Why is my expy burning so much oil? and what should I do about it?

[kanyeeast]

I have a 1997, 4.6L with 4wd and 174k miles, the only thing not stock is a k&n air filter.

There really isnt a leak to speak of, just a tiny oil spot. I was using full synthetic but switched to a high mileage oil maybe 6 or 9k miles ago. Now, since it's been burning so much I just got castrol 10w-30 conventional.

I'm embarrassed to admit this but when I drained the pan it probably had 3 quarts in there (it takes six).

Also, it has been giving me some weird vibrations at idle (which has also been slightly high and inconsistent) and when I'm at a light where the wheel/pedals will vibrate.

Even after the oil change I've been getting a knocking or a pinging sound while driving.

Any bright ideas?

 

[FordandPolaris]

Does the knock sound like it is from the top end or bottom? Either way it is probably not something that will be fixed outside of a motor rebuild. Does the truck puff blue smoke on startup? Also have you watched for the leak once the engine is warm and running?

 

[kanyeeast]

If i had to put a location I would say from the top. I have not checked for a leak while driving but I will. There is no dark smoke on start up and no one has complained about dark smoke while driving.

So outside of a complete rebuild, nothing I can do?

 

[toms89]

Leaky valve guides common symptom is smoke upon start up.

Poor ring seal can cause it to burn excess oil at all times.

A small leak while it is parked could be a larger leak as you are driving and a source of oil loss. It may be leaking at as you drive but stops when it is shut down.

How long does it take to "burn" a quart?

If you have not recently, I would recommend basic tune up to start. Fuel filter, air filter, spark plugs (properly gapped). Doing so may take care of the issue or at least give you some idea how the cylinders are running in relation to each other.

And it is tough to diagnose the sound / vibration without being there. Many, many possibilities. Misfire, loose timing chain due to faulty tensioner, spun bearing / rod knock, bad motor mounts, failing accessory. I can think of a thousand things..

 

[stamp11127]

In addition to what Tom has said I would also recommend looking underneath the engine. My valve cover gaskets are leaking and doing a wonderful job of undercoating the floor boards and front cross member. Not a drop on the ground though.

 

[toms89]

In addition to what Tom has said I would also recommend looking underneath the engine. My valve cover gaskets are leaking and doing a wonderful job of undercoating the floor boards and front cross member. Not a drop on the ground though.

I 2nd that. When I did my build my original valve covers (w/ new gaskets) were leaking fairly bad but only while driving. Would rarely leave any sign of oil on the ground. After I replaced them with brand new oem valve covers complete with gaskets, bolts etc.. no more leaks.

It was also obvious when comparing new to old that the channel in the valve covers where the gasket is held had opened up significantly with age.