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Loud Tapping Sound Near Valve Cover

Posted: Wed May 10, 2017 2:38 pm
by Nacho
Didn't get much joy from FB post so I thought I'd post here.

Putting together another FTO and it was running beautifully until one day when I was running through the engine and radiator flush processes I got a weird tapping sound out of the front bank. Sound consistent with revs and speeds up in time with revving higher. Sound is definitely a bit louder than your average tappet sound.

Suggestions so far: bent valve, missing collet.

Timing hasn't jumped so I'm leaning towards missing collet and looking to pop the rocker cover open this weekend. Any ideas if this is what it sounds like when a collet has broken and metal crown has been mislodged? Any other thoughts?

It helps to watch the video with bass on the sound so you get a feel for how deep the clunk is. And no......it's not coming from the bottom end.

https://youtu.be/PNQW9SmVGQg

Re: Loud Tapping Sound Near Valve Cover

Posted: Wed May 10, 2017 3:37 pm
by spetz
The lifter adjuster screw may be broken.
There is a bit at the end of it that sits on top of the valve that has a plastic holder which I know are known to break so perhaps that has gone down into your sump and hence the gap has become way too big

Re: Loud Tapping Sound Near Valve Cover

Posted: Wed May 10, 2017 5:38 pm
by Nacho
Yep that's my first thought too. Been searching this forum for hours and couldn't find the answer to this question........replacing the tappet adjustment screw (which I'm assuming you're talking about) anyone done it before? What needs to be removed to do this?

At least I read that you can't just replace the collet, you have to do the whole screw and bigpitty says you have to remove the whole cylinder head? Or just the bracket that holds the cams? I've looked at all the pics and can't seem to understand why you can't screw the adjustment screw in from the top?

Sorry about all the questions :lol:

Re: Loud Tapping Sound Near Valve Cover

Posted: Wed May 10, 2017 9:06 pm
by spetz
I've actually recently replaced one ($35 from Mitsubishi Australia each FYI).

The cylinder head most definitely does not need to come off.

In my case the cam tray was out already so it was an easy replacement for me and just thinking about how you would go about replacing it with the minimum amount of effort... it does not seem possible to do so with the camshaft in place because the tappet adjustment screw screws in from the bottom and there simply isn't any room to do this.

The easiest way (in my opinion) would be to remove just the camshaft that is over that tappet adjustment screw.
I've heard of people doing this (in other cars) without removing the timing belt and just removing the camshaft from the cam gear after the cam caps have been removed.

If this does work then it is not too big a job... you would need to put the pin in the hydraulic tensioner though I would expect, then unbolt the cam gear, cam caps, remove camshaft but leave the camgear in place and once that's out then the rocker arms are free to swing up and this gives plenty of space.

In my case when all 4 cams were out 2 of the cam cap bolt holes stripped and I had to use the helicoil stuff on them.
Again my cam trays were out so doing this + cleaning up making sure no aluminum flakes stayed behind was easy but it will be much tougher if you don't remove the cam tray

Re: Loud Tapping Sound Near Valve Cover

Posted: Thu May 11, 2017 2:58 am
by Nacho
Perfect answer mate. I think bigpitty might have been talking about the cam frame and not the whole cylinder head. I was wondering wtf that was all about lol.

Sounds like removing the cam bracket is the go to replace the screws. Even if we undo the timing, we had to do it anyway when we replaced the water pump. We'll just loosen one of the pulleys to loosen the belt. I'm assuming the cams and valves will stay in their position when I remove the bracket? Eg. I turn the cams and they won't go out of alignment? Coz I'm picturing I'll have to turn the cams to loosen the tappet holding nut.

Re: Loud Tapping Sound Near Valve Cover

Posted: Thu May 11, 2017 8:02 am
by silverGPX
You'll probably spend more time pissing about trying to get the camwheel off without affecting timing.

Just redo the timing, it's possible you haven't tightened the belt enough and that bank has slipped a tooth hence putting the tolerences out.


Sent from my iPhone using Tapatalk

Re: Loud Tapping Sound Near Valve Cover

Posted: Thu May 11, 2017 8:46 pm
by spetz
First thing you would do is obviously take the rocker cover off to confirm that this is in fact the issue.

You won't need to turn the cam/engine to loosen the tappet screw nut as once the cam is lifted out of place you will have nothing obstructing it.

As far as what is easier to do (removing the camgear and then cam or just cambelt all together) is up to you.

If you cambelt hasn't been done for a while you could use it as an opportunity to change that while everything is off

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 15, 2017 4:57 pm
by Nacho
Popped the rocker cover off and wasn't expecting to see anything but spotted a shim lying behind one of the valve springs so I think that there was def one tappet causing all the racket. When I lifted the cam tray I saw a few more shims fell down but I'm assuming that they probably dropped when I lifted the tray.

All shims are accounted for and only one plastic bit missing however all of the plastic collets have a little split in the really skinny section. Is that little split meant to be there to aid in the initial installation? Or is that a split that's resulting in everyone's 'missing collet' issue?

