Engine oil removal through diptube and others....
Engine oil removal through diptube and others....
(OP)
Why?
A few newish European cars now have no sump plug and the oil is sucked out of the dip tube when changing it, I can't think of a more stupid idea, but there must be a reason for it, anyone any ideas?*
I like to look at how things are done on new cars when I get chance (incase there are things to be learned and applied to my own older car), but I just can't get my head around some of the weird things I see sometimes - I had a look at the intake manifold that was removed from a VW turbo diesel, the inlet was at one end, it ran along, did a U-turn, back the other way, another U-turn then went into the plenum, but why? Why make the air go further and round more flow losing U-bends? Noise reduction perhaps?
*It would be too easy to say it is to thwart any keen DIYers as hardly any 'normal' people get their hands dirty these days and for those that want to the tools to do the job are readily available....
Any additions or answers appreaciated.
A few newish European cars now have no sump plug and the oil is sucked out of the dip tube when changing it, I can't think of a more stupid idea, but there must be a reason for it, anyone any ideas?*
I like to look at how things are done on new cars when I get chance (incase there are things to be learned and applied to my own older car), but I just can't get my head around some of the weird things I see sometimes - I had a look at the intake manifold that was removed from a VW turbo diesel, the inlet was at one end, it ran along, did a U-turn, back the other way, another U-turn then went into the plenum, but why? Why make the air go further and round more flow losing U-bends? Noise reduction perhaps?
*It would be too easy to say it is to thwart any keen DIYers as hardly any 'normal' people get their hands dirty these days and for those that want to the tools to do the job are readily available....
Any additions or answers appreaciated.





RE: Engine oil removal through diptube and others....
So far as the manifold goes, all sorts of reasons are possible, noise is quite likely the main one.
Cheers
Greg Locock
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RE: Engine oil removal through diptube and others....
Had this happen with my car at an authorised dealership !
By the way this is not a new idea...I first saw it advertised at a national franchise car wash and vacuum clean distributorship in the late 1970's.
The idea being anyone who knew where the dipstick was could carry out an oil change.
Never tried it myself.
Pete.
RE: Engine oil removal through diptube and others....
RE: Engine oil removal through diptube and others....
Franz
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RE: Engine oil removal through diptube and others....
RE: Engine oil removal through diptube and others....
mercedes was the first manufacturer to introduce it way back in the 80-ties(after thorough testing), together with an oilfilter that was easily accessible from under the hood.
they took care to position the dipstick guide in such a way that the (rather wide) suction pipe reached the lowest part of the oil pan so only a minimal amount of oil remains in the engine when sucked empty this way. they also stipulated the use of only a view types of suction apparatus that are compatible with their design. basically these have a metal suction pipe and they work better then apparatus with a plastic pipe that may deform under the heat still in the engine.
RE: Engine oil removal through diptube and others....
I don't know why they don't just put a small access hole in the belly pan to allow the drain plug to be reached without taking the whole belly pan off. I've thought about doing that myself, but every time I'm doing an oil change I can't be bothered, so it's never gotten done.
RE: Engine oil removal through diptube and others....
Regards
Pat
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RE: Engine oil removal through diptube and others....
If it really torques you off, then drop the pan, weld on a plate, drill and tap the plate, and install a removeable plug.
RE: Engine oil removal through diptube and others....
I'd hate to suck steaming hot oil out of a car that just drove in (a la Jiffy Lube).
RE: Engine oil removal through diptube and others....
My neighbor has one of those lockable quick-drain plugs. The odd thing is that the only position it locks in is "open." It's held closed by friction, gravity, a whole lot of luck, and a very small spring.
RE: Engine oil removal through diptube and others....
It has been suggested elsewhere that this could have been done for health & safety reasons, not only the danger of splashing hot oil, but also its potentially carcinogenic properties. However, it has to be said that any proper mechanic over the age of 13 should be able to drain the sump of oil without bathing in it, not only through experience and having the correct tools, but also from having some decent degree of manual dexterity.....
RE: Engine oil removal through diptube and others....
RE: Engine oil removal through diptube and others....
nowadays the system is only used in workshops servicing cars and vans that are expresly designed to have the oil changed that way.
RE: Engine oil removal through diptube and others....
RE: Engine oil removal through diptube and others....
Pete.
RE: Engine oil removal through diptube and others....
The kits I've used had a relatively stiff plastic pick-up tube of diameter small enough to slide inside the dipstick tube of the engine in question, even though the engine had the standard dipstick tube of around a quarter of an inch (6mm) ID. Sliding the stiff pickup tube into the dipstick tube gave a better access to oil in the bottom of the oil pan.
The small diameter of the pickup tube made the oil change a bit slow if the oil was cold, but we all know that oil should be changed hot anyway.
old field guy
RE: Engine oil removal through diptube and others....
How does all that lovely sediment in the sump get sucked up?
- Steve
RE: Engine oil removal through diptube and others....
As far as the funny shape of the intake I would venture to guess it would be to increase the available air charge to help the torque of the motor down low and let it breathe easier at high speeds. Like a common single plane intake versus a dual plane intake. Just my .02 cents.
RE: Engine oil removal through diptube and others....
same way it always does - the oil pump intake tube draws it in and the pump sends it to the filter, where the particles are trapped.
another reason to change your oil while "hot" is that the particles are more likely to be suspended vs deposited.
