Diagnosing glazed bores on high mileage engine
Discussion
The v8 in my Audi S4 has started consuming oil more oil than it used to, the garage has looked at it and think it is glazed bores causing the excessive consumption.
The engine has 141k on the clock so are there any alternative causes for high oil consumption e.g. knackered PCV or a way of definitely confirming the glazed bore diagnosis?
If it is glazed bores then a replacement engine is an option but don't to go down that road if not certain of the cause.
Appreciate people's views on this.
The engine has 141k on the clock so are there any alternative causes for high oil consumption e.g. knackered PCV or a way of definitely confirming the glazed bore diagnosis?
If it is glazed bores then a replacement engine is an option but don't to go down that road if not certain of the cause.
Appreciate people's views on this.
Do you mean worn bores? Glazed bores should only be an issue if it happens during the bedding-in process i.e. the bores become glazed before the rings have bedded in. At that mileage increased oil consumption doesn't seem unusual. Unless the engine is something special I'd have thought you either put up with it, or buy a younger car if that bothers you.
Have a look at the bores.
https://www.youtube.com/watch?v=9pv5Eg1PwLE
Cheap enough for a one time use.
https://www.amazon.com/Best-Sellers-Industrial-Sci...
https://www.youtube.com/watch?v=9pv5Eg1PwLE
Cheap enough for a one time use.
https://www.amazon.com/Best-Sellers-Industrial-Sci...
GreenV8S said:
Do you mean worn bores? Glazed bores should only be an issue if it happens during the bedding-in process i.e. the bores become glazed before the rings have bedded in. At that mileage increased oil consumption doesn't seem unusual. Unless the engine is something special I'd have thought you either put up with it, or buy a younger car if that bothers you.
Glazed bores can happen after the bedding in period, too light running can cause it at any mileage, especially if the engine is cold. Something for the people who won’t work an engine until the oil has reach a certain temperature to think about...
If possible a leakdown test will confirm piston blow by or valve seat issues , I sincerely doubt you will be able to tell if the bores still have honing marks or not via a bore scope, or if a ring is broken. Compression test may show an issue but is unable to identify the reason.
Shelsley F2
Shelsley F2
gazza285 said:
GreenV8S said:
Do you mean worn bores? Glazed bores should only be an issue if it happens during the bedding-in process i.e. the bores become glazed before the rings have bedded in. At that mileage increased oil consumption doesn't seem unusual. Unless the engine is something special I'd have thought you either put up with it, or buy a younger car if that bothers you.
Glazed bores can happen after the bedding in period, too light running can cause it at any mileage, especially if the engine is cold. Something for the people who won’t work an engine until the oil has reach a certain temperature to think about...gottans said:
gazza285 said:
GreenV8S said:
Do you mean worn bores? Glazed bores should only be an issue if it happens during the bedding-in process i.e. the bores become glazed before the rings have bedded in. At that mileage increased oil consumption doesn't seem unusual. Unless the engine is something special I'd have thought you either put up with it, or buy a younger car if that bothers you.
Glazed bores can happen after the bedding in period, too light running can cause it at any mileage, especially if the engine is cold. Something for the people who won’t work an engine until the oil has reach a certain temperature to think about...IIRC it was around a litre every 1000 or so miles, haven't done my normal mileage lately so consumption figure is a bit vague.
I have read about the PCV but the garage didn't think that was the cause, will get it changed to see if that is the cause.
Not noticed the car smoking on startup but will check.
I have read about the PCV but the garage didn't think that was the cause, will get it changed to see if that is the cause.
Not noticed the car smoking on startup but will check.
Isn't that around the consumption limit that Audi use to have for this engine, before they did something about it under warranty?
Are they any signs of oil leaks, although it would have to be a serious leak to be using that much?
The valve cover seals are known for leaking, plus the seal between the oil filter housing and engine block can leak. I found that this leaked oil into the V of the engine under the intake and eventually down the front of the engine, but due to the space it can be difficult to spot.
Are they any signs of oil leaks, although it would have to be a serious leak to be using that much?
The valve cover seals are known for leaking, plus the seal between the oil filter housing and engine block can leak. I found that this leaked oil into the V of the engine under the intake and eventually down the front of the engine, but due to the space it can be difficult to spot.
bmwmike said:
GreenV8S said:
High mileage engine used over the full rev range on a regular basis makes me think it is probably just worn out. I wouldn't say it owes you anything under the circumstances.
Is 140k considered high mileage? I must be out of touch..
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