The 'E' Type Forum

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 :) .

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.

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.

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.

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

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.

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!

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.

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.