Image Please bare with us while we are carrying out some much needed maintenance to the forum. New look coming soon!

Engine Knocking! :( Big End Bearing!

Post info/questions on engine mods and issues here
User avatar
Tosh21
Altezza Guru
Posts: 521
Joined: Mon Jan 20, 2014 10:12 pm
Location: Oxfordshire

Re: Engine Knocking/Rattle! :(

Postby Tosh21 » Tue Jan 20, 2015 3:43 pm

Had a chat with my go to guy on diagnosing he reckons it's little end. Big end would make a heavier noise. The reason it's only at 2.5k is because it's not that bad yet so it only does it under load.

First thing is to whip the plugs out and have a look at them for oil deposits. If number 1 is all oily and horrible chances are the rings are dead which can mean the piston has scored the liners scrapping your block. If they seem fine though you Mau be very lucky as the rings will hold the piston so it won't score the bore. If you can get a bore scope even better just have a look inside and see if it's scratched up.


Then drop the oil and look for metal filings. Can also pull the filter off and cut it then unravel the paper inside and inspect it for metal again. Or you can send a sample to Lucas or mocal I can't remember who does it and for a few quid they can analyse it and tell you what's in it.

Another thing is to drop the sump and pickup and see if you can get access to the bottom of the cylinder. If there is baffles in the way you can probably drop the crank case off easy enough and see the piston. You could try getting up there and giving it all a little push to see if the piston rocks on the gudgeon pin. If so Then that's your problem. Then obviously you'd have to pull the head off and push the piston out.

Either way, it's gonna be a big job

Soiled
Altezza Guru
Posts: 705
Joined: Sat Dec 11, 2010 3:35 pm

Re: Engine Knocking/Rattle! :(

Postby Soiled » Tue Jan 20, 2015 9:39 pm

Just remember that engine for sale is auto, and that the heads are different between auto and manual so don't rush into buying it.

Trd Shane
Tezza Fanatic!
Posts: 232
Joined: Mon Dec 02, 2013 10:44 pm
Location: Dublin

Re: Engine Knocking/Rattle! :(

Postby Trd Shane » Tue Jan 20, 2015 11:08 pm

Soiled wrote:Just remember that engine for sale is auto, and that the heads are different between auto and manual so don't rush into buying it.


Can heads not just be swapped over and bobs your uncle ??

That's if it is bottom end failure

And if it is bottom end failure i wouldnt say it would be worth rebuilding
Unless your thinking of forging that Is ??
"If it can't be fixed with a hammer it's an electrical problem"

Soiled
Altezza Guru
Posts: 705
Joined: Sat Dec 11, 2010 3:35 pm

Re: Engine Knocking/Rattle! :(

Postby Soiled » Wed Jan 21, 2015 3:27 am

If bottom end is screwed it'd work, if head is screwed no go.

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Thu Jan 22, 2015 1:33 pm

Tosh21 wrote:Had a chat with my go to guy on diagnosing he reckons it's little end. Big end would make a heavier noise. The reason it's only at 2.5k is because it's not that bad yet so it only does it under load.

First thing is to whip the plugs out and have a look at them for oil deposits. If number 1 is all oily and horrible chances are the rings are dead which can mean the piston has scored the liners scrapping your block. If they seem fine though you Mau be very lucky as the rings will hold the piston so it won't score the bore. If you can get a bore scope even better just have a look inside and see if it's scratched up.


Then drop the oil and look for metal filings. Can also pull the filter off and cut it then unravel the paper inside and inspect it for metal again. Or you can send a sample to Lucas or mocal I can't remember who does it and for a few quid they can analyse it and tell you what's in it.

Another thing is to drop the sump and pickup and see if you can get access to the bottom of the cylinder. If there is baffles in the way you can probably drop the crank case off easy enough and see the piston. You could try getting up there and giving it all a little push to see if the piston rocks on the gudgeon pin. If so Then that's your problem. Then obviously you'd have to pull the head off and push the piston out.

Either way, it's gonna be a big job


The engine isn't an auto so no issue if I do go that way :)

Cheers for the help Tosh :) Interesting about the small end bearing theory (might explain the noise travelling more too?) Thanks for speaking to the engine guy for me.
All sound like sensible ideas to try and I plan to look with Dad on Saturday to see if the bearing has gone by trying to move the piston. Also I'm hoping I can borrow the camera from work to look down the bore for signs of damage ;)

Trd Shane
Tezza Fanatic!
Posts: 232
Joined: Mon Dec 02, 2013 10:44 pm
Location: Dublin

Re: Engine Knocking/Rattle! :(

Postby Trd Shane » Thu Jan 22, 2015 5:57 pm

Best of luck with it pal .. Hope it's sinething simple .. But doesn't sound good .. But there's always hoping :D let us know the findings :)
"If it can't be fixed with a hammer it's an electrical problem"

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Sun Jan 25, 2015 3:45 pm

Right then, done a few checks over last couple of days.

First dried up the oil out of the plug holes and removed the spark plugs which looked ok. Then tried pushing on the piston to see if the small or big end bearings had any movement. Expected it to be more likely on cylinder number 1 so did that one first - no movement!
So tried other three too - still no movement on any!
Hmmm, bad news hadn't found a fault where we thought we might but good news that a bottom end issue looks a bit less likely!

Next thing we thought would be easy and decided to check was the timing belt and the water pump/oil pump/tensioners etc. Took aux belts off first. The bolt holding the wiring loom (that crosses in front of belt covers) on the top right, broke and I will need to drill out so decided to remove belt covers without removing the other wiring loom bolt (on left), which was tricky and took a while but managed it. Belt looked fine and nothing seems to be wrong there. No wobble or movement or noises from any of the pump drives/gears or pulleys either!

