Changed my oil today...
 

and it didn't appear to have a crush washer

The bottom of the oil pan bolt has a ring to it (and the pan has paint missing from the same spot), but, I tried getting it off by hand (no tools, don't want to miss and screw the bolt up), and the ring wouldn't budge, so as far as I can tell, it's part of the bolt.

So, I used a crush washer (aluminum) like what I have to use on my bike.

No leaks...


For the oil filter - I used a Mobil1 M1-110 filter, which is a bit taller than the M1-108. I figure the extra surface area should flow better. (these correspond with the K&N HP-1010 and HP-1008 filters (1008 is recommended, 1010 is taller))

Yeah mine didn't have a washer on the drain plug either. I bought my Z in OKC so maybe a trend among OK dealers? :S

Bought you Z on OKC, but you're in LA? How does that work :tiphat:


Was your bolt like what I described?

I was stationed out in Tinker AFB and bought my Z back in January when I was still in service. Got raped by sales tax twice for a total of $4500.

As for the bolt, it's exactly what you described.

That sucks about the tax - maybe you'll get double the tax deduction come next year...

Thanks for the confirmation on the bolt too :)

They all have the crush washer unless the last person who did your change didnt put one on. Sometimes they almost seize on. You have to take it out with a very fine tipped flathead screwdriver.

So the bottom of the oil pan bolt is flat/smooth?

I'll check when I hit 3750 miles...I figure it'll be fine - there should be enough torque on the threads, and compression on everything to keep things tight enough to not leak any oil.

Yes, it can be difficult to see the crush washer. You're right that it should be tight enough though assuming you used the right amount of torque. Once the washer is crushed (which it should be), it can almost seize on and will take some prying to get loose.

OK, I still have one more point/question on it...

Looking from the threaded end towards the head - in my case, there is a ring around the threaded portion, that has approximately a 1mm gap all the way around - this in turn has a about a 1mm rise, a 1mm width, then a 1mm drop, then the remainder of the bolt head.

On top of that, the outside of this area I've described also has black paint on it...as if it's part of the bolt. This in combination with it being centered (unlike a washer which generally will not center and seize), leads me to believe that it's part of the bolt, and not a seperate crush washer, however, it also makes sense that it's not a crush washer, as I've not seen a bolt that has something like this. Lastly, regarding not a crush washer, the crush washers I'm familiar with are aluminum, and tend to be the same size as the bolt head...

If I take a hammer to it, and it is part of the bolt...well, I just damaged the landing surface of my oil pan bolt and it'll potentially leak.


Maybe it's worth a call to Nissan to verify that ALL 370z's come with an oil pan bolt that have a crush washer.

This would be a "Crush Washer". Quit obsessing about this. I've had 57 cars and only replaced crush washers when the parts guy taped one to the filter box (rare). never had a leak.