ES9J4 V6 oil leaks
Posted: Mon Sep 28, 2009 8:34 pm
When I got my 406 V6 not quite three years ago, it obviously had a minor but long-standing oil leak which seemed to end up round the bottom engine mounting - not a good thing as you don't want the big rubber mounting to jellify due to oil contamination! These are the areas which I have found (so far) to be contributing.
1. Only evident with the styling cover removed, the rubber sealing ring at the base of the oil filler cap had hardened with age, and was leaking oil which then filled up the spark plug recesses. Messy to put right, but cheap and simple to do.
2. Sump leaking as the (silicone?) gasket sealant had given up in places. Lots of little bolts to remove, but a cheap fix and easier to remove the sump than the 2-litre alloy one. You can also clean out the bottom of the sump while you're at it.
3. Crankshaft pulley oil seal. Not something you'd do on its own, but I changed mine while doing the cam belt job. The water pump which is located directly above it had been weeping, and this maybe caused the oil seal to dry out and leak. Incidentally, it's MUCH easier to remove and replace this seal with the front section of the driver's side wheel arch liner removed. It's a dear seal though, at £15.
4. Camshaft covers. (Any one up to four of them!) These have no separate gasket, but a neat bead of grey polymer which, on my engine, was still firmly attached to the metal. With the styling cover removed, the front two covers can be checked; the back two require removal of the inlet manifold, but can be conveniently tackled at the same time as a spark plug change. The back one was the culprit on my engine, but you can check it when the engine is cold by kneeling (!) on the radiator crossmember, (no fatties please!) and running a cloth or hand along the join, which can just about be seen. With the inlet manifold off, I took the opportunity to do all four covers, re-sealing them with blue Hylomar. Very cheap fix, but lots and lots of spanner work. So far so good..........
I hope the above might help other V6 owners to locate leaks - even with the odd drip it's a fantastic engine, even with 150K miles on the clock - just two oil and filter changes a year with quality semi-synth. is all it gets.
1. Only evident with the styling cover removed, the rubber sealing ring at the base of the oil filler cap had hardened with age, and was leaking oil which then filled up the spark plug recesses. Messy to put right, but cheap and simple to do.
2. Sump leaking as the (silicone?) gasket sealant had given up in places. Lots of little bolts to remove, but a cheap fix and easier to remove the sump than the 2-litre alloy one. You can also clean out the bottom of the sump while you're at it.
3. Crankshaft pulley oil seal. Not something you'd do on its own, but I changed mine while doing the cam belt job. The water pump which is located directly above it had been weeping, and this maybe caused the oil seal to dry out and leak. Incidentally, it's MUCH easier to remove and replace this seal with the front section of the driver's side wheel arch liner removed. It's a dear seal though, at £15.
4. Camshaft covers. (Any one up to four of them!) These have no separate gasket, but a neat bead of grey polymer which, on my engine, was still firmly attached to the metal. With the styling cover removed, the front two covers can be checked; the back two require removal of the inlet manifold, but can be conveniently tackled at the same time as a spark plug change. The back one was the culprit on my engine, but you can check it when the engine is cold by kneeling (!) on the radiator crossmember, (no fatties please!) and running a cloth or hand along the join, which can just about be seen. With the inlet manifold off, I took the opportunity to do all four covers, re-sealing them with blue Hylomar. Very cheap fix, but lots and lots of spanner work. So far so good..........
I hope the above might help other V6 owners to locate leaks - even with the odd drip it's a fantastic engine, even with 150K miles on the clock - just two oil and filter changes a year with quality semi-synth. is all it gets.
Not looking forward to doing that job. I hate draining oil - so mucky and it always ends up splashing everywhere as it's coming out 
but suggested I use a rubber o-ring to shim it instead, but I can't really see how that'd work successfully. Any ideas/suggestions?
