My 2007 G35 Sedan has 138k miles. Recently I've noticed some oil dripping and my local mechanic found that both valve covers are leaking.

He is recommending that I replace both gaskets and covers instead of the gaskets only. He said that the covers are plastic and start to go brittle after so many years. Thus, replacing both is recommended. I'm not sure if I just misheard about his plastic comment or not.....

Question for the group is.... it is generally advisable to just replace both or should I just focus on replacing the gaskets?

Replacing both covers and gaskets is about $950 in parts (OEM) and $450 labor. I'm sure if I just replace the gaskets, the cost of the parts will be much lower.

 

The primary reason for replacing the entire valve cover has nothing to do with plastic getting brittle, that's not true at all on these cars. The reason is the spark plug well tube seals are embedded in the valve covers and are technically not serviceable.

There are ways around this by drilling/cutting them out then replacing them with other seals. However you're probably not going to find a shop to do this because the labor cost would be significantly higher.

Don't use the OEM valve covers at that price, you can pick up new OEM ones from Z1 Motorsports for $500 plus shipping, or you can buy aftermarket ones for like $200.

Just verify that you actually have the HR engine (two intake tubes, one on either side of the engine bay). Sometimes folks post in the wrong subforum, you posted in the V36 chassis subforum which uses the HR engine.

https://www.z1motorsports.com/cylind...21dfe727d60908

 

I made the mistake of not researching and let my local indy buy OE covers and paid out the a** for them. Z1 is the way to go here.

 

Thanks so much cleric670. Your explanation is very helpful. Definitely buying the part myself and save a good amount of $$$ is the right way to go.

I have a 2007 G35 base sedan but I'll double-check the engine model to reconfirm.

 

The 2007 sedan was the V36 chassis with the VQ35HR engine. However you still need to either look at the engine, or check the metal vehicle tag in the engine bay near the wheel well which will verify which engine. Sometimes a 2006 model will sit on the dealership lot until 2007 and the your state may register a vehicle based on it's initial sale date and not production year, so a 2006 that didn't sell for a year could say 2007 on the vehicle registration.

 

VQ35HR engine confirmed! Just placed an order through Z1.

Thanks again Cleric670... you just saved me hundreds of dollars with your guidance.