RE: Engine oil removal through diptube and others....
Rod
RE: Engine oil removal through diptube and others....
I would have said "what's the sludge matter, as long as it stays put" but I'm aware of at least one example where accumulated sludge (at the end of a crankshaft drilling) came loose and relocated to a less-benign position, resulting in engine failure.
That sounds like a pretty extreme case, Rod. Do you think a modern commuter car with modern lubricants produces/accumulates that much "sludge?" What's the "sludge" made out of, anyway? Soot+oil?
RE: Engine oil removal through diptube and others....
Good question, Isaac. I don't really know. If memory serves (and, of course it usually does not), the gunk was more like a thick layer of varnish. Quite hard with a black, sludgy, gooey stuff on top.
Rod
RE: Engine oil removal through diptube and others....
I would call black lumpy deposits carbon. They build up on very hot surfaces like parts of pistons and where oil splashes on exhaust ports. I think they are oil decomposed to the point that they are pretty much carbon.
I would call golden to black thin shiny deposits varnish. this normally builds up in very tin areas that get hot, but due o space get worn and polished. I think this is a mixture of oil molecules that have cross linked and some small particles of carbon from decomposed oil. They are thin and shiny mainly due to polishing action. The cross linked oil is the result of enough heat to start some degradation, but not enough heat to fully degrade most of it to carbon.
I would call the grey pasty stuff that lays in corners and crevices and on the bottom of the sump sludge. I think this is a mixture of fine carbon, some degraded oil additives, some detergent, some fine metal and metal oxides and dust particles and some water.
I have seen the grey sticky toothpaste like deposits 1/2" thick on the bottom of a sump. I have seen it come loose and plug a gallery or pick up screen or both. This has always been on engines from cars that had owners not interested in cars and only use it for local shopping with no highway or high speed long trip use and were long overdue for an oil change.
The change to a new owner who changes the oil and drives longer and faster stirs the sludge up, wella, spun bearing.
Regards
Pat
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RE: Engine oil removal through diptube and others....
Talk to the kids at Jiffy Lube et al; they all have burns from hot oil getting up their sleeves. They are probably applauding this move.
RE: Engine oil removal through diptube and others....
By contrast, Shell Gasoline has apparently decided 'deposits' isn't alarming enough to attract consumer attention and so scrupulously refers to them in their marketing by the equally descriptive 'gunk'.
Sludge and varnish form from oxidized components of the oil. Oxidation makes them more polar and hence less soluble in the oil. Anti-oxidants are included in oil to prevent their formation, and dispersant ingredients are incorporated to prevent their precipitation. I think sludge tends to have water present and so tends to form at lower temperatures, while varnish is more of a high T issue, but it's not unusual for them to be observed together. I speculate there may be more cross-linked polymers in varnish, too. But the definitions are practical rather than chemical.
RE: Engine oil removal through diptube and others....
How much of all this stuff comes out of a sump drain compared with a sump suck?
- Steve
RE: Engine oil removal through diptube and others....
RE: Engine oil removal through diptube and others....
Engines that when torn down had lots of "gunk" in the bottom of the pan usually had irregluar maintenance, lots of idle time or used fuel from Mexico.
Never really saw where doing the oil change via the dipstick caused any additional problems as long as the right equipment was used and the oil was warm when pulled. This experience is mostly based on high speed diesel engines from 35 to 1500 bhp that ran 100 to 2000 hours a year.
Hope that helps.
RE: Engine oil removal through diptube and others....
For pans I have made for my boats, I run a slight trough along the bottom of the pan getting deeper at the drain point end and tend to form the pan to direct oil to that trough. At the drain point I drill a hole in the side of the pan at the trough and insert a short steel tube into the hole so it is flush with the grove and weld or braze it in place. I attach a rubber hose to the tube and run it through the transom via a skin fitting. I install a ball valve along that hose in a protected position that is also easy to access. I remove the handle of the ball valve but keep it safely stored in the boat. I also install a plug in the tube so the plug is removed from outside the transom. the plug is a type that can be removed by hand, but will seal in oil if the ball valve is left open. That way I can easily drain oil to outside the boat while it is on the trailer. No risk of spillage or accidental release into the hull or the waterway. It drains to the last drop if the oil is hot.
Regards
Pat
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RE: Engine oil removal through diptube and others....
"Some late 80s onward Hondas and Toyotas had a plastic underbelly under the engine compartment. It had to be removed to change oil. After ten or so years of removal and replacement, the attachment points become so damaged that they cannot be refitted."
Ten years? Here where they lay down lots of salt in the wintertime, the bolts usually snap off after one or two years, to be replaced by sheetmetal screws or cable ties, assuming the undertray isn't just discarded.
I assume the reason why they still continue to use 6mm thread bolts is because the issue is isolated to this region. Vehicles that use 8mm thread bolts generally have no issue.
RE: Engine oil removal through diptube and others....
Regards
Pat
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RE: Engine oil removal through diptube and others....
I'm the sort who goes for lunch while the sump drains out; I don't like leaving even a drop of dirty oil in there and I take care to jack up the car so the sump plug is sitting at the low point. Hopefully, draining this way, the old oil pulls all the loose gunk and debris out with it.
PW