Contour Enthusiasts Group Archives Forums General Troubleshooting Oil Consumption

What would be some of the reasons why my motor would consume oil so quickly without any leaks whatsoever. It eats about under a quart a week of normal driving; there are no leaks that I can find anywhere! Any suggestions ideas?

Thanks,
Eric

Well,

It's leaking or burning. It could be leaking on to the exhaust and burning off, so you never see the puddle.

Or you are simply burning it.

What do your plugs look like? Are they oily or have grey deposits on them?

Have someone follow you to see if blue smoke comes out of the tail pipe.

How many miles in a week?

TB

I haven't checked my plugs and will do so today, there is no smoke whatsoever coming from my tailpipes. I do however have a faint soot that builds up in a few days on the tailpipes.

Thanks

there is also the possibility of oil vaporization. As the oil heats up it evaporates faster. Every liquid has this property, it is called volitility.

Every brand and grade of oil has a different volitility based on its formulation and base stock. Generally, synthetic oils have a lower volitility than a mineral base oil.

If this condition occurs there will be little or no indication of it on the spark plugs. Usually this happens with low quality oil, if the oil gets too hot, or with oil that has become contaminated over its course of service. In either case, increased volitility is usually a good sign that its time to change it.

Change your oil, try a different brand if you like, and see what happens.

Thats just raw carbon from the normal combustion of the fuel. My car does the same thing. Right now the inside of my tailpipes are covered in a heavy film of soot from the long trip to and from Michigan. I checked my oil regularly during the trip and the oil is on the same spot on the dipstick as it was when before I drove there and back.

By the way, I use 5w30 Mobile 1 full synthetic..my car has never seen anything other! Hope it's something I can find soon, it really worrying me.

Could be a leak that is only really bad when the engine is running (oil under pressure). My brother had a rear main seal leak like this in his Mustang many years ago...only a tiny drip on the pavement when parked, but a gusher when driving.

Very good point. However, since the engine is essentially closed, I'd expect these vapors to burn, leaving deposits on the plugs.

Plus, I would be shocked to have 1qt of oil vaporize in 1 week, unless you are driving 500 miles a day

TB

Also, if that much oil were vaporizing the crankcase breather hose that leads to the intake manifold would be wet with condensed oil vapors.

It is possible for carbon to build up on the piston ring lands and casue them to stick and not make a good seal with the cylinder wall allowing oil to get into the combustion chamber, as well as combustion gasses to blow by the rings and contaminate the oil. Sometimes, using an "engine flush" where a cleaner is added to the oil right before an oil change and the engine is allowed to idle at operating temperature for a few minutes before draining the oil sometimes does the trick.

I have used Mobil1 oil in the past on a F-150 I used to own that I drove an average of 600 miles per week, and afer a few months of using Mobil1 I noticed an increase in oil consumption. I used an engine flush, then switched to Castrol Syntec and after 2 oil changes while using castrol and engine flush before draining the oil the problem went away.

PCV Valve.