds and more frequently traveling up long grades however it may happen under any situation and speed does not seem to be relevant except to say that it appears to occur mostly when in a higher gear/lower RPM. I'm telling you that the severeness ranges from subtle to almost seismic scale and the whole chassis will shudder(not to be confused with a failing torque converter). We have replaced the ignition coil/plugs and wires out of "likely culprits" logic. Except when this problem occurs the Ranger drives normally. I'm beginning to think this out along other possible issues e.g. vacuum/tranny, U-jt. or differential slipping even perhaps a slipping timing belt? Please advise or ask for a more detailed description if you care to enter my world and thx. Bill D.
Reply With Quote
Old 06-17-2015
cheese_man's Avatar
iTrader: (1)
Join Date: Nov 2009
Location: arthur
Posts: 2,100
shake or faltering indicates to me that what you are experiencing is actually fuel PRE-IGNITION

what octane of fuel are you burning in your engine presently , if it is 87 octane that may be the culprit

try running 2 tanks of ESSO 91 octane fuel ( there are NO cleaners or additives or ethanol in that octane of fuel )

to see if the problem occurs still ( it might just be the fuel that is causing the problem )
Reply With Quote
Old 06-17-2015
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 7,603
Yes, +1 ^^^

4.0l SOHC engine has a Knock sensor under the intake manifold, these do fail.
This engine has 9.7:1 compression ratio so "they" had to add a knock sensor because it WILL ping/knock(pre-ignition) on 87 octane.
The knock sensor detects the pre-ignition(before you can hear it) and the computer retards the spark timing so spark plug ignites fuel before it can self ignite.
This represents a loss of power and if knock sensor was intermittent it could fit those symptoms.
These are a PITA to replace, lol.

Clean the MAF sensor, dirty MAF sensor will cause "bucking", which sounds similar to your description.

Long shot is TPS(throttle position sensor), this sensor tells the computer if gas pedal is being used and in what position it is in.
This sensor works like a light dimmer or volume control a simple rheostat(variable resistor)
Computer sends it 5 volts
TPS send back under 1 volt if your foot is off the gas
TPS sends back above 4.5 volts if gas pedal is pushed down to the floor.
So gas pedal at 1/2 way might be 2. 15 volts, 3/4 3.5 volts, ect....
Now if there was a worn spot on the TPS, the volt might suddenly drop, so computer thinks you took your foot off the gas, then voltage jumps back up where it should be so you get a "bucking" in the vehicle like you where pumping gas pedal only a faster response.
TPS is easy to test with volt or ohm meter, they rarely fail, but rarely is not never, lol, long shot but not a no shot.

9 out of 10 sensors, or controls, replaced by DIYers were not broken, so never replace anything without testing it.
And just FYI, 6 out of 10 sensors replaced by professional mechanics were not broken, lol, but I think some of that is just padding the bill.

Last edited by RonD; 06-17-2015 at 10:13 PM.
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Clunk and jerk on reverse when cold Dan R Drivetrain Tech 2 03-10-2014 01:21 PM
4x4 clunk/jerk; fine in 2-wheel drive 2000 ranger akfr Drivetrain Tech 2 10-04-2012 02:20 PM
Engine starts choking and misfires then starts to jerk violently 97ranger666 SOHC - 2.3L & 2.5L Lima Engines 3 10-09-2011 12:36 PM
Clutch won't release intermittantly Dave7060 Drivetrain Tech 3 04-03-2011 07:00 PM
Rough Jerk in Brakes or Transmission... mar01Edge 4.0L OHV & SOHC V6 Tech 16 10-11-2006 07:38 PM

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 11:16 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.