Bealescooby

iTrader: (36)

On start up my cousin's Scooby is noisy and sounds like its knocking

As soon as the car is warm the noise completly disapears , i'm sure i've read that forged lumps are noisy on cold start but can't remember

Also the car is stupid quick and loses no power

Fat Boy

Normal to sound like a skeleton wanking in a biscuit barrel when cold , but as long as all goes quiet when 80C or so then fine

DDS789

iTrader: (2)

I got my car back from scoobyclinic a couple weeks ago, after a forged 2.1 build and have to agree its very noisy when cold!

Makes tapping noises and alsorts, gets better when warm but still has some noises. When i have the turbo connected up and it get "properly warm" i was assured by them it will be quiet.

Its the pistons that make the noise. They are slightly too small for the bores and click at the end of each stroke, when the car warm/hot they expand and fit the bores, hence go quiet.

TingTongPJ

iTrader: (24)

mine sounds like an old escort diesel when cold, soon quietens down when warm.

DDS789

iTrader: (2)

Its good to hear other peoples experience! I was very paranoid about mine lol Mine seems to get better and better as i get closer and closer to it being run in.

TimH

iTrader: (11)

Mine too. Some piston slap when cold, and the injectors are really noisy all the time which led me, at first, to think I had cam bucket problems. Had me worried for a few days

Ian

iTrader: (10)

the make of piston make a big difference as well.

DDS789

iTrader: (2)

Dont know about the OP but mine are Marhle 2.1 pistons with STI 10 rods.

Are they noisy pistons?

TimH

iTrader: (11)

I have Mahle pistons (with Manley rods) and I was told that Mahle ones are generally quieter than others. Assuming they're sized right of course!

DDS789

iTrader: (2)

Thats cool. I shouldnt worry as the engine builder at SC told me it was completely normal, and when the turbo is hooked back up then they should quiet down significantly.

Bealescooby

iTrader: (36)

thanx for the reply's peeps
Best thing about it all is he brought the car not knowing what goodies it has

happydude303

iTrader: (1)

just out of interest how does he now what is in there has he been told it has forged pistons

Steve Whitehorn

iTrader: (13)

My forged lump is noisy as hell. sounds like the big ends gone when cold.
I drive it real slow up to about 80 on the temp guage. Pistons knocking away...oil also getting past them a touch....
Then gradually start driving it touch harder. get the oil temp up to 90...wait to the car feels right and nice and warm.
Then I give it all hell - loads of heat into the pistons and it is sweet as anything. Pulls great. Pistons now fitting the bores - still a slight piston noise but it dies right into the background.

So my experience is that the engine is only sounds truely happy when it is hot and it is really being worked.

merlin24

iTrader: (1)

And the piston to bore clearance - depends what it was set to when it was built


Mick

Mus

iTrader: (2)

You sure they told you once the turbo is on it will go quiter?? I don't get it??

I heard coated pistons don't make noise again not sure?

MartynJ

No slap from yours eh Mus

Mus

iTrader: (2)

running great no slap or funny noises mate lol

DDS789

iTrader: (2)

Tbh I dont either. I guess with the turbo running and full revs, the engine will get hotter than non turbo 3.5k revs, expand the pistons more ect

If it does still sound bad ill be asking questions as its under warrenty.

JohnD

iTrader: (5)

So, has it actually had a re-build with forged components?
Although the title is "Are forged engines noisey" you haven't actually confirmed that it was re-built?

JohnD

Andy916

iTrader: (8)

My newly run-in build with Mahle pistons (not sure what clearance) and Manley rods (phnaar phnaar) is quiet when cold. Has a slight tappety 'tick' at tickover when fully warm, very slight and am not sure of cause. Could be injectors, but they weren't noisy before the build... Otherwise runs great and has loosened up nicely over the last 1000 on fully synth (following the first 1500 on mineral).

happydude303

iTrader: (1)

my forged engine was very quite for the first years or so then it got a little sounds when first tunred on in the mornign for the first minutes but my bores where done really well but in time all engines loosen up a bit

Jay m A

iTrader: (2)

Mine sounds like a diesel with big ends gone when cold, still slaps a little if off boost and up to temp.... but it all disappears when on full power - I call it the calm with the storm, lol

joz8968

iTrader: (13)

Mine was rebuilt by Zen with STi 3/4 pistons. I have the piston slap too, when cold. But once warmed through at c.83C, all's fine. Never slapped at all on the original WRX non-forged pistons. Bloody slappers lol.

It's 'normal' - well, on forged pistons at least.

tsl202

mine isn't noisy at all and it's an RCM forged one lol!