Valve Cover Seal Leak

[brettj]

Hi All,

I have noticed a bit of oil seapage from the left bank valve cover seal in my 450SE. I replaced that same seal in April of 2007 and again in October 2007. My mechanic replaced the seal in October because he felt it might have been installed incorrectly. Why would this seal keep leaking? Is there a trick to the installation of the valve cover seals? Could the problem not be the seal but a bad valve cover itself?

I'm sick of replacing that seal for nothing. How bad would it be if I just left it alone?

[Big_Richard]

things to check;

excessive blowby - pressurisation of the crankcase will cause oil seals to leak, no matter how good they are, the weakest one will always fail. Ensure your crank case ventilation system is working and not clogged. How many Kilometers / miles has this engine clocked up.

Warped valve cover - If its warped, the seal is going to fail. Check the cover for warp next time its off.

[WGB]

You either have a warped valve cover as Patrick says - caused by incorrect torqueing down in the past - the 450 rubber gasket is a very low torque - or a mark on the top of the head which is stopping the gasket from sealing.

Blowby won't help but that is more likely to put oil into the air-cleaner - check the breather off the right camcover isn't blocked.

Bill

[brettj]

My car has 156,000 miles on it. I did have a problem with the hose that attaches to the left bank valve cover from the air cleaner. The clamp that holds that hose down fell off and the hose became disconnected. The other hose that connects to the right bank valve cover near the air slide  has a crack in it. I purchased new hoses and a spark arrester which fits into the hose for the right  bank. Haven't had a chance to put them in yet. Are the hoses in question part to the crankcase ventilation system?