Feeling a right idiot as have knackered the sump on the BMW doing regular oil change,having clocked up 6,000 miles in just over two months (2200 on the continent without fault great car!!)
I didn't get the car hot enough wasn't really thinking. The plug was quite stiff to undo and when I put it back in will not go tight and there is now a constant drip!!
Hasn't leaked too much in the 500 miles since the oil change (Sunday) but I hate seeing it leaking, have been to Halfords and have purchased some gasket sealer (any good??) as will have a go at at least stemming the flow at the weekend. Obviously I am going to need a more permanent solution new sump/retapping the sump please any suggestions would be helpful also if anyone can recommend a good BMW specialist in the London area it would be very much appreciated.
BTW a mate has had the same problem with his E30 320i as this! so not un common.
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u could try and see if u can get it helicoiled
or re tapped to the next size up
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Helicoiled??
Hole is re-tapped to accept a stainless steel spring insert that mimicks the characteristics of the original thread.
Goto any search engine and type the word in for more info.
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Tom,
When you say that the plug won't go tight, do you mean that it keeps going round and round? If so, I wouldn't chance driving the car in case the plug works loose under vibration as it heats and cools!
Could it be that the damaged thread is on the plug, not in the sump? A new plug would answer that. I am assuming that the sump is steel, not aluminium, in which case there is at least a 50% chance that it is the plug that has the most damaged thread.
If the threads on both are damaged but not excessively so in the case of the sump, a run through with a tap should clean up the thread without removing too much metal - this would help the new plug to engage the thread in the sump without cross-threading.
If the thread in the sump is badly damaged, you could have it helicoiled as already suggested but this is usually a repair for aluminium parts. If the sump is steel, the drain boss is probably too short for a helicoil and you might have to have the boss drilled and (a) re-tapped to a larger size or (b) have a insert welded in and tapped to the original size.
Finally, the cheat's way out would be to clean the threads and use a strong Loctite to ensure that the plug stays in place. However, this would need to be repeated at every oil change and it is not always easy to remove Loctited parts. It is also unfair on future owners of the car (I have old-fashioned principles on such things!).
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Tom,
I've just taken a 'reminder' look at the sump on my BMW 525 engine which is probably similar to the one on your 325, though my engine is the M50, not the M20.
My sump is aluminium with a horizontal drain boss having a parallel thread. If yours is the same, it shouldn't be too difficult for a local machine shop to put in a helicoil with the sump in situ. This shouldn't be too expensive and would solve the problem once and for all.
I take my hat off to mav for coming up with the helicoil suggestion in the first place and without the housing estate of 'ifs & whens' that I posted!
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Like the M50 my M20 has an aluminium sump will investigate the helicoil option.
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I don't think you caused the problem this oil change. If the plug was hard to unscrew, odds are it was cross-threaded when it was put back on last time. Thread in the sump is probably damaged and will need retapping/new sump/helicoil as suggested.
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I did the last oil change and didn't have any problems so I'm to blame!!
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I did the last oil change and didn't have any problems so I'm to blame!!
Doh! Always do bolts/nuts up with your fingers.
Helicoiling is the answer. It will be cheap, 100 per cent effective and can be done in situ.
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Parp, Parp!
Note: All Toad posts come with an implied smiley.
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Tom. Might I suggest a temporary measure, just until the plug/boss fault can be rectified. Buy a roll of PTFE sealing tape from any plumbers or DIY store. Run the plug back slightly (unscrew) to show one or two threads. Wind a length of tape, clockwise into this gap and retighten(gently)the plug back onto it,s seat. The tape should give a much better seal that any liquid.
I am not conversant with this engine but, if it is a steel sump,the plug thread is probably a "parallel" one and if you can ascertain the size/diameter of the plug (14mm ? or thereabouts) it might be possible to tap the hole to the nearest BSP thread.
This would be a "taper" thread and the seal would then be made as the thread tightens instead of the existing "face to face" joint, this new thread being sealed also with PTFE tape.
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Personally I dont advise on PTFE tape with engine oil, as more often of not the PTFE will slowly dissolve in the oil from my own experience with silicone oils. Perhaps if its not synthetic, it might be ok.
S.
_____________________________________
SVPworld (incorporating PSRworld)
www.svpworld.com
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No problem with PTFE on oil joints. The oil industry uses it on a wide range of installations
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Have booked the car to have the plug helicoiled going to cost around £50 in central London as convenient but cheaper than a new engine!
Cheers for all the advise and I'll keep you posted with the progress.
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Have booked the car to have the plug helicoiled going to cost around £50 in central London as convenient but cheaper than a new engine!
Seems a bit steep! You could buy the kit yourself from a motorfactor for that!
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Parp, Parp!
Note: All Toad posts come with an implied smiley.
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I know but
a)hopefully won't have to do it again
b)my DIY confidence has taken a hit!
c)I need the car for work and so can't afford to muck it up or have it off the road for any more time.
I know it is going against everything I would normally advise but knowing it is fixed properly is more important.
Tom
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I know it is going against everything I would normally advise but knowing it is fixed properly is more important.
Yeah. I wasn't being critical. 50 quid to know the jobs a goodun is good value.
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Parp, Parp!
Note: All Toad posts come with an implied smiley.
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more often of not the PTFE will slowly dissolve in the oil
A sort of DIY version of Slick 50 engine treatment, then?
Richard Hall
bangernomics.tripod.com
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All fixed for the sum of £45 well worth it for peace of mind but won't be doing it again in a hurry.
Thanks for all the help.
Tom
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An estimate of 'around fifty quid' works out to a bill of £45 ?
Tom, can you put me in touch with any builders who operate this accounting system?
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