Plastic sump plug leaking after oil change

[IansMusical]

Hi All,

So yesterday I changed the oil in my 2013 1.8 Leon and replaced the plastic sump plug with a Febi one from RSC Automotive (ebay). Note I usually suck the oil out so this is the first time I've replaced the plug. I used the correct tool, it's not cross threaded and it's fully in the lock position. Today I find a small patch of oil on the drive. The original sump plug and new one both use an O-ring and look the same to me.

Has anyone else experienced this? I'm thinking to quickly swap the plug for the original one and top up the lost oil as a solution!?

Thanks in advance,

Ian

 

[RUM4MO]

That is annoying, my older daughter has a 2019 Leon Cupra, so when it ran out of warranty and pre-paid service plan, I bought a proper tool for working with these plastic drain plugs - okay lots of people use large "flat" screwdrivers, but I wanted to try to minimise risk as it was not my car, that tool came with one or two new drain plugs, but again I chose to buy the genuine VW Group part and did not have a problem at oil filter and oil change last year, for this year I've bought another genuine drain plug and oil filter. Not much to go wrong as you know, the tightening torque figure is irrelevant if it exists as the design of the fitting means that you know when you have completed the "tightening" - or fitting, a strange one that, Febi should be good enough.

 

[SuperV8]

I would swap out with a new genuine plug and oring. The genuine ones are cheap.
I would want to inspect the condition of the bore in the sump where the oring seal against so would drain/catch all the oil in a clean container - and carefully check the bore is perfectly smooth. Then re-use the oil.
I would also double check the surface of the new plug to check for any flash where the oring need to seal.

 

[Mo_86]

Is it worth changing to a magnetic one?

 

[IansMusical]

Thanks @RUM4MO and @SuperV8 for your input. Did you go direct to Seat for the plug? I wouldn't be surprised if Febi wasn't the OEM for the plugs anyhow, so the one I used should be genuine "enough", as opposed to a Chinese copy etc. I must admit I didn't check the bore nor wipe it so yes it's possible that some dirt has fouled the o-ring. I always thought it was a no no to re-use the oil even if it is brand new and only been circulated (to check the level), something to do with sediment?

 

[RUM4MO]

Originally, I could not find any VW Group type idents on the original drain plug or the new one that I bought from a Skoda dealership(I pass it every Wednesday), this year's one is a revision of the first version - well going by its part number which has been revised, and moulded into the body of the drain plug.

 

[SuperV8]

Thanks @RUM4MO and @SuperV8 for your input. Did you go direct to Seat for the plug? I wouldn't be surprised if Febi wasn't the OEM for the plugs anyhow, so the one I used should be genuine "enough", as opposed to a Chinese copy etc. I must admit I didn't check the bore nor wipe it so yes it's possible that some dirt has fouled the o-ring. I always thought it was a no no to re-use the oil even if it is brand new and only been circulated (to check the level), something to do with sediment?

If the oil is only a few days old it wouldn't concern me be re-using it.
Maybe VAG used some silly proprietary o-ring like Citroen did for their sump plug o-ring - and Febi just used an of the shelf o-ring? or maybe there is some dirt in there - or maybe so plastic flash from the moulding process.
I wouldn't think the febi part is a re boxed OE part - just an aftermarket part.

 

[DEAN0]

I am tempted to do a steel sump pan swap at my next oil change.
The old school threaded sump plug with copper or aluminium sealing washer has never let me down over many cars/bikes.

 

[IansMusical]

Quick update: It looks like the issue was caused by me! I inadvertently over tightened the plastic sump plug which I noticed when taking it out, the plastic was bent.

In order to get back some credibility I did originally feel the plug easily click to the stop position but while it wasn't loose it didn't feel like it was home (kind of a hand tight bolt in a metal sump).

So, for anyone doing this as soon as it clicks into place at the stop, just leave it In my case I actually put the old sump plug back in and not a drop has leaked out since!

Thanks all for the input

 

[RUM4MO]

Oh yes - with regard to how you fit these plastic plugs, forget conventional "tighter is better".

