bennytyper

want to check a few things if anyone can help, gutted after bottom end on my v5 has just given way. only had service 2 weeks ago! i always check oil levels(when cold), should i be doing this when car is cold? should i be checking anything else? (always checking coolant also)what is the main reason for bottom ends going? thanks

joz8968

iTrader: (13)

Who did the oil change? Were they a reputable specialist that know their Suabrus!

Seems like you've fallen foul of the infamous crank sensor not being removed for the dry cranking priming process...

Rosy

All V5/6 bottom ends are prone to failure for lots of reasons that I am sure you have read about eg MAF failing/not changed, not dry cranked at service, power level, sustained high speed, and most importantly run on the correct octane fuel and mapped (any changes need a need tweak even an induction kit).

I am sure many still fail or run fine when doing these things as luck has a bit of a hand in there as well. I speak from experience as I had my first block fail at service (just bought it), and then again at the 1000 mile run in service on the new block.

I am sure others will add too or disagree, but I just know I have been through a few blocks in my P1 and havent put my finger on the reasons fully.

Hope you get sorted

bennytyper

northants subaru did service, i asked whether they remove the crank sensor, they said no need they just fill oil filter up first, car mapped to run all current anchillaries.

nick172sport

iTrader: (6)

as joz said subaru need to address this problem contact vosa like ive done with leaking fuel fault thet are investigating it

bennytyper

can u explain a bit more please? thanks

TonyBurns

iTrader: (3)

Oil starvation to the main bearings, det, unmapped for UK fuel etc.

No reason to go to vosa, the version 5 car is a JDM domestic market car, vosa have nothing to do with them.

Tony

bennytyper

thanks for reply, car has been mapped for uk fuel, is oil starvation a result of not removing this crank sensor thing (should this be removed for oil service?)or something else? cheers

TonyBurns

iTrader: (3)

When the oil is drained there is no oil in the oil wells, when you top up/replace the oil (even with filling the filter) this can put strain on the oil pump and/or not provide the oil needed to the main bearing for a few seconds, so one of the failures is the oil pump due to it needing to work hard or the bearings due to no oil, so dry cranking is recommended as it builds up the oil pressure to start with.
I would also replace the oil pump at 60k miles to be on the safe side on a classic.

Tony

bennytyper

thanks mate, hope u dont mind me asking another question but when checking oil levels do i do it when engine is cold? thanks

nick172sport

iTrader: (6)

i think the problem needs addressing as uk cars suffer from this problem hence im frightend to death at having a oil change done

Steve Whitehorn

iTrader: (13)

Just make sure you take it to someone you can trust. Not a dealer!
Someone who WILL dry crank it

nick172sport

iTrader: (6)

this is the problem even my local garage wont dry crank and they service subarus they say its nonsence so wont be using them they stick to the book

TonyBurns

iTrader: (3)

Not that many cars suffer in reality, its mainly older classics with old worn out oil pumps, most will have bad service history, run ragged and cheap oil used, P1's suffered from det when modified and not remapped, that caused issues with the big end bearings.
There is no one cause, probably multiple causes, and as most cars are 9+ years old that suffer this, not much that can be done, they are well outside their warranty and pushing 100k+ miles.

Tony

Steve Whitehorn

iTrader: (13)

Without opening the old can of worms. Many do get away with not dry cranking and just wont listen. But not doing it during an oil change can lead to engine failure. where are you? If you are on that island listed on your profile - then I guess your options are limited

How old is the car...as the screws in the oil pump can work their way loose. Worth replacing at somepoint.

And as Tony has said. This is just one cause of engine failure.

ginger321

excuse my ignorance troops, how do you dry crank the engine?

nick172sport

iTrader: (6)

i know lads im in manchester its a 2001 bug and im overdue the oil change cause off this

my94wrx

iTrader: (4)

i agree with tony on the multiple causes as for dry cranking, have never done it in 5 years and wont ever do it on just a oil change, this is just my opinion.

joz8968

iTrader: (13)

Not dry cranking in itself prob won't be the DIRECT cause of the failure, but could be the "final nail in the coffin" for an old, worn engine, if transient metal/metal bearing /journal contact is made, due to the high combustion pressure driving the air above the oil level through the bearing/journal gap. This is the theory, anyway - as has been documented in many "oil change" threads now.

This is prob why you sometimes hear of bottom end failures either hours, days, weeks or months after...

fieldy1978

I really dont agree with dry cranking, if an engine cant start and run for a second with no oil on the big end then its on its way out anyway. I always fill the oil filter but the pressure from the pump will lube the engine in less than second!