Oil consumption

[Mathewsky]

I make my oil change 3 monts ago, I drove 1500 km since this operation. I noticed that the check oil light was illuminated this morning, so I check oil level, and I saw that it was on the min! Do you have an idea about what what can be the reason of such a huge oil consomption?
My exhaust is damaged and rusty, is it the reason?
thanks in advance

 

[Wolfie_85]

Most likely, you either have a leak you aren't noticing, or your engine is simply starting to burn oil. Did you change oils? How is your PCV valve?

 

[vq5speed]

If you don't have a leak an engine with a lot of miles do consume oil. Worn out rings oil can seep into the chambers. Worn out valve seals if you see blue smoke on first startup or from taking off from a stop is a sign of worn out valve seals. Also crudded up PCV valve can suck a lot of oil into the motor. I would suspect PCV valve and bad valve stem seals as the culprit of most of oil consumption in the motor if you don't have a leak.

 

[natenkiki2004]

If you want to know if it's piston rings, find a long and somewhat steep hill to go down, drop it into 1st and go down the hill, not applying the brakes. When you get to the bottom of the hill, quickly pop it into Drive (or 2nd if manual) and accelerate while watching the exhaust. Might be good to have someone at the bottom of the hill. The theory behind this is that the unusually high vacuum in the cylinders (caused by the throttle plate being closed) will actually suck oil or at least oil vapors into the combustion chamber if the rings are really bad. When you get to the bottom of the hill, you'll see a lot of blue smoke when you accelerate (burning the oil) if the rings are getting bad. A light oil burning problem will be shown with this test. Obviously, a bad oil burning problem will be evident most of the time with blue smoke out the exhaust all the time.

 

[Mathewsky]

Most likely, you either have a leak you aren't noticing, or your engine is simply starting to burn oil. Did you change oils? How is your PCV valve?

Hi Wolfie, thanks for your reply, no leak on my explorer because There's no mark on the floor, yes I change oil, it's 10W50, Yesterday I bought 10w40, I think I will refill with this one. I can't tell you about PCV valve because I didn't check.

 

[natenkiki2004]

Woah, no no no. Don't use 50 or 40 weight oil. Only use 5w30. Thicker oil (when cool or warm) will exaggerate top end lubrication issues. Why are you using 50 and 40 weight oil?

Also, you may not have drips on the floor but it could be seeping out still.

 

[Mathewsky]

If you don't have a leak an engine with a lot of miles do consume oil. Worn out rings oil can seep into the chambers. Worn out valve seals if you see blue smoke on first startup or from taking off from a stop is a sign of worn out valve seals. Also crudded up PCV valve can suck a lot of oil into the motor. I would suspect PCV valve and bad valve stem seals as the culprit of most of oil consumption in the motor if you don't have a leak.

Hi vq5speed? So I confirm you that's there's no leak, an old car with high mileage do consume oil but my explorer is only 190 000km (115 000miles)
My mechanical skills are weak so I will Check with my stepfather and check PCV valve...

 

[Wolfie_85]

PCV valve is super easy. Driver's side valve cover toward the firewall, just pulls right out and has a rubber vacuum line on it. If you get a Motorcraft PCV valve, $10-$12, others are cheaper. Which is best? Probably Motorcraft, but it's a fairly simple device. Only place I found that can get thr Motorcraft PCV valve here besides the dealer is O'Reilly's.

 

[vq5speed]

I will Check with my stepfather and check PCV valve...

If you pull the PCV hose off that connects to the intake manifold you can see if its wet from oil passing through it.

 

[natenkiki2004]

Just get a premium PCV valve at any auto parts store. It's not critical to engine performance, it just helps suck only vapors from the engine. If you look at the tube routing, there is another hose on the opposite valve cover that supplies clean air into the crankcase. You'll never have excess pressure in the crankcase due to this design but the PCV just helps only suck vapors.

 

[Mathewsky]

Woah, no no no. Don't use 50 or 40 weight oil. Only use 5w30. Thicker oil (when cool or warm) will exaggerate top end lubrication issues. Why are you using 50 and 40 weight oil?

Also, you may not have drips on the floor but it could be seeping out still.

Hi Natenkiki, last time when the garage make the oil change, he put 10w50. That man use to work many years for chrysler, so I thought it was good oil... But one of my friend (bronco II owner) told me that 5W30 is the best, just as you.
So next time i'll bought that oil

 

[natenkiki2004]

Personally, I'd change it out ASAP. Perhaps if you want, drop some kind of engine cleaner in, run it as per the instructions then drain it out.

Using thick oil won't be good for the upper valvetrain unless you live in the desert in Mexico or something.

10W-30 might be fine for warm climates or if you find oil creeping around and burning off each time you start the vehicle (but not while running) but a good quality 5W-30 will do best all around.

 

[2stroke]

this time of year, neither 10w40 or 10w50 will cause problems. I wouldn't run it in the winter, but I wouldn't worry about it either. Europeans tend to run heavier oil than Americans too. Choosing an oil is 90% tradition 10% fact.

 

[natenkiki2004]

Like I said, 40 MIGHT be ok if you're in a hot climate and it's summer. 50 is no good, way too thick.

Here's the issue, the thicker the oil, the harder it is to pump. The reason anyone only ever sees 60-65 PSI on the oil pressure is because there's a relief valve built internally. So, when the engines cold and the oil is thick, the pump builds to 60 and then 'vents' excess pressure. This means that the oil is taking a long time to reach the top end, the camshaft, lifters, rockers, valves. The longer you see the oil pressure pegged like that means that the oil is restricted. You do want some restriction but not too much.

Thinner oil means it flows easier and provides less restriction so fresh oil reaches critical areas quicker. Thicker oil takes much longer, especially when the engine isn't up to operating temp.

The other side to this is that if you have a really worn out engine and the clearances are much larger than normal, adding a thicker and more robust oil may help keep PSI higher which can mean a more constant flow. This does not help the engine as the damage is already done, it simply masks the problem.

 

[Mathewsky]

Thank you for your answers, but don't forget that I live in France, weather might be different than yours... So when you say that 5W30 will do best all around, do you mean that I can keep that oil the whole year?

 

[Wolfie_85]

Yes, I use 5W30 year round in mine. Works just fine.

 

[natenkiki2004]

Yes, 5W30 year round. The exception there would be if you use the truck as a prerunner in the Baha then a HDEO 15W40 is probably a better choice. Another exception would be excessive creep due to worn rings or valve seals, 10W30 may help out with that, on a vehicle that sits a while, in some cases.

 

[Mathewsky]

Yes, 5W30 year round. The exception there would be if you use the truck as a prerunner in the Baha then a HDEO 15W40 is probably a better choice. Another exception would be excessive creep due to worn rings or valve seals, 10W30 may help out with that, on a vehicle that sits a while, in some cases.

I bought that explorer 10 months ago, the previous owner only drive it 2000 km during his last three years, so this car was sleeping in his property... Do you think I can add 5w30 gradually? Or like you say replace the whole oil by 5w30?

 

[Number4]

????? Double post? What gives? Deleted.

 

[Number4]

Bonjour [MENTION=285710]Mathewsky[/MENTION], wait, are you Polish or French? As a rule never mix oils. Either all 5w30 or all 10w40. There may be some exceptions, but just stick to all of one only.

And welcome to the forum.