11 replies to this topic

[Raggedroy]

Hi all, any ideas?

 

I have an odd tapping noise that comes and goes. It sounds like a really noisy tappet/rocker, when it is there it changes with engine speed. It is not there when the engine is first started, it appears when cruising for a while but disappears after the engine has been idling for 15 secs ish. It can sometimes be heard when revving the engine but not always.

 

I have just had a problem with the bottom pulley/ damper and have just fitted new Vernier timing gear while it was in bits. The noise was there before this.

 

It has good oil pressure and compression is equal on all cylinders. It drives fine and has just been set up by Pete Baldwin.

 

Does it sound like a cam problem or possibly a broken cam follower?

 

Engine spec;

MED built an good few years ago.

1380cc

300 duration MED cam

1.5 roller rockers

 

Cheers

[Thelowrider]

Rocker cover isn’t fowling a tappet?

[Raggedroy]

Rocker cover isn’t fowling a tappet?

I hadn’t thought of that, I will check tomorrow. It would be great if that is the problem.

[Thelowrider]

Rocker cover isn’t fowling a tappet?

I hadn’t thought of that, I will check tomorrow. It would be great if that is the problem.

Slacken the rocket cover fittings off enough just to be able to move the cover itself slightly and see if the noise goes once happy the clearance is okay then nip them back up

[sledgehammer]

another thing to check - if you have a manual fuel pump

 

they can get noisy when idling (not pumping) or the arm / pivot could be failing

[Raggedroy]

another thing to check - if you have a manual fuel pump

they can get noisy when idling (not pumping) or the arm / pivot could be failing

Cheers, unfortuently it has an electric fuel pump.

[Raggedroy]

Rocker cover isn’t fowling a tappet?

I hadn’t thought of that, I will check tomorrow. It would be great if that is the problem.

Slacken the rocket cover fittings off enough just to be able to move the cover itself slightly and see if the noise goes once happy the clearance is okay then nip them back up

Doesn’t seem to be rocker cover. Changed cover and repositioned.
Just taken it for a run 10 minute , 4000rpm. At the end of the run I can hear the tapping noise when moving and stationary. On tickover the noise fades away and I now can’t hear it when I take great revs back up. Clutch doesn’t make any difference.

[sledgehammer]

starting to sound a bit like a follower problem

 

first check all the really simple easy things to do - even if they appear to be non related - just to eliminate them

 

I would at this stage , take plugs out , look down the push rod holes , have someone spin the engine over -

 

look for a push rod slightly bending & hitting the head , can make a weird knock sometimes amplified by the rocker cover at certain revs when push rod is under load

 

if nothing found , slacken rocker - check rocker feels good , take push rod out - look down hole , spin engine over , look for follower that stays up & is hard to push down

 

follower shouldn't fall out into chest - as 1275 engine shouldn't have the chest - unless the rare cooper engine

 

hope you find the cause - & it isn't some bizarre problem related to ends / small ends

 

best of luck

 

ps - use a stethoscope on the block - I use one of these , worth it's weight in gold sometimes , sometimes too load to narrow down

 

https://www.ebay.co....u8AAOSw-jFaMnXZ

 

or a long screwdriver does a similar thing - but harder to use in a tight engine bay

Edited by sledgehammer, 03 June 2018 - 10:02 AM.

[Raggedroy]

I have had the rockers off and put a camera down all holes. Everything looks fine but it is a little difficult to see in enough detail as they are so shiny inside a there is a lot of reflection. With some oil in the bottom of each cam follower, I dropped the push rods in, on extraction the vacuum in the cup allowed all followers to lift and then drop back into place.

I have tried the screwdriver trick but can’t pinpoint it.

[sledgehammer]

if they all lift with the vac from the follower cup - I can't see the followers being the problem

 

I assume all the pushrods are straight ?

 

pity you haven't found the noise yet - would have been easier

 

were there any marks in the inside of the timing chain cover ?

[Raggedroy]

if they all lift with the vac from the follower cup - I can't see the followers being the problem

 

I assume all the pushrods are straight ?

 

pity you haven't found the noise yet - would have been easier

 

were there any marks in the inside of the timing chain cover ?

I have been working on this problem for quite a while. I have had all of the push rods out and they all look straight and unmarked, I have even changed them to MED steel ones while I was in there. I really should have put my DTI on the push rods to check the cam lift. It has an 11 stud head, the cut outs on the rocker cover for the additional nuts looked to be limiting the fitment, for a second I thought that was the problem. I changed the rocker cover for one that used to be on it and the tapping is still there, no internal marks.

 

I think I will soon have to pull the engine out. I was planning on doing this at the end of the summer and fit a new SC gearbox. I was thinking of using all MED gears etc. Are MED the ones to go for or are other better or cheaper for the same quality?

[sledgehammer]

 

if they all lift with the vac from the follower cup - I can't see the followers being the problem

 

I assume all the pushrods are straight ?

 

pity you haven't found the noise yet - would have been easier

 

were there any marks in the inside of the timing chain cover ?

I have been working on this problem for quite a while. I have had all of the push rods out and they all look straight and unmarked, I have even changed them to MED steel ones while I was in there. I really should have put my DTI on the push rods to check the cam lift. It has an 11 stud head, the cut outs on the rocker cover for the additional nuts looked to be limiting the fitment, for a second I thought that was the problem. I changed the rocker cover for one that used to be on it and the tapping is still there, no internal marks.

 

I think I will soon have to pull the engine out. I was planning on doing this at the end of the summer and fit a new SC gearbox. I was thinking of using all MED gears etc. Are MED the ones to go for or are other better or cheaper for the same quality?

 

 

John guess is the man to ask for that -- aka gearbox god