Strange Knocking.

[djinuk]

On my J plate r5 there has always been a knocking (not rattling sound), Ive only drove it on a very short journey and it seemed to run very well, i cant tell if its coming from the head or the bottom end, any advice ?

[Brigsy]

Is it slight knocking on idle or death rattle all the time? Always reset tappets before condemning the engine.

Every gtt i have owned/worked on always seems to have an intermittent knock on idle, i assumed it was piston slap, or possibly timing chain tensioner is worn.

If the oil pressure is good & no rattles when driving id be inclined to use it a bit & see what happens.

[dangerous dave]

knock with revs or speed? i've had loads of things knock on mine, drive shafts, gear box engine mount, down pipe to the rack, front steady bar, intercooler, air filter tapping on the strut..

not had an engine knock yet..

[djinuk]

its a knock with the revs, i think best bet is if i catch it on cam to show you.

[dangerous dave]

do the old pipe in the ear trick..

[Daz.]

Ive got this on idle, its like some 1 knocking on a door :scared: but every so often. was going to re set tappets, but i did have the same knocking on idle on my last 5, may just be worn parts while using finer oil, im using mobile 1 10w/40 fully synthetic.

[djinuk]

still not worked this knock out, it sounds very mechanical as opposed to somthing blowing, gota feeling its going to be somthing daft but just cant figure it out.

[J$£5GTT]

Is it slight knocking on idle or death rattle all the time? Always reset tappets before condemning the engine.

Every gtt i have owned/worked on always seems to have an intermittent knock on idle, i assumed it was piston slap, or possibly timing chain tensioner is worn.

If the oil pressure is good & no rattles when driving id be inclined to use it a bit & see what happens.



have you reset the tappets yet??

:)

[raj]

just to add, i had a knocking coming from my old 5s engine, it would knock in sync with the engine rpm, after much head scratching it turned out to be the larger downpipe knocking against the steering column:brickwall:

[djinuk]

yea set the tappets, might readjust them again, all being well it will be at nationals day so maybe somebody will have a good idea of what it is.

[djinuk]

ok, just to bring up on old thread... i was under the 5 earlier trying to work out where oil was leaking from..

Anyway whislt under there i had a listen to the knock mentioned, .. it appears to be 100% bottom end related and is coming from the side right next to the gear box.. Car drives fine :S

[Tony Walker]

My 5 allways did this especially when cold, very very noisey, i was pretty sure it was piston slap, but recently something dropped in my carb and munged the piston closest to my flywheel, so i replaced the piston and all the big end bearings. my 5 has never ran/sounded so sweet :D

[djinuk]

gota be big end then.. yea its very noisy , can hear it from like 10 meters away, as soon as its warm n had a bit of a blast though it goes 100% silent :S

[Brigsy]

If it goes silent after a blast it could be piston slap, i mean when the piston gets hot making the piston-liner clearances smaller, like a forged piston when cold...

[djinuk]

that would make sence i guess, car drives great and seems to pull really nice.

[SCHWARTZ]

If it goes silent after a blast it could be piston slap, i mean when the piston gets hot making the piston-liner clearances smaller, like a forged piston when cold...

would a comp test prove this? tested when cold then when hot? Would assume that all would have better compression when warm but if one is extremely different could prove this theory.:confused: maybe :laugh:

[Tony Walker]

I also think it was piston slap, as all my bearings weren't too bad, and my crankshaft journals were like new. I only mentioned it as it was the piston closest to the flywheel so im not sure if there is a common theme here with the c1j and piston slap on no.1 cylinder?

[Fordy]

anyone found the issue of cylinder 1 knocking?

just rebuilt with forged rods and pistons and the engine revs lovely, idles smoother than ever, but knocks and cannot pin point it down even with ear on sump :confused:

[Matt Cole]

Could be a number of things. Did you check the crank and bearings for compatibility / correct sizing to the rods?