Hi guys,

I am new to the forum, any information is greatly appreciated!

I have a 2005 F150 with 66,000 miles on it. Bought it back in Aug of 13. I have a constant ticking noise going on, both at idle and when driving it. I had a mechanic run some tests on it and it currently shows low compression in cylinder 3, about 40 psi lower than the rest. I was told that it was not cam phasers, but could possibly be coil packs, valves, or even bent rods, so I'm kind of at a loss on what it could be. I wouldn't think that a truck with 66,000 miles would need a rebuild. If anyone has any info on this I would greatly appreciate it. Thanks.

 

Pull the passenger valve cover off and look at the cam and follower on #3 cylinder. If it looks normal, you are looking at a teardown and rebuild.

Coil packs can't affect compression, I'd find a different mechanic.

 

Cylinder #3 must be a popular cylinder...

Had low compression on #3...dealer replaced head, catalytic converter and injector...I think Injector went bad and messed up the exhaust valve, and catalytic converter...this happened t 81K...then about 30k later I had a misfire on #3...bad coil...

 

Do you have any codes? A missfire code should be present if your compression is that low. Did the mechanic swap compression test hoses with another cyl to confirm that the test hose was not defective? An intake follower off will keep the intake valve closed and show zero compression as no air can enter the cyl to compress. A bent rod caused by a hydrolock can show low compression in varying degrees depending on the amount of bend in the rod. This can also generate a knock but on these engines sometimes a rod knock actually sounds like a loud ticking. A bent valve will also cause a miss fire and a code. If the truck is running fine but making a tick then look for a exhaust leak or some other cause. As GLC said remove the passenger side cam cover and have a look at the lash adjusters etc.check for follower movement and soft lash adjusters.

 

There is another possibility. The fuel injector could have leaked enough gasoline into that cylinder to wipe the oil off the cylinder walls and score that cylinder or rings. I would get Ford to check to see if a fuel injector has been replaced on that cylinder. If so, you may have some recourse with Ford since they are warranting the injectors for 120k miles or so and if one does damage, they are supposed to repair it.

 

Yes good call Roadie also a bad injector may have caused a hydrolock which may be grounds for replacement engine/repair under the extended warranty. I forgot about that.

 

Thank you guys for the info... I currently do not know the codes but will be getting the codes in the morning, I'll post them as soon as I get them. I'm also having a leak down test done to see if they can have a better idea of what could be going on. Since I did not buy the truck from a Ford dealer, will that cause problems if it does happen to be a bad injector to a hydrolock, as to the warranty on the truck? Cylinder 3 is currently at 110psi as the others are at 150. The truck seems to run fine, I don't really feel a loss in power or anything, the tick is fairly loud, especially at idle, theres an aftermarket exhaust on it, so when I do accelerate I don't notice it as much but it is still present. What about like a sticky lifter or valve? Would running some additive (seafoam) through it help out at all?

 

https://www.f150online.com/forums/v8...ram-07m08.html

 

Thank you glc!