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

[Carnie]

Hmm cool didnt know that at all!Cheers,ill get my mate to buy some and give that a bash then.

[DOA]

Better yet, buy the proper stuff for the job and at least then you have the manufacturer of the stuff to blame if it goes pop due to putting random liquids in your engine on the advice of someone you dont know (no offense meant here Rubjonny!).
http://www.wynns.be/product.aspx?nav=1&g=1&s=25&b=768&p=76864&l=EN

Saying that, if you finish the head gasket job properly by doing an oil and filter change you will probably not need to do anything if they werent making a racket before. Out of interest, have you checked the oil level at all since?

[Carnie]

Yeah i was looking at that stuff before but when Rub mentioned that Dexron i though i mays well give it a try instead.He always gives sound advice on all the forums so i know i can take his word for it.

[rubjonny]

this is a tip i got from cgti, iirc it was the legend that is TSC who I got it from! certainly never casued my 1.8 engine to sploderise, though as i say it was the last straw for my oil cooler. to be fair it had done 170k, so was well overdue a replacement!  Used it on the 2.0 after I fitted it as well, didnt do that any harm either.

I've used the proper engine flush too, just whatever you can get for cheepie!

[Carnie]

  Yup a stuck tappet it was,let it run for ten mins and bam,it went away,seems to be running a bit lumpy though,only on idle?Hes not had it used for about 2 months so maybe its just getting over that,also its low on fuel,cut out a few times when i took it for a short spin so hopefully its just the that.Anychance it could be anything else,leads plugs n dizzy are fairly new,checked the connections and all seem to be fine,was dark though so ill have a proper look on sat.Anyway,cheers for the help chaps,another mystery solved!

[danny_p]

ATF is an age old trick well known in the trade.  take rover v8's they gunk up something spectial engine flush don't do a lot to them  ATF dose tho

[Carnie]

Hey,sorry to start up an old thread but i figured i may's well use this since its the same car and problem haha.My mates left his car sitting again for a few months and this clunking noise has came back on start up.Only this time after running the car for a good 30 mins its still there.I took the cam cover off and turned it over by hand.All the tappets are moving free with the cam and there doesnt feel like anything catching,all are getting a good oil flow aswell.Going to buy him some of the wynns stuff tomorrow and see if that will solve it.I was just wondering where the clunking noise is actually coming from,is the mechanism inside the tappet thats stuck or something or is something clashing and causing damage?
Cheers!

[Carnie]

Found this site that explains hydraulic lifters pretty well.

http://www.ratwell.com/technical/HydraulicLifters.html#operation

Think i understand why it would be knocking if it was dirty or dry etc, ill try the wynns stuff and see if that gets it working properly again!

[Carnie]

Ok need a bit of help if anyone is listening,took the tappets out and they all look fine to me,how can i tell if there bad?Theyve all got oil,no obvious marks ,dents etc.What else would make this knocking noise?I gave all the valves a push down and they all move fine,im confused!!!!
We ran the car for about10 mins last night and put some of that lifter treatment in and then left it to run for a further 20mins,still nothing!Just making this loud knocking noise