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I may have a minor leak from the cooler/filter housing, and am looking into options. From both a price and effort level, it seems like bypassing the cooler is the way to go.
A few questions from what I'm finding online:
1) I see some XJS people remove the cooler housing altogether, and bolt the filter housing directly to the block. Is this possible in a Series III? Are there any downsides? I assume I'd need a gasket of some sort...anyone have a part number?
2) I see that the next generation XJ6 (A6??) actually had a "built-in" bypass, part number EBC4124.Would this work for a Series III? The main difference I'm seeing in the diagrams is that it looks like the later cars had the cooler line on the bottom of the housing, while the SIII has them on the top... a bit less convenient but I don't anticipate it being an issue.
On a former car I had a shop attach the old hose heads to a single new hose and looped it, but that was a bit of a bear to refit, and having a random hose hoop was weird, so not looking to repeat that lol.
Not 100% sure. I haven't been able to visually confirm an active leak, but have had some drips visible on the hose fittings, although with all the work I've been doing on it it's possible it's residue from various sprays and spills. There also appear to be hose clamps on the hoses, as if someone attempted a repair at some point. I may drive it more and see if I can figure out anything more definite, but thought I would do some research since it's an issue I've experienced before.
so you can tell exactly what's leaking. This picture is from my MGB but it shows how UV dye can help you pin point an oil leak. I replaced the oil pan gasket, rear main seal (twice!), and then finally learned about UV dye. It was the cam back plate that was leaking, running down the engine, and looking like a rear main seal leak.
Update here: the oil cooler bypass does work for the SIII - you need the bypass housing, as well as two brass connectors and 4 o-rings. Here's a link to the full kit with part numbers (XJS Oil Cooler Bypass Kit XJSBPK - Berkshire Jag Components) You may also want either a spacer or a shorter stud to screw the bypass on. The process is pretty simple, but IT IS VERY IMPORTANT TO NOT OVERTIGHTEN THE NUT BECAUSE IT WILL CRACK YOUR OIL FILTER HOUSING LIKE I DID TONIGHT - AARRRGGHH!
Painful lesson learned...I'll get a new housing and gasket and go from there.
Addendum to this. Now that I have the filter housing off, I see that the bypass housing (EBC 4124) does not quite fit the housing, which likely caused my break, as I could not clearly see that was the case. I'm not sure if the part is off spec, or if the heating/cooling cycles have possibly slightly changed the shape of the filter housing.
Does anyone know if EBC 4124 oil cooler bypass will work with a SIII, or is there another way to bypass the oil cooler?
To clarify, part EBC4124 DOES NOT fit a Series III - it's only millimeters off, but they matter and you can't get a straight seal like you can with the later cars.
This is definitely turning into a "shortcuts make long delays" situation - should have just replaced the hoses LOL. For now I'm interested to try Wilkinson’s copper cap solution...will see what happens.
Final thread here unless I blow something up. Went with 3/4 copper pipes on top of o rings, and drilled a hole in the housing to connect the two chambers normally joined by the cooler. Picture attached.
so far, all seems well. Admittedly a janky fix, but this car was always going to be a bit experimental.
09-06-2023, 01:47 PM
Oil Cooler bypass (1987 XJ6 SIII)
