Change oil every three months?

[DrRocket]

Originally Posted by DrRocket

I've got a little over 20,000 miles now on the new car I bought last May. I just had the oil changed for the second time, which makes for a little over 10,000 per change. And THAT'S per the factory oil monitor. This car has the latest generation of engine monitoring systems, and it's quite specific on how much oil life you have left.

Just ticked over to 31,000. The oil was changed at 30,000. I'm getting around 10,000 miles on each change before the engine monitoring system says I've reached the limit. Not bad.

I used my last "freebie" coupon though.

I'll keep using the Chevy dealership I got the car from. They're quick, courteous, and they vacuum the carpet!

Troberg, did you ever find out the cause of your engine failure?

[A Turtle Named Mack]

Originally Posted by DrRocket

Just ticked over to 31,000. The oil was changed at 30,000. I'm getting around 10,000 miles on each change before the engine monitoring system says I've reached the limit. Not bad.

In my car, the Engine Oil light tells me that the oil has gotten dangerously low, and that I may be doing damage to the engine. Are you sure yours is telling you when yours needs changing, rather than that it is badly low?

[DrRocket]

Originally Posted by A Turtle Named Mack

In my car, the Engine Oil light tells me that the oil has gotten dangerously low, and that I may be doing damage to the engine. Are you sure yours is telling you when yours needs changing, rather than that it is badly low?

Yes. There's a screen I can bring up that tells you the percentage left in the oil life. I'll get a picture of it and post it for you.

EDIT: here ya go!

[A Turtle Named Mack]

How curious. Fancier buggy than I have.

[DrRocket]

It's a nice feature, I must admit. I cut it pretty close the last time. It read 1% when I pulled it into the service bay. I discovered when it gets down to 3 to 4%, it starts nagging you every 100 miles or so.

[overyonder]

Originally Posted by DrRocket

It's a nice feature, I must admit. I cut it pretty close the last time. It read 1% when I pulled it into the service bay. I discovered when it gets down to 3 to 4%, it starts nagging you every 100 miles or so.

Are you sure you're supposed to change at < 5%? I was told 15% was time to change. (of course that's hear-say).

OY

[DrRocket]

The book says you can take it down that far. If you run past it, they consider it grounds for denying warranty work on the engine. I usually don't wait quite that long. In the past, I've had it changed aroun 5% or so, but various events caused me to stretch it out this time.

[WildaBeast]

Originally Posted by A Turtle Named Mack

How curious. Fancier buggy than I have.

And yet it has the exact same fuel and temperature gauges as my 17 year old Saturn. I see GM has gotten plenty of use out of those components.

[DrRocket]

Originally Posted by WildaBeast

And yet it has the exact same fuel and temperature gauges as my 17 year old Saturn. I see GM has gotten plenty of use out of those components.

GM is famous (notorious) for wringing every last bit of use out of compenents before going to new designs. The full sized van is a great example. They used the same design for 25 years before finally replacing it in 1996.

[Alchemy]

Originally Posted by DrRocket

Just ticked over to 31,000. The oil was changed at 30,000. I'm getting around 10,000 miles on each change before the engine monitoring system says I've reached the limit. Not bad.

I just rolled over 10,000 miles in mine; right around 1k a month. I had my last change a bit early, when my oil had around 18% life left according to the monitor. It seems that with my driving style I also should be able to manage 10,000 miles before I hit 1% oil life, although I'll likely get a change at 10% or every 9000 miles.

I'll keep using the Chevy dealership I got the car from. They're quick, courteous, and they vacuum the carpet!

Mine throws in a free car wash too.

[Troberg]

Originally Posted by Troberg

I might have said too much there. Last week, my engine seized on me...

I think it had about 80000 km without oil change, but the oil still looked good, so I don't think it was the oil that was the problem. My guess is the oil pump or the oil filter, but I'll have to wait for the "autopsy" report for the final word.

Forgot about this, but here's the theories about the failure:

* Garage guess: Worn oil pump not giving enough pressure. Possible, but I don't think so. Pump replaced anyway, just to be sure.
* Car inspector guess at annual inspection: Mixing oils might cause them to gunk up. Very possible, as I have no idea what oils the garage use, so I just top up with whatever oil I have available.
* Guy I know who is a technical materials planner at a major Swedish vehicle manufacturer: They have started to mix ethanol into the gasoline (don't know why, probably to scam more money from the drivers), and that can cause the oil to gunk up. Apparently, they've seen a lot of problems with that, especially in the summer when the ethanol content is higher (engines becomes hard to start in the winter if run on too much ethanol).

