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Car's computer's idea of oil change interval..
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Sparky
Joined: 08 Dec 2003
Posts: 17308
Location: Portland, OR

4/14/13 11:42 AM

"78 Peugeot 504 Diesel"

I bet that is a heavy particulate polluter too. ;)

I would have to come look at that if it was within a little closer range. ;)

The 94 Del Sol is what I have settled on. And uses so little gas it is a joke if you stay away from the VTEC RPM Range. ;) This prospective coming from driving a 1988 E350 with no overdrive that is.

I hate econo boxes for the most part, but this little targa has a few mojo points going for it. Least of which is that it will actually boot it if you use the VTEC range of the power available. Not quite the mojo of 96 or ID19, but you can use it daily.

So unlike the 69 MGB-GT we sold in TN before the move, it is a fairly practical daily driver. And wheels off I can fit a bike in the trunk with it closed as long as the Targa roof is not in the trunk mount. I just have to sell off the first one, and this is the second DelSol and much better condition one I decided to get.

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dan emery
Joined: 11 Jan 2004
Posts: 6228
Location: Maine

4/14/13 12:04 PM

Saab stories

A few years ago I was getting my Saab serviced and got into a conversation with a retired paper company forester who had been driving Saabs forever. He said the old ones were the best cars for driving way back into the woods. The pipes on the underside were flexible so they'd just kind of bounce over stumps, etc. The motors were "throw away" so if you trashed one I guess you just bolted on another one (sort of like changing a wheel). They would always start at -20F though with the 2 stroke adding the oil could take awhile at that temp. He talked of moose running alongside "polishing the paint." One time he was driving a somewhat newer Saab on a road and hit a moose. The State Trooper got there and said "that car doesn't look like it hit a moose." The forester said "He's right over there..." One year the company got a couple of Land Rovers and they completely sucked. We looked at some 9-2s (the "Saabaru") and he didn't care for those at all.

Peugeots, I learned to drive on a 404 sedan, then got the wagon. A 504 Diesel would be cool, but...

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April
Joined: 13 Dec 2003
Posts: 6577
Location: Westchester/NYC

4/14/13 8:36 PM


quote:
In modern cars, engines should not burn oil for the first 100K+ miles or so.


quote:
my car burns ~2 qts/year. bums me out, but i believe that's in the range of acceptable variance. i think its BS, but its a 2007 and i'm past warranty coverage and just crossed 75k miles...so i live with it.

Why should engine burn oil?

My car just went over 100k, now the computer tells me the oil is low and I need to add a qt. I don't have a problem adding more but I'd like to know why that's considered "normal".

My previous car was also in the 100k range for quite a while. Never had any problem with burning motor oil between oil changes.

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Sparky
Joined: 08 Dec 2003
Posts: 17308
Location: Portland, OR

4/14/13 10:58 PM

April, some use is, or can be normal. Do you change your own oil and measure what came out? Or check it just before your oil change to verify it is right up to the same line it was at after the last oil change?

Curious...

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Nick Payne
Joined: 10 Jan 2004
Posts: 2421
Location: Canberra, Australia

4/15/13 2:28 AM

Our old Toyota Corolla, bought new in 1982, clocked up almost 300,000km before we sold it, and even at the end of that time it wasn't burning oil - the service interval was 10,000km and we never had to top the oil up between services. However, a lot of that distance was done in long trips - one of the things I remember from studying chemistry of lubricants, as part of an engineering degree, is that about half of all engine wear happens in the first 30 seconds or so after starting an engine from cold. When you start from cold, there's only a boundary layer of oil on the cylinder wall, and you have metal-to-metal contact between the piston rings and cylinder wall. It takes the 30 seconds or so for hydrodynamic lubrication to kick in and put a fluid film between the two surfaces.

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April
Joined: 13 Dec 2003
Posts: 6577
Location: Westchester/NYC

4/15/13 7:53 AM

So what happen to the oil that got "burned"? I thought that's a closed system. Where did the oil go?

The last car I had that "burn" oil was a Buick build in the 70's, and it was because there's a leak! All my other cars (only 3) never needed topping up between changes (according to the computer anyway, confirmed by dipstick - or its equivalent).

So naturally I'm concerned if the engine oil slowly disappearing is a sign of something else going wrong, down the road...

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Andy M-S
Joined: 11 Jan 2004
Posts: 3201
Location: Hamden (greater New Haven) CT

4/15/13 8:00 AM

Burning Oil

Oil "Burns" when it leaks past seals and gets from the lubrication system into the fuel system. Typically, the piston rings wear, and oil gets past them into the cylinder and burns together with the gas-air mixture (typically resulting in blue or white smoke from the exhaust, depending on how much is getting through and being burned). The point is that oil burning happens when it's no longer a closed system...

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Sparky
Joined: 08 Dec 2003
Posts: 17308
Location: Portland, OR

4/15/13 9:31 AM

I think valve guide and seal as much as rings. Also PVC issues can cause use of oil if I am not mistaken.

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Andy M-S
Joined: 11 Jan 2004
Posts: 3201
Location: Hamden (greater New Haven) CT

4/15/13 9:37 AM

Sparky, you're right

I know little about automobile engines--but one thing I *do* remember from my your is the relatively costly and much-feared "ring job" to deal with burning oil...

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Sparky
Joined: 08 Dec 2003
Posts: 17308
Location: Portland, OR

4/15/13 10:00 AM

A malfunction where oil fumes are going into the intake more than designed can use quite a bit of oil. Not to mention the PVC system not operating correctly can raise crankcase pressure high enough to cause leaks and use off the chart. The E350 Van I just sold leaked oil very badly everywhere it seemed, but @ the rear main noticably. The PVC was solid clogged, I replaced the PVC valve and de-gunked the lines and even the rear main quite leaking. It still leaked oil in a few places, but a quarter size drip in a few days instead of a 5-6" circle in a few days.

I read on the internet about folks having the main seal changed out and having the same leak rate due to too much positive crankcase pressure. So I started there, abated it by a large degree, then traded it for an Escort I gave to my kid that need a cam seal that leaks pretty badly. 20 years cars....

The Del Sol is 19 years old and has a small leak that which apparently is common @ the sideways distributor.

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dan emery
Joined: 11 Jan 2004
Posts: 6228
Location: Maine

4/15/13 10:09 AM

PVC issues?

>>Also PVC issues can cause use of oil if I am not mistaken.<<

You mean for engines made of polyvinyl chloride? :)

Ha ha I know its actually PCV for positive crankcase ventilation.

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Sparky
Joined: 08 Dec 2003
Posts: 17308
Location: Portland, OR

4/15/13 12:46 PM

I am actually working on plumbing right now, so the usual brain fart with added fart support. I am using ABS and PVC due to previous existing blend. Gotta love working on a 40 year old house and 20 years of Home Depot by owner interventions..

PCV is correct in the context of course.

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