Engine oil change - drain or vacuum?

[AndyID]

Recently I bought a vacuum tank thingy so I can change my car's engine oil without having to get underneath it. It seems to work very well.

 

My car has so little ground clearance that I can't get it up on ramps and even if I could I'd still have to remove a bunch of bolts to take off the skid plate that protects the engine before I could get at the drain plug.

 

However, some people don't seem to think these vacuum things are such a good idea. What do you think?

[APOLLO]

A vacuum thingy wont pull all the sh1te that lies at the bottom of the sump, draining via the plug will at least move most of it - dependent on the state of the sump / oil change interval history etc. Also a vacuum wont remove all the oil, as the tube may not get to the bottom of the sump. I tried one on my old Rover once, nearly two litres of oil was still left in, found after I did the right thing and removed the sump plug.

 

Of course cars differ, perhaps some cars may be OK, but I wouldn't use one again.

 

Brit15

 

 

[Titan]

They can't suck out the oil that needs changing the most, the sludgy stuff that collects at the very bottom of the sump.  I suppose they might be alright if you reduce the mileage between oil changes...

[Titan]

31 minutes ago, AndyID said:

My car has so little ground clearance that I can't get it up on ramps and even if I could I'd still have to remove a bunch of bolts to take off the skid plate that protects the engine before I could get at the drain plug.

 

Would be worth modifying the skid plate, perhaps by drilling a hole beneath the drain plug. Might even be worth making it really easy by replacing the drain plug with a drain valve/tap. If there is a skid plate there is little chance of the tap getting knocked or damaged.  Has it been modified to lower it?  There are good reasons manufacturers choose the ride height they do, this being just one...

[pH]

33 minutes ago, AndyID said:

Recently I bought a vacuum tank thingy so I can change my car's engine oil without having to get underneath it. It seems to work very well.

 

My car has so little ground clearance that I can't get it up on ramps and even if I could I'd still have to remove a bunch of bolts to take off the skid plate that protects the engine before I could get at the drain plug.

Where do you put the (presumably) hose to drain the engine? 
 

I had the same problem of not being able to get a car up on ramps , and it was just a compact sedan, unlike yours. I ended up just using a “quick lube” place, which I felt bad about, having changed oil and filters myself for many decades.

[AndyID]

Yes, probably not good for sludge removal but the only way to really get rid of that if you have it is to drop the pan.

 

Sludge probably indicates a rebore and a new set of pistons are in order. I don't seem to have that problem but that's probably because our cars are seldom used for short journeys. It's a forty mile round trip when we go to town.

[AndyID]

12 minutes ago, Titan said:

 

Would be worth modifying the skid plate, perhaps by drilling a hole beneath the drain plug. Might even be worth making it really easy by replacing the drain plug with a drain valve/tap. If there is a skid plate there is little chance of the tap getting knocked or damaged.  Has it been modified to lower it?  There are good reasons manufacturers choose the ride height they do, this being just one...

 

Thanks. That might work. The car is a bog standard Fiat 124 (aka a Fiata).

 

The extraction tube goes all the way to the bottom of the sump. I measured it with a piece of wire and I can hear it clonking when it gets there so I'm not too worried that I'm leaving a lot of old oil in behind. Also, if there was any sludge I doubt if the extractor would work. The sludge would likely plug it up. It won't work with cold oil. It has to be warm enough to lower the viscosity.

 

It might make sense to do a couple of changes with the extractor at closer intervals and do the next one via the drain plug.

[AndyID]

19 minutes ago, pH said:

Where do you put the (presumably) hose to drain the engine? 
 

I had the same problem of not being able to get a car up on ramps , and it was just a compact sedan, unlike yours. I ended up just using a “quick lube” place, which I felt bad about, having changed oil and filters myself for many decades.

 

It goes into the dipstick tube. The engine has to be warmed up to reduce the viscosity. The one I have runs on compressed air. It takes a little while but the tank is calibrated so you can tell how much it has actually removed. The good thing is a lot of cars now have the oil filter accessible from above the engine so you can do the whole thing without having to get under the car at all.

[WIMorrison]

We tested them many years ago in the Maintenance Advisory Group (6 MAG)  when I was in the Army as industry was trying to sell them to us for our B Vehicle fleet (cars, land rovers, trucks, etc) and they were rubbish. Granted that was 20 odd years ago and they may have improved however the mechanical parts of engines are much the same but the demands on oil are significantly higher due to higher efficiency of the engines and the ubiquitous turbo meaning you really need to get all the crud out when changing oil, these devices left a lot behind.

