14 replies to this topic

[SamMason]

Afternoon all, 

 

Time to fess up to an amateur mistake I made yesterday & ask for some advice on how to fix it.

 

So the story goes;

 

I've got a leaking rod selector seal, ordered a seal repair kit from MS & read the section in the Haynes manual many times to know exactly what to do. Got the car jacked up, found the correct socket to undo the oil drain plug & set about undoing it. It was stiff to start with but soon freed up & after a short time I stopped to check progress, to find it wasn't coming out. At that point I realised I had been turning the plug the wrong way & I'm pretty sure I've screwed the thread off.

 

(Silly mistake I know, but I'm sure everyone's done something similar as a learner, right?)

 

Anyway, I tried to pull the plug out with mole grips, but it wouldn't budge. Its still quite tight so I've decided to leave it alone for now & haven't driven the car since.

 

So my questions are;

 

• Which thread have I knackered - The plug? The sump/gearbox casing? Or both?
• Will the car still be safe to drive? With the engine running will the oil pressure blow the plug out or is it an unknown factor?
• What is the best method of going about fixing the mess without making it worse? 

 

 

For reference, its a completely standard 998cc motor.

 

Thanks in advance.. Needless to say I'm still feeling pretty angry with myself for doing it     

[IainNeon91]

If you can eventually unscrew the sump plug and the thread comes out with it (it's happened to me) either get a good mate at a local garage to bring home a sump plug tapping kit (my brother brought home his from work haha) or you'll have to call up someone who can do a helicoil on it.

 

I would say don't drive the car mate, because it may even fall out while you're driving, leak all of your oil and then you'll seize your engine... (unlikely, but you never know!)

 

Hope this gave you a heads up!

 

Iain.

[freaker]

not so good then.

 

got a picture of it when its half out of the thread ? 

 

you may need to try and drill it out, so you can heliicoil it and get a new bolt in 

 

freaker

[Dan]

You will have stripped the thread in the casing, it's ally and the plug is steel. You shouldn't drive it really. The sump shouldn't be pressurised unless the engine is quite poorly or someone has messed with the ventilation system. So the plug won't be forced out but once the oil is hot it will pour out through the damaged thread and you will loose it all very quickly. You need to get you sump Heli-coil repaired. You can do it yourself but the kit is fairly pricey if you only want to make one repair, call some local mobile mechanics or engineers from the Yellow Pages. Make sure whoever you get knows what they are doing, it's easy to get it wrong. If done right it will completely solve the problem permanently, if done badly it will leak forever.

[SamMason]

Ahh I see.. Thanks for the info guys.. I imagined that would be the case. 

 

Just having a look online at Helicoil kits, what size would I need if I were to do it myself?

 

Also, just found this on from Minispares - http://minispares.co...lassic/DP2.aspx - is that likely to help at all? Should I then fit a magnetic plug afterwards?

 

 

Thanks again! 

[dklawson]

Do not feel bad.  You are certainly not alone and there have been drain plug problems for many already this year.  For reference and brackground on the problem, please see the three recent threads linked below.

 

http://www.theminifo...n-on-sump-plug/

 

http://www.theminifo...mini-sump-plug/

 

http://www.theminifo...rain-plug-size/

[expilgrim]

Just for imfo if you used the taper plug from mini spares you couldn't then use the magnetic plug as different thread.

[tiger99]

DO NOT USE THE TAPERED PLUG!

 

It is a typical amateurish bit of work, with many problems of its own, and will eventually render the gearbox casing scrap. And you MUST always use a magnetic drain plug in any Mini, and its relatives, because the gears eject thin slivers of steel, which will rapidly destroy the oil pump and every bearing in the engine if they are not retained by the magnet. Check the magnet on any Mini at the next oil change if you dispute that!

 

The helicoil is almost always the correct fix, or one of two possibilities at least. But, it is going in to a relatively thin casting, compared to the hole diameter, and needs to be exactly perpendicular to the sealing surface of the casing. The necessary accuracy is very unlikely to be achieved with a hand tool, only with a stripped casing on something like a milling machine, however with great care it may be good enough if you use a bonded rubber "Dowty" seal instead of the usual copper washer. I believe that the drain plug washer from a Ford Focus will also do the trick, and every Ford dealer will keep them in stock.

