Burning oil

[superboondee]

So have used valvoline for years in my 04 GT and never a leak or burning problem. Then about 6 months ago I switched to Royal Purple and now my car burns oil about a quart for every 2500 miles driven. Is it normal for the full synthetic oils to burn up?

[Slow2V]

Probably a leak ,


Synthetics are notorious for leaking throug gaskets because they are a thinner texture

[Pony_Boy]

Synthetics can exacerbate slow leaks in old engines. An oil specifically for high mileage engines could help, or back to valvoline. Each oil has a wear profile, it's better to run the same type of oil repeatedly then continually changing it... Synthetics last longer and protect better. I personally run synthetic in my mustang and my wifes old golf (which uses oil too, but not too much. Just keep topping it off).

Consumption is normal for engines, in fact it's part of the design, generally anything under 1qt/1000mi is OK.

Have you found a leak in the engine? You could just change the seal. If you see no leaks, it could be excessive blow by, you'd need new piston rings, this could also lead to fouled plugs and damage the catalytic converters.

Good luck! Let us know how it goes!

[LAS97GT]

Originally Posted by Pony_Boy

Synthetics can exacerbate slow leaks in old engines. An oil specifically for high mileage engines could help, or back to valvoline. Each oil has a wear profile, it's better to run the same type of oil repeatedly then continually changing it... Synthetics last longer and protect better. I personally run synthetic in my mustang and my wifes old golf (which uses oil too, but not too much. Just keep topping it off).

Consumption is normal for engines, in fact it's part of the design, generally anything under 1qt/1000mi is OK.

Have you found a leak in the engine? You could just change the seal. If you see no leaks, it could be excessive blow by, you'd need new piston rings, this could also lead to fouled plugs and damage the catalytic converters.

Good luck! Let us know how it goes!

Good info. I'll remember that on my next oil change. Good thread!

[superboondee]

Well I don't have any oil puddles in the garage. I will get high mileage oil or go back to valvoline. Thank you for the help.

[tc x 4]

Originally Posted by superboondee

Well I don't have any oil puddles in the garage. I will get high mileage oil or go back to valvoline. Thank you for the help.

It don't get any better than valvoline, stay away from the high mileage sh!t. Only use it as a last resort.

[Pony_Boy]

High mileage oils, even valvoline, are the base oils/blends with extra conditioners and cleaning packages. They are ok, but a full synthetic is better IMO. stay away from anything that claims to stop leaks, that'll gunk up the engine fast.

Taking off the valve cover is a great way to see how clean an old engine is. Shorter changes, ie 3kmi, with a quality synthetic like valvoline platinum will also help clean a dirty engine.

[cliffyk]

I know the flame potential for the heresy I am about to spew is great, nonetheless:

In my experience, spanning some 30+ years of the availability of consumer grade synthetic motor oils, there is a 50/50 chance that an older engine changed over to synthetic will exhibit minor oil leaks and a like chance that oil consumption will increase. Therefore I never recommend making a change to synthetic on a higher mileage engine that has been run on dino oil for years.

Beyond that, and despite that synthetic motor oils have a number of characteristics greatly superior to conventional oils, in 99.44% of automotive applications there is no practical advantage to using synthetic oil. It is the nasties (mostly by-products of combustion) that collect in motor oil that are bad guys and nothing in synthetic oil's superior character can prevent those from being created or building up in the oil.

So, and again this is 100% IMHO, if you wish to run synthetic oil do so as it will cause not harm (except to your wallet), or just run a top-grade on dino oil and keep in clean with 2500 to 3500 mile changes.

One other FWIW, for that same 30 years as our cars get along in mileage (someplace between 125k and 150k) I have changed them over to "hi-mileage" oil--usually Valvoline MaxLife--at the first sign of oil consumption. We then run them to at least 250k to 335k miles before retiring them, my wife's '89 Celica GT has the record at 385k at which time it still ran quite well but we sold it in 2006 and bought a used 2003 Highlander that she has now...

[Pony_Boy]

Originally Posted by cliffyk

I know the flame potential for the heresy I am about to spew is great, nonetheless:

In my experience, spanning some 30+ years of the availability of consumer grade synthetic motor oils, there is a 50/50 chance that an older engine changed over to synthetic will exhibit minor oil leaks and a like chance that oil consumption will increase. Therefore I never recommend making a change to synthetic on a higher mileage engine that has been run on dino oil for years.

