VQ37VHR Compression Test

Z34NA

VQ37VHR Compression Test —
Did a compression test on my 370Z today and I’m honestly pretty surprised with the results considering the mileage and how the car gets used.

2010/11 370Z 7AT, VQ37VHR, currently at 284,266 km / ~176,600 miles
I bought the car at around 80,000 km, so I’ve put just over 200,000 km on it myself. It’s been my daily to work and most weekends it gets a mountain run.

Setup is Eugene flex-fuel tune, Bosch EV14 550cc injectors, AEM 340 LPH fuel pump, Setrab 25-row thermostatic oil cooler, updated gallery gaskets + hardware and Boundary oil-pump backplate.

I run 5W-40 PAO/ester oil and normally change it around every 4,000–6,000 km, give or take.

The car gets used pretty hard. Usually 15–20 min mountain runs at around an 8–9/10 send. Oil temp normally sits around 120–125°C. If I ever see around 135–140°C, I back off, cool it down and usually change the oil and filter afterwards.

For the compression test I used the 370Z FSM EM compression-test procedure as the basis. Engine was hot with oil temp around 82°C, all 6 plugs were removed, fuel was disabled and both throttle bodies were removed, leaving both plenum inlets open.

I also had a jumper pack connected to support battery voltage during cranking.

For each cylinder I kept cranking until the gauge needle stopped rising, then recorded the final reading.

The Nissan FSM lists the VQ37VHR compression figures at approximately 200 rpm as:

Standard: 242–341 psi
Minimum: 178 psi
Maximum difference between cylinders: 14 psi

I didn’t record the actual cranking rpm during my test.

Tester used was a Daytona DPETCM 4-piece petrol engine compression tester, 0–300 psi. Can’t really comment on the absolute accuracy of the gauge since I haven’t compared it against a calibrated one, but the cylinder-to-cylinder readings came out very close.

Results:

#1 – 270 psi
#2 – 275 psi
#3 – 272 psi
#4 – 273 psi
#5 – 275 psi
#6 – 270 psi

Honestly I was expecting worse at 284k km considering I’ve owned it since 80k, daily driven it and given it regular weekend sends for years.

The readings fall within the FSM’s published range, although I didn’t log the actual cranking rpm. I’m still surprised at how close all 6 cylinders are at this mileage.

Part of me is wondering if I somehow did the test wrong lol.

Anyone here with a high-km VQ37 had similar results, or see anything in my test procedure that I should double-check?