I don't know. I only know that it cost me a shitload of money...

[DrRocket]

Troberg, what's the % of ethanol?

Here, they've been using a 10% blend for some time now, and I've encountered no problems whatsover in any of the cars in my herd.

Even the '65 Cutlass that was built with leaded gasoline in mind doesn't seem adversly affected by it.

[jimmy101_again]

Originally Posted by Troberg

Forgot about this, but here's the theories about the failure:

* Garage guess: Worn oil pump not giving enough pressure. Possible, but I don't think so. Pump replaced anyway, just to be sure.
* Car inspector guess at annual inspection: Mixing oils might cause them to gunk up. Very possible, as I have no idea what oils the garage use, so I just top up with whatever oil I have available.
* Guy I know who is a technical materials planner at a major Swedish vehicle manufacturer: They have started to mix ethanol into the gasoline (don't know why, probably to scam more money from the drivers), and that can cause the oil to gunk up. Apparently, they've seen a lot of problems with that, especially in the summer when the ethanol content is higher (engines becomes hard to start in the winter if run on too much ethanol).

I don't know. I only know that it cost me a shitload of money...

Your earlier post said 80KM (50K miles)? If that is correct the engine seized because the oil was no longer oil, even if it did "look OK". Plus, at about 10K the oil filter probably quit working and all the grit was just being constantly recycled through the engine. Even if the engine didn't seize I doubt it had much compression left.

Ten or fifteen percent ethanol in the gas makes very little difference. People love to claim that it is a problem but there really isn't any data suggesting that is true. Indeed, the ethanol will remove water from the fuel system by solubilizing it and feeding it to the engine. Trace amounts of water in the combustion process are no big deal, besides the engine generates water as an exhaust gas anyway. Many fuel additives and stabilizers contain ethanol and other alcohols to help deal with moisture in the fuel system.

[Troberg]

Originally Posted by DrRocket

Troberg, what's the % of ethanol?

5-10%, depending on season.

Originally Posted by jimmy101_again

Your earlier post said 80KM (50K miles)? If that is correct the engine seized because the oil was no longer oil, even if it did "look OK". Plus, at about 10K the oil filter probably quit working and all the grit was just being constantly recycled through the engine. Even if the engine didn't seize I doubt it had much compression left.

Well, apart from where it seized, the garage said that the oil looked and felt nice and smooth, without metal in it. Black, but not bad.

Originally Posted by jimmy101_again

Ten or fifteen percent ethanol in the gas makes very little difference. People love to claim that it is a problem but there really isn't any data suggesting that is true. Indeed, the ethanol will remove water from the fuel system by solubilizing it and feeding it to the engine. Trace amounts of water in the combustion process are no big deal, besides the engine generates water as an exhaust gas anyway. Many fuel additives and stabilizers contain ethanol and other alcohols to help deal with moisture in the fuel system.

As I understand it, the main problems are:

* More difficult to start in cold weather. A very important factor here, with our winters.
* It gunks the oil.
* It loosens dirt from the surfaces it comes in contact with, moving it to places where it's more likely to be a problem (possibly linked with the above problem).
* It burns hotter, causing more wear on the engine.
* It has less energy content, increasing fuel consumption and decreasing power and torque.
* It tends to leak past the piston rings, contaminating the oil.

So, for these reason, I'm switching to 98 or 99 octane petrol instead, which has no ethanol mixed in it. I'm not taking the risk of sacrificing another engine on the altar of ethanol, especially as there is no real benefit in it.

[overyonder]

Originally Posted by Troberg

I don't know. I only know that it cost me a shitload of money...

80,000km since the last oil change and you wonder what happened? Oil is the lifeblood on an engine and is certainly not meant to go 80,000km without being changed.

OY

[ganzfeld]

I have this old thread that's been running for four and a half years and no one has ever changed the oil. As far as I know.

[Troberg]

Originally Posted by overyonder

80,000km since the last oil change and you wonder what happened? Oil is the lifeblood on an engine and is certainly not meant to go 80,000km without being changed.

Well, the garage didn't see the oil as being bad (remember, I top up the oil every now and then, and I use quality oil).

[Der Induktionator]

We had a 1980 Pontiac Phoenix that we got rid of after (at least) 170,000 miles. Maybe more, the odometer rolled over but we didn't keep track of it properly. For the last 50,000 miles we never changed the oil, we would just top it off with another quart every month or so. I don't really remember why we got rid of it other than being 15 years old and wanting something new.