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Disappeaing engine oil

I have a 2003 Mazda B3000 truck that is using or losing oil. The engine was replaced with a re-manufactured one 2 yrs ago and only has ~9000 miles on it. At first I couldn’t find a leak & there is never any oil on the ground under it. I replaced the pcv valve and noticed there is oil in it and the hoses/tubes that are attached to it. It does seem to have more power now, but I think the oil is still going somewhere and today I finally found a place where there is oil running down the passenger side of the engine at the back of it (closest to cab). There is no oil visible on top of engine anywhere. Also, today and the time before, when I changed the oil, the oil filter was nearly impossible to get off, don’t know if that could be related to the oil problem. One more thing, I think the oil that I wipe off the dipstick smells kinda like gasoline. I took it to the Ford dealership and they charged me $90 to tell me they couldn’t figure it out & suggested I get another new engine. Not happening, even if it needs it!

Any ideas?

Thanks in advance

How much oil is it using?

The oil leak you mentioned at the rear of the passenger side of the engine is usually a valve cover gasket leak.

It is using ~ 1 quart every 500-600 miles. Is a valve cover gasket something expensive and hard to get to? Could I change it?

When you change oil how many quarts dose it take to fill it?

4 1/2 quarts. I have not been negligent on the oil changes and always put on a new oil filter too. Also don’t see any sludge where the oil goes in, on the dipstick, or in the old oil. I use motorcraft 5w20 synthetic blend and the motorcraft filter that is recommended. I have always done the oil changes my self since the re-manned engine 2 yrs ago, and before that, on the original engine, I started changing the oil as soon as the warranty ran out. Prior to the warranty expiring, I took it to Valvoline, mostly.

The dip stick on many Ford models caused much confusion and often caused over filling with oil. To avoid confusion I file a notch in some dipsticks after filling with the correct amount of oil and ignore the dots and all the herring bone.

Really, I always add 4 1/2 quarts. It puts the oil on the dipstick about halfway between min and max. The ford dealer added a quart the other day, and I believe it was not a qt low because oil showed on the dipstick all the way up to the max line.

It sounds like your real problem is worn out rings, causing excessive blow-by.

Guess I’m getting rid of it then. I’ve already sunk a small fortune in it and not willing to pay for any more major repairs. Thanks for your help

You’ve got the right idea by filling it to halfway between full and add. That’s where it’s supposed to be on a Ford. I also think tardis has the problem right by suggesting blow-by. If the rebuild was done wrong, incompletely, or the break-in period not done right, the rings may have been damaged, resulting in blow-by. As far as your oil filter being difficult to remove, applying a thin film of fresh oil to the filter gasket, as well as not overtightening it, will help prevent that. If you are afraid of undertightening it, a nice oil filter wrench will make your oil changes easier.

If the oil has a gas odor, you need to find out why gas is getting into the oil. Something like a leaking fuel pressure regulator can cause this. When gas gets in the oil it causes the oil to thin out and it becomes more volatile. This then causes the oil to easily vaporize as it gets hot. This oil vapor is then drawn into the PCV system where it gets burned in the engine. And the thinner oil gets past the oil control rings where it gets burned in the engine.


Thanks, this time I only hand tightened it instead of using the oil wrench.

Hmmm. I don’t think I can check that. would it be worthwhile to take it somewhere and ask to have a fuel pressure check done? If so, how much does that generally cost?