lccjblu

Is changing oil from the underside instead of extracting it detrimental to he car??

I've read through all these forums and there is so much controversy. I've called a bunch of shops in my area, mostly ones specializing in European and Mercedes cars and most are doing oil pan exchanges and actually saying top-side extraction is sloppy and the cheap way of doing it. So what's the consensus here? I've read stuff on this forum about how frequently removing plugs can cause leakage or that it won't adequately drain.

Funkwagen

It's not harmful. WIS states it can be done either way but vacuuming from the top is preferred as it's quicker, etc. I do believe if you drain from the pan that the car has to be level, though. So it'd be ideal to get the car up on four jack stands, or a lift if you can, otherwise the pan might not drain fully.

. It always vacuums up the full amount of oil

Plutoe

Why do they include on most cars a drain plug on the crankcase---I think it is there to drain the crankcase---screw the topsider weekend ***** stuff---use gravity.


"I've read stuff on this forum about how frequently removing plugs can cause leakage or that it won't adequately drain"-----is this something you heard at daycare!!

michail71

I don't think it really matters all that much. For a shop with a lift the drain pan is going to be faster and more reliable for a wide variety of vehicles. For at home you can't beat the convenience, safety and cleanliness.

But I have done two top side extractions so far and much to my surprise have gotten all the oil out based off of refill quantity. But some oil will remain with either method. You can leave a drain pan plug out for hours and it will just keep dripping. Whatever oil gets left behind just gets diluted and run through a new filter.

jbt56

This made me shake my head. Absolutely no offense to the OP. Cars have used oil drain plugs quite successfully for 100 years and billions (trillions?) of miles and many millions of oil changes. It's only been the past 10 years or so that oil 'vacuuming' systems have really existed. If you change your oil every 3000 miles, and drive a car 100k or so, you may eventually have to replace the drain plug- although most cars never need a new one. Some use crush washers (gaskets) that require replacement periodically, but I've never seen an oil change place charge for one.
If your preferred service shop uses gravity to drain your oil, don't worry about it. If they use a vacuum, don't worry about that, either. As long as either is done properly/correctly, you should never have any associated problems.

dennish

For me, it makes perfect sense to use the vacuum method on a MB. It eliminate jacking the car up, and taking off the under shield. Besides, the oil filter is topside so it's an easy job. All done from the top. PITA to drain it.

ghlkal

No.

But I do understand your concern if you read through some threads on here. Either way is just fine. I change mine via the drain plug.

Carsy

Take a look at these posts ,especially the photo of the solid set oil at the end. Drain plugs are mentioned.

https://mbworld.org/forums/diesel-fo...-seized-8.html

I would say the regularity of the oil change is more important than how you do it.

michail71

LOL, but for at home use I think the vacuum method would be better. You don't run the risk of stripping the threads on the drain pan, having a stuck bolt, making a massive mess, etc. But for an actual shop with a lift it's a different story.

I had shop over tighten a drain plug and strip my pan before and the car already used the largest plug size available. So I had to get a new pan and couldn't prove the last shop messed it up on what was it's first oil change.

spielnicht

Drain plug or vacuum, investing in an extra $20 per oil change by using the Liqui Moly Engine Flush goes a long way to keeping your engine running good. It will remove any and all sludge build up in the engine or oil-pan.

Funkwagen

Someone correct me if I'm wrong but I think it's advised not to do any sort of engine flush on these motors

michail71

I've heard that with just about every engine but it's one of those topics that can get endlessly debated on car forums.

In the past I've added seafoam to engines the day before oil changes but I don't think I will do that with this car.

spielnicht

And every european car maker also states never to use oil additives, yet all their dealers use BG crap products when performing regular required service.

If Liqui Moly makes it, I trust it. I've used it with every oil change on my wife's ML350 and at now 120K, engine still running smooth as silk.

95Sinned420

Don't fall for all the marketing hype with adding snake oil to your engines.

Don't be cheap, buy the filter from the dealer (~$17) and use the recommended Mobil 1 oil and you can't go wrong. Change it religiously and your engine will outlast your love for the car

Personally, I do vacuum method for service A intervals and drain plug for service B intervals. It's nice to be under there to check for other concerns. Also, I've seen the drain plug drain dirty/gritty substance, where the vacuum method will fail to suck up. Not a big concern though, as any of this dirty crap will be filtered by the filter. It's just good to know it's been drained out from the bottom of the pan.

Alfadude

I guess I am one of the skeptics when it comes to these sorts of products that claim to make a good think "more gooder". 120K on an engine is really nothing provided the oil was changed regularly and any other issues that might pop up were addressed as needed and I would venture to guess that if that was done the engine would still be running smooth as silk. Not saying that it will do any harm, just that I don't necessarily see the benefits either. Everyone wants to do what's "best" for their cars and I doubt that everyone will always agree what that means. Glad your car made it to 120K and I hope it makes it another 120K.

dennish

I have driven my 190E on a 350 mile road trip down Central Ca. for years. Car is well maintained. I consistently got 24 mpg. I Started using Liqui Moly MOS2 a couple years ago. Now I consistently get 26 mpg on this trip with this 24 yr old 205k mile car. I will be using it in my C350's (new road car) first oil change since I got it. This is the one additive that gets high ratings and acceptance on Bob is The Oil Guy forum.