Excessive oil use

In the great plan of things simply claiming excessive oil consumption is not enough. You think you know what you mean but how much is excessive?

Car manufacturers insist before taking any warranty action for excessive oil consumption a test must be carried out to decide whether the consumption is excessive and whether repair will be economic. Even though your car isn't under warranty the principle generally will be the same.

An oil consumption test is carried out after a few basic checks and means topping up the oil exactly and then driving 750 miles of mixed town and country driving that doesn't include any sustained high speeds or heavy congested traffic. The oil is then checked and topped up exactly and if the quantity is less than 1 litre it is considered acceptable due to any improvement being uneconomic to achieve.

How many miles is your car covering per litre?

Of course if the engine is producing smoke things are somewhat different...

if it is a 2 stroke , reduce the ration of oil to fuel at the oil pump meter jet
if it is a 4 stroke , go up a grade in the engine oil ( 15w 20 to 30w 50)
replace the rings

White smoke is usually coolant burning, but you say no loss of coolant, so must be oil burning. PCV is possible fault, especially since you say smoke is intermittent. Part itself should be cheap, less than $20. One your car I believe it is located in a pipe running from intake to valve cover.

oil consumption of say 1/2 litre in 5.000miles would be normal even 1 litre in 5.000miles would be ok but any thing else is staring to be excessive. Oil consumption is an indication of a problem with the oil control rings and valve stem seals . Add to that your statement of a knock coming from the exhaust I would be inclined to have a compression test done to determine the condition of the engine . I consider 65.000 miles to be a little young for bad oil consumption so with the noise I would suspect a broken ring and a scored bore

Wherever the engine stops there will be at least a couple of valves held open and overnight the force of the valve springs can force the oil from some of the hydraulic tappets (if fitted). Some engine designs can take as much as 20 miles to cease tapping...

Some timing chain tensioners are oil damped.

If noise disappears when you top up the engine oil the clear solution is to top up more often - the engine oil level should never be allowed to fall more than 1 litre below the maximum level and it should never be overfilled.

Locating and curing the cause of excess oil consumption can be expensive and complex and the process involves a certain amount of guessing and eliminating so sometimes it is better, quicker and cheaper just to have the engine overhauled.

The general rule is it isn't economic to repair excess oil consumption unless it exceeds 750 miles per litre of mixed driving that doesn't include any sustained high speeds unless there is smoke when the engine must have attention or be scrapped.

Before testing the oil consumption the engine breather should be checked and the oil topped up accurately.

If there are no visible crankcase emissions caused by excess piston ring/bore wear, the most likely cause of excess oil consumption is the valve stem oil seals - unless the engine is so gunged inside the oil being pumped to the top of the engine can't drain back fast enough...

Several ideas.
1) When the dealer completed servicing it, did you check the oil to see if it was full? If it wasn't it would need added oil sooner.
2) .9 litre does sound excessive, but what was it using before?
3) Find a way to give the bottom side of your Toy a really good flashlight inspection to look for leaks and seepage.
This should give you a clue as to what is going on.
If it is dry underneath, someone needs to check the oil weekly until a pattern is established of oil usage.
Be blessed.

well if its not leaking i would say check the antifreeze for oil in it and if there isnt any then i would say your piston rings are going bad these are all possibilities if you have high miles

hi, this consumption seems high, i would take it to a dealer and ask them to check the oil sensor.......
P.S. is there a lot of smoke coming from the exhaust, if so, it may be burning a little oil, ask dealer to check it

2006 C4S Tip, 26,000 miles Now in Porsche dealership having the engine stripped. They are suggesting that one of the pistons is starting to fail. Their diagnostic equipment shows no fault codes but further testing has shown that one bank is having to work harder than the other side. Their prognosis is a new engine. Do not let your warranty expire!!! Also see here: http://www.pistonheads.com/gassing/topic.asp?h=0&f=48&t=731645&mid=154532&i=0&nmt=OPC - Does this sound odd to you?&mid=154532