Weeping sump plug

[Shaguar]

This week I gave Elle an oil change and also fitted the spin-on filter conversion. You can see from the picture that the sump plug was in a bit of a state, so I decided to replace it.

The problem is I think in the past the thread has been damaged and the new plug wouldn't tighten with the copper washer in place so installed it without and now it's weeping oil :( . Any advice would be grateful :) .

[Heuer]

Unfortunately there is not much you can do other than buy a larger size (British Pipe Thread) plug and have the sump drilled/threaded to match, and this is difficult with the sump in place. Helicoils do not work so forget about that option. Others have tried a tapered plug but this risks cracking the sump if you over tighten it. Best plan to remove the sump and have the hole welded/filled and a new correct size hole drilled/tapped to match your new plug. This is the safest long term option.

[Moeregaard]

That doesn't look like a factory drain plug. I agree with David that pulling the sump and having the hole welded and re-tapped is the best approach. I suspect that installing a helicoil would result in leakage, since these are nothing more than stainless wire having a diamond-shaped cross section. I would avoid a tapered plug at all costs. Once repaired, obtain the correct plug and washer, and don't over-tighten.

There is a very nice alternative to helicoils, known as a "Timesert." These have been popular with the antique-motorcycle guys for several years, and I was able to restored some badly buggered sparkplug holes in my vintage Mercury outboard motor (my other "disease"). The installation kit is a little pricey at $125US, but for repairing damaged threads in alloy these inserts are unbeatable.

[Heuer]

I think the plug pictured is one of the tapered ones which is most certainly the cause of the problem. The original should be parallel and have a hex head. This one looks like the plug off the differential with that square head but the size precludes it from being Jaguar.

[andyp]

There's actually plenty of meat in the sump to drill and tap it for a larger plug which saves the bother of building it up first.

Andy

[Shaguar]

As usual a big thank for all your advice.

I've been on the Timesert website (http://www.timesert.com/html/drainplug.html) and they actually have sump plug repair kits (I like this solution as it seems it can be carried out in situ) and they have a distributor here in the UK in Wurth UK but I need to know the thread size and pitch of the plug, anyone know this? Thanks again for any help.

[Heuer]

Standard Jaguar is 5/8" -18. You could try one of Mike Frank's Coolcat repair plugs: http://coolcatcorp.com/Merchant2/mercha ... y_Code=Oil or one of his easy drain plugs to stop the sump from stripping: http://coolcatcorp.com/Merchant2/mercha ... y_Code=Oil
The repair plug must be worth a try!

[Moeregaard]

While we're on the subject of thread repair, consider installing inserts in the camshaft oil-feeds at the rear of the cylinder head. I once had one of these strip while finger-tightening the banjo bolts, after torquing down a newly rebuilt head. After pulling the head I installed helicoils, but Timeserts or Keenserts (sp?) could be used.

[Shaguar]

As an update I took the route suggested by David, that of the Oil Plug Repair from Cool Cat Express Corp. and it has worked :D . So thanks to David and to all those who posted suggestions, I'm concious this may only be a temporary fix so may get the sump properly repair at the next oil change.