So today we took the cam cover off to look under there at the top end. All looked ok at first glance. So then checked the valve clearances and they were all good.
Turning the crank, the cams seemed to turn ok.

Then tried something else and potentially found an issue!
If we put a spanner directly on the exhaust cam and try to turn it to look for play, as we expected it wouldnt turn and was presumably trying to turn the cam gear and belt etc. BUT then we tried to directly turn the intake cam and there is some backlash in that one! Can turn it probably about 15 degrees maybe with not much resistance at all before then it seems to stop. Can also turn it back the other way, again by the same 15 degrees. So in that "window" it's free to turn but doesnt turn the cam gear or belt etc while it is turning!

Is this normal (seems a bit odd) or does this show a fault in the intake cam/gear?

Any advice on this would be great please? Really hope we've found something but need to know a bit more about the VVTi before I get my hopes up! LOL

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Sun Jan 25, 2015 3:46 pm

Sorry for long post, just want to thorough with information :-)

Trd Shane
Tezza Fanatic!
Posts: 232
Joined: Mon Dec 02, 2013 10:44 pm
Location: Dublin

Re: Engine Knocking/Rattle! :(

Postby Trd Shane » Sun Jan 25, 2015 5:43 pm

How did you check the bottom end play !! By just pushing down on piston ... I wouldn't rule out bottom end issue as you wouldn't get significant access to see if there's play pushing down on the piston from top end won't really reveal any play as such if take off sump and check for play by pushing up and down on the conrod ... That's if there is significant access .. That would be your best bet I'd say ...
"If it can't be fixed with a hammer it's an electrical problem"

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Sun Jan 25, 2015 9:31 pm

Usually a goid method for checking cos even though u can't see the piston you can feel it or if it's bad and there's a big gap might hear it knock. Not ruling it out completely but wanna check out this VVTi thing first and remove as little as possible until ive ruled out simpler stuff one by one :-)

Seemed odd that it would turn independent to the cam gear and belt and could throw the timing out and/or cause a valve to contact maybe?

mikeb
Trc Off
Posts: 85
Joined: Mon Sep 19, 2011 8:40 pm

Re: Engine Knocking/Rattle! :(

Postby mikeb » Mon Jan 26, 2015 12:48 am

Dual mass flywheel failure a possibility?

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Mon Jan 26, 2015 1:03 am

Good thinking but it's nit got the dual mass still as previous owner replaced with a lightened aluminum one ;-) ( that's what he told me anyway)

User avatar
Tosh21
Altezza Guru
Posts: 521
Joined: Mon Jan 20, 2014 10:12 pm
Location: Oxfordshire

Re: Engine Knocking/Rattle! :(

Postby Tosh21 » Mon Jan 26, 2015 2:35 pm

If the rings aren't broke you won't be able to move the piston as they hold it central so you would have to get under and move the con rod to check for a bearing failure. Sorry I just realised I said try wiggle the piston from underneath, I meant con rod. My bad.

The pulleys should not move independently at all. No backlash or anything. Did you try turn it with the cambelt Still on? And as you turn the middle of the pulley the middle spins but the big outer gear which does your timing doesn't move?

It could be that as the engine turns the inner bit of the pulley is getting thrown backwards and forwards causing that noise.

If you decide to take it off and replace it take it apart and see what went wrong. Just make sure it's in a vice so the thing doesn't explode when you undo the bolts lol

When you take it off undo the big Allen in the middle which is just a seal cap and then there is a nut under that. Put an spanner on the flat bits of the cam to stop it spinning its done up quite tight.

User avatar
Gojira san
Trc On!
Posts: 57
Joined: Fri Jan 09, 2015 3:04 pm
Location: Japan

Re: Engine Knocking/Rattle! :(

Postby Gojira san » Mon Jan 26, 2015 2:39 pm

i hope you can get it sorted soon. and that it's a small problem.
while it's no competition, if my engine man was right? i'll buy him a coffee on your behalf.

i could even try to scratch up some cam pulleys if you don't find any. :wink:

keen to know the end result.

User avatar
RS Tom-Hundred
Tezza Fanatic!
Posts: 450
Joined: Fri Nov 28, 2014 3:31 pm
Location: Cambridgeshire

Re: Engine Knocking/Rattle! :(

Postby RS Tom-Hundred » Mon Jan 26, 2015 8:28 pm

Thanks for the replies :-)

I see what u mean about the piston rings. We were not trying to rock the piston within the cylinder though, rather push straight down on it when it was just after TDC to see if there was any up/down play caused by the bearing being worn and there being a gap between the rod and crankshaft.
This sort if thing:
http://m.youtube.com/watch?v=pYleKxjl0u ... e=youtu.be

That's interesting (and promising) that there shouldn't be any play on cam shafts, as we thought! :-)
Yes, the cam belt is still on. We took the cam cover off and put an open end 24mm spanner directly on the flats of the camshafts. Exhaust one had no movement/play at all - totally solid and wouldnt turn the shaft.
Intake one moved with not much resistance at all but not even a tenth of a turn probably, then stopped solid. And we could then turn it back again by same amount in opposite rotation, then stopped solid again. As it is being turned, neither the cam gear nor the timing belt etc moves.

I've just been out and tried turning the outer casing bits of the VVTi stuff on the ends of the cam gears and no movement there (as u would expect but realised I hadn't checked that yet)

So is it 100% that the intake cam shaft shouldn't move like this? Has anyone got their cam cover off (or planning to soon?) and could do me a massive favour and pop a spanner/adjustable on there and triple check this for me please? :-)


Return to “Engine & Transmission section”

Who is online

Users browsing this forum: No registered users and 4 guests