 

I was given one to try on my tractor last year by a friend and I know that it didn’t work as when I serviced in the old way a few months later the oil was the worst it has ever been because the pump didn’t clean it out properly, therefore two lots of crap to clean out.

 

I have learned the lesson now, there is no gadget that replaces gravity and oil needs to be changed when specified by the manufacturer - much cheaper than replacing the engine

 

 

[AndyID]

33 minutes ago, WIMorrison said:

I have learned the lesson now, there is no gadget that replaces gravity and oil needs to be changed when specified by the manufacturer - much cheaper than replacing the engine

 

 

But why was there so much crap? That might indicate a lot of wear in the engine. I won't even try it with my tractor. The sump has two drain plugs!

 

The advantage of this thing is it's dead easy to change the oil and as oil is relatively inexpensive you can change it at shorter intervals while you sit back and have a mug of tea

 

The only time I had a problem with sludge/gunk was with some "magic" long-life oil (Castrol?) in an air-cooled VW 1500 getting on for fifty years ago. The answer was to to back to good old straight 30 and change it often.

[pH]

1 hour ago, pH said:

Where do you put the (presumably) hose to drain the engine? 

 

1 hour ago, AndyID said:

It goes into the dipstick tube.

Eh ...  yes! Sorry for the stupid question.

[peach james]

We used them on the Yanmar 3 cylinder 16 hp diesel generators.  They worked a treat.  No, you couldn't get to the plug...without getting wet.  However, you had to run the engine for 30 minutes or so first, and then change the oil.  

I suspect that they don't get the sludge out very well either, but that was as good as it got.  The engines were on stringers on the bottom CL of the boat, with no way to get to the plug...  The engines seemed to have happy lives, some of the hour meters were >10 000 hrs running time.

[PatB]

I've been using one on my Fiat Scudo since the drain plug seized beyond my inclination to remove it.

 

Pros:

Now I don't have to fart around getting the drain plug out.

An oil and filter change can now be done entirely from the top, which is kinder on my ageing joints.

 

Cons:

Bit slow (but faster if the oil is hot).

Question mark over getting the sludge out of the bottom of the sump.

 

Not entirely sure that it doesn't get the sludgy stuff out though. When inserting the suction tube, I can actually feel firm contact with the bottom of the sump, and the engine takes more than its stated capacity to fill back up again, so I'm fairly confident it's getting pretty much all the liquid out. This is a fairly new engine (by my standards), mind you, that's had regular changes of high quality, full synthetic oil. There shouldn't be that much sludge in it. I'd be more circumspect on an older engine or one with a more uncertain history.

[AndyID]

33 minutes ago, PatB said:

I've been using one on my Fiat Scudo since the drain plug seized beyond my inclination to remove it.

 

Pros:

Now I don't have to fart around getting the drain plug out.

An oil and filter change can now be done entirely from the top, which is kinder on my ageing joints.

 

Cons:

Bit slow (but faster if the oil is hot).

Question mark over getting the sludge out of the bottom of the sump.

 

Not entirely sure that it doesn't get the sludgy stuff out though. When inserting the suction tube, I can actually feel firm contact with the bottom of the sump, and the engine takes more than its stated capacity to fill back up again, so I'm fairly confident it's getting pretty much all the liquid out. This is a fairly new engine (by my standards), mind you, that's had regular changes of high quality, full synthetic oil. There shouldn't be that much sludge in it. I'd be more circumspect on an older engine or one with a more uncertain history.

 

Thanks for that Pat.

 

My 100% unscientific opinion is that if any sludge accumulates in the sump it's not going to be too inclined to re-enter the lubrication system. As far as I'm concerned it can stay there until the next punter goes to the trouble of dropping the pan and cleaning the whole thing out

 

The worst thing you can do with an IC engine is run it cold. Do not idle it to warm-up. Get moving gently as soon as possible. Remote starters are the work of the Devil.

[jcm@gwr]

I would use an engine flush, it's designed to dissolve all the sludge, 

and then hold it in suspension, so it will come out when you drain,

or suck out, the oil.

[rab]

1 hour ago, jcm@gwr said:

I would use an engine flush, it's designed to dissolve all the sludge, 

and then hold it in suspension, so it will come out when you drain,

or suck out, the oil.

Agreed, always used engine flush when I did my own oil changes.

[jcm@gwr]

When I first started out as a rep in the motor (oil/additives) trade, I acquired an old

Mk1 Carlton estate from a mate.

