Timeline for Do (modern) ICE cylinder walls build a patina that unusually consumes engine oil during the break-in period?
Current License: CC BY-SA 4.0
13 events
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| May 8 at 18:09 | comment | added | Pᴀᴜʟsᴛᴇʀ2♦ | @Sam7919 - For the most part, warranty laws north of the border (from us) are fairly much the same. You can expect them to be comparable if not the same. | |
| May 8 at 14:09 | comment | added | Sam7919 | @Pᴀᴜʟsᴛᴇʀ2 That sounds ideal. I can't determine whether we have anything comparable north of the 49th. I'll keep looking. Thanks. | |
| May 8 at 9:51 | comment | added | Pᴀᴜʟsᴛᴇʀ2♦ | @Sam7919 - Here in the States we have warranties on vehicle's emissions equipment which far exceeds the length of bumper to bumper or powertrain warranties. Because of this, you won't see cats go bad as you're suggesting very often if at all. If it does go bad, you take it back to the dealership and get it replaced free of charge. And because of the federally mandated coverage, manufacturers are going to do what they can to mitigate any issues which might occur as you're suggesting, mainly because they don't want to have to pay for this on a bunch of vehicles. | |
| May 8 at 1:58 | comment | added | Sam7919 | Does the question "Sometimes a catalytic converter will last the life of the engine, and at other times it'll be toast while the engine is still relatively young. How can I avoid the latter outcome?" have an answer? Don't answer it yet. If it has an answer, I'll post it formally and you can answer it then. | |
| May 8 at 0:16 | comment | added | Pᴀᴜʟsᴛᴇʀ2♦ | @Sam7919 - Why? Just because oil consumption is higher, doesn't mean it's going to kill the cat. Hundreds of thousands of cars go through the break-in process, yet their cats survive the life of the vehicle. What you're suggesting doesn't make sense. Higher oil consumption does not mean the new engine is going to be using a ton of oil. It's just slightly higher than after break-in is all. | |
| May 7 at 23:46 | vote | accept | Sam7919 | ||
| May 7 at 23:42 | comment | added | Sam7919 | This all makes sense. Thanks Paulster2 and @MTA. Just a comment: If oil consumption is higher during the first while, I wish it were possible to extend the life of the catalytic converter by disabling it during that break-in (for say 500 km), since the initial burnt oil presumably extracts a heavy toll on its life. | |
| May 7 at 20:46 | comment | added | Pᴀᴜʟsᴛᴇʀ2♦ | Well said, @MTA. | |
| May 7 at 19:33 | comment | added | MTA | @Sam7919 The oil film does not burn off the cylinder wall because the film does not reach combustion temperature – not even close – even though it is exposed to flame. This is because the thin film of oil is in contact with the cylinder wall, which acts as a heat sink during the very brief time that flame is in the cylinder. The cylinder wall remains at a constant temperature a little higher than the coolant temperature, and this keeps the cylinder's oil film cool enough to survive the brief flame without itself burning up. | |
| May 7 at 19:31 | comment | added | MTA | @Sam7919 There is a very thin film of oil on the cylinder wall about 1-3 microns thick. (1000 microns in 1 mm.) See journals.sagepub.com/doi/10.1177/14680874221088547 There is no metal to metal contact between piston ring and cylinder. If contact ever occurs, the cylinder becomes scored. So in normal conditions the rings slide on a film of oil. | |
| May 7 at 17:31 | comment | added | Sam7919 | @MTA Understood. My problem with going down your line of reasoning is that there is either an oil layer (of any form) between the cylinder wall and the cylinder, or there isn't. If there is an oil layer — during normal life after break-in — then that layer would be regularly burnt off, leading to oil loss, in any engine. If there isn't an oil layer, then we're saying that we have metal touching metal 1500+ times / minute (same as the rpm), and this scrubbing has to wear one or the other. What is happening, if neither? | |
| May 7 at 16:00 | comment | added | MTA | This is the answer. Further: Food grade oils on cast iron form a coating due to oxidation and polymerization. Motor oils are specifically formulated not to oxidize or polymerize, as that would form "varnish" then "sludge" in the engine. If you did ever manage to form a food grade oil patina on a cylinder wall, it would be scraped off by the rings within moments after starting. | |
| May 7 at 15:44 | history | answered | Pᴀᴜʟsᴛᴇʀ2♦ | CC BY-SA 4.0 |