 

I have an idea about making the tooling to do this repair properly and accurately in situ, as the need seems to be very common these days. But I don't, as yet, have the machinery to make the tooling. Hopefully, one day....

 

The other way that I would be prepared to use on my own vehicle of any type, not just Minis, would be to make up a tapped top hat bush, the face and internal thread being cut on the lathe so will be correctly perpendicular. The bush is then welded in to an slightly enlarged hole, the weld being around the edge of the large sealing face, well clear of the washer seating area. The main problem is getting the area sufficiently free of oil to be able to produce an oil-tight weld. I would use MIG, to keep the heat input as low as possible, rather than TIG, but Lumiweld, intermediate between solder and weld, would probably be ok too, maybe even epoxy.

[Rog46]

I suspect you will have trouble extracting the plug. You need to pull it at the same time as unscrewing it!

The only way I can think of (if all else fails) will be to drill and tap the plug and screw in a threaded rod. Now build a "bridge" a short bar with a hole at each end and one in the middle. Put a longish bolt in each end hole with a nut either side of the bar to hold it away from the sump plug. Slide the centre hole over the threaded rod in the plug an tighten a nut onto the rod to start to pull on the plug. Don't tighten too much as the heads of the spacer bolts are pressing on the gearbox casing.

Now unscrew the plug with an open ended spanner, as it comes out keep tightening the nut on the rod to keep the tension.

Alternatively call a mobile mechanic or get it towed to a garage!

Edited by Rog46, 01 March 2014 - 02:06 PM.

[tiger99]

That is good advice, but try clamping on a pair of Mole grips first, and pulling as you turn, as you may be lucky and get it out easily.

[Guess-Works.com]

If the thread has been completely stripped then the plug thread will be clogged, and as you've found out fit's like an interference stopper...

 

I've lost count of the number of boxes I've encountered like this, and the best way I've found to get them out is with the use of a windy gun ( or fairly powerful cordless drill ), a 15/16" socket and differing thickness's of wedge...

 

Get the sump plug spinning, anti clockwise and then introduce a wedge between the head of the plug and case ( I start with a knife ) and then move up to a large flat bladed screwdriver... drawing the plug out. This is the only method I've found which does not risk cracking the case at the sump plug..

 

If you have the kit of a slidehammer which will fit onto a spotwelded bracket ( usually used in body work manipulation ) then this is an alternative.

 

If you can, drain the oil from the sump first by using a suction tube down the dipstick hole, if you can't it's going to get VERY messy.

[tiger99]

So those things that suck oil out through the dipstick hole have a legitimate use after all! I prefer not to use them for regular oil changes, because the debris that sticks to the proper magnet tells you a great deal about imminent problems (I found some needle rollers there once, labouriously fixed once I knew which bearing they were from, without lifting the engine), and they probably leave a lot of crud in the bottom.

 

I have seen an Australian woman topping up Mini oil through the dipstick hole, but she would not have known how to drain it. Unfortunately it was my Mini, and she then lent it out, without my knowledge, to a mad Kiwi woman, who was very strong, and bent the controls by using excessive force, even denting the toeboard under the accelerator pedal in her attempts to get it going faster.

[KernowCooper]

Kiwi woman, who was very strong, and bent the controls by using excessive force, even denting the toeboard under the accelerator pedal in her attempts to get it going faster.

 

I shudder to think what she looked like

[tiger99]

Quarter Maori, half Irish, mother was a gang leader in Auckland. Not the best looker!

[SamMason]

Thanks for the reply's & information. I'm going to try & get it helicoiled. But I don't trust doing it myself. I haven't tried to remove the plug as yet (too busy at work to be honest), I have tested the car briefly without trouble though. The mini is booked into the garage on Thursday/Friday & I'll have a chat to see what they say - she's going in for a dodgy wheel bearing so this may or may not be done as well. 

 

I've also found an engineering firm locally that specialises in classic & performance engines, so I'll give them a ring & see what they can do after I get her back from the garage if they cant do it, as I am expecting.

 

 

On a brighter note, I managed to change the rod change oil seal as per my original plan with no major failures or faults & the new seal is working perfectly. *touches wood*

 

Thanks once again, I'll update in the future with when/how it gets sorted!