Did my mechanic lie to me?
 

I’m female and know nothing about car mechanics. I'm looking for input on what my mechanic told me. I have a 2014 370Z Touring Sport (manual) with 43K miles. Since my 350Z days, I’ve always gone to the same mechanic for oil changes, and they check for any issues that need fixing while they’re at it. I’ve always trusted them and never had a reason not to.

At my last oil change, the mechanic asked if I’d noticed any issues when shifting gears—nope. Any leaks? Nope. Then he told me I had the following problems:

Dirty cabin air filters
A leaking valve cover gasket on the left side
A broken rear differential bushing that leaked all its fluid

He even showed me a diagram explaining how difficult it is to replace the bushing, how the entire area where it sits needs to be taken apart, etc. The total cost? $5,400.

My dad’s friend Jerry, who builds custom car engines and seems to be a car wizard (especially with vintage cars), took a look today. His verdict? “There’s nothing wrong with your car. Don’t do anything.”

What do you think for those of you well-versed in the 370Z mechanical stuff? Does it sound like my mechanic lied to me? Or maybe misinterpreted what they were looking at? Or is Jerry maybe unfamiliar with something that is very specifically Z related and is a common problem for a 10-year-old 370Z?

The rear diff bushing is filled with fluid. They will leave a stain down the diff when they go out. It is a common issue. The diff has to come out to fix it. It's a pain in the butt. Valve cover gasket leaking is common also. There are seals in the spark plugs holes also. Common issue over time. Would have to see the break down itemized list to see what he is charging to do what. In cabin air filter is just normal maintenance stuff.

^^^^^^^^^^^this

What shop?

The point of my question is that Jerry said I don't have a problem, while my usual mechanical shop said I do. Is it likely that a guy who can build an engine from scratch could miss that the issue is there simply because he doesn't know Z cars specifically?

He does not know our cars. He would have a hard time building one of our engines from scratch.

The cabin air filter should be looked at once a year.

The other issues are common. The diff bushing is a royal pita. It's about a day and a half job. I've done 3 of them. If you were closer. I'll do it for a couple of hundred. If they replace it with oem. They replace the whole sub-frame. You can buy aftermarket bushings.

Poly bushings. $99.99

https://www.z1motorsports.com/z1-pro...t-p-10356.html

Solid bushings. $179.00

https://www.splparts.com/products/37...-bushings.html

I have the solid bushings in my Z.

I found the answer to my question. After further discussion with Jerry, it is clear he is correct. He explained how it all works and told me the bushing had some rust on it, but no oil, nothing loose, no crack, and in fact, the screw holding it in looks brand new. So, it turns out my trusted mechanic lied to me. As a woman who is clueless about car mechanics, this is pretty devastating; it's like finding out a boyfriend cheated. FWIW, I live in Huntington Beach, CA (Orange County). My next post on a different thread will ask about a good mechanic near me.

Are you saying the rear differential bushing on a Z completely differs from any other car?

Yes and no. There may be another manufacturer that uses fluid filled bushing, I'm not sure.

The main factor is how its installed. It is not a replaceable part by itself. The entire rear sub-frame gets replaced if you take it to Nissan.

The aftermarket Bushings can be used but the differential must come out and then you must drill, cut, press out old bushing and press in new one.

Probably just as time consuming as removing the rear sub-frame, but obviuolsy a lot cheaper and less intrusive.

The Ear bushings on differential are basic rubber and pop right out. So those will be very similar to other cars.

that may explain the high estimate??

The rear subframe at Courtesy Nissan is only $1,034, I get cabin filters for $8, and the valve cover gasket is $40 including the spark plug hole unit at Nisssan. So no you're being killed by labor and parts markup to the tune of $4,318!! :eek:

I HIGHLY recommend finding a mechanic specializing in Z's and getting the bushings swapped and valve cover gasket done. You'll probably save at least the labor value above!
You can do the cabin filter easily via youtube vids as they're designed to be serviced.

You're in HB. Just call Specialty Z in Simi Valley. They'll do all of that work and you'll leave happy at a fraction of the cost quoted. Many of us on here have been his customers for years. Zs from other states and CAN shipped for more specialized work.