klucas1

Have a 04 g35 6mt vq35de. Mileage is 160k. Decided to do a compression test this morning and here are my results.

Windshield
190. 205
195. 190
185. 190

The 205 in reality is probably around 190, the tube had a good bit of oil from the common valve cover seals

My question is on the 185. All cylinders I did 8 revolutions. The 185 was 150 first at 8 revolutions. I did 11 and it got to 180 unplugged and put back in tighter and got 185 on 11 revolutions.


All the revolutions on all the other cylinders were all in tempo I guess would be the right word. All the same time apart except for this cylinder. Seems like the first 3 revolutions were fast then went normal speed after that. It did it the same way all three tests on that cylinder.

Is this cylinder ok or does anyone have any opinions on this. Btw car runs fantastic and pulls hard never had an issue the 2 years I've owned it

klucas1

Also some other info as I'm trying to tell everything. When I had it at 185 I let it hold for like 30sec and it wasn't dropping. just sat there at 185 not leaking out or anything and I did not do a leak down test as I assumed my rings ha've normal wear just from mileage just want opinions on this one cylinder

iideadeyeii

iTrader: (6)

Seems fine to me

guitman32

iTrader: (15)

On your second and third tests, did the compression stay at 150 after 8 revolutions like the first time? Or did it always take 11 to get to 185?

Not sure what you mean by the "tempo," but are you talking about how it sounds when it cranks? Or how the compression gauge moves? Did you remove all plugs when doing the tests?

Just curious, but why are you concerned with compression on the motor if its running great?

klucas1

Thanks for the reply. I had all spark plugs out when I did the test. On second and third test I just did 11 revolutions instead of going to eight like the first test since it was just myself doing it I didn't have anyone to watch the gauge.

I've been considering nitrous for about a year. I have a 90 300zx Twin turbo torn apart and needs more money that expected to get it built and been itching for some speed haha

Been researching nitrous on these cars so I'd end up doing wet 75shot With all the extra items and tune since my car is drove a lot everyday being my daily.

Motor runs excellent and I've been hesitant to do the nitrous because of the mileage but after doing the test my numbers seem Damn good considering the standard says 185, it's just that one cylinder that kinda stumped me

And I used tempo because I didn't know how to explain it lol. But kinda like the rhythm of the cranks how the sound is consistent. All cylinder were the same except the 185, the first three cranks were very fast then like revolution 4-11 sounded like the others. And it did that on all 3 tests


Maybe I'm being paranoid I just wanted to see what you guys thought about it

iideadeyeii

iTrader: (6)

Did you rent the tester from autozone?

klucas1

No, Tester is pretty much brand new I only used it on one other car. And I tested the other two cylinders on that side after the cylinder I had a concern about so I know it's not the tester. That's why after the first 150 I tightened then did more revolutions then third time I took completely out and put back in just to make sure. Sparks plugs all looked good as well. Pcv valve hissing pretty loud right where the cylinder is too but after doing research this morning looks like that is normal


I'll probably just end up calling z1 and see what they say whenever I get time. I just don't want to run nitrous if that cylinder could end up being a problem being as this is my only car driveable at the moment and I need daily transportation