Jeep Grand Cherokee 2001 knocking noise

My 2001 Jeep Grand Cherokee 4.0 straight 6 was running perfectly. I parked it up and locked it. I left it for 10 minutes came back started it up and this knocking sound instantly was there. (in this video it is important to know that there is wind hitting the microphone, the engine, oil pressure, oil level and there is no shuddering or smoke. Everything about the car is running normal. just this annoying knocking noise).
I have looked at the valves, (had the rocker cover off) I have also taken the belt off to cut out the possibilities of this knocking coming from the water pump or alternator or air-conditioning.
I just want to see if anyone else has had a similar sound coming from the front of there car. (we had a stethoscope on and around the engine, the knocking was at its loudest on the exhaust manifold right at the point where it joins the engine. I have been advised that this doesn't sound like a rod or anything to do with the performance. BUT! im still open to suggestions.
There is a small list of things I believe it could still be:
1) Timing chain tensioners
2) Flex plate (cracked or loose)
3) Vacuum hose
4) heatplates rattling

Also I just wanted to add that when the revs go up to around 2000rpm, the 'knocking' fades out, but not completely.

I appreciate any comments.

Category:

Autos & Vehicles

Tags:

• engine
• automobiles
• Flex
• plate?
• Vacuum
• hose
• heatplates
• rattling
• Timing
• chain
• tensioners

[hondaride20012000]

mine did the EXACT same thing. Broken piston skirt laying in the bottom of the oil pan. This is very common, the other thing is the wrist pin as someone else mentioned. Either way, the motor is on its last legs. If you are going to rebuild this motor, don't damage it by running it like this.

[jemaguy]

I have a 2000 Cherokee Sport...doing this same thing, I pulled the engine....This NOISE is from the Wrist pin..............SORRY TO BE THE BEARER OF BAD NEWS !!!!  The Engine WILL BLOW

[vipalffy]

Our Jeep 2001 sounds exactly like yours!!!!We just changed the oil and oil filter (10W30) it was ok, and next day when we start the engine we heard a loud ticking noise. When accelerating and reach approximately approx. 50 miles/hour the noise is less noticeable.The noise is louder when the engine is cold and it is less noticeable with warm engine and hires speed. Do you have find out what caused that or any idea what that can be or caused that noise? Your help is greatly appreciated. Thank you

[mikemaz420]

I had a sound like this in my 98 grand Cherokee, it ended up being the water pump hitting something. Maybe that?

[AnOm75]

Did you actually resolve this? It sounds like a leaky exhaust manifold or gasket. I'm familiar with the sound. You can hear it puffing a bit. It's also consistent with your observation that the sound comes from the manifold area.

[TheLonetreecreations]

Bad lifter



[mrnashjr1]

sounds like my jeep so after I pulled the moter I had 3 piston broken and 3 had small cracks so new piston's same rings thou ran just like new still driveing it been over a year now

[pbartolomeo05]

Sounds like a manifold leak.

[MikeM8891]

bad hydraulic lifter

[jakenos87]

sounds like a bad lifter to me