Oil Changing.

[sworks]

Originally Posted by Mike Trident

I have been told a growing number of modern cars are not fitted with sump plugs anymore.

I’ve not seem a car with no sump plug but many manufacturers don’t use dip sticks anymore. Some Ford’s now don’t even have a sump plug as such just a twist and remove item in a plastic sump a bit like the dsus undertray fastenings with a sliding retaining clip

[MSS]

Originally Posted by Groundhog

When I bought my Freelander in August 2017 I was lucky enough to have Brian with me to give it the once over.

The car was a 14 year old one owner, with 21k recorded mileage, and a Land Rover
(full service history????)

The first job Brian did was to give it a service, the undertray had never been removed from the day Land Rover fitted it at the factory, the oil was, to put it mildly disgusting .

So when I read threads about pela pumps and how good they are I come to the conclusion the sump plug is put there for a reason.

Perhaps its put there for people without Pela pumps?

It is never going to be black & white situation. I tend to use both methods and am perfectly happy with my approach. But then my cars do get oil/filter changes at half the recommended intervals.

[T-Cut]

I remember reading a report on an investigation into the efficiency of changing engine oil using a vacuum extractor compared with the conventional drain down. It's important because the car servicing industry, both professional and amateur, will use whatever methods save time and money. I've been unable to relocate the report, but it may still be on the 'Net somewhere. The results were quite surprising in that there was little difference between the two methods. I believe they tested several different cars to investigate sump design variation. They applied a set time limit on the drain down period (you'll always get that extra drip if you wait long enough), and other important factors like oil temperature were taken into account. After the job, they removed the sumps to see what residual oil was left. Statistically, there was no difference. There were variations across cars, but overall there was little difference. So, for your 75/ZT, we're simply guessing because nobody has done the test. In general terms, either method is fine because no method removes all the old oil. It's impossible to do that. Additionally, the question of 'sludge' removal hardly comes into the equation these days. The ACEA oils specified by car manufacturers don't form sludge and remain homogeneous during the recommended service life. Whatever metallic particles may exist will be in the filter. So whatever runs out of a drain plug will also be sucked out with a pump. Wonder whether the sump floor slopes away from the plug when it's jacked up? I suspect it does, but I haven't checked. I think it comes down to personal preference and feel good factors. If jacking up the front or driving up ramps to access the drain plug is the only way for you, that's fine. If doing all the work from above is more to your taste, then that's fine too. Personally, I reckon it's not worth worrying about the difference.

[BoroRover]

My diesel is having a service done in May, I'm putting it in the hands of an expert, Brian, no one better in my book

[Sheraton]

Originally Posted by mss

Either really Brian, although I was thinking of the Caterpillar at the time.




The sump does not maintain oil pressure!

This is the only method guaranteed to remove almost all traces of the old oil from the engine as otherwise small amounts of oil remain in various places in the engine which can only be diluted/moved to the sump when the engine is running.

The ideal oil change method surely would be to drain the oil conventionally once and then run fresh oil through the engine whilst it is running.

Surely any Engine with a Sump draws it's supply of oil From the Sump ? I may be missing something, I'm no expert just curious

I fail to see how the method you describe could work on a Running Engine - if you are draining the supply whilst filling - do you bypass the Oil Pump? if not, surely the old/new oil will just mix - if so, would the oil Pump not be at risk ?

Is it actually a method used for Engine Oil changes ? I only ask to clarify - as the initial post Mentioned Gearbox Oil Changes - I can accept how this would work and be a benefit on a Gearbox......

can't see how it would work or be of any benefit r.e removing more of the used Oil from a Running Engine



I'm closing on 5000 miles with my current Oil - so I'll be doing an Oil/Filter change soon (maybe even later today) I'll do it the Old fashioned/Proper way



Paul.

[Mike Trident]

Originally Posted by T-Cut

I remember reading a report on an investigation into the efficiency of changing engine oil using a vacuum extractor compared with the conventional drain down. It's important because the car servicing industry, both professional and amateur, will use whatever methods save time and money. I've been unable to relocate the report, but it may still be on the 'Net somewhere. The results were quite surprising in that there was little difference between the two methods. I believe they tested several different cars to investigate sump design variation. They applied a set time limit on the drain down period (you'll always get that extra drip if you wait long enough), and other important factors like oil temperature were taken into account. After the job, they removed the sumps to see what residual oil was left. Statistically, there was no difference. There were variations across cars, but overall there was little difference. So, for your 75/ZT, we're simply guessing because nobody has done the test. In general terms, either method is fine because no method removes all the old oil. It's impossible to do that. Additionally, the question of 'sludge' removal hardly comes into the equation these days. The ACEA oils specified by car manufacturers don't form sludge and remain homogeneous during the recommended service life. Whatever metallic particles may exist will be in the filter. So whatever runs out of a drain plug will also be sucked out with a pump. Wonder whether the sump floor slopes away from the plug when it's jacked up? I suspect it does, but I haven't checked. I think it comes down to personal preference and feel good factors. If jacking up the front or driving up ramps to access the drain plug is the only way for you, that's fine. If doing all the work from above is more to your taste, then that's fine too. Personally, I reckon it's not worth worrying about the difference.

