I'm a little worried to say the least!
I've had the car a few months now,I love it to bits,it's a V3 STI with some nice mods.

On cold starts it's noisy,from my reading up I do understand that forged builds can be pretty noisy so I haven't been worried as when it's warmed up the knock/slap disappears,well that was until the other day
Now the noise does get quieter when warmed up but it's still there and seems to be getting worse every day.

I'm going to take a proper look at the weekend or next week if the weather permits and have done plenty of reading up over the last few days so I know where I need to start,I plan on doing an oil change and filter the old oil through some cloth to see if there's any metal bits in there which would indicate that it's the bottom end that's on it's way out.
Also going to check the cambelt tensioner as watching a few youtube vids leads me to believe it could well be this causing the knocking? But would this get quieter as the engine warmed up??
The knocking is only there at idle and below 1500RPM

What else should I be checking?
If it's a failing con rod would this also leave metal bits in the oil?

I do have some electronic detcans I've made so could use these to check areas of the engine to track down the noise,so have you any tips on where to check and what to listen out for?

Cheers
Rich

 

my m8s is the same theirs about 30 thou piston clearance

 

It's done about 30k on the build and was done in 2008,when I got the car a few month back it was noisy from cold but now the knocking is there even when warmed up,it's not really loud when warm but as it's only just started doing this over the last week then it's started to worry me.
Does your mates still knock when warmed up?

 

the fact it is a new noise wouldn't point towards it being "normal" or wouldn't the noise have been there since the build ?

 

its hard to get used to the forged piston knock. you can still hear a noise even when fully warmed up in normal driving

if the car is running as normal then i wouldnt be too worried about it

 

same as mr Gambit here with my forgies, noise seems to change a little as it warms up but it's always there. If the sound has recently changed though it does no harm to investigate a little anyway - have you noticed any changes in the logs, extra knock events or anything strange occuring?

 

I've not done much data logging recently and since I started hearing the knocking when the car's warmed up I've not been on boost much,the logs I have taken tho all look as normal and the only knock events I'm getting are 3-4 every time on a cold start up.
I have just replaced the knock sensor as the old one was faulty,I was going to relocate a bit higher up but ended up putting it back in standard location.

I wasn't worried at all about the slappy engine when cold but I've only just noticed it now making the noise when fully warmed up and I'm sure it's getting louder?

Cheers guys,I guess the only thing to do is stick my head under the bonnet and have a good poke around,I'll get the detcans rigged up to see if I can track down any specific area but I'm guessing if it is just the noise of a forged build then the noise will be even on all cylinders ??

 

Any loss in oil pressure?

 

Not sure banny,I've still not got around to fitting my gauges,I have 3 to fit so this will be on the list of jobs to do next week! What pressure readings should I be getting and what kind of numbers should worry me?

 

Will depend on the clearances used on the build, mine shows 6 bar at cold idle and hot idle is about 2.7/2.8bar, will check on boost oil pressure next time I drive it

 

Cheers

As it's a 2008 build then no idea what clearances were used,it's an off the shelf Graham Goode short block so i will contact them to see if i can get any info.

 

Hopefully you're just being paranoid bro and all is normal

 

Cheers pal
I'm on my 4th classic and this one(maybe because it's new to me) does make me paranoid ffs,I need to get a grip haha!
Never felt paranoid with the others but this one's pretty highly modded,the others were very standard.
My Terzo had the bottom end let go on me but that was like an instant boom and this noise I've got now is somewhat different,it's just strange that it's still knocky when warm now where as it wasn't when I got the car.

 

Maybe just the cold weather yess lets blame the crappy cold weather don't let it do your head as it went this cold wen you got it bro you'll be right

 

Weren't I ment

 

Yeh never thought of it like that mate,stupid cold weather!
I will put some fresh oil and a filter on next week and get those gauges fit then i can carry on enjoying the car and get back to tweaking the map and see if i can squeeze a bit more power out

 

is this after your oil change ?
if not have a damn good look at the old oil when it comes out, sure sign of bad things about to happen if you have metal shavings in the old oil.

 

No i will be doing the oil change next week and will filter the oil to see if there's any metal bits floating around in there.

 

My last forged engine was slighty noisy when warm horrendous cold, as long as it has good oil pressure and not using much oil it be fine.

 

Yes jay horrendous is a good way to describe when cold!
It only uses a little oil,but has a slight oil leak from somewhere,looks like rear crank oil seal,which is a surprise as it's had a recent 6 speed conversion and would have thought a new seal would have been fitted at the time?
Car is on fuchs oil atm but will be swapping to millers and fitting some gauges next week,at least then with all them gauges fitted I can step my paranoia level up

 

could be the timing belt tensioner, Ive had 3 scoobs now and every one made a piston slap like noise when the the tensioner/belt needed replacing.

 

I've heard loads of scoobies slap hot and cold mine included. Nothing g to worry about.

 

I think I will get the timing belt done next week too,it's only done 30k on the rebuild but with that being 8 years ago and don't think it's had a fresh one since then it's a good idea to get it done.

 

Hopefully its nothing to worry about bud, but suggest getting that oil pressure gauge fitted, anything below 2 bar at hot idle then thats when you start to think big ends are going, anything above 2 bar, all good (As long as everything else is as it should be, oil pump working correctly etc

 

Cheers mate.
There's a good guide on here to fitting gauges so should be pretty straight forward.

 

As you already mentioned - cam belt tensioner or front pulley loose on keyway could cause the noise.
Hope it's a simple fix though

Mick

 

Thanks Mick
I will order a kit tomorrow and get it fitted ASAP
At least that will be one less thing to be paranoid about haha

 

Mine gets a little "rattley" when fully warmed up, its a two-year-old build by a very much respected builder. I bought a mechanics stethoscope with a probe and eventually pinned it down to the alternator. Waste gates can rattle if worn or the actuator isnt adjusted correctly apparently. I think engine parania goes hand in hand with ownership if you have an ounce of mechanical sympathy.

 

Again get that pressure gauge fitted. I would add that if the gauge flickers up and down that can indicate a problem. If the gauge works smoothly indicating different pressures but in a measured controlled smooth way then usually all is good. (Hard to explain but hopefully you get my drift)

I would check cambelt tensioner first
Hope you get it sorted

 

Really dont wanna worry you but get it looked at rather than driving it, I got a call from my mate last night about his RA, "car has just died mate coming up to a set of lights...just lost power and noticed coolant on the floor after", I went to look at it today and stripped it down,













He said he thought he'd heard a noise ...looks to me the water pump bearing failed which in turn moved the belt to wear through the cam covers before the pump pulley dismembered itself through the cover too, just gonna try a pump and belt...time it up and hope for the best, saving grace is he was tootling along to a stop