Big End Bearing Failure?????

[Hailz]

Ok so I hear more and more about the unfortunate folk out there that have had a big end bearing go in there Subbys.

The question I want to know is why the hell does this happen so often? There must be a reason for it? Obviously things like thrashing the tits off it when cold, never doing an oil change or letting the oil level sit at the "shell be right mate" (low) level for a month or so would all contribute to this kind of thing happening. Is there any main cause for it? My mates B4 has done 190km's on the original engine and it runs like a trooper - doesn't miss a beat! Yet I hear of some guys just clocking up 80kms and having it crap out. Someone must know what causes it????

[Guest boostcut]

detonation would be a main cause, and as you already know, poor servicing and crap oil.

[rockr]

backing plate on the oil pumps come loose causeing a drop in oil pressure.

[Guest DMSREX]

 boostcut said:

detonation would be a main cause, and as you already know, poor servicing and crap oil.

X 2

Det, along with wrong oil grade being used leads to spun bearings.

[ReubenH]

Keep it on the good oil, magnatec's is as low as i'd ever go on a stock engine, edge is a good choice. Change at least every 10,000KM's, but it's better to do it every 5000. And keep it on the good gas to avoid det. NEVER use 91, and do NOT up the boost if you're on 95.

When i did my first oil change on my car (it was ex repossessed), it was a black goo that came out. 2 or 3 weeks later, after getting on some 10w-40, it blew it's big end. I put it down to poor service... damn poor service. Something tells me if the previous owner couldn't afford to keep the car, he could afford the good oil, and the frequent oil changes.

Oh well, i had to rebuild it... damn, what a pain

(i love my built engine)

[Jammasta]

 ReubenH said:

Oh well, i had to rebuild it... damn, what a pain

(i love my built engine)

Do you still love it?

And what everyone else said, good oil and good fueling, i got 195ks out of my type R, and AFAIK is still going well with the new owner.

[Guest boostin]

I don't agree with servicing and quality oil. The number of cars I've seen that are regularly serviced and not thrashed to have blow a big end is shocking. I doubt even oil surge was an issue in these cars. They are just daily drivers for Joe and Jane Average, who just commute around town and drop the kids off at school.

Sure it does happen for the above reasons, but not anywhere near to what you are thinking.

I put it down to -

1. AFM's dying and leaning out mixtures, causing detonation.

2. Fuel pumps dying causing the same.

3. Crap NZ fuel detonating. Most hi-po imports from mid 90's on were designed around 100+RON.

4. Faulty bearings. With that many made, not all can be perfect!!

I worked on a Legacy a month or so back that had the oil light on and a squeaking noise from the engine. It turns out it hadn't been serviced in 60,000+ kms and the oil was pure sludge. It fell out in gobs when I pulled the sump plug out, and even though the oil filter was full nothing came out when I turned it upside down. We ended up dropping a secondhand engine into it, there was no way it was coming back from that!

I have heard of places fitting new AFM's and fuel pumps at the 100k cambelt service. Probably not a silly idea!

All I can say is to use 98 wherever possible, and get your AFM and fuel pump checked annually. I cringe when I see people filling up BH twin turbos on 91. That poor engine doesn't stand a chance. Sadly most people have no idea what gas they are supposed to use and just throw in whatever is cheapest.

[ReubenH]

Damn that must be depressing seeing good cars in states like that.

[Hailz]

 ReubenH said:

Keep it on the good oil, magnatec's is as low as i'd ever go on a stock engine )

Hey I use Magnatec 10/30 thats what Armsrtongs in Chch put in it, is that a decent oil? I've been told so?

[Guest keltik]

Magnatec works for me. Especially when ubercheap otto have a 20% sale.

Wasnt a big fan of edge at all. Elf was awesome

[Guest]

What does detonation sound like? and how can you tell if your afm is on its way out??

[dubbedup]

possibley easiest way to describe det is shaking coins in a steel tube....

[Guest boostin]

Or go thrash a twin turbo on 95...

[dubbedup]

lol put some 91 so it definatly happens...

(I take no responsability for a blown motor)

[Stoffa]

I had a vacuum line pop off my MAP sensor after some mods were carried out and ran a bearing on the track in about 10 mins. I was using an external boost controller forcing it to hold high boost while the ECU thought it wasn't boosting. So not enough fuel causing detonation.

and its still in 1000 pieces :'(

n.b make sure you use cable ties or clamps on vaccuum lines

[Guest NZBG]

Bugger bugger bugger. Only had mine a week. Just found out the owner for last two years has been putting 91 in, bugger bugger bugger...

[nt_a_foz]

 NZBG said:

Bugger bugger bugger. Only had mine a week. Just found out the owner for last two years has been putting 91 in, bugger bugger bugger...

wait for nunga nunga nunga ...its a lovely noise to the ear (NOT)

[Guest boostin]

 nt_a_foz']

[quote name='NZBG said:

Bugger bugger bugger. Only had mine a week. Just found out the owner for last two years has been putting 91 in, bugger bugger bugger...

/quote]

wait for nunga nunga nunga ...its a lovely noise to the ear (NOT)

Or like the 2005 EJ25 I had the other day, a very loud clack clack clack!! It helps to have oil in the sump though. This car had less than 500mls....

[swiftbrad]

is there a short answer as to how you can tell/check if ur afm and fuel pumps sweet or getting tired?

[Guest boostcut]

mechanic. short enough?

[Guest]

I still remember the sound of nunga nunga nunga like it was yesterday, tho i don't think i'v ever heard det before, is it loud? loud enough to hear over the exhaust (big bore)?

[swiftbrad]

 boostcut said:

mechanic. short enough?

yip thats pretty short alrite

[Guest boostcut]

you will/should know what it sounds like when it happens...

[Guest boostin]

If you know anyone with a TT get them to take you for a spin. 1st boost usually gives a pretty good rattle!!