Hey everyone.
I have a 2000 d2 4.0 with 62k miles on it. I've had it for a year and run synthetic oil in it for about 11k miles. I'm running a K&N oil filter. 20w40 Castrol Syntec
Recently, in the last couple thousand miles I get a knocking noise. At first I thought it was exhaust leaking as it was not a sharp rap but lately it increased in volume somewhat. Not real loud but more noticable by me.
On start up and idle the engine sounds fine, when it's put in gear the noise increases and when I start to move I start getting the louder, I hate to say it, metalic rap.
I was thinking connecting rod since it happens under load but the noise goes away after running under load for a few seconds which sounds like a lifter.
I'm running seafoam in the oil to see if it frees anything up.
The noise isn't always consistent either. Some days I'll get the rap, others I don't.
If it is a rod, can I get away with just changing the bearings for now? I know it's cheating but I really can't afford a tear down. If it's a lifter what is best to free it up.
I need to change out an engine mount, maybe it would be a good time to open up the sump and check the oil pick up tube
Thanks guys, unless you just want to boost your post count by flaming me, then :flipoff2: !

I had a real bad knock. Sounded just like a rod was going to let go. It was a bad cat!

I had a real bad knock. Sounded just like a rod was going to let go. It was a bad cat!
Was it consistent, or did it come and go? My noise is mostly right after start up especially when it's cold. That's what makes me think oil problem. How did you find out it was you cat?
My ex had a cherokee with loose flywheel bolts that I'll check, I just thought of that.

It would come and go. It finally started knocking when I was wearing the right clothes. I just laid under the truck with the engine running and it was clear as day that the sound was coming from the cat.

bad rocker arm?

hydraulic lifter? take a look at that, maybe it's leaking. i've heard of weird noises coming from having a bad lifter.

have you been putting in 90+ octane in it, and then suddenly switched to 80+? were you in baja and put in leaded gas by accident? :D

oh the joys of pushrod v8s

i think the sound Old Scout is referring to is the "marble in a plastic cup".. the honeycomb bounces around in there sometimes if the cat(s) is/are shot. rap on the cat with a rubber sledge or something, see if you can reproduce the noise

switching to synthetic can get tricky if not done properly (not taking anything away from you, but it happens a lot)

bad rocker arm?

hydraulic lifter? take a look at that, maybe it's leaking. i've heard of weird noises coming from having a bad lifter.

have you been putting in 90+ octane in it, and then suddenly switched to 80+? were you in baja and put in leaded gas by accident? :D

oh the joys of pushrod v8s

i think the sound Old Scout is referring to is the "marble in a plastic cup".. the honeycomb bounces around in there sometimes if the cat(s) is/are shot. rap on the cat with a rubber sledge or something, see if you can reproduce the noise

switching to synthetic can get tricky if not done properly (not taking anything away from you, but it happens a lot)
Please explain to me the proper way to switch to synthetic. :rolleyes:
Rocker arm? Maybe.
How do I look at a bad lifter?
Didn't switch octane rating or done any baja driving. Deserts are very limited in VA.
I don't think the cat noise Old Scout was refering to is the loose inside thing and I've been all over the bottom with a mallet chasing another noise I'm having problems with.
Thanks for the reply.

no need to get testy. switching to synthetic can wreck seals on higher mileage cars that havent been runnin synthetic thats all--different chemical compositions. whatever, i'm sure you knew this. im no chemist

im new to rovers and the rover v8, and basically my disco is sitting on blocks as i totally take it apart :D so take any advice i try to give with a grain of salt

if you do think its valve lifters, check them to see if there's wear or they're really dirty or whatever, i can draw you a map if you want :flipoff2: hint: under tappet

while you're doing that check out the rods too for any damage, and cams/timing gear.. just for fun.

You are running 20w40? Is it really hot where you live? What is the recommended visc. for that engine? I had a problem with a Jeep GC with the 4.7 sounding like it was going to come apart. My goofy brother had put castrol 20w50 in it. Switched back to 5w30 and it ran fine. I do not know if the 4.0 is sensative to oil viscosity, but it is worth a shot. I work for a oil company (I crunch #'s, little about the rest of it) I listen in to several of the claims filed by people ruining engines because of running the wrong oil. Best of luck.

Is it just me, or is this thread starting to sound a lot like Dweb ??

