Ask Cars: Valve cover gasket replacement
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.
Don't be afraid to try this if you can follow basic instructions. Cars are pretty stout and unless you do something crazy this should go fine.
I would guess you can find some good YouTube videos that will walk through he specific steps/process for your car. Or a car forum/FB group to search any specific issues changing valve covers. Generally this is a pretty straightforward job.
I have no idea what maintenance has been done previously etc. But if it has plug wires might consider changing them as well, however a lot of cars today have coils right on the plugs so no maintenance needed if yours is like that.
Realize the small bolts holding the valve cover on will not take a ton of force to tighten. They're small bolts going into small holes. Pay attention to how tight they are when taking them off if you don't plan to use a torque wrench to tighten them. Make them snug not crazy tight.
Thanks for the reply! I already did find a couple videos and forum posts about this specific job, so I'm hoping it'll go fairly smoothly. I do believe the coils are right on top of the plugs, along with a plug boot. Are the coils worth replacing, and what exactly is a plug boot? From what I'm reading, them being missing can cause some issues in removing the plugs. I do plan on grabbing a rental torque wrench just to be sure I don't do anything crazy 😂
I would say Honda coils are darn reliable and if you aren't experiencing a problem, don't sweat it. They are easy to replace if that time ever comes. I've had a couple DOA aftermarket coils and certified parts were stupid expensive.
The plug boot mostly just keeps dirt out of the plug hole. It can degrade if the spark plug is failing allowing some blowby to heat things up.
Good, the prices I've seen for the coils would not make my wallet happy lmao. I might try @dmtalon@infosec.pub's suggestion and hit up Autozone about the boots
Autozone or Oreillys should also have a torque wrench to borrow for tightening the valve covers and intake (you rent it, but they only keep the money if you keep it too long so it’s free unless you forget to return on time).