It had a bit of a breather problem, he had rigged up an old (metal) oil can under the 

bonnet and diverted the breather pipe from the air filter into the can, this collected

quite a bit of oil, and he would empty it back into the engine every week!

 

I used engine flush at every oil change for the next few services, and after about six

months* I was able to refit the breather pipe to the air filter box, and the oil stayed

golden between changes.

*I was clocking approx 1k miles per week

 

Most flushes are as good as each other, they all do the job to the same standard, and

you just add them to a warm engine and run it at a fast idle for about 30 minutes, then

drain the oil in the usual way. The one exception (if you can get find it) was Mega-Power

(No 15 I think), which was so good you could put it in and drive around normally, mainly

because it had a friction co-efficient better than normal oil!

[APOLLO]

As to undertrays / skid plates the one on my Galaxy is huge and a pig to replace. I measured carefully and cut a 4" dia hole, now I can drain the oil easily. The cut piece was fitted with a couple of "chock block" type connectors and self tappers, now off & on in a minute.

 

I change my cars oil & filter every year, using good oil & OEM filters. Never seen any sludge (even on my 1973 Rover). As my dad used to say "Oil is cheaper than bearings" !!

 

Edited to add - I've never used flushing oil in my 50 years of car ownership. Just change the oil & filter yearly and use good stuff. NEVER had oil related engine problems either.

 

Brit15

 

 

Edited February 16, 2021 by APOLLO

[maico]

If you enter the promo code MID60 applied to the basket you can currently get 5L of fully synthetic 5W40 oil for £18.89 delivered.

I've been using this for years without sludge with MB, BMW and Mazda https://www.eurocarparts.com/p/triple-qx-fully-syn-5w-40-a3-b4-5ltr-521776031

Edited February 16, 2021 by maico

[jcm@gwr]

There are many reasons for sludge build-up in engines, oil quality/type,

how/where/when you drive it and the age (mileage & time) of the engine.

 

You need to use the right type of oil (specification/viscosity/etc), and it is 

relevant how the vehicle is driven, no abuse/thrashing when cold, but it

must be allowed to revved properly on a regular basis. 

Being driven gently round town is never going to give it a good clear out,

crankcase gases build up, causing oil to break down, also the exhaust can

get a build-up of clag!

A worn engine will obviously create more sludge, but a interesting fact for

you- when oil passes through the camshaft bearings, is destroyed by the

extreme pressures it is subjected to (breaking the long-chain molecules),

but. after approx 10,000 miles, less than 10% of the oil has actually gone

through those bearings!

[stewartingram]

My Rover 75 won't go on to the ramps without the front bumper hitting them.

Simple solution.

A 12" length of 3"x2" timber laid lengthwise immediately in front of each ramp, this raises the car enough to get the bumper clear of the ramp when I drive along the wood.

I've later added a hooked bracket so that the wood clips on to the first rung of the ramp. This does 2 things. Firstly it holds the wood  to the ramp - not really necessary, but secondly is easier for storage. The ramps are hung on the wall in the garage, with the wood hung from the ramps

 

Stewart

 

[russ p]

I bought one last year,  mainly for my ZT makescoil changing so much easier as you don't have to remove the under tray so I now change the oil more frequently. 

I've been told a lot of main dealers for modern cars used vacuum to change oil rather than gravity 

[kernowtim]

I use a 18 inch length of scaffold plank laid between the first rung of my inspection ramps and the ground,  its the only way to get the car,mk5 golf, up without taking off the front bumper!

Still have to remove the undershield though!

My 1980 Renault fuego ,anyone remember those? Had a small hatch in the metal undertray to access sump plug .

I was told by an engine builder that engine flush loosens crud that then finds its way into the fresh engine oil causing more issues, so have never used it myself.

Suction pumps are generally used for speed, or on boats or smart cars where sump plug is difficult to access! 

Edited February 16, 2021 by kernowtim

[APOLLO]

Bought a pair of these off ebay. Very wide, low angle, 16000lb rating (vehicle). Just the job.

 

https://www.ebay.co.uk/itm/161921-2-KATSU-Plastic-Car-Service-Ramps-Special-Extra-38CM-Wide-Detachable/283612353000?epid=18034251974&hash=item42089d11e8:g:Ao0AAOSwvFxdett0

 

Brit15

 

[AndyID]

4 hours ago, APOLLO said:

 Just the job.

 

 

For you maybe but not at my age