• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

need help im going crazy. 3.0L Flex rough idle.


jaksun

New Member
Joined
Apr 14, 2015
Messages
2
Reaction score
0
Points
0
Vehicle Year
1999
Make / Model
Ford
Transmission
Automatic
Guys this is my first time posting on here but i need your help. Im going crazy trying to figure out whats going wrong. My truck has a periodic rough idle and misfire. Giving me the codes P0301, P0401, P1171. ive replaced the cylinder heads, PCV valve, Dpfe sensor, dpfe hoses, coil pack, spark plugs, spark wires, egr solenoid, and vacuume tested the egr valve it holds pressure fine, did a top end cleaning, and injector cleaning, did a compression test it failed because the air would escape out of the other spark plug holes, and did a cylinder leakdown test and the rings are good. If any one can help me with this i would greatly appreciate it.
 


Big Jim M

New Member
Joined
Apr 18, 2008
Messages
2,728
Reaction score
30
Points
0
Age
86
Location
Austin
Vehicle Year
2002
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
did a compression test it failed because the air would escape out of the other spark plug holes.
WHAT! You are waaay wrong on that. Tell us what the compression was (is)!
Yeah the other holes are making sounds but that sound is from each of their cylinders, not the one you are testing at the time.
Big Jim
 

jaksun

New Member
Joined
Apr 14, 2015
Messages
2
Reaction score
0
Points
0
Vehicle Year
1999
Make / Model
Ford
Transmission
Automatic
It would not hold any compression untill i pluged the other spark plug holes. Thats what made me think the exhaust valve was not seating properly so i did a top end cleaning and injector cleaning. But it made no differance. Still the same codes.
 

Big Jim M

New Member
Joined
Apr 18, 2008
Messages
2,728
Reaction score
30
Points
0
Age
86
Location
Austin
Vehicle Year
2002
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
check again

It would not hold any compression untill i pluged the other spark plug holes. Thats what made me think the exhaust valve was not seating properly so i did a top end cleaning and injector cleaning. But it made no differance. Still the same codes.
Do a compression test on all cylinders and write down what is in each and get back to us.
Take all plugs out and install the tester gauge in one cylinder and spin the engine till the pressure stops rising. Then go t the next and do them all. You will most likely find out what is wrong with the engine missing right there.
Big Jim
 

Sponsored Ad


Sponsored Ad

Members online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top