Extend oil change interval?

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Hi all. New here. Love the place. I've already searched for answers to the questions as to whether or not I an mix conventional and synthetic oils and viscosity.

I have a 2001 Buick LeSabre with the 3.8L engine, about 73,000 miles.

I have to add a quart of oil about every 1,500 miles. My mechanic says that is fine. There are no oil leaks and emissions tests are good. So where's the oil going?

Anyway, the car's manual says that I should change oil every 3,000 miles because most (but not all) of my trips are in the suburbs and of about 10 miles each. They call it City duty.

Since I add a couple of quarts of oil every 3,000 miles which replaces old oil, at 3,000 miles, I've already changed out 2 quarts of oil. The old oil has been replaced with new oil. With that, I think I can extend oil changes to 5,000 miles.

Does this make sense?
 
Welcome to Bitog! What you wrote makes sense. As far as where the oil is going? If it isn't leaking, it could be a PCV valve issue, oil stem seals, or blow by, to name a few things. You could spend a lot of time or money to find out, I wouldn't. A qt./1500 miles is considered normal, although it might bother some people.
 
Yes. Most oils are good for 5k anyway. There are also plenty of folks that have leaks and only change the filter every 10k or so.

That said, the only way to be 100% sure about the oil's condition is to get a UOA. So in your situation you might consider testing the oil at 3k(leaving it in).
 
Thanks all. Good to know that I'm not far off base.

Question (because I'm new here) - how do I go about getting a UOA? I looked up the acronym. Used Oil Analysis.

Question 2 - once I get the analysis, how do I evaluate it?

Thanks much,
Tony
 
http://www.blackstone-labs.com

This site has about all the information you will need to get started. The kit is free and you pay only when you get the analysis done. I sent them an email to get a kit and I had it in my mailbox in 3 days.
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The only thing I question in your situation is how valid your results will be with the amount of oil change-out you have to do. Some of the guys here will be better able to tell you whether they think you'd get your money's worth from a UOA considering you are burning and replacing so much oil. The analysis costs $25 and is an extra $10 if you get the TBN done. What is the TBN? It's an add on testing that is over my head at the moment (has something to do with testing the additive package and how much further you can go on that oil??) and so the other guys will be better able to explain that as well if you are interested.
 
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I thought your LeSabre had the OLM, which picks the OCI for you. In that case, you can follow its suggestions with confidence.

And yes, your question makes sense, because you're replenishing new oil, so effectively you can go longer.

What kind of oil do you use? Consider a HM oil like Maxlife, if you're not already doing so.

Oil analysis kits are available at any Napa. It's about $15, which is cheaper than Blackstone's kit, and TBN is included in the price. Ask for part #4077
 
I typically use Castrol 10W-30 conventional oil. I've been using a Fram oil filter and I see there are folks here who are not fond of Fram.

The last time I had the oil changed at my mechanic's place, he used a high mileage oil. What makes those different from non-high mileage oils?

About that OLM (had to look up that acronym), how does it know the oil life? It now says I have 3% left and it's been almost 5,000 since the last oil change. Does it just look at mileage? A friend of mine says it looks at the number of starts, if the engine got to temperature, and probably a few other parameters.

Sorry for all the questions. You've all probably answered them before.

I have a NAPA place close by. Will definitely look into the analysis kit.
 
A PCV valve is a cheap fix. If you do a UOA it will show you how the oil is reacting to your daily routine.
 
I like the PCV suggestions above.
On consumption at 1 quart every 1500 miles, you could just change your oil filter every year, and your oil every 2 years. You're already putting in a lot of additives/oil back every time you put in another quart.
Also, in case your rings are gummed up and might be letting oil get past them, put in a pint of https://gumout.com/multi-system-tune-up/ into your oil filler hole, found at Walmart and autoparts stores, etc. and run it for a month and then change the oil to any name-brand synthetic oil you can find in a 5w-30 weight.
 
