Engine Knocking / Ticking


dom.robles

New Member
Joined
Jul 4, 2020
Messages
12
Location
Orange county
Ive been noticing lately that my 99 TJ has a knocking or ticking going on immediately after startup and at idle whenever i come to a stop. It doesn't seem to happen while the engine is at speed but it does however put off a terrible screech/rattle at higher rpm's. Originally i thought I had a rod knock but after some research i found that these 2.5's had a pretty common issue with the valve train. I may have a stuck lifter or maybe need to replace the pushrods and rocker arms (hopefully). I have some videos coming soon of the sounds that I'm experiencing but for now I hope someone may have some insight for me. Also, when idling cold, it runs a little rough and at times the rpm will drop and send some vibration through the cabin, idk if that may help with a diagnosis. This is really the first car I've had to work on myself so I still have quite a bit to learn and not much experience with funky sounds. I know i may need to do a compression test or remove the sparj from each cylinder to identify a piston or rod issue but i dont have those tools and im hoping i could pin point or narrow down my optione before i go digging. Thank you al so much in advance i greatly appreciate any input you could give me!
 

Attachments

  • F56565D5-289F-469E-BD84-B0B217606FB2.mov
    6.2 MB · Views: 0
  • 7284ADAC-061F-4259-B2ED-500439F9F03F.mov
    14.3 MB · Views: 0
OP
dom.robles

dom.robles

New Member
Joined
Jul 4, 2020
Messages
12
Location
Orange county
Doesn't sound healthy. Change the oil and look to see what the old oil looks like coming out.
i'll do that tomorrow i think. I'm thinking about dropping the oil pan and checking out the rod bearings and lifters while im down there. maybe i'll take a look at the timing chain, do you have any other ideas?
 
OP
dom.robles

dom.robles

New Member
Joined
Jul 4, 2020
Messages
12
Location
Orange county
Today I pulled the valve cover and checked for loose valve train components I pushed around the rocker arms and the bridges and found no exceptionally loose parts. i was able to twist all of the pushrods that were not under pressure and I could tell each rocker was getting sufficient oil flow through the push rods as each one was filled with oil and continued to flood when i ran the engine without the cover (kind of a mess but i thought it would be necessary to rule out top end valve train issues). I also pushed down on the rocker arms on the push rod side because i read that i might be able to tell if the lifters were bad/leaking if they sunk down which none of them did. I decided not to pull the rocker arm bolts and check the lifters because i didn't have the proper torque wrench to put them back into place but everything seemed sound. This is leading me to believe that i may have an exhaust leak somewhere or i'm experiencing rod knock or piston slap, although i don't know if i fully ruled out lifter tick which still could be the issue i suppose. I also drained the oil today which was quite dark i would think it hadn't been changed in awhile and i replaced it with a conventional 10w30 and let it idle for awhile followed by a short drive. I listened to the idle after the drive and the knock was still there but i personally think it was quieter, i asked some of my family members and they told me it sounded the exact same to them so maybe that is wishful thinking. I'll attach that video to this post. Tomorrow im gonna cut open the old oil filter to see if theres any obvious metal scraps that didn't get stuck in the pan. i'll keep u guys updated, and once again would greatly appreciate anyone who has more insight!
 

Attachments

  • A4D1EA7C-2FF2-4D10-BCA8-528EA9701114.mov
    434.4 KB · Views: 0
  • 4273C5F1-F9D1-44C7-B4E7-64D801F13E22.mov
    5.8 MB · Views: 0
  • 01E7F582-9E97-41B9-9D25-D0345B344BF6.mov
    12.1 MB · Views: 0
  • Like
Reactions: Skylinessuck

Chris2004

New Member
Joined
Jul 2, 2020
Messages
19
Location
Los Angeles
My 2004 4.0 was idling rough with a tapping so loud you would swear it was rocker arm or push rod related. Even a mechanic diagnosed it from inside the garage as I pulled in. Turns out the coil pack electrodes were fouled with dielectric grease and producing weak spark. My new motto is take apart everything, clean and inspect.

I also replaced the spark plugs and injectors on my quest to solve the issue. Plugs are cheap and the injectors were Bosch units that were pulled from wrecks.
 
Last edited: