Hello! I own a 08 Acura TL that has an oil leak from a bad valve cover gasket. I took it to my mechanic for some other things, but also wanted a quote for a replacement. The number they gave me was too high for my liking, and I did some research and decided to attempt the replacement myself. The shop would’ve done a spark plug replacement as well, so I also plan to do that. My issue is I have never done work on a car, not even an oil change. In total so far, I need 2 sets of valve cover gaskets, spark plugs, an intake plenum gasket, and maybe an air filter boot (since I’ve heard they have a tendency to crack, if anyone has a good source please let me know). What other parts should I preventatively replace, and what are the normal steps to working on the top of the engine?
Context: I am a professional autotech, worked on various models at dealerships for 8 years, and independently for 4.
Do not allow dirt/dust/debris to get anywhere inside the cylinder head or timing cover while the valve cover is off because it can cause damage such as scratched or gouged cam lobes.
Be careful not to overtighten the valve cover bolts/nuts. Also be ready in case the valve cover breaks during removal, if its made of plastic its very common for them to break. Also properly follow the manufacturer specs for tightening order and torque.
You may need silicone gasket sealer depending on the design to seal where the timing cover, cylinder head, and valve cover meet.
Get a spark plug socket, you will hate yourself if you don’t.
Don’t drop the spark plugs. If you do, buy new ones since there may be a hairline crack in the insulator you can’t see and its not worth trying to fiddle over which one is damaged later.
Make sure the gap on the spark plugs is correct per manufacturers specifications. Sometimes the gap is not.pre-gapped or is wrong when you get them from the parts shop.
Sometimes valve cover gaskets have separate spark plug hole seals, make sure your new valve cover gasket comes with them if it needs them.
Do not drop anything into the spark plug holes. Those go directly to the engine cylinder and youll have a hard time fishing it out. If something falls in there fish it out before starting the engine, as irreversible damage will occur.
If you pull the cover and the oil in the head is very dark and very thick, just stop and don’t do any more work on it. Personally I recommend replacing a sludged engine over gambling on trying to clean it out. But if there is no sludge you’re fine.
I’ve read it’s a good idea to clean up the engine bay before starting to prevent number one, will that help at all? This engine also does need those spark plug seals, but I found a well reviewed kit for a decent price. And when you mention sludge, what would that indicate?
You can clean it if you want but be careful with where you get the water. Also let it dry completely before starting to work on it because you dont want water getting into the oil.
I never clean the engine bay, but I do get some painter’s masking plastic and I lay it over the top of the exposed cylinder head once I remove the valve cover to keep debris out.
Sludge would mean you didn’t change the engine oil often enough (in some cases it can also indicate very excessive blow-by, but in my experience I have only seen that once). I don’t know the past history of maintenance but I find it more times than I want to when working on customer vehicles. If you take care of your engine you probably have nothing to worry about.
Also, sometimes the underside of the oil cap or the inside of the valve cover can sometimes have a slightly milky yellow film on it, this is fine as it is a mixture of oil and condensation build up. As long as it is not all over the whole cylinder head, it is okay to just wipe it off or spray it off with something like brake cleaner.