Engine noise any ideas? Help needed


EK9 Matt said:
Piston slap is a possibility, what pistons you running and did you measure your piston to wall clearance? Sounds very bottom endy that though, strange how it goes away. You got good oil pressure??
Click to expand...
81.5mm wiseco forged pistons. P2w clearance was 0.003 as the spec sheet. Oil light doesn't stay on for longer than usual or anything, I don't have a gauge yet but I need 1 asap.
 
Right, did a stethoscope test. 100% sounds around cylinder 1. 2 spots I can it pretty clearly! One around the lower middle of bottom end, then the other is loudest right on top of the rocker cover.
 
That video sounds just like a rod bearing.
 
The speed and pitch of the knock sounds wrong for a big end,

After hearing that second video I would think small end bearing or damaged piston skirt/bore/piston slap.

Do you have oil squirters or are they removed?
 
Last edited:
If it's coming from the middle of the block you're looking at a rod bearing as @b16 mini says small end. Maybe a wrist pin clip has come adrift.
One thing to check from experience, especially if you've fitted forged pistons is the oil squirters, they need to be bent to clear the piston skirts.
Mine although I bent them touched slightly and one broke off! I got rid and put golden eagle blanking plugs in.
Just a thing to check.
Take the sump off and look up you'll see them towards the front of the engine. You will also be able to inspect the lower notes while you're there.
 
Although I don't think an oil squirter touching will have a knock that loud.
 
jesse888 said:
That video sounds just like a rod bearing.
Click to expand...
That's what I thought tbh :( but it has been some time with sounding pretty much the same and the car still pulls nicely. Doesn't feel like it's lost any power, from what I've driven so far anyway. I'm gonna get an gauge to help try rule out if it's bottom or not asap. Does sound it as you say though
 
b16 mini said:
The speed and pitch of the knock sounds wrong for a big end,

After hearing that second video I would think small end bearing or damaged piston skirt/bore/piston slap.

Do you have oil squirters or are they removed?
Click to expand...
Oil squirters are all there. Bit bummed if it's small end bearing as the parts were all brand new and checked. If it was piston skirt as the engine warms up, does it not get progressively quieter?
 
B16Swt said:
If it's coming from the middle of the block you're looking at a rod bearing as @b16 mini says small end. Maybe a wrist pin clip has come adrift.
One thing to check from experience, especially if you've fitted forged pistons is the oil squirters, they need to be bent to clear the piston skirts.
Mine although I bent them touched slightly and one broke off! I got rid and put golden eagle blanking plugs in.
Just a thing to check.
Take the sump off and look up you'll see them towards the front of the engine. You will also be able to inspect the lower notes while you're there.
Click to expand...
Bummed if it's a small bearing as they were all new parts down there and checked :( I'll double check with the builder about the oil squirters but I'm sure they are all there. I think I'm going to pick up a gauge this week if can at least to try help rule if it's bottom or head then whip off the sump too if need. Cars rarely used atm. Okay mate nice one thanks!
 
B16Swt said:
Although I don't think an oil squirter touching will have a knock that loud.
Click to expand...
My thoughts were that a squirter could be broken off causing it to leak off excessive amounts of oil pressure, possibly meaning (depending on the route the oil galleries take) full oil pressure is not reaching other areas of the engine, long shot I know!

I think we could all make guesses all day long, but at the end of the day I think it's time to strip it down and try to repair before something lets go and destroys it self
 
Am I right in thinking I could try a cold start with cylinder 1 spark plug disconnected (since that's where I heard it most) and listen if it's any quieter at all? If it is, suggesting its indeed bottom related
 
I think the best thing to do here is start to strip it down, something isn't right. It sounds like one hell of a knock tbh, have you had the rocker cover off yet just incase it's something in there?

Just make sure it's nothing daft, I say that as I've just been out to fresh build where the guy thought the engine was locking up, was about to strip the whole motor! I diagnosed it as a brand new clutch cover hitting the webbing inside the gearbox housing, small grinder sorted it and saved him a lot of time and money!
 
What ever it is seems to be happening on cold start when the oil pressure is low, and when hot, when the oil is thinner hence at a lower pressure. It's something oil related, ie bearings, LMA etc.
 
EK9 Matt said:
What ever it is seems to be happening on cold start when the oil pressure is low, and when hot, when the oil is thinner hence at a lower pressure. It's something oil related, ie bearings, LMA etc.
Click to expand...
Yeah definitely related to that mate. Plan to have the cover off asap this week. Car isn't being used anyway. When it was last checked not long ago to adjust valve gaps where needed, nothing abnormal was found. Lmas were checked by the thumb press and none seemed of concern. Still questionable though with the upgraded valve train.


Did a cold start with cylinder 1 plug and injector disconnected. It still made the noise though? Could this signify it's not bottom end? Or is that test not 100% sure
 
I wouldn't rely on that test tbh, at the end of the day everything is still connected and could still transmit the noise I reckon. I feel for you as I've been there so many times before!
 
EK9 Matt said:
I wouldn't rely on that test tbh, at the end of the day everything is still connected and could still transmit the noise I reckon. I feel for you as I've been there so many times before!
Click to expand...
Yh it really sucks lol :( cheers mate!
 
Id atleast pull the sump off after hearing that
 
You must log in or register to reply here.
Back
Top