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Big end bearing questions

PostPosted: Thu Jan 27, 2011 8:27 pm
by chopster
Hi guys and gals,

I have tried to read up as much as I can regarding the big end bearing failing on our cars, but I still have a few questions.

1. Is it the result of prolonged low oil levels only? Or can it occur from neglecting other things?
2. Is it something that can be avoided? Or is it just a matter of time on some H6's regardless of how well you maintain it?
3. What are the earliest signs pointing to eventual big end bearing failure (presuming the signs are ignored)?

Looking forward to your comments.

Re: Big end bearing questions

PostPosted: Fri Jan 28, 2011 9:50 am
by nico
From my 1st hand experience...

1. No rhyme or reason (Serviced with Subaru, oil always topped up between services, no hard driving while cold)
2. See 1.
3. 1st sign is knocking noise from engine. Once you hear this it's too late

Keep your car serviced (preferably by Subaru) at regular log book intervals - 6 months or 12500 k's, whichever comes 1st (I had a fight on my hands because I'd always servicd @ 12500k's & gone past 6 months a couple of times :angry2: ). If you do have a failure you have a good chance of Subaru coming to the party even if you are out of warranty, as this is a known issue (even if they won't admit it).

PM me if you want any more info

Re: Big end bearing questions

PostPosted: Fri Jan 28, 2011 10:44 am
by chopster
nico wrote:From my 1st hand experience...

1. No rhyme or reason (Serviced with Subaru, oil always topped up between services, no hard driving while cold)
2. See 1.
3. 1st sign is knocking noise from engine. Once you hear this it's too late

Keep your car serviced (preferably by Subaru) at regular log book intervals - 6 months or 12500 k's, whichever comes 1st (I had a fight on my hands because I'd always servicd @ 12500k's & gone past 6 months a couple of times :angry2: ). If you do have a failure you have a good chance of Subaru coming to the party even if you are out of warranty, as this is a known issue (even if they won't admit it).

PM me if you want any more info


Thanks Nico.

1. not good (Complete service history with Subaru, I plan on doing that, I never do that)
2. :(
3. not good at all :( :(

I read your thread about your big end bearing failure and the issues you had with Subaru. Very informative; thank you for taking the time to post it up. I just purchased my car and the previous owner had it serviced by the book according to the kilometre intervals but not the time intervals. For example, it has done 54K kms and the 50K service was done at 48K but that was in February 2010! The previous service was done at the appropriate kms but was in early 2009! So... 12 months between servicing. I don't think I will have any luck with Subaru should ANYTHING go wrong, let alone a big end bearing failure. Slightly paranoid now.

Re: Big end bearing questions

PostPosted: Fri Jan 28, 2011 11:13 am
by Robbks
Tip...
do an oil change at 5000km intervals yourself
don't necessarily need to do the filter either

always LOOK at your oil for signs of metal particles or a metallic "sheen" to the oil which can show the beginnings of excessive bearing wear.

also get a Fumoto Oil Drain Valve for no mess oil changes
http://fumoto.com.au/

i've used them on all my cars, except i buy the one with the nipple on it.
attach hose to nipple,
other end of hose in an empty oil bottle
open valve
no drips, no fuss, no hot oil to burn you

I also don;t care for super-fancy modern synthetic oils
for anything with 50k km's or more on it
Castrol Magnatec 10W40
It has high detergent properties (it goes black quickly) and removes all the sh!t from your engine components and bearings.

Re: Big end bearing questions

PostPosted: Fri Jan 28, 2011 11:37 am
by nico
chopster wrote:I just purchased my car and the previous owner had it serviced by the book according to the kilometre intervals but not the time intervals. For example, it has done 54K kms and the 50K service was done at 48K but that was in February 2010! The previous service was done at the appropriate kms but was in early 2009! So... 12 months between servicing. I don't think I will have any luck with Subaru should ANYTHING go wrong, let alone a big end bearing failure. Slightly paranoid now.


I think most reasonable people do only service by the k's! I wouldn't worry too much though, I think it's less than 1% failure rate. Just try to enjoy what is a fantastic drivers car - go the wagon :ok:

What I would recommend is, if you're gonna service with Subaru, make sure you keep it at the one dealer. Then he'll get to know the car & any good mechanic after a certain time servicing a car will take ownership over the health of that vehicle, so should you have any major failure I would hope that he'd go into bat for you with Subaru Aust.

You can always do what I did & just don;t take no for an answer :wink:

Re: Big end bearing questions

PostPosted: Mon Jan 31, 2011 4:09 pm
by chopster
Robbks wrote:Tip...
do an oil change at 5000km intervals yourself
don't necessarily need to do the filter either

This is a possibility. I'm going to see how much oil she uses between standard 12.5k service intervals first.

Robbks wrote:always LOOK at your oil for signs of metal particles or a metallic "sheen" to the oil which can show the beginnings of excessive bearing wear.

Thanks, good advice. The oil on the dipstick was in very good condition. Not black or 'sludgy'; pretty much what I would expect oil to look like after only 4-5K kms since an oil change in an engine in good condition.

Robbks wrote:I also don;t care for super-fancy modern synthetic oils
for anything with 50k km's or more on it
Castrol Magnatec 10W40
It has high detergent properties (it goes black quickly) and removes all the sh!t from your engine components and bearings.

For now I will be sticking to what the Subaru dealer uses as I will be taking it back to them for servicing.

