Knocking noise

[landroverisbroke]

I have a 2003 Landrover Discovery II that had a loud knocking noise coming from the engine so I replaced the gears in the oil pump and while I was there I replaced the water pump.

After finishing my repairs I started the engine and the loud knocking noise that seems to be coming from the top of the engine remains.

Has anyone had this experience and know what the problem is and how to fix it?

Thaks,
LandRoverisbroke

 

[Disco Mike]

Sure, many have. The question for you is how many miles on the engine, did you do an oil pressure test first, when does it make this noise, hot or cold, did you inspect the crank bearing for wear and is it a knocking sound or a ticking noise?

 

[landroverisbroke]

Thanks. 2003 Disco II has 142,000 miles. Did not do an oil pressure test, but when I removed the old oil pump gears, the outer (big) gear was broken cleanly in two pieces. The noise is a loud metallic knock, rpm dependent and begins immediately when engine starts, then goes down a bit as rpm decreases at idle. Hot or cold. Have not looked at crank bearing. I have an audio file (.m4a), but doesn't look like I can attach it to this thread. Replaced head gaskets at about 136,000 miles and it ran just fine until a week or so ago when this loud noise just sprang up one day. Never overheated, just sounds like two major pieces of metal hitting each other.
Thanks,
Landroverisbroke

 

[Disco Mike]

So, if it were mine, I would check the oil pressure, cold at idle and 2000 RPM's and agin when hot at idle and 2000 RPMs. Then depending on the results, I might check the crank bearings for wear and if good, tear into the valve train.
Might want to look at the sticky I posted on both the LRO and the LRD, at the top of the D2 section regarding head gaskets and valve train noise.
If you have any questions, send me your number and I'll be glad to help.

 

[BrianH]

I have a similar situation. 2003 Discovery II with 115,000 miles. Oil pressure light came on at idle and I read about the oil pumps so I replaced the front cover with an almost new one. The guy at the LR service shop had one that he had on a Disco for less than a day and gave it to me for a good price since I only wanted the gears in the first place.
Took the other one off and found it to be broken into 4 pieces. Replaced with the new one without opening it to be sure the gears were in order and put it all back together. I also had to replace the o ring on the strainer with a similar one from Autozone because it was the weekend and you can't get genuine pars on a Sunday.
Now the oil pressure light comes on after a few seconds at start up and stays on unless its above 1500 rmp. As much as I don't want to, I feel like I should take it back apart and check out that o ring on the strainer and if it looks ok check the oil pump gears to be sure they were new.
There has also been some intermintant ticking in the engine when it starts up as well.
Any advice before I crack it open?

 

[BrianH]

Low pressure after oil pump change 2003 D2

I have a 2003 Discovery II with 115,000 miles. Oil pressure light came on at idle and I read about the oil pumps so I replaced the front cover with an almost new one. The guy at the LR service shop had one that he had on a Disco for less than a day and gave it to me for a good price since I only wanted the gears in the first place.
Took the other one off and found it to be broken into 4 pieces. Replaced with the new one without opening it to be sure the gears were in order and put it all back together. I also had to replace the o ring on the strainer with a similar one from Autozone because it was the weekend and you can't get genuine parts on a Sunday.
Now the oil pressure light comes on after a few seconds at start up and stays on unless its above 1500 rmp. As much as I don't want to, I feel like I should take it back apart and check out that o ring on the strainer and if it looks ok check the oil pump gears to be sure they were new.
There has also been some intermitant ticking in the engine when it starts up as well.
Any advice before I crack it open?... again.

 

[Disco Mike]

Does the engine make any noise when the oil light comes on? I would do an oil pressure test to see all 4 pressure readings, if they are OK, then I would replace the oil pressure sending unit next. Let us know what you find.

 

[BrianH]

2003 doscivery oil pressure

i dont have an oil pressure tester. the knocking is only when the pressure is low enough long enough to keep the oil from flowing. i got the genuine o ring from LR and it looks the same as the one i installed. I'm still going to check it today. I'm thinking about doing the connecting rod bearings while I'm in there. Is that as straightforward as it seems? do i need to measure or just get regular size ones? if i take the front cover off again, i will do the timing chain and gears. there was slack in the chain, but i don't know enough to say if it was too much slack or the normal amount.

 

[Disco Mike]

Before you tear into to it, if you are interested send me your number and let me walk you thru things to do/check.

 

[BrianH]

update... the strianer o ring from autozone was the problem. when i pulled the strainer tube out the o ring fell out. split down the middle. i didnt think it would make a difference, but now i have pressure and all is well.