I was running 5w50 and still got the noise on start up.
Cherub rock, if you read you will notice that the engine is not disassembled nor do I want to disassemble it. Read the initial post again.
I've been running synth oil in cars for years and have never had the mythical and/or old motor problems that people used to have when these oils first came out.
What I'm looking for is someone that has experiance with this engine and may know of any common problems and solutions, not "tear it apart :flipoff2: and see what's up". If I have to do that I'll get a used low mileage 4.6 and be done with it. It would probably be cheaper in the long run.
Thanks for trying to help.

Is it just me, or is this thread starting to sound a lot like Dweb ??

Took the words right out of my mouth :flipoff2:

(I'm gonna get banned again)

Took the words right out of my mouth :flipoff2:

(I'm gonna get banned again)
At least on dweb they didn't tell me to "look" at my lifters. :flipoff2:
Actually, i think your post on dweb have been very helpful to all the great un-knowing like me.
So, any suggestions?

i guess i assumed a certain amount of experience--not to be insulting at all. if you want i can dig up my digicam and ill post some pics of where to look, and what healthy non-brassy looking valve lifters look like... just not now, gotta do some homework :(

any im done here, dont want to incur the wrath of the heavy hitters :D

good luck with your probs bro.. if i could just straight up tell you whats wrong, believe me i would!

I KNOW what valve lifters look like. The engine is in one piece and it's going to stay that way.
I've had engines apart and know what they look like inside but, I have to drive this to work in the morning so pulling the lifters out is out of the question.
There have been service bulletins about noise on start up on these motors and I just want to know what LR did for this and if there is a common problem and solution.
If I had my mom's Honda, believe me the sucker would be disassembled on my living room floor as we speak but i don't.
If you read my first post you can see that the engine is in one piece, I want it to stay that way and that I don't want to pull it out of the truck.
Go do your homework before dad gets the belt to you in the tool shed.
I hope part of your homework is reading comprehension. It is on the SATs you know.

You should be driving your mama's Honda, tough guy.

Just take it to the dealership, I'm sure they'll get you to the office in no time. Stop off at Yuppie Joe's Wash'n Wax for that nice parking garage shine.

Look at that, my youthful proclivities have somehow conjured up a clever rhyme.

Jerk off. :flipoff2:

Looky here a post count bout.
Cherub you should have given up on this guy after a couple rants, he no likey you.

Could you maybe have a camshaft shifting in the timing cover? Oh wait I didn't read your first post well enough so disregard my thoughts.

JP

Looky here a post count bout.
Cherub you should have given up on this guy after a couple rants, he no likey you.

Could you maybe have a camshaft shifting in the timing cover? Oh wait I didn't read your first post well enough so disregard my thoughts.

JP
Don't know. I guess it is a possibility. I'm just hoping to eliminate all possibilities before the engine needs to come out.
I know it's hard to trouble shoot over the internet so I'll give it up.
I'll need to change my valve cover gaskets soon so at least I'll get a look at the top end.

I'll need to change my valve cover gaskets soon so at least I'll get a look at the top end.

With 62K miles, you shouldn't be having any of these problems. If you must pull the valve cover gaskets, contact me as I have a plenum gasket I do not need and the vendor (who sent me the wrong part) won't take it back-I'll make you a deal on it :flipoff2: I also have a throttle body gasket and one of the plenum deicer hoses if you need those too.

When you pull the valve covers, grab ahold of each rocker arm and try to rock it as it would when doing its job. If one (or more) seems loose, this might be your problem although I have never heard of it happening on a Motronics engine.

I have had several situations recently with noise from the exhaust that sounded like something much worse. Two were from busted flanges at the manifold and one had the seam around the round cat, completely busted! A coupla minutes with the MIG (and a coupla hours getting the Y-pipes off) and thenoise was either gone or severely reduced.

Thanks PT. I'll let you know about the gaskets. Aww hell, just e-mail me what you want for them, I'll have to do it sooner or later. wdent@yahoo.com
Thanks. I don't know if I mentioned it in my first post but I also need to replace an engine mount. I'm wondering if this is causing a mis-alignment with the exhaust. I'm groping I know but what the hell?

Thanks. I don't know if I mentioned it in my first post but I also need to replace an engine mount. I'm wondering if this is causing a mis-alignment with the exhaust. I'm groping I know but what the hell?

Ahhhhh - engine mounts.

Yes, severe collapse of one of the engine mounts could break or crack a manifold flange or cat pipe. Actually, collapse of the drivers side (NA) mount drops the manifold right down on the frame rail and could cause vibration that might sound like valvetrain badness.