Engine knock/rattle with video

[cg2002]

My car has just started making a knocking sound. It's most noticeable when the engine is cold. When it's up to temperature I can only hear it with a stethoscope. It's loudest on the side of the block and on the rocker cover up near the distributor. I'm sure it's not good news but does anyone have any ideas of what it could be? The knock started after the oil pump was replaced. It's not the oil pump chain - that's been replaced and the tension is to spec. I'm wondering if it's a small end bearing.

 

 

 

[JerryC]

Maybe I'm missing something, but I didn't hear anything all that unusual in the video. If you think it's linked to whatever you did to the oil pump, check the oil pressure at the sender. If you think it's in the valve train, check the valve lash and go from there. And, don't rule out an exhaust manifold gasket leak.

[halboyles]

+1 on doing a valve adjustment.

[cg2002]

Thanks for the advice. Sorry forgot to mention I've already done a valve adjustment but sadly the noise is still there. It's a knocking noise that's fairly loud and can be heard outside the car on a cold idle but when the engine is warm you can only hear it with a stethoscope. Sounds like whatever it is expands when the engine warms up. The oil pressure is fine now. I don't think it's the manifold as it's not noisier in that area but will take another look.

 

 

[Harv]

Timing chain tensioner?

 

i too think it sound normal. You should hear what my bucket of bolts sounds like with a 304 cam!

 

what did you set the valves at?

 

john

Edited June 23, 2017 by Harv

[Stevenc22]

Agreed, doesn't sound bad at all. Might as well do a valve adjustment and check the timing tensioner for some peace of mind.

[BarneyT]

+1 on Valve adjustment...fresh oil

[cg2002]

Here's a video after a cold start. Valves adjusted to service manual spec. I can't hear anything unusual around the timing chain cover and the exhaust manifold gasket is in good condition. I'm hoping it's not a small end bearing. I had the block rebored about 10 years ago and I'm thinking they missed out the small end bearings when putting it back together. Apart from the knock everything runs perfectly for the first time in about 10 years. I don't really want to start tearing it apart again.

 

 

 

[Mike87]

It kind of sounds like piston slap. That also explains why it goes away when warm.

[cg2002]

It could be piston slap. Maybe the rebore wasn't done right.

[PaulTWinterton]

53 minutes ago, Mike87 said:

It kind of sounds like piston slap. That also explains why it goes away when warm.

 

+1

 

Don't sweat it.  With the re-bore, did you replace the pistons?  And how many miles/K in 10 years?  AFAIK, piston slap occurs because of wear on the leading face of the piston and cylinder wall over time.  As the engine heats up the gap reduces and the slap dissipates.  

 

Just make sure you let the engine warm up completely before you push it too hard.

 

As for valves, I've heard the statement "loud sewing machine".  If the valves sound like that, then you've done it right.  

[cg2002]

Yes new over size pistons with the rebore with only about 20k since. Top end sounds like a loud sewing machine just as it should except up near the distributor where the knock is loudest. I was hoping it was the oil pump chain as that was flapping around before I put a new one on. I'm thinking of taking it up to Jaymic to get the bodywork done and a respray at some point so if that happens I'll ask them to poke around. 

 

Here's another video...

 

[PaulTWinterton]

Is the engine still cold in the last video?  If so, I wouldn't worry as long as the sound dissipates once it's warm.

 

Double check your rocker clearances as well.  If one is significantly looser than the others it will also be louder.

 

Your engine appears to run smoothly.

[TobyB]

Hey, do a valve adjustment

 

Have you tried putting the stethoscope on the distributor itself?

Long shot, but I had one that broke, and one of the weights was just

clipping the outside of the housing.  Freaked me right out.

 

Small ends of rods are almost indestructable on these cars, and at 20k, I wouldn't expect piston slap

(no- one expects the Spanish Piston Slap).  Yes, it's possible, but I wouldn't think either would be very likely.  At all.

 

Something to try- set the valves .002" tighter.  If that makes any difference,

you'll know it's valve related.

 

Oh, and tighten your exhaust manifold nuts.  A 2002 makes a very not- exhaust

noise when there's a leak there.  You'd SWEAR it was mechanical.

The stethoscope seems to indicate it's mechanical, but exhaust leaking is very, very common.

 

t

 

[cg2002]

Thanks for all the advice. Yes engine is cold in all videos. The distributor itself doesn't seem noisy. One of the manifold nuts is leaking oil. Would be good if it was just that. Engine is very smooth with no other problems. The other odd thing is it takes a few seconds to start rattling but once it starts it doesn't stop until the engine is warm.