 

[Mr Pig]

I use steel drain plugs with copper washers on all the cars. Alloy or steel pan.

 

[RUM4MO]

I use steel drain plugs with copper washers on all the cars. Alloy or steel pan.

The thing is, this discussion is only about the VW Group cars that come from factory with a plastic sump pan, so that determines which type of drain plug that should be used if sticking with the manufacturer's original plan.

The detail/design of how the drain plug fits does not include the normal VW Group M14 X 1.5, so unless converting the drain "hole" to suit that, then the only way to address this when changing the engine oil is to buy and fit a new plastic drain plug - these plastic drain plugs come with the same instruction as the other ones, which is "only use once" - which in the case of the slightly older cars with steel or alloy sump pans, seems a bit crazy when the replacement drain plug has a separate sealing washer - the official instruction for newish engines that come the one piece "steel drain plug with retained sealing washer", is to bin that at the first oil change and replace with another version of steel drain plug and fit it with a separate drain washer, but next time, once again bin both!

 

[SuperV8]

Googling EA888 steel sump - there seem loads of aftermarket steel versions to 'upgrade' from the OEM plastic sump!

Plastic sump's don't still well with me!

 

[Legojon]

Plastic sump's don't still well with me!

Makes me nervous too!

 

[eltawater]

I had mine changed to a steel sump pan as I got fed up of the leak from the tiny hole in the plastic sump.

I expect it's probably ok if you have a full under tray from the factory but my cupra only has the front section, leaving the whole sump exposed to every bump and scrape in the road surface.

 

[Mr Pig]

Plastic sump's don't still well with me!

Years ago we had a Mazda 6 which sprang a coolant leak. Wasn't a high millage car. Turned out to be plastic coolant manifold on the end of the engine had cracked. I remember looking at it thinking that if it had been made of alloy it would never have cracked.

The well publicized issues with the Ford Ecoboost engines include an overheating problem caused by a plastic coolant pipe cracking.

 

[DEAN0]

Years ago we had a Mazda 6 which sprang a coolant leak. Wasn't a high millage car. Turned out to be plastic coolant manifold on the end of the engine had cracked. I remember looking at it thinking that if it had been made of alloy it would never have cracked.

The well publicized issues with the Ford Ecoboost engines include an overheating problem caused by a plastic coolant pipe cracking.

There are enough VAG EA888 owners saying exactly the same thing about the plastic Thermostat housing/water pump.

"If only VAG would make this from alloy - hundreds of us owners would not be paying appx £750 to get it replaced when it cracks and leaks."

£1500 ish if you are daft enough to take it to a dealer.

 

[RUM4MO]

Materials, typically a tricky design issue, my 2011 Audi S4 was built just after Audi had binned the plastic bodied water pump for an aluminium alloy one, but it was built before the aluminium alloy coolant flange/fitting, at the front of the engine was binned for a plastic one!

The weakness with the plastic body of the water pump would have been the usual cracking leading to leaking, the weakness of the aluminium alloy coolant flange was that as it faced the front of the car, road salt in winter time would get into the "open" end of the rubber coolant pipe that fitted over it, and that, after a few years meant that a track of corrosion crept down and across the sealing area of the hard plastic "push on" fitting that was bonded onto the end of that coolant pipe. For me, the fix for that small/slight coolant leak was to scrub up the flange pipe stub and fit a new rubber hose with that hard plastic "push on" fitting, so far so good!

Again, on the 1.2TSI EA211 engines, the aluminium alloy throttle body<>plastic turbo output pipe join is vertical and facing the front of the cars, road salt in winter time drops down into that joining area, and corrosion grows/creeps down and across the rubber O-ring seal and so oil in the incoming air weeps out onto the throttle body flange - just looks nasty, ideally I'd remove that charge pipe at every service, scrub clean the sealing area on the aluminium alloy throttle body and fit a new O-ring seal to the plastic charge pipe..

Cheap designs on consumer goods always comes with compromises.