Engine Knock/noise
 

Hey All...posted a few times on various threads about this engine knock I have...I was under the truck tonight to measure the drive shaft for replacement. Truck was running and i could hear the noise under the truck clearly. It sounded like it was coming from the oil pan/transmission area, around where the circle with the three bolts is. There is also a single tube that goes in there(not a mechanic so not sure what that is). Also from there it didn't sound like a knock so much as something rubbing????

Any ideas on this, as i have said before I can't find a mechanic that will work on this truck around here so outside of the dealer my options are limited. Any insight would be appreciated.

Thanks

Does it make the same noise when you put it in gear?

hmmm...
 

The noise is constant at idle although it seems to go away at cruising speed. Might be because all the other noise is drowning it out. It gets louder when you accelerate...

what kind of gas have you used?

I use 93 from Valero...not sure what was used before, I have only owned the truck for 5 months.

Back under today...
 

Got under the truck again to today to replace the Bank2 sensor and checked the noise again. Its there at idle and then when you put it in gear it gets louder. Any ideas what this could be...ran it through all the gears and everything seemed smooth...as it gets warmer it gets quieter but when you accelerate its louder.

Any insight would be appreciated....

Glad I have a day job...
 

So here is the video of the knock, you can also here the very loud tick I have as well. The car is still warm so its not as loud as it is when driving the car cold but please let me know on either sound. It gets louder when you put the car in gear...

As always any advice appreciated.

http://www.youtube.com/watch?v=KGbEZNC34xI

How is your tranny fluid level?

Sounds like something grinding hmmmm I have never taken one of these trannys apart so it's hard to say what it could be. That grind noise is definitely coming from inside there though.

Maybe do a flush and add a new filter. You prob will not be able to see anything with the pan removed that would lead to the problem, I bet its up higher.
________
Big dick video

That sounds EXACTLY like my noise. Let me know what you figure out.

You could poke around with a stick with one end to your ear. Maybe you can pinpoint better the source of the noise.

François

RegT - did you ever find out what caused this noise in your D2?

Great great video.
You caught the noise
That noise is always around when you FIRST start the truck in the morning.
With the engine DEAD cold.
BOTH my Discovery I and my Discovery II make that exact noise.
Goes away in about 3 minutes.

Listening to it - may be pre detonation or pinging in the cylinders.
Because - the noise ONLY happens upon acceleration or on the increasing end of the RPM when you are going from low to high RPM or revving the engine from low to high.
This is the ONLY time the sound happens.

For this sound to even happen at all:

1) First thing in the morning.
2) Engine revs from ldle to 1,500 RPM or so.

Once the engine gets to 1,500 RPM - noise gone.

My Discovery I has this noise very morning for the past 12 years.
It is still going at 165,000.

My Discovery II has it at almost 100,000 miles.

Discovery I has GEMS
Discovery II has Bosch.

So to have both of those pre detonate at startup is unlikely.
Plus to pre-detonate you need a lot of heat already in a hot engine.

Still - if the timing is advanced ..
Would be interesting to put a mark on the harmonic balancer in chalk or paint
and see if the timing changes greatly when this noise is present to when the engine heats up.

Sort of a rapping noise. Has the sound of a clattering piston.
IF the engine is really cold - will the piston clank in the bore just a bit to make this noise?

If this is true, the noise will be extended in the winter - around 20 degrees or so.
Does not get that cold ever where I have owned my Land Rover.

This may be also called piston slap.
Other vehicles have it too

The infamous "piston slap"

Summary

• Description: Clicking, tapping, or knocking noise eminating from the engine after a cold start. The noise lasts until the engine is warmed, usually 5-15 minutes. The sound may be heard in the passenger compartment.
• Affects: 2.5L DOHC engine, particularly from 1997 to 1999.
• Diagnosis: The pistons are engineered for operation at temperature. In an effort to save weight in the engine, the piston skirts were shaved down. When the pistons are cool, however, they do not have sufficient contact with the cylinder to keep from 'slapping' or rattling against the cylinder sides. At temperature, due to thermal expansion, the pistons match up properly with the cylinder and do not rattle.
• Reported solutions: In some cases, SOA has rebuilt the engine short block, while in others SOA prescribed "countermeasure pistons" with longer skirts that do not slap. Most dealers will initially state the sound is "normal."
• Detrimental effects: SOA has said that the noise causes no engine problems or abnormal engine wear; Subaru engine expert CCR Engines of Colorado has said that the engine may experience a 10% reduction in life.

That was, in fact, one of my guesses - piston slap, when the cold piston is knocking in the bore because it has not yet fully expanded with heat to close the gap between it and the steel liner (which expands with heat at a different rate).

Mostly, however, I'd just love the original poster to follow up on this to let us know what the cause of the noise ended up being. I can't tell you how many threads I've read where I want to know the outcome. I see reply after reply after reply, and I think..."great, the answer will be in the next reply!" And then the discussion ends. It's like hearing a great joke, and then the joke teller leaves before they get to the punchline!

PLEASE - if you ask a question and your problem got resolved, come back and let everyone know what the cause and solution ended up being!

This video claims to diagnose piston wrist pin knock..

This knock sounds a bit like the Cold start knock we get..