Engine Knock after Head Gasket change(sorry to revive an old thread)

[Carnie]

My mate decided to do his head gasket today since ive done mines.We bolted it all back up and timed it.Gave it a few turns by hand and it was all good.No resistance and no sound.Anyway we turned it on and at idle its making a rattle-knocking noise from the head,runs fine otherwise,then when you give it a bit of gas it goes away.As far as i can see the engine it timed up fine,cam shaft is at tdc,No1 piston is at the top and the dizzy is at No1 too.This is everything i checked with mines and thats works fine,no nise or anything.We let it run for about 30 secs and gave it a few revs but it doesnt help.Any idead chaps?Oh its a 1.8 btw
cheers
Jamie

[rubjonny]

could be tappets, give it a litre of dexron II atf oil and run it about for a week gently then do a full oil/filter swap.  the ATF has detergents in which sometimes cleansou out the tappets and quietens em down.  be aware thatg if any other parts of the oil system are weak this could unclog em, i found my oil cooler died a week after i did this. basically it cleaned out all the crud holding it together!

what oil did you put in it, and did you use a decent oem quality filter?

[Carnie]

He didnt do an oil or filter change,should this have been done at the same time?I only did my first head gasket last week so i didnt know it shouldv been done.He treats his car well though so itll have good oil and a good filter on it just now.Is there anything else this could be?Just worried that its maybe not timed right and the valves n pistons are clashing.If it was out by like 1 tooth would this be the case?Is it ok to drive like this then?hes left the car at mines till we figure it out.Its odd though,why would the tappets decide to make noise now,dont think they were before?I dunno,like i say im new to doing the whole thing myself.

[Carniemk1]

Is it possible this could have came about from not using the car?He just told me he thinks it may have been like that when he brought it down, he had just put it down to his exhaust knocking?If we leave the car to warm up properly and let the oil circulate will this help it?

[Carniemk1]

Stuck tappet maybe?Should we just let the engine run for 10mins and see if itll clear,just dont want to do any damage. to it.

[rubjonny]

go back over the timing and double check, worth noting that the dizzy will spin freely once the belt is off so easy to mess the ign timing up even if you were carefull not to move cam & crank.  as you say after its warmed up a bit the problem may go away, but might be an idea to give it some good oil and a new filter from GSF if its not been done recently

[Carnie]

Cheers,ill start it up tomorrow after work then as itll be a bit late when i get back tonight and see if it quietens down. We went over the timing a few times on sat so im pretty confident its right,hopefully thisll fix it.Ill report back with my results.Cheers!

[Ben Lessani]

could be tappets, give it a litre of dexron II atf oil and run it about for a week gently then do a full oil/filter swap. 

I wouldn't do it for a week - about 100 miles at most is enough (ideally, with 1 journey), and even then I had some pretty poor experience with trying it - my engine is an oil burning monster now

[Carnie]

Hi,just looked into that Dexron stuff,am i right in thinking that it really is automatic transmission fluid that i should use?Like this?

http://cgi.ebay.co.uk/ATF-DII-DEXRON-2-Automatic-Transmission-Fluid-1-ltr_W0QQitemZ370282346730QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item56368c38ea

[rubjonny]

yup!