Subject: Cam chain rattle Mon Aug 10, 2020 6:44 am
Afternoon folks. I want to get to the bottom of a cam chain rattle I've noticed get progressively worse of late. Just changed oil with fresh 10w60. Checked valves. took out RHS tensioner and cleaned in a bath of petrol. I've ordered a thicker sump gasket and a replacement lower gasket so will fit these when they arrive. Anything else I should be doing at this time? I have an experienced mechanic i can drop to after all this if still there.
Thanks Shane
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Cam chain rattle Mon Aug 10, 2020 7:57 am
What year model and is it rollerised?
If it's a roller engine it will most likely be the spacer gasket.
If it's getting worse don't ride it until it's fixed, you'll torch the big ends.
If it's a roller engine it will most likely be the spacer gasket.
If it's getting worse don't ride it until it's fixed, you'll torch the big ends.
Its a 2010 se (in the lovely green!) that has been rollerised. Hopefully the spacer will sort it so. Not hearing it all the time, Just now and then! Thanks will update when i swap.
Subject: Re: Cam chain rattle Tue Aug 11, 2020 12:01 am
I'll bet with Pete! Pretty safe bet I reckon...
Eire1400 GRiSO Capo
Posts : 74 Join date : 2018-07-20 Age : 46
Subject: Re: Cam chain rattle Tue Aug 11, 2020 12:04 am
any quick explanation as to how the gasket causes the rattle? A dummies guide if u like?
Oz1200Guzzi Don Abbondio
Posts : 6086 Join date : 2014-03-13 Age : 69
Subject: Re: Cam chain rattle Tue Aug 11, 2020 12:14 am
a bit blows out, oil sucked in let's in air/oil vapour, bubbles form, hydraulic tensioner can't tension properly/consistently because of bubbles, hence the rattle
lcjohnny and Eire1400 like this post
Eire1400 GRiSO Capo
Posts : 74 Join date : 2018-07-20 Age : 46
Subject: Re: Cam chain rattle Tue Aug 11, 2020 12:48 am
Thanks for that. Just waiting on lower gasket to arrive before i tackle. Will update when done.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Cam chain rattle Tue Aug 11, 2020 3:00 am
I mistakenly thought that the gasket tends to blow out around the pick up gallery. Now I know that that didn't make sense but I looked at the galleries and I thought that the larger gallery had to be the pick up gallery.
Once again from memory, I think when I held the wretched spacer in my hand, I found that the gasket blows out around the delivery gallery.
Now this makes no sense but it's the way it is.
Anyway, the reason why it's a problem is that the gallery in question is after the oil pressure relief valve and therefore the already regulated oil pressure can bleed off through the gap left by the missing part of the gasket meaning that the oil delivered to parts 'Downstream' is not only insufficient in volume but also in pressure!.
What is important for the cam chain tensioner require VOLUME of oil. Bearings rely on PRESSURE which is multiplied by the wedge in the oil film.
Before the big ends, (Always the first to go.) torch themselves pressure has to get really low. Luckily this, in this situation, will have a corresponding lack of volume. The cam chain tensioner plungers which are fed by splash, will cease performing optimally due to this long before the big ends go but the rattle is the engine's way of telling you it's fucked! Ignore it at your peril!
As I said. Don't ride it until it's fixed. You really don't want to run a big end.......
OK, changed. Just waiting for new oil filter, to see result. But during change I've found: - in filter on picture there were 2 metal pieces [You must be registered and logged in to see this image.] - no gaskets from engine to exhaust pipe - in RH cylinder there are screws (one loose, second broken), LH cylinder nuts to connect to exhaust pipe. Is it normal such combination of screw / nut?
No, the headers are retained by collars secured by two studs. The gaskets may be there, they compress and become virtually invisible but if there was a broken stud or bolt or the clamps were loose there is a good chance they will of burnt away.
hezovka Don Abbondio
Posts : 76 Join date : 2015-09-03 Age : 58
Subject: Re: Cam chain rattle Sat Sep 19, 2020 5:52 am
OK, I did ordered new exhaust pipe studs, as original were replaced with screws. Prior filling up new oil let me ask, to be sure, all hex screws on oil sump removed during gasket change should be tighten to 10 Nm? [You must be registered and logged in to see this image.] Want to prevent unwished damage. Thank you
It would appear from looking at the torque table that any associated M6 screws are torqued to 10 Nm.
My take would be to do an initial torque of 5 Nm then a final of 10 Nm to get even torque across the sump. I would also do a couple rounds in a cross sequence, opposite sides. I think that's the way I did it when I replaced the sump and spacer gaskets. No leaks yet.
That's just me being overly concerned about tightening across large areas. Who knows what the guy at the engine plant does?
Is the spacer gasket one of the two sump gaskets ? I'm having similar issues,cheers Silly me just looked it up on another part of this great site, happy days