Excessive oil consumption through intake - Cars & Trucks

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...

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.

Check or replace your PCV valve.

definitely an oil consumption problem. How many miles? Could be worn rings and or valve guides. The oil light on when hot indicates low level or possible or weak oil pump. Check compression for possible head gasket or cracked head. I wouldn't drive it untill diagnosed.

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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...

The PCV valve does not control the oil situation, it just keeps the pans and valve covers from blowing off during a backfire. Excessive Oil in the breather is a result of excessive crankcase pressures, usually due to a worn engine, specifically rings.
SOME oil is normal, especially if you are loaded heavily and hard on the throttle.
There is a tester that measures crankcase pressures, but usually some other manifestation shows, like excessive oil consumption.

the PCV system draws crankcase fumes into the intake at idle and lower throttle situations. air going into the crankcase is filtered by the small PCV filter, where the oil shows up....

At highter throttle and lower intake manifold pressures, the system reverses, the PCV valve closes, and the fumes exit the crankcase VIA the breather filter. All of this is normal.

It costs tons less to periodically clean or replace the PCV filter.

No more than 1 quart between oil changes ... usually about 3000 miles under most circumstances.

this could be an air intake problem, check the air filter but what ive seen before is the flexible intake pipe collopse only when the engine was under pressure as you describe.Try removing this pipe & driving again but not for long as dust would enter the engine .it might confirm or elimiate this.

U need o repair the pcv vacuum source it is the cause of the oil consumption, which is excessive crankcase pressure.

oil though throttle body bad. Will foul up mass flow sensor.