Grit found after oil change
Discussion
Finished an oil change on the weekend and my heart sank a bit when I was decanting old oil into bottles for disposal. At the bottom of the washing up bowl (brand new) I used to collect the oil from the car was a fair amount of what can best be described as grit. I have a link to a large image below:
Image here
The grit ranged in size from tiny specs of sand to about 1mm in diameter and was very rough to the touch, if you rolled in between your fingers it would eventually crumble into smaller particles.
My thoughts initially were that it was something fairly bad (big ends?) but wonder if it could possibly be something less sinister. I do know the previous owner wasn't that careful when it comes to fuel, they used premium supermarket fuel as far as I know.
I have had the car for about a year and around 5,000 miles and this is the second oil change in that time. Since owning the car I have used only Shell v-power (apart from 2 fill-ups when I got the car). Is it possible that these particles are carbon deposits being 'cleaned' by the prolonged use of the much better fuel?
So far there are no other symptoms, the car starts fine first time everytime from hot or cold with no rattles or knocks. There's no smoke other than when completely flat-out, when there is apparently some dark smoke coming from the exhaust. The car doesn't use up a lot of oil and the coolant hasn't needed topping up since being completely replaced last spring. The car does pop a little on the overrun especially when hot.
I have good mechanically sympathy but am I kidding myself with the above ideas? Are there any other easy ways of checking? I am planning on doing another oil change next month to have another look.
Image here
The grit ranged in size from tiny specs of sand to about 1mm in diameter and was very rough to the touch, if you rolled in between your fingers it would eventually crumble into smaller particles.
My thoughts initially were that it was something fairly bad (big ends?) but wonder if it could possibly be something less sinister. I do know the previous owner wasn't that careful when it comes to fuel, they used premium supermarket fuel as far as I know.
I have had the car for about a year and around 5,000 miles and this is the second oil change in that time. Since owning the car I have used only Shell v-power (apart from 2 fill-ups when I got the car). Is it possible that these particles are carbon deposits being 'cleaned' by the prolonged use of the much better fuel?
So far there are no other symptoms, the car starts fine first time everytime from hot or cold with no rattles or knocks. There's no smoke other than when completely flat-out, when there is apparently some dark smoke coming from the exhaust. The car doesn't use up a lot of oil and the coolant hasn't needed topping up since being completely replaced last spring. The car does pop a little on the overrun especially when hot.
I have good mechanically sympathy but am I kidding myself with the above ideas? Are there any other easy ways of checking? I am planning on doing another oil change next month to have another look.
I think you're frightening yourself over nothing. If there are no rattles, knocks, slapping etc... Your engine is very probably just fine.
Wasted engine oil comprises of very fine particles of many different sorts of metals, combustion materials, carbon etc etc....The metals come from the cylinder walls, piston rings, pistons, bearings, crank etc...
A lot of these will clump together and form larger particles but will break down if you rub them. If there were large particles of metal you would know about it, and they don't crumble either.
Next time you do an oil change, drop the old oil, empty the oil filter too. Then flush the engine with a very cheap 10W40 mineral oil, don't forget to fill the old oil filter with fresh oil before you put it back. Don't use a flushing agent/chenicals before you do an oil change as that doesn't do the engine any good at all.
Then take the car out for a gentle run, up and down the gears/revs and then drop the flushing oil. You'll see how much more crap comes out of the engine. Then when you put a new filter on and refill with the good stuff you know you're putting it into a nice clean engine.
Then the next oil change see how much crap is in the oil when you drop it, you may find there is a lot less of it and hopefully no sharp and hard metal particles or bigger shards. Then you'll know for sure what's going on if there is anything going on.
Wasted engine oil comprises of very fine particles of many different sorts of metals, combustion materials, carbon etc etc....The metals come from the cylinder walls, piston rings, pistons, bearings, crank etc...
A lot of these will clump together and form larger particles but will break down if you rub them. If there were large particles of metal you would know about it, and they don't crumble either.
Next time you do an oil change, drop the old oil, empty the oil filter too. Then flush the engine with a very cheap 10W40 mineral oil, don't forget to fill the old oil filter with fresh oil before you put it back. Don't use a flushing agent/chenicals before you do an oil change as that doesn't do the engine any good at all.
Then take the car out for a gentle run, up and down the gears/revs and then drop the flushing oil. You'll see how much more crap comes out of the engine. Then when you put a new filter on and refill with the good stuff you know you're putting it into a nice clean engine.