Beyond that, and despite that synthetic motor oils have a number of characteristics greatly superior to conventional oils, in 99.44% of automotive applications there is no practical advantage to using synthetic oil. It is the nasties (mostly by-products of combustion) that collect in motor oil that are bad guys and nothing in synthetic oil's superior character can prevent those from being created or building up in the oil.

So, and again this is 100% IMHO, if you wish to run synthetic oil do so as it will cause not harm (except to your wallet), or just run a top-grade on dino oil and keep in clean with 2500 to 3500 mile changes.

One other FWIW, for that same 30 years as our cars get along in mileage (someplace between 125k and 150k) I have changed them over to "hi-mileage" oil--usually Valvoline MaxLife--at the first sign of oil consumption. We then run them to at least 250k to 335k miles before retiring them, my wife's '89 Celica GT has the record at 385k at which time it still ran quite well but we sold it in 2006 and bought a used 2003 Highlander that she has now...

Good points! +1.

The largest advantage to synthetic oils is that you can run them longer and hotter with less 'wear' on the oil. My changes are every 7500mi, proven with UOA from Blackstone Labs to be acceptable. I prefer this as it is a little cheaper per mile. Either is good for the right application, my brother in-law runs dino because he drives 2000mi a year and needs changes based on oxidation, not contamination from the combustion process. Most important is to fill with recommended grade of oil with quality filter and change regularly. Regular maintenance is key to keeping cars like Cliffyk.

[Butch]

Originally Posted by cliffyk

One other FWIW, .

What does FWIW stand for

---------- Post added at 04:23 PM ---------- Previous post was at 04:21 PM ----------

I've used GTX, mobile 1, valveline I believe, and Lucas, no burning always stayed topped off during the 3k intervals. Once I used motorcraft and it burned about half a qt within 2k. Guess it just depends on what your motor says/likes
Plus a Lucas oil stabilizer

[cliffyk]

My grandfather told me over 55 years ago that "oil is cheaper than engines" and I have lived by that--I just could not bring myself to keep oil in an engine for 7500 miles regardless of what Blackstone might say--however whatever floats your boat. Most people don't keep a car long enough that it matters all that much anyway.

Since I retired I am like you brother-in-law, my Mustang moved less than 3000 miles in the last 1-1/2 years as I have been mostly riding my bike (actually a Burgman 400 maxi-scoot), put 13,500 on it in the past year. So the Mustang oil gets changed every 6-8 months--got a change coming up this week.

The wife drives 8000 or so miles a year, 3 changes...

-----------------------------------------------------
the "scoot", note the family resemblance?:

[Pony_Boy]

Originally Posted by cliffyk

My grandfather told me over 55 years ago that "oil is cheaper than engines" and I have lived by that--I just could not bring myself to keep oil in an engine for 7500 miles regardless of what Blackstone might say--however whatever floats your boat. Most people don't keep a car long enough that it matters all that much anyway.

Since I retired I am like you brother-in-law, my Mustang moved less than 3000 miles in the last 1-1/2 years as I have been mostly riding my bike (actually a Burgman 400 maxi-scoot), put 13,500 on it in the past year. So the Mustang oil gets changed every 6-8 months--got a change coming up this week.

The wife drives 8000 or so miles a year, 3 changes...

-----------------------------------------------------
the "scoot", note the family resemblance?:

Great advise, oil is cheaper then engines. I believe that the new engines and better refined oils have no problem lasting 7500mi, it's the filter I worry about.

I respect your opinion of shorter intervals, couldn't hurt anything. I would follow the advise if it didn't mean changing every month.

Congratulations on retirement, I hope I can enjoy it one day too!

[cliffyk]

Originally Posted by Butch

What does FWIW stand for

---------- Post added at 04:23 PM ---------- Previous post was at 04:21 PM ----------

I've used GTX, mobile 1, valveline I believe, and Lucas, no burning always stayed topped off during the 3k intervals. Once I used motorcraft and it burned about half a qt within 2k. Guess it just depends on what your motor says/likes
Plus a Lucas oil stabilizer

For What It's Worth...