Nathan Long

I really hope you guys have some ideas.

I recently bought a 1997 f150 Lariat with a 4.6 and 200k miles. I got it cheap because of a clicking noise it was making. The truck seems to run great but it makes a noise that sounds similar to a baseball card in a bicycle spoke that is constant and speeds up with RPM. The lady I bought it from said the local Ford dealership had told her it was a "bad lifter".

We have tried everything we can think of to isolate the noise and nothing has worked.

Here is a list of everything we have tried.
Replaced the
Timing chain
Timing chain guides
Timing chain adjusters
Oil pump
Water pump
Spark Plugs

We have checked every valve lash adjuster and replaced all 8 on the passenger side (I'm not sure why, but non of them held pressure. You could push them all the way in and they did not pop back up.)
All of the rockers look good and the cams do not appear to have excessive wear.

I thought we had it, but after I put everything back together today, the noise was still there.

Did I miss anything? Where should I look next? Searches haven't turned up anything that seems promising.

I'm running out of things to check, so any suggestions would be welcome.

Thanks,
Nathan

white89gt

"Clicking noise" is pretty vague. You should really upload a video.

Nathan Long

Thanks for the reply! I'm waiting on a new phone to arrive and I can make a video then.

Honestly, it sounds like a bad lash adjuster. But we eliminated that possibility this weekend. It kind of sounds like a bad timing chain guide, but I replaced all of that.

I found a video that seemed like the same scenario last night. The guy figured out it was a cracked flex plate. Is that a reasonable direction to turn?

akdoggie

Did you clean the oil pump screen when you did the chains and oil pump? You could be having oil restriction starvation to the adjusters. If it's a 4x4, it's a simple pan and front axle unbolt. I'd be checking there.

white89gt

Did you put the tensioners on the correct sides? They are oil charged... and they are marked with a R and an L for right and left. BUT, the drivers side is left.

Nathan Long

I did make sure the tensioners are on the correct sides and had my father in law double check me.

We did not drop the oil pan to check the oil pickup, but we have verified that oil is getting to the adjusters. We also took each rocker out at a time to see if it made any difference in the sound. Same sound no matter what we do.

akdoggie

A cracked piston skirt can also cause that lifter tapping sound. Had a 5.8 that wouldn't quiet up, only to find a cracked pin skirt. New piston and no more noise. I hope you don't have to go that deep into it. Remember that modular's can have a lot of piston slap in certain conditions. I hope you can isolate the noise.

lonestarjeff

I've had a similar noise that started back last November on my 2000 F-150/4.6 & I went through a similar list of repairs & replacements you described. One thing mine was doing you didn't indicate on yours was the tapping would stop when the engine was up to temperature. Mine is definitely one particular cylinder on the right side, but it's hard to replicate long enough in the driveway to nail it down to the exact cylinder. It only occurs under transmission load. Only explanation I've been able to find so far that fits the "tap going away when hot" scenario is a worn piston wrist pin. I'm no expert in metallurgy or pistons, so I don't know if it's the answer or not. The story goes like this: cold engine there is just enough wear on the wrist pin to create space between pin & bearing; hence the "tap" on each stroke of that piston. As the engine heats up expansion of the parts closes the wear space just enough to diminish the noise.

I've been driving the truck some since it started the noise, mostly one to 2-hour trips with no problems. Ironically, my gas mileage has increased about 15%(maybe that's the new COPs). I noticed on the last trip for the first time I was starting to hear tapping at low rpm after it was up to full temp. I assume whatever it is will continue to get noisier until it lets go completely.