Then the next oil change see how much crap is in the oil when you drop it, you may find there is a lot less of it and hopefully no sharp and hard metal particles or bigger shards. Then you'll know for sure what's going on if there is anything going on.
Cheers for that. I've done plenty of oil changes and never noticed quite as much crud but I've never use any engine cleaners or fuels with 'cleaners' in them. That's a great idea, re: the flush with cheap oil, I will do exactly that. I have been using Gulf Competition 10w-40 fully synthetic along with a blue OEM Subaru oil filter, I assume this is OK?
Thanks again, the car seems fine but with so many horror stories involving Imprezas that are getting on a bit it's good to get some reassurance with something like this.
Thanks again, the car seems fine but with so many horror stories involving Imprezas that are getting on a bit it's good to get some reassurance with something like this.
Fuchs is good stuff, nothing wrong there. Subaru STi oil filter is good too, probably the best to use. Go to B&Q to their motoring section and they do a really cheap 10W40 mineral oil for about £12.99.
You only get horror stories with Subaru when people don't do things right or there is some inherent problem with something specific due to bad design or manufacture/build, but more often than not with Subaru it's down to how the servicing is done.
Follow some simple procedures, even down to starting your car with your foot on the throttle pedal flat to the floor to avoid the car starting until it's built up enough oil pressure to turn the oil light off the first time after you've done an oil and filter change.
Simple things to make sure your P&J goes on forever.
You only get horror stories with Subaru when people don't do things right or there is some inherent problem with something specific due to bad design or manufacture/build, but more often than not with Subaru it's down to how the servicing is done.
Follow some simple procedures, even down to starting your car with your foot on the throttle pedal flat to the floor to avoid the car starting until it's built up enough oil pressure to turn the oil light off the first time after you've done an oil and filter change.
Simple things to make sure your P&J goes on forever.
ScoobieWRX said:
Follow some simple procedures, even down to starting your car with your foot on the throttle pedal flat to the floor to avoid the car starting until it's built up enough oil pressure to turn the oil light off the first time after you've done an oil and filter change.
Not trying to sound like an arse, just curious 
What's the difference between starting your car after an oil change, and starting your car after its been sat, say over night? if you've filled the oil filter before installing a new one then isn't it the same? I mean all the oil will be in the sump and oil filter so, its the same isnt it?
After an oil change your oil galleries and oil pump will be empty. When you drain the oil from your engine you would normally take the dipstick out and remove the oil filler cap to allow air in so the oil freely empties without any vacuum, resistance. Your bearings, crank, rods etc...won't be bone dry because there is always a very thin film of oil left behind but nothing will be covered or soaked in oil properly until the pump starts doing it's thing and oil pressure builds to normal levels.
That thin film of oil in the bearings won't be there very long if you start the engine and let it idle. The light doesn't go out straight away. Oil pressure from a fresh refill takes a little while to build up even with the engine started. When your oil light goes off you know normal oil pressure is restored. This is why it's better to crank the engine over on the key for just a few revolutions without starting so there is less danger of doing damage. This way you keep engine loads extremely low, good for your crank, as there is no combustion going on.
With a parked car over the space of a few hours or overnight some of the oil from from the inner workings of you engine drains back into the sump, but enough is left behind in the oil galleries and oil pump to build oil pressure very quickly on next startup.
Next time you do an oil change see how long it takes for oil pressure to build up on first start after a refill. You'll see it takes considerably longer than when the car has been stood for just a few hours, or overnight. Normally you turn the key and within just a couple of engine revolutions the oil light goes out very quickly.
That thin film of oil in the bearings won't be there very long if you start the engine and let it idle. The light doesn't go out straight away. Oil pressure from a fresh refill takes a little while to build up even with the engine started. When your oil light goes off you know normal oil pressure is restored. This is why it's better to crank the engine over on the key for just a few revolutions without starting so there is less danger of doing damage. This way you keep engine loads extremely low, good for your crank, as there is no combustion going on.
With a parked car over the space of a few hours or overnight some of the oil from from the inner workings of you engine drains back into the sump, but enough is left behind in the oil galleries and oil pump to build oil pressure very quickly on next startup.
