davcos

Ive just done the head gasget on my 87 cossie , put everything back as it came off started it up and there is a knocking comin from the head . I didnt drive it just left it running for a couple of hours last night , is this common and will it stop ,

jon@work

iTrader: (5)

are you sure the cam timing is correct ? (valve/piston contact)

Aaroncast

knocking comin from the head . I didnt drive it just left it running for a couple of hours last night , is this common and will it stop ,

DO YOU THINK THATS A GOOD IDEA TO LEAVE IT RUNNING!!
METAL TO METAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

mechanic28

iTrader: (5)

are to 100% u have got your cam timing correct?if so could just be a noisey lifter and should quiet down

Alvyn

iTrader: (1)

how have you time'd the cams and bottom pulley up? if you used the V on the pulley then it's wrong m8!

tabetha

It should not knock under any circumstances.
Immediately check the cam timing, which as hinted at is done on the LUG nearst the "V" notch this being TDC.
Did you have the head skimmed ?
tabetha

ickey818

Check all the pulleys are torqued up properly, if any of these are slightly loose they will cause a knocking noise when the engine is running.

Alg1k

iTrader: (2)

Big end ,Little end gone piston just kissing head,

garrett-killer

i´ve got the same problem,
a loud knock from the camshaft
i removed the rocker cover again,and
checked clearance between valves and pistons
by pressing down a cam follower with a fat screwdriver.
all ok,but

if you removed the cams and pull out
the cam follower,you have to store
they up side down,
otherwise the oil run out and it need
~50km with warm oil,till they fill it and
the knock removes.

sorry for my bad english

chris

tabetha

It does not matter at all in any way shape or form how you store the followers/hydraulic tappets.
Around the outside they have a oil hole, oil under pressure is squeezed in here and so takes up the clearance between the valve and tappet base.
If it takes 50KM/31miles to get them quiet something is very wrong with the oil supply or the tappets, even on new ones a few miles should not even be needed, just a few mins of running when hot.
tabetha

garrett-killer

i bought my car 20.000km ago,
with a upgraded oilpump
and "upgraded" tappets.
and never had a oil pressure problem

perhaps the "upgraded" tappets
needs longer to fully filled

chris

tabetha

Perhaps they are not the correct ones ?
tabetha

Daveysaff

iTrader: (9)

Dont run it and double, triple check your timing. The tit who did my last HG set the timing up off the vee in the crank pulley rather than the lug nearest it and the noise was a loud tapping. Turned out to be valve contact. And that gets expensive if you dont sort it right away.

davcos

Ive just re done the head on my 87 cossie had a problem with knocking in the head but it has calmed down . Now it has a problem starting , the engine management light does not go out when ignition is turned on and will not fire there isnt any spark there at all or fuel coming to the injectors . Then it would start the day after or so on . Any advice anyone,

mechanic28

iTrader: (5)

crankshaft sensor maybe

col cos1

iTrader: (5)

when my engine was built it tapped like fuk for 1000miles,i was raging after spending so much money on it

but eventually the tappets became fine and quiet

and my mates done it for only 100miles

and another mate almost silent

luck of the draw tappets have a mind of their own

but if yours is knocking and not tapping ive just wrote all this for nowt

sorry