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Originally Posted By: TonyDee
Hi all. New here. Love the place. I've already searched for answers to the questions as to whether or not I an mix conventional and synthetic oils and viscosity.

I have a 2001 Buick LeSabre with the 3.8L engine, about 73,000 miles.

I have to add a quart of oil about every 1,500 miles. My mechanic says that is fine. There are no oil leaks and emissions tests are good. So where's the oil going?

Anyway, the car's manual says that I should change oil every 3,000 miles because most (but not all) of my trips are in the suburbs and of about 10 miles each. They call it City duty.

Since I add a couple of quarts of oil every 3,000 miles which replaces old oil, at 3,000 miles, I've already changed out 2 quarts of oil. The old oil has been replaced with new oil. With that, I think I can extend oil changes to 5,000 miles.

Does this make sense?


Heck its doubtful you ever need to change oil. Change the filter every 10k.
 
Originally Posted By: slacktide_bitog
welcome2.gif


I thought your LeSabre had the OLM, which picks the OCI for you. In that case, you can follow its suggestions with confidence.

And yes, your question makes sense, because you're replenishing new oil, so effectively you can go longer.

What kind of oil do you use? Consider a HM oil like Maxlife, if you're not already doing so.

Oil analysis kits are available at any Napa. It's about $15, which is cheaper than Blackstone's kit, and TBN is included in the price. Ask for part #4077

Yes, High Mileage oil and PCV valve may eliminate or reduce the oil consumption.
 
Originally Posted By: TonyDee
Since I add a couple of quarts of oil every 3,000 miles which replaces old oil, at 3,000 miles, I've already changed out 2 quarts of oil. The old oil has been replaced with new oil. With that, I think I can extend oil changes to 5,000 miles.

Does this make sense?

No, it does not. Water and acidity that builds up during normal engine operation (especially on short trips) will remain in the engine, because it will mostly condensate on top (valve cover) where cooling is faster.
New added oil, especially if conventional, will have the additives quickly worn by the increased acid in the used oil.
PS: Increased acidity will also eat away faster the crank bearings.
 
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Originally Posted By: TonyDee

About that OLM (had to look up that acronym), how does it know the oil life? It now says I have 3% left and it's been almost 5,000 since the last oil change. Does it just look at mileage?



No, it's not just based on mileage. It is based on various parameters such as rpm, oil temperature, coolant temp, ambient temp, and idle time. The mileage suggested by the OLM may vary widely, giving anything from 2k all the way beyond 10k.

The only time should change the oil before the OLM tells you to is if it doesn;t come on after a full year.
 
Some oil change reminder systems just look at miles and some are more sophisticated.

1 qt per 1500 miles is not normal but I wouldn't spend much money to solve the issue.
 
Your good to go for 5k with just what your doing already. Motor oil has improved a great deal even since 2001.
You don't need to worry about having a uoa done with a 5k oci( oil change interval).
Your thinking was perfectly sane and reasonable.
 
My parents took a '96 LeSabre 3.8 to 302K miles before the original transmission let go. After being purchased at 70K, it received Havoline conventional at 3-6K OCI.
 
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Originally Posted By: SoNic67
Originally Posted By: TonyDee
Since I add a couple of quarts of oil every 3,000 miles which replaces old oil, at 3,000 miles, I've already changed out 2 quarts of oil. The old oil has been replaced with new oil. With that, I think I can extend oil changes to 5,000 miles.

Does this make sense?

No, it does not. Water and acidity that builds up during normal engine operation (especially on short trips) will remain in the engine, because it will mostly condensate on top (valve cover) where cooling is faster.
New added oil, especially if conventional, will have the additives quickly worn by the increased acid in the used oil.
PS: Increased acidity will also eat away faster the crank bearings.


New oil has additives to combat the acidity.

10 miles is not that short of a trip.

3k intervals are a waste of time and money.
 
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