fuckin tapping noise

Josh · backyard mechanic Joined: 04 Oct 2001 Posts: 602

Hey doodz, I got a bloody tapping noise and I know it's not the bottom end coz thats only done 2000km's. On the other hand the head isnt new and it has a stage 2 Crow Cam. The engine is a G180 btw balances and all that crap. I'v adjusted/checked the valve clearences twice now and yer it hasnt made much difference. Could it be a valve guide? any ideas???

hypaTG · backyard mechanic Joined: 15 Oct 2002 Posts: 524

i have heard a few people saying that custom cams in gemini's tend to be quite noisey. have u checked rockers?
just a thought???

Josh · backyard mechanic Joined: 04 Oct 2001 Posts: 602

yer i have hey, maybe they fucked up the grind and the cam has a flat spot or something?

Soop · backyard mechanic Joined: 30 May 2002 Posts: 748

It could be the timing chain. The guides wear out and it makes a tapping sound. A bit like tappet noise but on steriods.

I had it on my old boonger wagon and it sounded like a deisel !

Frederick Stienheld · petrol head Joined: 05 Sep 2002 Posts: 2719

Yeah custom cams can be a bit noisey in gems. Mine is a little bit

rob_w · tinkerer Joined: 19 Feb 2002 Posts: 395

uhhmm.....firstly, never rule out bottom end noise....

also, as you are using the stage 2 crow cam, [2500-6500rpm powerband]? The bottom of the valves may be kissing the tops of the pistons. did you use a new timing chain when you put the cam in? if you didnt, go and buy the crow 1800-2000 gemini adjustable timing set....about $113 from autobarn......

That cam needs to be advanced a small amount [way less than 1 tooth, but more than none....], or the valves will clash with the pistons. you my want to pull the head off too, to see if you have any dents in your pistons...i know all too well.

hope its nothing serious.

rob.

GEMTEC · tinkerer Joined: 02 Aug 2003 Posts: 216

Have you got oil in it (engines kind of umm... need it)? might sound stupid but i know a bloke that had a tapping noise and he took the tappit cover off before he had even checked the oil. i just hope that you aren't another one. Razz

S N 3 A K Y · tinkerer Joined: 18 Jul 2003 Posts: 153

The easiest way to check if it's a bottom end bearing knock is
1) Get the engine up to normal operating temps
2) listen carefully to the dull knocking sound
3) Pull the spark plug lead off No. 4
4) See if the knock dissapears
5) re-attatch lead
5) Repeat procedure to No's. 3, 2 & 1, pulling a lead off at a time.

If the knock goes away with one of the leads disconnected, you may have found your culprit.
If the sound doesn't go away using this method, then it will most likely be something else. My uneducated guess would be that the new cam isn't dialled in properly. Unless you have had your head shaved considerably, i cant really see the valves hitting the pistons.
As other people have posted, it may be timing chain slap, but it normally sounds more like a rattle than a tap.

S N 3 A K Y

Josh · backyard mechanic Joined: 04 Oct 2001 Posts: 602

yer that was pretty stupid. If i know whats a balanced bottom end is then i know how to put oil in my engine. The oil is brand new just changed it on the w/e and the timing chain is brand new as well

Josh · backyard mechanic Joined: 04 Oct 2001 Posts: 602

Hrmm the bottom end is built by my dad's mate who is a drag racer who worked out at a bit engine reconditoner shop. I reallly doubt it is the bottom end fellas. There is plenty of oil pressure and like i said the bottom end has only done 2000km's not 200 000. as for the cam it's not brand new, it's been in my old 1600 for about umm 30 000km's? the head isn't massivly shaved so i really doubt the valve are hitting the pistons. thats doesnt really leave me much other choices...

What about the valve guides like i first suggested? I run premium too all the time so could that wear out the guides or seats? I hear a lot of niosy G180 and G200's out there and i dont like it too much. There must be a way to over come this or do I have to do all the experementing?

cheers fellas

Josh