When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The D is more of a solid and not cupped out to the extent as the pic . Sealing pressure would be equally important radially around the D as in the flat parts . Important to put some high temp sealant in and around the corners of the D's . I think there are 2 D's on the back side . I'm pretty sure mine is an original like the spark plugs . I reacted like Sam Kinison hell when I first pulled them . Oh , Oh , Oh . Check the oil cap for the rubber seal can be dried out and break off small pieces into the oil and the metal T clip can unglue as well , I put a bolt through mine smashing the threads so the nut wouldn't back off
I am also dealing with oil leak from the valve cover gasket at the rear of the engine. The gasket was fitted only about eight months ago. So not sure if there is one or more problems of the following
(a) the cam cover gasket (#2 in the diagram) that is of bad quality - mechanic found it contracted at the rear;
(b) the bolt rubber isolators (#9 in the diagram, 13 of them in all) were over-tightened (most have deformed) or made from poor quality rubber), or
(c) there is imperfection in the re-conditioned cam cover.
Well please disregard. I removed the gasket and started from the rear part and ended up fitting well. So will be finishing the job today! Will post pics once it is complete
Qvhk , if you feel with your finger along the very back edge the 2 D's can easily fall out of position , did it myself . Oil runs down the back of the engine .
The cam cover bolts are a shouldered bolt so the seal pinch dimension can in reality only go so far in reality . There is a torque pattern and value but then it is shouldered bolts . Read somewhere where someone added round o-rings directly under the head of the bolts to give the seal a tighter pinch but you have a new seal so it should be soft and not smashed .
May have to put some high temp sealant in the groves of the cam cover including the round well seals ( and isolaters ).
The # 9 isolators appear to be hard plastic and could be cracked .
I will be putting gasket sealant on the corners as recommended. It seems like my car leaked a lot of oil from the rear. Very well could be from the corners of the D's in the gasket as Lady P mentioned. Didn't finish job because I didn't have sealant available and stores were closed lol
Okay okay now I see what you mean. My question is though would the fan/wind blow the oil to the back and not the front? The reason I say that is if you look at the oil sitting on top of the VIN #, you can tell it's only sitting at the right side. Any other possible culprits? I will be giving it a good clean and see where it is seeping from.
Don't think I ever found a part number for the seal in the recess as someone had a leak there and the previous owner tried a form a gasket product . I don't think the area gets too hot and a common rubber O - ring from the hardware store may work .
A bead of sealant where the bottom of the T seal goes into the cover may be the easier try as the grove surface gets textured , same with the plug well seals .
Last edited by Lady Penelope; 12-28-2017 at 11:44 AM.
Quick tell tale is grab a can of athletes foot spray. Clean the oil up. Spray a light coat of white Athletes foot spray on and the powder will show you easily where it comes from.
On an Xj40, that leak (common) is from fitting an earlier style (non improved) head gasket.... there's an oil gallery very close to the edge of the head and in the early (and some after-market head gaskets) the oil will make its way out of the engine and seep down on to that exact place you show in the pic ...jes sayin'.
Even the 'improved' head gaskets can leak.
The intake cam oil feed has a dowel surrounding the hole but the exhaust cam just has a copper washer type seal.