loud tapping noise

Post by **richardlansdown** » Tue Aug 11, 2009 1:09 pm

Hi

my 1098 engine in my van had developed loud teppet noise over the last couple of years. I have just had the engine rebuilt, useing a new high lift cam shaft and new cam followers. i had changed the cylinder head two years ago, with new rockers the double valve springs and it is since then that the tapping grew in earnest.

I was hoping that the engine rebuild would have solved tappet noise, but no! tightening up all the valve clearences to practically nothing seems to make no difference. There is no difference between the engine warmed up or running cold.

Anyone have any ideas??

Richard!

Post by **katy** » Tue Aug 11, 2009 3:38 pm

Quote: "tightening up all the valve clearences to practically nothing seems to make no difference", so obviously it's not a valve clearance problem.
Seeing that you have "double valve springs" I would suspect a broken valve spring, most likely an inner one, but may be an outer one.

Post by **rv8** » Tue Aug 11, 2009 7:56 pm

valve springs are bottoming out

Post by **bmcecosse** » Tue Aug 11, 2009 9:10 pm

I think something would have broken by now if the spring were bottoming out! So - this noise was there before the 'high lift cam' (what cam is it ??) was fitted - with new followers ? Have you looked at /fitted a duplex timing chain ? Is the engine otherwise in good condition - it's not a big-end bearing that's rattling - or a loose piston slapping in the bore ?? What's the hot oil pressure reading ? And - if you take the oil filler cap while the engine is hot - and idling - is the noise louder - and is there a plume of oil/smoke from the filler hole ?

Post by **richardlansdown** » Wed Aug 12, 2009 9:23 am

thanks for all this, just going out to start it up and check these possible issues....

engine has done less than 20 miles since rebuild. it has new rings, bearings and oil pump. Duplex kit was fitted three years ago. oil pressure cold is 60 psi and hot 40 psi, at idle hot 25 psi. last night i took the tappet chest cover off and felt the push rods and there is plenty of play side to side when the valve is closed anyway i m off to look at it now!!

Post by **richardlansdown** » Wed Aug 12, 2009 10:49 am

right

have driven car to garage, we looked for broken valve spring or binding springs and all seems to be in good order. no smoke when oil filler cap is removed, but the noise is a little louder...

cam head and rockers are from mini sport, of their own manufacture, all recommended to work toghether. The rockers are 1.5 roller tip type. the chap who has been doing the work for me seemed sure that the noise was valve gear but couldn't explain why i can't get rid of the noise.... hoo hum!

Post by **bmcecosse** » Wed Aug 12, 2009 8:00 pm

Well -that oil pressure is 'not good' - 40 psi hot running pressure is pretty desperate - espcially if that's after new big end shells have been fitted. The noise started when you fitted the fancy rockers ?? I have NEVER been a fan of high lift rockers - roller tip or otherwise - so right away I would change the rockers for normal pressed steel rockers - and report back.

Post by **richardlansdown** » Thu Aug 13, 2009 12:54 pm

thanks for the advice! i kept my old rockers so will clean them up pop them in and let you know.

Chap at garage seemed pleased with this oil pressure. At least i have shown him, and if it all goes wrong will point the finger!

Post by **bmcecosse** » Thu Aug 13, 2009 1:07 pm

Well - the cold oil pressure should be nearer 70 psi - so you could pack a littl under the relief valve spring to raise it. But that won't make any difference to the hot running figure of 40 psi - which should also be 70 psi! With pressure as low as 40 psi - the engine will last long enough IF you treat it carefully - but not if you push it!

Post by **Kevin** » Thu Aug 13, 2009 4:59 pm

richardlansdown wrote:right

have driven car to garage, we looked for broken valve spring or binding springs and all seems to be in good order. no smoke when oil filler cap is removed, but the noise is a little louder...

cam head and rockers are from mini sport, of their own manufacture, all recommended to work toghether. The rockers are 1.5 roller tip type. the chap who has been doing the work for me seemed sure that the noise was valve gear but couldn't explain why i can't get rid of the noise.... hoo hum!

Hi Richard when you fitted the high lift rockers did you by chance change the rocker cover as lots of the aftermarket ones dont have enough clearance and often have to had bits ground away to give clearance, however the standard covers do have enough clearance.

Post by **bmcecosse** » Thu Aug 13, 2009 10:21 pm

I did think of that - but rather assumed that in two years the rockers would have made a space for themselves - but perhaps not!