Ticking Noise Identification
 

Hello all,

I've noticed a strange ticking sound coming from my Ranger over the past few days, and I'm looking to see if anyone can help identify the noise.

I have a 04 XLT with a 4.0L SOHC and about 139k miles. I keep up with the maintenance and keep it very clean. I just changed the oil about 500 miles ago, and the levels are still good. The sound seems to be coming from the top of the engine on the passenger side. I have a small leak coming from the valve cover gasket that I'm planning on fixing in the coming days. The leak has been there for a while, but doesn't leak enough oil for me to add oil between changes. I've replaced the timing chain tensioners at 99k miles and haven't needed to do too much engine work since.
Since the sound is more noticeable towards the top of the engine, it leads me to believe it's possibly valvetrain or lifter/rocker related. I noticed it very faintly the first time a few days ago, but it's been getting louder, and I wanna do something before I have irreparable damage. I've attached a sound file after driving for about 20 minutes with a warm engine. The first part is recorded above the engine and then in the wheel well. The noise is more noticeable when first starting the engine and at idle (at a stoplight or at the end of my drive), but once I get on the gas, I tend not to hear it anymore. Any feedback would be helpful, I hope it's not too late haha.

Thanks!

At least it doesn't sound like recordings of bad timing gear posted here.

There's an odd rhythm to it.....possibly that of one valve? Maybe it's a bad lifter?

Are you the original owner? If not, when and at what mileage did you get it and what kind of shape was it in?

I'm not the original owner, I bought it in 2021 with 92k miles. CarFax came back clean, and the previous owner had it serviced every 5k miles. The previous owner was an older man in Miami, and I got the truck in really good condition. I think it's strange there's a rhythm to it. I watched a few videos online and haven't been able to find anyone with a similar sound. Under the wheel well, I believe you can hear the timing chain riding up against the track, but I don't think that is a concern.

I think it kinda sounds like one valve opening and closing, or maybe even a lifter on the rise and return down, but I can't tell for sure.
Another thing that might be worth mentioning is sometimes after a drive, I put the truck in park, and it will idle down really low, then catch itself and return to a normal idle. It's never completely died after putting it in park tho. This happens in the span of about a second or two and not very often.
Another thing I can mention is when accelerating in 2nd or 3rd gear(not sure which one off the top of my head), if im about 70-90% throttle, The RPMs will struggle around 3-4k and it boggs down about 500 rpms, then they will go back up and will shift to the next gear. It's something that always kinda happened, and I never put much thought into it, but it might come into play here.

I drove the truck this morning after it cooled overnight, and it didn't have the sound at startup. Even after driving about 20 minutes, it still wasn't making the sound. It seems to kinda be come and go, but I also didn't sit and listen very closely after my drive.

Just a thought on the noises.
What kind of oil do you use? I can't throw oil chemistry at you, but there are attractively cheap, deficient oils out there.
Maybe a change to a known, good, affordable, available oil like Castrol 0W-30 or Mobil1 0W-40 would help?
There are many other very good oils. I typed Castrol and Mobil1 as they are readily available.
At this time of year in Fla., you could use a 10W-40 without concern.

Re the low-and-recovering idling:
I'd check for vacuum leaks. Remember, the PVC system's big "L" shaped plastic pipe can crack.
Also check the IAC for proper operation. Replace with a Motorcraft or Hitachi ONLY as others do not work.

Re "accelerating in 2nd or 3rd gear...struggling...bogs down to 500rpm..."
Could be vacuum leaks or weak fuel pump. Test it for output pressure.

Also check the TPS for proper functioning. A worn one can mess with shifting.

Q: Ever cleaned the MAF? Use real MAF cleaner as many electronic cleaners contain a lube.
Q: Is the throttle and intake clean?
Q: Do you use it locally only? Does it ever see long trips?

I usually use Mobil 1 5W-30 full synthetic. For my last oil change, I used Amsoil and tried to get my hands on it again for my most recent one, but I couldn't get it in time.

I'll look into the vacuum leak stuff. I can hear a very faint, high-pitched, continuous squeal noise, and it's always been there. I assumed it was a vacuum leak but could never determine the location. I already replaced the PVC valve at 92k miles when I first got the truck, so I don't think that's an issue. What is an IAC? I can look more into that as well.

I've never cleaned or really looked at the MAF sensor. I believe the throttle is clean, could be a bit dirty because I do some light offroading every now and then, but it's been a few months. Yes, I only use it locally. I've always been too worried about long road trips. Furthest I'll take it is about an hour or two, but that doesn't happen very often.

Keep whichever oil clean.

Faint high pitched squeal SCREAMS vacuum leak. Unhoop the fan belt and start the engine. You gat over a minute to listen in silence.

IAC means Idle Air Control valve. It sets atop the air handling tube just before the throttle body and is what controls idle speed.
It's small and easily removeable. I bought a replacement gasket when I removed mine -to examine and clean it- but the original was just fine.
At idle, unplug the IAC and the engine should stumble and even die. If it runs on, you got a vacuum leak.

No maintenance records? Maybe change the gas filter? Mine had weird black tar in it. I'm glad I changed it at 15 years of age. Yours is older.
" " " ? Ever do trannie maintenance?
PCV fumes are introduced to the intake, so yes, the throttle body can become dirty. Examine, clean as necessary.

Did you PCV have the heating yoke on it (1/4" pipe)? Do you wrench at all?