Excessive oil consumption

[jmd4100]

I have a 2007 1500 5.7 with just under 140k miles (139,946) and I’m losing a quart of oil every thousand miles or so for some reason. It doesn’t seem to be leaking and i cant smell oil out the tailpipe. I haven’t replaced the Pcv valve because it seems to be operating normally and the intake doesn’t have a lot of oil in it. Anyone have any ideas? This one really stumps me. No smoke, smell, and no visible leaks anywhere...


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[TheEnder]

I have a 2007 1500 5.7 with just under 140k miles (139,946) and I’m losing a quart of oil every thousand miles or so for some reason. It doesn’t seem to be leaking and i cant smell oil out the tailpipe. I haven’t replaced the Pcv valve because it seems to be operating normally and the intake doesn’t have a lot of oil in it. Anyone have any ideas? This one really stumps me. No smoke, smell, and no visible leaks anywhere...


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I know this was posted over a month ago but when was your last tune up? I’ve heard a few times that this could cause it, i don’t know how, but it can apparently. Regarding the PCV, if you shake it it’s supposed to rattle, does yours?

Or the 3rd answer that’s a tad far out there, maybe it’s burning it but only when you’re accelerating? I don’t know. This stumps me as well.


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[huntergreen]

I know this was posted over a month ago but when was your last tune up? I’ve heard a few times that this could cause it, i don’t know how, but it can apparently. Regarding the PCV, if you shake it it’s supposed to rattle, does yours?

Or the 3rd answer that’s a tad far out there, maybe it’s burning it but only when you’re accelerating? I don’t know. This stumps me as well.


Sent from my iPhone XS Max in my 2013 Magnum 4.7L V8

Just because it rattled doesn't mean it's working. It's a cheap part and easy install. I would just change it.

 

[TheEnder]

Just because it rattled doesn't mean it's working. It's a cheap part and easy install. I would just change it.

^^^^^^This.


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[jmd4100]

^^^^^^This.


Sent from my iPhone XS Max in my 2013 Magnum 4.7L V8

Ok great! Thanks for the reply! I'll try changing it. It does rattle, but I guess that doesn't mean it's working properly... what causes the oil to burn if the pcv is bad? Does oil get through it? Pretty sad I've rebuilt engines and transmissions but I don't know how a pcv works[emoji1787]

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[07Sport Quadcab]

I think it's because pressure, caused by blowby (even engines in good shape have it), isn't relieved by being sucked out thru the PCV valve. This forces some oilpast the rings, where it is burned.

 

[LoneWolf3574]

It is possible that the PCV is stuck open due to buildup on the check valve seating surface allowing oil vapor to leak by, increasing your oil consumption. You'll never notice any issues just by the "rattle test" method. Do you have any other symptoms? A CEL, any misfires, is the engine running lean, is the engine hard to start, oil buildup on the PCV assembly, or does the engine idle rough?

PCV valves run around $20-$30 for the 5.7L Hemi and vary in price depending on the manufacturer. I prefer Mopar so mine ran about $40 on Amazon about 2 years ago, though the price has come down since then. Still cheaper to replace than taking it to a shop to troubleshoot.

https://axleaddict.com/auto-repair/How-to-do-a-PCV-valve-test

 

[BamaRam022]

I’m having the same problem.

 

[Dodge 1500 4X4]

Try a leak down test to see how the rings and valves are doing, followed by a compression test, it should be smoking out the tail pipe if the PCV is sucking out the blowby, do you get allot of smoke on startup.

 

[jmd4100]

Try a leak down test to see how the rings and valves are doing, followed by a compression test, it should be smoking out the tail pipe if the PCV is sucking out the blowby, do you get allot of smoke on startup.

No smoke at all... thats why it confuses me. No smell of oil burning at startup so I'm pretty sure its not the valve seals. Thinking maybe just rings wearing a little but only way to know for sure is to test it... once I finish the honeydo list ill get to it[emoji1787]

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