Next time you do an oil change see how long it takes for oil pressure to build up on first start after a refill. You'll see it takes considerably longer than when the car has been stood for just a few hours, or overnight. Normally you turn the key and within just a couple of engine revolutions the oil light goes out very quickly.
corvus said:
BurgerKing said:
the sort they used before moving to the smaller blue filters.
Smaller? I thought the black ones were small enough.The bits of crud that came out were all black and stony, literally like tiny gravel. Some were very hard but several that I 'massaged' between finger and thumb just crumbled. There were no bits that resembled filings or slithers or anything that was silver or brass, so come to think of it I probably was just worrying too much. The thing that struck me as odd is the amount of it, it just seemed like a lot for just over 5,000 miles. Should I decrease the interval to say 3,000? The car lives 95% of its driving life on the M% at the moment.
As for the foot to the floor on startup, I assume this has the same basic effect as removing the crank position sensor, as in the car will not start on full throttle?
Is the amount of grit in the photo typical of an STi after an oil change?
As for the foot to the floor on startup, I assume this has the same basic effect as removing the crank position sensor, as in the car will not start on full throttle?
Is the amount of grit in the photo typical of an STi after an oil change?
Probably nothing to worry about then. If I recall correctly it's possible to drop the sump with the engine in situ. Then it would be easy to give it a damn good clean out. At least then you can be 100% sure what's going round your engine is clean. Aside from the bits of big end my sump was also full of what can only be described as black oily gunge in the bottom. Like soot mixed with oil would be the best description.
ScoobieWRX said:
After an oil change your oil galleries and oil pump will be empty. When you drain the oil from your engine you would normally take the dipstick out and remove the oil filler cap to allow air in so the oil freely empties without any vacuum, resistance. Your bearings, crank, rods etc...won't be bone dry because there is always a very thin film of oil left behind but nothing will be covered or soaked in oil properly until the pump starts doing it's thing and oil pressure builds to normal levels.
That thin film of oil in the bearings won't be there very long if you start the engine and let it idle. The light doesn't go out straight away. Oil pressure from a fresh refill takes a little while to build up even with the engine started. When your oil light goes off you know normal oil pressure is restored. This is why it's better to crank the engine over on the key for just a few revolutions without starting so there is less danger of doing damage. This way you keep engine loads extremely low, good for your crank, as there is no combustion going on.
With a parked car over the space of a few hours or overnight some of the oil from from the inner workings of you engine drains back into the sump, but enough is left behind in the oil galleries and oil pump to build oil pressure very quickly on next startup.
Next time you do an oil change see how long it takes for oil pressure to build up on first start after a refill. You'll see it takes considerably longer than when the car has been stood for just a few hours, or overnight. Normally you turn the key and within just a couple of engine revolutions the oil light goes out very quickly.
thanks! good explanation, makes more sense now. That thin film of oil in the bearings won't be there very long if you start the engine and let it idle. The light doesn't go out straight away. Oil pressure from a fresh refill takes a little while to build up even with the engine started. When your oil light goes off you know normal oil pressure is restored. This is why it's better to crank the engine over on the key for just a few revolutions without starting so there is less danger of doing damage. This way you keep engine loads extremely low, good for your crank, as there is no combustion going on.
With a parked car over the space of a few hours or overnight some of the oil from from the inner workings of you engine drains back into the sump, but enough is left behind in the oil galleries and oil pump to build oil pressure very quickly on next startup.
Next time you do an oil change see how long it takes for oil pressure to build up on first start after a refill. You'll see it takes considerably longer than when the car has been stood for just a few hours, or overnight. Normally you turn the key and within just a couple of engine revolutions the oil light goes out very quickly.
That sounds like the kind of job I would love to do, although there are mixed stories regarding how easy it is to get the sump off. One method sounds pretty straight forward though:
Stick the jack underneath the sump, unbolt the 2 bottom engine mounts and lift up the engine. Undo the 4 rear bolts then put it down, undo the rest. Remove sump then clean/install new one and do up all the bolts you can get to. Put jack under sump and lift up engine. put in the rear bolts. tighten everything up and set the engine mounts back into place.
That sound about right?
Stick the jack underneath the sump, unbolt the 2 bottom engine mounts and lift up the engine. Undo the 4 rear bolts then put it down, undo the rest. Remove sump then clean/install new one and do up all the bolts you can get to. Put jack under sump and lift up engine. put in the rear bolts. tighten everything up and set the engine mounts back into place.
That sound about right?
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