Thanks for the advice and comments. Greatly appreciated. :biggrin:

Re: Big end bearing questions

PostPosted: Mon Jan 31, 2011 4:18 pm
by chopster
nico wrote:I think most reasonable people do only service by the k's! I wouldn't worry too much though, I think it's less than 1% failure rate. Just try to enjoy what is a fantastic drivers car - go the wagon :ok:

What I would recommend is, if you're gonna service with Subaru, make sure you keep it at the one dealer. Then he'll get to know the car & any good mechanic after a certain time servicing a car will take ownership over the health of that vehicle, so should you have any major failure I would hope that he'd go into bat for you with Subaru Aust.

You can always do what I did & just don;t take no for an answer :wink:


I agree with you. The whole time interval thing seems like a bunch of crap to me and just a way for car manufacturers to ensure they get your money one way or the other. Nothing like scaring people into believing their pride and joy will fall apart if they wait more than 6 months between servicing to get them to part with their hard earned.
I'm trying not to worry too much and, as you said, enjoy driving the car.

Thanks for taking the time to let me know your thoughts and advice. :biggrin:

Re: Big end bearing questions

PostPosted: Mon Jan 31, 2011 6:13 pm
by Robbks
chopster wrote:
Robbks wrote:always LOOK at your oil for signs of metal particles or a metallic "sheen" to the oil which can show the beginnings of excessive bearing wear.

Thanks, good advice. The oil on the dipstick was in very good condition. Not black or 'sludgy'; pretty much what I would expect oil to look like after only 4-5K kms since an oil change in an engine in good condition.


The issue with the oil being clean IS a problem in itself.
the engine in my Legacy has only done 50K Km's and is extrememly healthy
and the oil is black by 3000km. which is a good thing as it's removing the carbon deposits in the engine.
oil that is clean after 3000km is NOT cleaning the gunk out of there.

Re: Big end bearing questions

PostPosted: Tue Feb 01, 2011 7:38 am
by chopster
Robbks wrote:
chopster wrote:
Robbks wrote:always LOOK at your oil for signs of metal particles or a metallic "sheen" to the oil which can show the beginnings of excessive bearing wear.

Thanks, good advice. The oil on the dipstick was in very good condition. Not black or 'sludgy'; pretty much what I would expect oil to look like after only 4-5K kms since an oil change in an engine in good condition.


The issue with the oil being clean IS a problem in itself.
the engine in my Legacy has only done 50K Km's and is extrememly healthy
and the oil is black by 3000km. which is a good thing as it's removing the carbon deposits in the engine.
oil that is clean after 3000km is NOT cleaning the gunk out of there.

I understand what oil is supposed to do and I should have been more clear with my previous comment. Whilst the oil is not black, it is certainly not clean or the colour of new oil. That's what I meant by it looking like what I would expect it to.

Re: Big end bearing questions

PostPosted: Mon Feb 28, 2011 2:24 pm
by Jelwin
lack of oil will be the only thing that will destroy a bottom end
the same thing happened to my motor exactly 12 months ago just out of Glenmaggie in Gippsland. 8000kms after the last service i noticed a knocking sound. turns out that i had super low oil, which in turn dropped the pressure of the oil. this lack of pressure stopped the hydraulic tensioner for the cam chain from working, which then made the cam chain skip teeth. this made the valves literally bounce off the pisons on every stroke. if i had of stopped driving the only major damage would have been some bent valves etc. but the lack of oil meant that the bottom end was running near dry, and in turn melted three bearings sending 3 con rods through the crank case. really not good.

Re: Big end bearing questions

PostPosted: Wed Apr 06, 2011 9:14 pm
by Tradewind
Subaru had material problems with bearings across a range of their engines

I believe the issue has gone away with better materials etc, but there was certainly a period where both 4 cyl and 6cyl were dying from bearing failure.

Definitely not limited to H6

Re: Big end bearing questions

PostPosted: Thu Apr 07, 2011 3:04 pm
by MH3.0R
My opinion only, and not authoritive on anything automotive, but good filtration is as essential as good oil for the Subie engines. Personally, I use this one from Ivan at x3e Motorsport:

http://x3emotorsports.com/cart/index.ph ... ath=34_131

He also maintains stocks of the high grade particle filters and seals and has over the last 3 plus years I have known him.

Since using the Trasco filter, I have seen my oil maintain a new look for the entire period between servicing intervals. All the black stuff is held in the filter element and is discarded after servicing. Subaru always pack the dirty filter for me to see after a service.

I did revert back to standard filters for about two service intervals and now notice the discolouration of the oil at about 5k, so next service I will be back to the Trasco.

Re: Big end bearing questions

PostPosted: Thu Apr 07, 2011 5:43 pm
by kiks
A dirty big diesel cummins oil filter (12 dollars) and an eBay relocation kit for the pissy small filters Subaru use ftw. As for big end failure, or mains, or little end. Don't drive your car with low oil, and change
It every 5000km. This can be done in your driveway for 30 bucks a hit between overpriced dealer services if you like. Several 500+ hp ez30's get around with nothing special except big filters and total or castrol 10 50 fully syn.

Main thing is making sure it has warm oil and proper oil pressure before revving the tits out of them. A minute to warm up is not much to ask in such a highly strung close tolerance motor like an EZ. Or any motor for that matter, except a rental.

Re: Big end bearing questions

PostPosted: Thu Apr 07, 2011 6:17 pm
by Kekotic
kiks wrote:except a rental.

:lol:

My oil turned dark within 2,000km after my last oil change.
Do you recommend doing that diesel oil flush? How would you go about it.

Re: Big end bearing questions

PostPosted: Thu Apr 07, 2011 11:15 pm
by kiks
i meant a big oil filter. Like a Image

just relocated to somewhere convenient so it drains when changing. The size of the filters subaru use are disgraceful.