Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Big End Bearing expertise required
I am in the middle of investigating a knock on the lower end of the engine. ( Maybe being paranoid with small number of failures on here. Don't want mine to go same way) So i thought I would investigate the bottom end of the engine. Nothing much untoward, fore and aft crankshaft play within limits no signs of over heating. Dropped the big end caps to see if any bearing wear as I can't find any play with them. Pictures below. Some show slight signs of wear.
No spun bearings.
Some glittery metal particles in oil as sump dropped. 20miles driven and about 15 WOT for fuel pump diagnoses since oil filter and oil changed.
Any expertise out there would be appreciated, with comments on options.
Regards, Adam
Cylinder 1 Crank shows some signs of discolouring
No1 Big End Cap
No2 Big End Cap
No3 Big End Cap
No 4 Big End Cap
No 5 Big End Cap
No 6 Big End Cap
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2016 D4 Landmark Indus Silver
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14th Mar 2016 3:57 pm
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8246
Nothing there that would concern me, I admire you for checking, just make sure everything (shells and caps) go back in the exact order they came off.It can when others can't,
It will when others won't,
It goes where others don't.
14th Mar 2016 4:14 pm
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Thanks for your comment.
Don't worry. I marked the front direction and only one came off at a time. Just need to torque them up now. Not checked the main bearings yet. Thats next.Vehicles
2016 D4 Landmark Indus Silver
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14th Mar 2016 4:32 pm
lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
The silver in the oil can really only come from the shell bearings.
14th Mar 2016 5:03 pm
galwaygreen
Member Since: 30 Oct 2011
Location: plymouth
Posts: 6525
are they tagged bearing....did you take engine out to do
14th Mar 2016 5:35 pm
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
lynalldiscovery wrote:
The silver in the oil can really only come from the shell bearings.
Would you replace them?
No not tagged bearings. No engine still in place. Until I decide if they need replacing..Vehicles
2016 D4 Landmark Indus Silver
2005 D3 HSE Silver
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14th Mar 2016 7:34 pm
lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
As you have gone as far as you have I would replace them, I think they are now available at sensible money.
14th Mar 2016 8:17 pm
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Lynalldiscovery do you think they could be replace with the engine in situ. Otherwise body off which I can do, and engine out. Prob about another 3 days work for that. Vehicles
2016 D4 Landmark Indus Silver
2005 D3 HSE Silver
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14th Mar 2016 8:25 pm
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1476
I think the big end bearings can be changed in-situ.
Mains bearings require engine out - crank has to come out and because of that oil pump needs removing as well as the rear crank seal - which requires gearbox removal.
Before you go to those lengths, check the bearing clearances (wear of bearings against crank diameter) by using plastigauge which is a very accurate method to check amount of wear.
The following photos are self explanatory, as i used it to check new crank with new bearings for my own peace of mind ( i randomly checked both main and big end bearings).
Click image to enlarge
Click image to enlarge
0.100 is really about the limit although i was surprised at the clearance of the new crank and bearing as i was expecting a somewhat tighter clearance, but this may have been because i did not go through the full bolt tightening procedure of 60nm,145nm and 90 degrees - i settled for 60nm as it was only a check.
If you have problems getting hold of the plastigauge, let me know i can send a couple of strips and i can photocopy the 'measurement gauge' but it will still be accurate.
15th Mar 2016 1:39 am
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Thanks Defector. I am going to check the main bearings today. Do you think they could be checked in situ.
Then if they need replacing I will remove the engine and replace all.
Thank you for the offer of plastigauge I ordered some yesterday should be here today.
Don't want to worry you (and maybe reading it incorrect) but I read the the main bearing clearances should be between 0.022 and 0.040mm see image below. have attached the full document below as well.
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8246
With a minimum clearance of 0.022 You should be able to change them all in situ, did you check the oil pressure before strip down?- low pressure is a good indication of wear providing the oil pump is good. If you decide to change the shells I would investigate the possibility of fitting new type shells with the anti-rotating lugs.
High mileage can justify changing the shells.It can when others can't,
It will when others won't,
It goes where others don't.
15th Mar 2016 9:00 am
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Thanks M3DPO.
Car has only done 110000miles. oil pump was brand new in November. I did find what looks like a bit of filter material in the pick up tube which could of caused some of the wear due to a lower quantity of oil being pushed around by the pump.Vehicles
2016 D4 Landmark Indus Silver
2005 D3 HSE Silver
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15th Mar 2016 9:15 am
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1476
Yes you should be able to check the Main bearing clearance in-situ. Just make sure the plastigauge doesn't roll off when offering up the cap, may be worthwhile putting a dab of grease on one end of the plastigauge to hold it in place, just enough so it doesn't interfere with the plastigauge sticking to the journal/bearing surface.
The clearance figures you quote are fairly standard (and was the clearance -0.025- for the Toyota engine i rebuilt) and Plastigauge do provide a formula depending on journal thickness.
I will try it on another journal and go the full tightening routine, it did make a difference when i did it on a big end journal.
My new Mains bearings (not big ends) have the tabs to prevent turning. i just machined the cap with a Dremel after marking the location. Only takes a minute or so per cap.
15th Mar 2016 1:22 pm
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1476
Right,
Just been and done Mains No.2 with Plastigauge but tightened the full sequence - 60nm, 145nm and 90 degrees, and the reading was just fractionally over 0.038mm....phew. Within spec.
15th Mar 2016 2:14 pm
brightyuk
Member Since: 11 Apr 2013
Location: Bedworth
Posts: 394
Defector Thanks,
Unfortunately the main cap bolts on the left hand side of the engine aren't accessible with air con compressor in the way. So going to lift the body, and remove the gear box and replace the bearings with the engine in. If i am going to the trouble to check them might as well just replace them.
Do you have the part number for the timing ring from Citroen at all please.
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