I know your all probably sick and tired of hearing about someones engine knocking but Ive done a ton of research and desperatly need some opinions. I recently bought an 05 f150 reg cab 4.6l 2v from a ford dealer. According to the salesman the truck came in on trade with a slight engine tick (barely audible). after test drives and sitting the knock/tick got gradually louder and didnt sell. A year and sone later i come along and buy it for a steal of a price with the ticking engine. I am a marine diesel mechanic and was confident i could find were the tick from and fix it up until recently.

Ill start by trying to describe the tick/knock the best i can. When starting the engine from cold the tick is not audible hardly at all until 30sec to 1min at idle. It then increases in volume until the engine is at operating temperature. I have eliminated rod knock or piston slap because the the tick is too slow. its is definatly valvetrain. Its not quiet either. When the engine is warm its a clearly audible sharp knock. The kock is present at any rpm although its quietest around 1600-1800 rpm.

So here is were im at so far... I isolated the sound to the forward right bank of the engine. The sound is most concentrated at the top cam cover bolt, second from the front. I pulled the cam cover and ran the engine. nothing was obvious from what i saw. I put my finger on each follower while running, i could still hear the knock but couldn't feel any slack. One thing i noticed while the cover was off that bothered me was that the timing chain was slack on top. probably 1/2 inch free slack. Do the tensioners bleed off when the engine is stopped? could this throw her out of time enough to knock? It has not been working the way it should. I finally got a CEL thr other night for P0351, 0352 but im thinking this is a seperate issue.

So anyway i changed the plugs last night and scoped the cylinders and everything is ok. A bit of carbon but ok. I would love to have an opinion from someone with some experience on these engines before i start buying parts for process of elimination. Is there any way to check the lash adjusters function short of pulling them? From just listening to it i would put my money on a failed lash adjuster but after looking into it i really dont know. Some suggestions from guys who know these engines would be greatly appreciated!

 

I am having a problem just like you describe. I am pretty sure you have already looked into this but are you running a fram oil filter?

Other then that, I am curious to what your problem is, as it might help me with figuring out my problem.

Just wondering when you give your truck a bit of gas does the knocking noise go louder or just faster?

 

Yes it does have a fram filter on it now. I cant see this causing it to knock?...

I pulled the three lash adjusters that the knock was concentrated to tonight. I dont know enough about them to tell if they are sticking or stuck. I had to put them back in cause i haven't got my replacements yet. Can anyone explain how to dtermine if they are functioning properly?

The knock doesnt become any louder with rpm, just faster.

I had a mechanic friend of mine tell me today it was piston slap. I unplugged the coil.. knock didnt change. I even ran it with the plug out.. knock still idnt change. I would guess this rukles out piston slap?

 

Can you take some pics? I would like to see what the cam looks like. Frams are known for breaking apart internally and sending debris through the oil galleys which eventually plugs the orifices to the heads. You could have a bad chain tensioner causing oil pressure to bleed off and not pump up the lifters.

 

I am thinking about taking off the valve cover this weekend, whats a good way to check the chain tensioner and oil galleys to make sure there not worn or plugged up.

 

The orifices are in the front cam cap on the driver's side and the rear cam cap on the pass side. Pull the caps and look for debris in the passage.

 

I plan on doing this Saturday. my friend said put some Lucas oil stabilizer, or slick 50 in and see if it quiets down the valve train or the cause of the problem, should i try it?

I wanna figure out the problem before going into the engine but its getting harder and harder :/

 

Ive checked the oil galleys. No debris. Blew it clear with air. Stil knocking.

 

Hopefully I can revive this thread and hear a few more opinions cause it still has me stumped. I called to work first of the month and just got back this week so the truck sat for a while. When I first started it up I got a couple codes, 0351 and 0201. Im pretty sure this is an unrelated issue to my tapping. Cleared them and they havent been back since.

So for an update, I replaced the front four HLA's and followers with no change in the sound. I have removed all lash adjusters and followers numerous times checking for flat spots or anything that would cause a tap and nothing. Inside the cam cover is very clean with very little varnish and zero sludge. It looks like a motor with 100000km should look.

Yesterday I spent atleast an hour listening to all parts or the engine with the stethescope. The sound is definatly most pronounced on the second and third valve cover bolts from the front, top and bottom. Maybe just slightly louder on the bottom. No sound at all from the oil pan. Barely audible from the bell housing. One thing new I did notice is that the sound can heard quite loud on the intake tunnel for #2 cyl.

This got me thinking so this morning I did a proper compression test on the right bank. Heres what I got

#1- 130psi
#2- 128psi
#3- 160psi
#4- 157psi

Not good eh? Afetr seeing the results I drained the oil off and strained it through a rag. Zero metal particles or dirt of any sort but when i stir the oil with my finger it turns just slightly milky. Has anyone ever heard telll of a bad head gasket causing a bad tapping noise? I cant see it. Regardless, i wioll tidying the garage tonight to prepare for tearing things apart.

Does anyone have any suggestions or experiences with these types of symptoms? I certified and experienced on marine diesels but this is my first mod ford ive worked on.

I will be posting a video of the tap as soon as i find my camera. Its hard diagnose a sound without hearing it. Thanks in advance for any suggestions. Also, any tips or tricks for removing the cyl heads would be appreciated.

 

I put in a 1q. of Lucas oil stabilizer and it masked the noise, i can hear it for like 1-5 sec each time i start the engine. I am forced to believe that is the lash adjusters, or at least something to do with the valve train.

Sorry i can't help you problem, but would love to figure out the problem and find a solution for you and me both!

 

Here is a video of the tapping:


MVI_0238_zps1e224221.mp4 video by timbo670 - Photobucket

 

I started the tear down today to change the passenger side head gasket. Thisis definately avery time consuming job. I managed to get as far as the timing case tonight. The timing chain was a suspect of my tapping but there is zero wear marks or broken parts inside. I did notice an extreme amount of slack in the drivers side chain. Im not 100% on how much is to much but something doesn't seem right to me. If the chain was causing the tapping i would think there would be chaffing or marks on the guides? The guides are like new. Have a look and tell me what you think.



MVI_0256.mp4 video by timbo670 - Photobucket

 

The slack is normal and caused by the cam trying to turn from an open valve and pushing all the oil out of the tensioner. It won't cause the engine to jump time. As soon as it starts oil pressure will tighten the chain up. That noise almost sounds like the piston is hitting the head or possibly the crankshaft counterweight. I wonder if it had a failed injector that hydrolocked the engine and bent a rod. I would definitely pull the head and see if all the pistons come to the top of the cylinders. Good luck.

 

The cylinder head is off and there is still nothing obvious as to what is causing the tap. Head looks good. I haven't pulled all the valves yet to check for bent ones or check the guides but everything looks good. Ill be pulling the oil pan tomorrow and if there is nothing in there I dont know where else to look.

 

I pulled the oil pan today and here is what i found in the oil pick up



Does anyone recognize this or know where it may of came from?

I would imagine this would cause a serious decrease in oil volume coming from the pick up. As far as the rest of the crank, im very impressed with how clean everything is underneath. There is no marks on anything as to were something would of been tapping. There is no major play or slop in any of the rods or piston pins or pistons. It is a hard spot to reach but i cant manage to make anything move with the three fingers I can grab the rod with. Ill post pics of the crank later.