Crude based or synthetic oil ...

Page 3 of 3  


Regardless of the intervals, I always changed the filter. I didn't like the idea of leaving old oil in the filter to mix with 4 quarts of new oil. Dunno if you really save money but even if you did, I doubt it's much.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/06/2012 06:36 AM, Doug wrote:

the amount of oil residing in an unchanged filter is small* compared to the oil residing in oil galleries, the pump and the bottom of the oil pan. "mixing" is completely unavoidable. any "extra" from the filter is such a minimal percentage of the whole, it's insignificant.
* cheapo filters with defective anti-drainback valves can end up being completely empty. if the anti-drainback valve works**, the amount of retained oil can be higher, but it's still a negligible amount of the whole.
** most people "warm up" their car prior to an oil change so on removal, the filter is always full. apart from not really being necessary these days, this habit also serves to mask valve problems. [depending on filter orientation of course] if you let the motor stand for an hour before changing the oil, then remove the filter, you'll then find out if the anti-drainback valve actually works or not. if the filter is empty, it's defective.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/6/2012 7:40 AM, jim beam wrote:

On my previous cars where I could change oil myself without car lift, I alway had to wait about an hour after engine shutoff so I would not burn myself during oil change. Come to think of it, the oil filter was always full with oil. But that was in the '90s and before. Maybe they used to make better filters then.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

And between 8oz and a pint will be hung-up in the upper reaches of the engine and will not drain for you. "Better flow" won't help with that.
You wanna get as much oil as possible out of the engine? Leave it overnight, then let it sit for 15 minutes after pulling the drain plug. Bonuses to the above: Filter removal is mess-free, and the oil won't burn you.
You drain as much contaminants one way as the other. Unless the oil is so old that it's saturated, all the contaminants are held in suspension with the oil and will come out with the drain in any case. Contaminant- suspension is one of the primary functions of oil.
--
Tegger

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

this whole conversation reminds me of people who talk about "don't run your tank out of gas, your fuel line will fill up with all the crud that collects at the bottom"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Actually, running out of gas IS a bad idea these days. Not on account of any crud that might be in the tank, but bad for your catalytic converter.
--
Tegger

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/07/2012 04:27 AM, Tegger wrote:

the catalytic converter??? that's a new one - how's that supposed to be affected by the fuel being a homogeneous mixture that gets drawn from the bottom of the tank, not the top??? really, i'd love to read about this technically challenging phenomenon.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Honda says the reason is primarily damage to the cat.
--
Tegger

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/07/2012 03:41 PM, Tegger wrote:

how is that supposed to work? seriously, i'd love to read the cite.
and is it perchance written by the same honda analysis team that misdiagnosed the "faulty thermostat" causing lockup clutch problems on their automatics?
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

ummm....OK....which has nothing to do with the old wives' tale about low fuel causing "crud in the bottom of the tank to get sucked in"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/07/2012 04:06 PM, Elmo P. Shagnasty wrote:

lol - this is indeed an old wives tale. the only "low fuel" condition that could even vaguely influence pump life is "no fuel". and even that is a mighty stretch, even if it weren't something most drivers carefully avoid for other reasons.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

My understanding of the concern that routinely running with low fuel in the tank is as follows:
Electric fuel pumps are submerged in the fuel in the tank and cooled by the surrounding fuel and the fuel that runs through the pump.
In the past, most pumps were designed to deliver fuel at a certain pressure up to the maximum possible volume required by the engine. At lower engine outputs (at idle, at cruise, putting around, etc.) the volume of fuel delivered by the pump is far in excess of that actually used by the engine and much of the fuel is returned to the pump via the return line.
Pumping excess fuel around heats the fuel (heat added by pumping, heat added by running through the engine compartment, etc.).
When the tank is low on fuel, the heated fuel returning to the tank is a significant percentage of the total fuel in the tank. Continually recirculating (and heating) a relatively small volume of fuel raises the overall temperture of the fuel in the tank significantly.
Since the fuel pump is only cooled by the fuel, continually running the pump in a hotter environment can lower its life.
My feeling is that there was probably some truth to this 10/15 years ago. Some newer vehicles use variable displacement pumps / variable speed pumps that only deliver the needed volume of ruel and don't include a return line. Therefore heating the fuel in the tankk won't be a problem. Even in cases where the pumps still require a return line, manufacturer's know more and the pumps are better. I doubt that running the fuel tank low continually is much of a problem with new vehicles.
Ed
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/08/2012 08:58 AM, C. E. White wrote:

ok, let's examine this statement:
1. the fuel circulation from immersion is minimal. thus "cooling" effect is minimal. that's assuming there's even anything to cool int he first place - other motors like windshield wipers operate for hours on end without cooling. why would any automotive designer run something so critical so close to it's operating envelope that a known and expected operation condition would challenge its integrity?
2. the fuel circulating inside the pump /does/ have the capacity to cool significantly, because it's flowing. but again, why would any designer want to take a chance on this stuff?

