Compression specs for all 1st and 2nd gen tacomas

1st gen (95.5-04)
2.4L L4 (2RZ-FE) and 2.7L L4 (3RZ-FE)

Run engine until it's at operating temperature, remove coils and spark plugs, fully open throttle, and install your compression tester in the number 1 cylinder, engage starter for 4-5 engine revolutions, and read results. (Repeat or each cylinder)
Compression should be around 178 PSI , Minimum pressure is 127 PSI.

The difference between cylinders should be 14 PSI or less.

For the 3.4L V6 (5VZ-FE)

Run engine until it's at operating temperature, remove coils and spark plugs, fully open throttle, and install your compression tester in the number 1 cylinder, engage starter for 4-5 engine revolutions, and read results. (Repeat or each cylinder)

compression should be around 174 PSI , Minimum pressure is 145 PSI.

The difference between cylinders should be 15 PSI or less.

For 2nd gens (05-current)

2.7L L4 (2TR-FE)

Run engine until it's at operating temperature, remove coils and spark plugs, disconnect fuel injector connection, and install your compression tester in the number 1 cylinder, engage starter for 4-5 engine revolutions, and read results. (Repeat or each cylinder)

Compression should be around 178 PSI , Minimum pressure is 128 PSI.

The difference between cylinders should be 10 PSI or less.

For the 4.0 V6 (1GR-FE)

Run engine until it's at operating temperature, remove coils and spark plugs, fully open throttle, and install your compression tester in the number 1 cylinder, engage starter for 4-5 engine revolutions, and read results. (Repeat or each cylinder)

Compression should be around 189 PSI, minimum pressure is 145 PSI.

The difference between each cylinder should be 15 PSI or less.


I'm not sure how accurate this data is, but i pulled it off of the all data system at school.

 

189 psi seems a little high for the 4.0 but i dont know

 

Do you remove the all the coils/ plugs when testing or only for the cylinder you're testing and re-install them when you move onto the next one?

 

Altitude matters as well. We rarely see above 160. I’m 1km above sea level.

big thing is above 125psi and all within 10psi ideally.

 

Yup, you can’t just have a set number and say it’s supposed to be xxx when it comes to compression. Every elevation is going to be different. I live at 4500ft above sea level. I’ll never see the same as some one at sea level. The variation from cylinder to cylinder is far more important than any specific target number.

 

I'll share my preliminary & non-factory-spec compression test results here:

4.0L V6 1GR-FE, 2014 Taco with 68K miles, operating normally. No oil or coolant consumption. Normal power output, cranking & revving sounds, mileage, exhaust characteristics, etc.

Test conditions: ~58ºF ambient temp, altitude ~1350 ft ASL, engine COLD (had not been started / run for >24 hours.) Throttle CLOSED.
Opposite bank (other side of engine) had plugs IN & torqued during testing. (Bank under test had all 3 plugs out.)

Tools:

$80 Mityvac MV5530 Professional Compression Test Kit, Includes Everything Required for Performing Dry and Wet Compression Testing on Gasoline or Petrol Engines

Mityvac® MV5530 compression tester, using a single adaptor hose. (No multiple hoses/extensions.)

No key in ignition. Cranked using a remote starter cranking switch, 7 to 9 seconds or so, until compression gauge needle stopped increasing. Charged battery for ~10 mins between compression runs using a NOCO trickle charger.

Results, in PSI
Passenger side
Cylinder 1: 196
Cylinder 3: 199
Cylinder 5: 190

Driver side
Cylinder 2: 198
Cylinder 4: 197
Cylinder 6: 199

Happy with these provisional results. Next time I will do the test according to service spec on a warm engine, being sure to prop the throttle fully open & removing all spark plugs on both sides. Will edit/update this post with additional results then.

I also took extensive, good-quality flex-neck camera (not going to call it a borescope) video of the interiors of all the cylinders, including cylinder side walls, valve bottoms, & head gasket interface. Everything looks more or less normal, considerable (but not excessive) carbon build up. Some strong vertical scoring in certain cylinders, but all cylinders still show cross-hatch honing marks. No sign of slap or side-wearing. After I get all the video up (30+ minutes) on youtube I will make a separate post for that & then cross-link the post here for those interested. One person's data point for a "4.0 V6 1GR-FE in decent operating condition" baseline.

I tried to do a leakdown test as well, but found that my small air compressor can only put out around 95 PSI. Not enough to get decent leakdown results.