I've ordered some replacement collets but they won't arrive until later this week so I won't get to see til then. I'm thinking of playing around with some high temp (260 degree celsuis) and oil resistant epoxy to seal up the plastic split and go all the way around it with epoxy to make the plastic stronger and then reattach to the adjustment screw.

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 15, 2017 8:17 pm
by spetz
What do you mean by shim?


Those tappet adjustment screws are pretty expensive but I am not sure whether you can repair the original ones or not.
I guess it depends whether you're willing to take the risk.

I've often thought whether a 3D printing place can replicate those plastic "elephant feet" bits as these are what break but luckily all mine were fine, though I did break one myself and had to pay $35 for it :(

Much cheaper if you go from amayama of course especially if ordering many

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 15, 2017 9:48 pm
by Vectose
spetz wrote:What do you mean by shim?
The tappet screws are made of 3 parts, the screw itself, a metal shim and the plastic collet.

The shim pivots on a ball on the end of the screw and the collet holds the shim in place.

Re: Loud Tapping Sound Near Valve Cover

Posted: Tue May 16, 2017 12:34 am
by spetz
Thanks Vectose, I suspected as much but I know that often valve springs are shimmed too.
From having disassembled my head from what I can tell those shims will only really fall out if the clearances are too great, other than that there wouldn't be enough slack for it to pop out

Re: Loud Tapping Sound Near Valve Cover

Posted: Tue May 16, 2017 12:41 am
by Vectose
Correct, I've seen many engines without the plastic collets and the shims in place running fine.

Re: Loud Tapping Sound Near Valve Cover

Posted: Thu May 25, 2017 12:24 pm
by Nacho
So it's all fixed so I better close off this thread properly. Found issue to be a dropped shim.

Popped the rocker cover not expecting to see anything but with a bright torch I was able to spot the shim sitting behind one of the springs enough to confirm that I needed to pull out the cam tray. I ended up taking MIVEC NZs advice and was able to get a handful of collets and shims from the 4D series engine from Mitsi Australia for about $10 each (part number MD180514) and just transferred the collets and shims across. The screw was heaps longer with a different thread so couldn't be used for the FTO but all tappet screws were intact on the FTO anyway so no big deal.

I ended up using a high temp oil-resistant epoxy to seal up all of the other collets that were split and they seemed to latch on to the groove fine and they seemed to stay on even when I was pulling with a reasonable amount of force. I won't know how reliable this fix will be until I pop the rocker cover and cam tray off in future........if ever.

But I did send an enquiry to this mob to see if they can just supply just the plastic or sell the entire screw/collet/shim for $1-2 a piece. You can't use the screw but if all you need is the plastic bit and shim then it's a hell of a lot better than $10 each from Mitsi. https://www.alibaba.com/product-detail/ ... 66553.html

The engine is quiet as a mouse now......been a while since I've heard an FTO this quiet :D :D :D

Re: Loud Tapping Sound Near Valve Cover

Posted: Thu May 25, 2017 12:28 pm
by Nacho
This is the 4D series collet btw:
Image


But Viamoto from the UK also sell the actual screw for the FTO:https://www.viamoto.co.uk/proddetail.ph ... Mivec+DE3A

Re: Loud Tapping Sound Near Valve Cover

Posted: Sat May 27, 2017 12:45 am
by spetz
So the shim and plastic collet were an exact match from MD180514?

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 29, 2017 12:19 pm
by Nacho
Perfect fit :D And if anything, the thinnest part of the plastic on the collet was about 1-2mm taller than the FTO collet so it should be stronger in that area where all of my cracks were.

I'm still peeved that I paid $10 AUD each for them but like I said I only bought 5. I've just reached out to a supplier on Alibaba to see if they can delivery the goods at $1 USD per screw. At the end of the day you can't use the screw but if it's just the collet and shim you need then $1 each is pretty sweet. I'm gonna see if I can order a batch of 50 and see where we go from there.

I've got another engine to rebuild so may as well replace the full set of 24. Lead time from China might be a few weeks but I'm not in a rush.

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 29, 2017 1:38 pm
by spetz
You can get those from amayama for $5 each (genuine Mitsubishi) so a whole set is about $120 which isn't horrible I guess.
And for $10 each or so you can get the right part from viamoto in a 24 pack.

Are you doing the engine rebuild DIY?

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 29, 2017 5:23 pm
by Nacho
Yep doing it myself.......done it before. Mechanic prices I think are pretty outrageous these days especially on a car that's practically worth nothing now.

That's a good find on amayama! I saw it for $3.77 AUD each so I might order a set. I'm trying to negotiate on alibaba right now for $1.35 AUD but I can't work out the shipping stuff........CIF, FOB......whatever the f*ck that is. It's a real headf*ck. I might just buy from amayama lol.

But imagine buying a whole set for $30 AUD and just pay for a little bit of shipping!!! I'll see what the supplier says next.....I'm getting quotes from Fedex, TNT and UPS as well on shipping

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 29, 2017 6:23 pm
by Vectose
I'll look into replicating the plastic collets.

Re: Loud Tapping Sound Near Valve Cover

Posted: Mon May 29, 2017 6:35 pm
by spetz
What would the quality be like from Alibaba though?

Considering the amount of work to get to these things it may not be worth the risk of an inferior quality product to save $100?