I agree totally, rust and poor quality replacement parts will send more of our cars to the scrap heap than which way you choose to change your engine oil. Plus, any oil change has to better than non.

[bendrick]

Originally Posted by T-Cut

I remember reading a report on an investigation into the efficiency of changing engine oil using a vacuum extractor compared with the conventional drain down. It's important because the car servicing industry, both professional and amateur, will use whatever methods save time and money. I've been unable to relocate the report, but it may still be on the 'Net somewhere. The results were quite surprising in that there was little difference between the two methods. I believe they tested several different cars to investigate sump design variation. They applied a set time limit on the drain down period (you'll always get that extra drip if you wait long enough), and other important factors like oil temperature were taken into account. After the job, they removed the sumps to see what residual oil was left. Statistically, there was no difference. There were variations across cars, but overall there was little difference. So, for your 75/ZT, we're simply guessing because nobody has done the test. In general terms, either method is fine because no method removes all the old oil. It's impossible to do that. Additionally, the question of 'sludge' removal hardly comes into the equation these days. The ACEA oils specified by car manufacturers don't form sludge and remain homogeneous during the recommended service life. Whatever metallic particles may exist will be in the filter. So whatever runs out of a drain plug will also be sucked out with a pump. Wonder whether the sump floor slopes away from the plug when it's jacked up? I suspect it does, but I haven't checked. I think it comes down to personal preference and feel good factors. If jacking up the front or driving up ramps to access the drain plug is the only way for you, that's fine. If doing all the work from above is more to your taste, then that's fine too. Personally, I reckon it's not worth worrying about the difference.

Talking about sludge

As mentioned during the substancial thread following my mini disaster with an accidentally chopped off oil remover suction pipe, the upshot was that my local garage removed the bottom sump cover to check and recover the chopped off section of pipe.

Watching the whole operation out of interest and curious as to what build up of sludge or anything else might be present in the bottom of the sump I was pleasantly surprised to see none whatsoever, just a few smears of quite free running black oil. I was also surprised to see how relatively clean the bottom of the sump plate was with no real deposits of anything never mind little lumps of sludge or ingrained other sort of marking on the plate.

In fact a quick wipe with a rag and you could have quite happily cooked an egg for your mid morning roll on the base plate without any fear of suffering the cooking term known as black oily bottom egg.

Not being the most engine mechanically conversant person in the world I was expecting to see all sorts of detrius in the bottom of the sump but can only assume that the manufacturers claims of detergent action, suspension of sludge etc etc within their products are broadly correct.

i can of course only relay the condition of the situation in my car and appreciate that others experiences may be different.

[Mike Trident]

A first hand appraisal.

[COLVERT]

Originally Posted by Mike Trident

I must add, if the capacity of a diesel is 6.8 l

And I pour a 5l and two 1l cans in to get the level to the high Mark on the dipstick, there can't be 1l left in?

Allowing for the amount that stays in the oil bottles, I must be putting in about 6.8l so it can't be far off totally empty surely?

I find exactly that using my Pela pump. Always check the quantity coming out.

Ten years on I've had no problems. Still no oil use between changes and still averages 50 mpg overall during the year.----

When you consider that you have been happily going about your business with your sump FULL of old oil without giving it a second thought why would you start to worry about the 5% left behind ( maybe ) after an oil change ??---At a twenty to one dilution rate what possible harm could it do ??

Sludge. It doesn't go around the engine all the time, it tends ( if any ) to just lie on the bottom of the sump. If some did pick up it would end up in the filter which is why the filter is there, along with bits of shredded head gasket and surplus gasket cement etc.

[grivas]

Originally Posted by trikey

I prefer to change the oil the old fashioned way, doing it this way means every drop comes out.

The Pela way also removes every drop, and I have measured the volume. I have been doing it this way for 15 years, and I am happy it does a great job. But each to their own the traditional way is perfectly fine but not for me as I cannot lift the front of the car high enough safely.