get a shop vac and put your hand over the nozzle when it's running. does the motor slow down with the increased vacuum? or does it speed up because it's now doing less work? answer that question and you'll figure out that the fuel pump isn't working to "pump excess".
as for heat accumulation, again, what kind of designer is going to let their product out the door if it can't handle 50-60°C? because that's the most you're ever going to get from ambient under a hood. and even 120°C would not be much of a challenge.

that's just factless straw clutching - anyone saying that doesn't understand the physics.

the only way it could have been a problem is if the pump relied of fuel for bearing lubrication. [which is a fundamentally flawed concept in the first place.] and even if it did, then the pump would have to be run dry. drier than the engine would have already stopped at.
bottom line, this stuff is just presumption and nonsense. it's just like the old days of microsoft circulating the story about how cosmic radiation can flip bits in a chip, corrupt memory, and cause a crash. and for years, people believed it. but then came linux, and the same hardware stopped crashing. the truth was, microsoft software is buggy sub-standard crap and it is their poor code that causes crashes. similarly, pumps that fail are sub-standard crap. "cooling" as an excuse for failure in the event of an entirely foreseeable and expectable occurrence is just complete b.s.

--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/07/2012 09:07 AM, SMS wrote:

1. who here has had a fuel pump fail?
2. who here has had a fuel pump fail and then sent it in for analysis to determine the cause for real, as opposed to mere presumption?
3. better yet, who here has actually bothered to scope a pump /prior/ to failure?
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/06/2012 05:43 PM, Tegger wrote:

indeed. one pint is 1/7th of my drainable oil capacity.

if filer removal after being left standing /doesn't/ spill oil - and we're talking b-series and d-series here, then the anti-drainback valve is NOT working properly. honda filters are terrible for this. and that you're experiencing this with your 3k mile change interval demonstrates just how cruddy that domestic honda filter valve can be.

indeed.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/06/2012 12:24 PM, cameo wrote:

maybe. if it's one of the vertically mounted ones, mounted from the top, of course it's going to be full. but if like honda or toyota, it's horizontally mounted, or mounted at an angle, that's when you'll be able to observe whether the anti-drainback valve works.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/06/2012 05:26 PM, SMS wrote:

not for this purpose it doesn't.

if left standing, it's already drained!

not unless the oil is ridiculously over-loaded that it's already allowing precipitation. in which case, you should be changing the oil more frequently.

then you will never observe whether the oil filer anti-drainback valves are working properly.
--
nomina rutrum rutrum

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Somewhere on teh intarwebs SMS wrote: [snip]

Heh! I thought I'd enter the details for my Honda and see what it said but it only goes back to 1992! What about my 1985 AA 'City'*?
It's a good job that I have a supply of air filters, a couple of Gates timing belts, front and rear wheel bearings, a couple sets of brake pads and one of shoes for the rear, spare new dizzy cap and rotor (as well as a couple used ones), a clutch, including pressure-plate (all new, boxed) and a head-gasket set as none of these are available anymore from Honda or most of the after-market folks (except for a rapidly-diminishing few).
Great little car, 198,000 kms on the clock, doesn't use oil between changes and gets 55 miles per (imperial) gallon (46 US gallon) highway, 45 (38) around town (and I don't exactly have a light foot). I've replaced all but the headlights with LEDs, fitted LED DRLs and a high-stop brake light. Also I've removed the back seats (to reduce weight) as I'm single and, after I'd owned it for 18 months I realised I'd not 'unfolded' them (keep the weight low and maximise cargo area) once. Really effortlessly quick between intersections around town too, much faster than anything else on four wheels other than someone 'racing'
A real pleasure to drive too compared with modern small hatches. Good power-to-weight ratio and nimble and sure-footed. I wish I could afford to get one professionally rebuilt, like people do with rare and expensive cars. There's a little rust at the base of the A pillar that will require the screen being removed to be cut out and patched. I wish I could find an internet 'owners club' or similar, I'm sure there are tips and tricks particular to the car that would be handy to know.
[*] Or Jazz, depending on where in the world you are http://en.wikipedia.org/wiki/Honda_City_AA .
--
Shaun.

"Humans will have advanced a long, long, way when religious belief has a
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.