2005 ranger losing oil

[stx4.0]

My dad has a 2005 ranger with the 2.3 engine and recently it starting losing oil somewhere.It will go down almost a quart within a week (about 150 miles)He has a check engine light and he took it to ford and they thought the pvc valve was plugged so they replaced it and the truck was fine for a few days and then the CEL came back on and the oil went back down.They did a compression check and it has 170 pounds on all cylinders and the spark plugs they said were clean when they pulled them so its back to square one.Its really been a mystery of where the oil is going.When it sits for a day or two there are no puddles under it and nothing noticeable comes out the exhaust when its running which would back up the clean spark plugs.Is there something were missing on these engines.I would rather have the lima 2.3 any day over these.

 

[Dirtman]

How many miles are on the engine? At a quart per 150 miles I cant concieve of a scenario where it's not smoking a ton, or leaking a ton... What are the codes from the CEL?

 

[pjtoledo]

the clean-burn and cats on the Duratecs are amazing. my 2005 has 342,900 miles on it and consumes a quart of oil per tankful of gas. absolutely no visible smoke from the exhaust,,,,no rust on the inside of the exhaust either!!

 

[stx4.0]

It has 145k miles and I agree on the cats not making oil consumption visible.Ive told people for years as its not just duratecs that cat convertors burn out or otherwise get rid of oil vapor leaving your exhaust.Thats why many a convertor has gotten plugged up and damaged an engine but this one ford did a compression check and cylinder leak test and then said rings are fine which this deal happened all the sudden.It was losing not a drop of oil in 4k miles and then all the sudden it would lose a lot of it in just a few small trips.There were no codes thrown by the computer..only the check engine light comes on which doesn't mean it will have codes.Those are only thrown when a sensor goes bad.

 

[Dirtman]

There were no codes thrown by the computer..only the check engine light comes on which doesn't mean it will have codes.Those are only thrown when a sensor goes bad.

None of that is accurate.

 

[Craig0320]

None of that is accurate.

Second that. The check engine lights is a direct response from the computer telling you there is something wrong whether it is major or minor.

 

[stx4.0]

Second that. The check engine lights is a direct response from the computer telling you there is something wrong whether it is major or minor.

That is true but when a sensor is bad the computer will throw a code for it which you recover when running a scan..A check engine light comes on when there is trouble that the computer cannot throw a code for or tell you whats wrong.Ive been through that twice now on other cars.I took a mustang in once to ford because of a miss and had a CEL coming on.It turned out to have a bad terminal on the distributor cap.The other time I had a coil going bad..it still worked but was weak..Ford told me me the very reason of a CEL is because the computer cannot throw a code for the problem you are having and I had ran a scan and came up with nothing.That was the reason I took them in.Of course these were early 90s vehicles so maybe that's all changed.

 

[Dirtman]

Obd2 has over 2000 potential codes. The computer see's a problem, reports the appropriate code related to the problem and the CEL comes on. You cannot have a CEL without a diagnostic code. This was true even on OBD1 vehicles. Also not all scanners can read every DTC. So just because you throw some cheap autozone scanner on it and find nothing does not mean there isnt a code stored in the computer.

It would be absolutely impossible for a CEL to come on if the computer didnt see something not working within the predetermined specs. If it see's low voltage on a coil pack the CEL comes on and it will report a code related to low coil voltage.

You need a new ford dealer.