[Dubai335i]

Hey Guys

Was running some serious high speed WOT runs earlier and upon slowing down I noticed a horrible knocking sound. I crawled home a couple of miles and switched off the engine. Apart from the knocking noise the engine was not misfiring and no engine warning lights on dash. Initial online research suggests it's an rod issue but can't be 100% sure.

Any ideas please ?

[u2b] N54 Knocking Noise:

[/u2b]


Thx

[MDORPHN]

Spun connecting rod bearing?

Neil

[Dubai335i]

Sorry I'm a complete novice here so no idea.

[135Pats]

Originally Posted by Dubai335i

Sorry I'm a complete novice here so no idea.

He's saying you may have spun, or seriously damaged the bearing(s) that surround the connecting rod to the crankshaft journals. Rare on these motors, but it's certainly happened before so not unheard of by any means.

With that said, I find it really hard to believe that you spun rod bearings, and the motor is throwing zero codes and otherwise is running and idling normally. A bottom-end issue like that would make itself known, it's not subtle damage we're talking about.

I even further doubt you've buckled or deformed a rod. In that case, you'd either have a window in the block and would be vomiting oil, or if the rod never actually let go you'd be noticing more than a knocking sound. It would be utterly unusable.

The youtube videos aren't properly embedded for me, so this is just speculation. Knocking noises are never good though

[///Mposter]

Check your oil level and see if maybe it was a quart low, maybe leading to the bottom end knocking. Pull your plugs and see if they are in tact, maybe there is debri inside like a broken spark plug tip. If there is oil on any one of them or if they are wet from fuel, it could be an injector. But really since it seemed to happen almost immediately, I'm thinking it could be worse and not an easy fix.

[Ingeniator]

Originally Posted by Dubai335i

Sorry I'm a complete novice here so no idea.

Sounds rotational for sure. First steps for troubleshooting. Pull the belt. It will eliminate accessories. If the noise persists it is probably something in the bottom end. You should be able to start narrowing it down with a stethoscope. Run a leak down and see if you have a bad cylinder. Don't rev it until the belt is off. If the belt is off and you can't narrow the noise down I would personally(This is at your own risk) stab the throttle to bring the motor over 2-2500rpm listen to the noise change. It is hard to tell sometimes at idle. Could be a lot of things in the bottom end.

[ferocity02]

You can drain the oil into a clean container and inspect it for bearing material, which usually appears as a powder/small flakes that is gold in color. You can inspect the oil filter for the same thing.

Sounds like a spun rod bearing to me. Or maybe a bad lifter?

First and foremost, check for codes.

[atinybug]

Do these cars have magnetic oil drain plugs? If so, pull that out and see if there's any metal shavings attached to it. If there are, then yea you spun a bearing.

[WedgePerformance]

Doesn't sound good brother. I wish you luck, but more than likely it will need a rebuild or new engine.

[MiniXP]

The easy thing to do is going to be to pull the oil filer and see if there are metal flakes in the oil there.

When my motor died it was the oil there was full of metal flakes. (not sure what happened to my motor still as I have yet to tear it down).

If the motor is does you best bet is going to be finding a motor is a salvage yard. Not many people rebuild these and the one shop local to me that would have quoted me $12k for a full rebuild, not including removing or installing the motor.

[335NJ]

If my engine was making that noise, I'd be pulling the whole oil pan and checking for metal, not just the drain plug. ECS sells a magnetic one, I'm not sure if the stocker is magnetic, if it is I'd suppose it's pretty weak for ECS to sell they're own version.

Hope this gets resolved OP, start with the basics, like oil etc., but this doesn't sound good at all.

We're you at redline for like 10 minutes or something? Did you check the oil level before going out on these high speed runs?

[David1]

Bottom end is done.

[V8bait]

Originally Posted by David1

Bottom end is done.

+1 on the bearings

[Dubai335i]

Thanks for the advise guys. I had the oil change, JB4 tune and DCI added plus the oil filter housing gasket, spark plugs changed all within 3 days of this issue occurring . Before the WOT I warmed up the engine and then had a run. The issue occurred on the first run so wasn't even thrashing for that long. I tried to do everything correctly in prep for the tune however I guess it just come down to bad luck. Main thing is I got home in one piece and it's only a car I guess (well that's what I've been telling myself all day!)

Gonna have to get it checked out and will need to source a bottom end which is easier said than done given where I live.

Thx

[335NJ]

Originally Posted by Dubai335i

Thanks for the advise guys. I had the oil change, JB4 tune and DCI added plus the oil filter housing gasket, spark plugs changed all within 3 days of this issue occurring . Before the WOT I warmed up the engine and then had a run. The issue occurred on the first run so wasn't even thrashing for that long. I tried to do everything correctly in prep for the tune however I guess it just come down to bad luck. Main thing is I got home in one piece and it's only a car I guess (well that's what I've been telling myself all day!)

Gonna have to get it checked out and will need to source a bottom end which is easier said than done given where I live.

Thx

Here in the states you can buy an entire used engine for ~$3,500 on eBay. Check your ebay listings and see if anyone can freight the engine to your address or shop near you?

[tc535i]

might be a lifter issue, not necessarily a complete teardown

definitely check it out and stop running it tho

[Newguy123]

ouch pull out your spark plugs and look at them see if one of them has been smashed....that will tell you a lot more

[Jnat]

That type of knock is normally lower end bearing noise, upper engine noise can knock also but normally is more of a tap type of knock if that makes any sense. That dull loud knock is normally rod bearings. Used motor time. Good luck, sorry!@

[David1]

Originally Posted by tc535i

might be a lifter issue, not necessarily a complete teardown

definitely check it out and stop running it tho

Lifters do not make noise like that even on a big block chevy

[boost junkie]

Think of it as a good excuse to fully build the bottom end and slap on a motive 900 kit.

[FL335]

GL, OP. Let us know what happens.

[N3m3sis]

Originally Posted by V8bait

+1 on the bearings

+1000000. its a bearing.