I have bought an aftermarket rubber chain tensioner plug just to plug the hole for short period of time till I get to machining a propper aluminium plug.
After half a year I finally made an aluminium plug and when I removed the rubber one I found a strange thing… the plug has swelled from oil… I attach few pictures for comparison how it looks like now next to unused plug
I don’t know if OEM plug is any better (at least I hope it is better) from what I see, if this plug hardens with time, it will be impossible to remove it even if you have cut two ears before installing it.
John,
The OEM plug does harden with time. I had a difficult time getting it out of the 5.3L V12 in my wife’s 1990 XJ-S convertible last year when I adjusted the intake and exhaust valve clearances (most were out of spec). To get the hardened plug out I chipped and cut away at it with some sharp tools and then eventually I was able to pull the remainder out intact. I got a replacement OEM one (C37925) from the local Jaguar dealership along with a bunch of other parts (belts, hoses, seals, gaskets) when I cleaned up and restored the engine bay.
Paul, mine OEM was also hard as rock! Luckily my engine was out and sump and sump plate removed so I wasn’t worried about the peaces of the plug falling into the engine.
Now I have made this aluminium plug and can forget about the lousy rubber one
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
5
It might harden with heat. Like, if the engine has never overheated, maybe it stays pliable. Anyone know for sure?
I will say this: Having had to remove an old one, there is no way I would ever consider installing a new one without cutting the ears off first. I’m sure I ended up with a couple of chunks down in the sump, but I just left them there; they’re too soft to do much serious damage.
With the way I installed mine, it would have worked fine to cut off more than just the ears. Like, I could have cut off the inner half of the plug. Just slice it in two between those two ribs in the middle. The tang I fabbed to hold it in place was tapered – narrow at the end that sits on the plug, wider at the end with a bolt hole – and thin and springy, and I deliberately shaped it to apply a bit of pressure holding the plug in the hole. Just the outer flange of the plug being held firmly against the outer surface of the timing cover would provide more sealing than that plug normally achieves.
i took a different route, local plumping store, rubber and brass adjustable plug, tighten nut on outside it expands to seal , been over 20yrs still NO leaks, and i could just loosen nut and slide it out!
almost forgot, $2. Bucks USD.
ron
3 Likes
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
7
I did that first. No, it won’t come out later. Loosen the nut until it rattles, but the rubber has expanded and jammed itself in the hole. Then you have to figure out how to get it out without dropping the metal bolt and washer into the hole.
