I was finally able to perform a compression test today and I believe the results couldn’t have been better. Hope I’m not corrected (fingers crossed). I used a digital tester and the results are as follows:
Left Bank:
186.5
188.5
186.5

Right bank:
192
196
186.5

Has anyone else performed a compression test recently? I’m not to sure what the compression pressure should be for the newer version of the 1gr VVT-i but I found that the older version standard and minimum pressure was 193psi and 148psi.

That’s a really narrow range. Makes my OCD happy.


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From the FSM:

Note- I would make sure you're going wide-open throttle when you are doing your compression test, a lot of people forget that and it skews the readings.

Based on your results I'd say that's a healthy engine, I know a lot of people will point out that it's not near the "standard pressure" but it is worn in and I'm going to guess that the engine wasn't warmed up when you did the test. At the end of the day, what matters more is that the compression is decently above the minimum specification and more importantly that the variance between the cylinders is within specification.

I think so too. But now that you posted that I have one concern. I removed the air intake tube but I did not have the throttle body positioned open. The engine was warmed up and brought up to temp before the test. I removed the fuses for ignition and fuel, obviously all the spark plugs. Are you implying that the throttle body should be propped open? Getting the feeling I need to do this again.

Those numbers look excellent but you should also do (or have done) a leak down test while you are at it. If that comes back good then you have nothing to worry about.

And as far as test procedure, if you want to get the concern behind you, maybe have all this stuff done by a Toyota shop. Then you know for certain. Peace of mind is worth something.

Again good luck!

Alright so I performed another compression test and the results were higher then the first test. I believe the main factor for this was that I cranked the key 7-8 times per cylinder instead of the 5 I did previously. I also made sure to have the throttle body open as I performed the test. The extra 2-3 cranks definitely pushed the psi further before it topped out as I was getting similar readings as the first test with only 5 cranks. Definitely a dumb mistake. Not sure why I had 5 cranks stuck in my head. Might have been something i watched.

Left bank:
203
203
200

Right bank:
207
205
200

Great results. You definitely don't have a compression issue. I'm more interested in leak down.

again your engine is working great /............

Gorgeous numbers! pumping air like a champ!

Yeah you always want to hold the throttle open (just mash the pedal down when you're doing the test) so that the engine can breathe at full capacity, if you have it closed you're essentially at idle (think difference between trying to breathe through a straw and just taking a breathe normally.)

Thank you for all the help and insight. I decided to change the oil early at 3k miles like my last oil change due to winter and higher idle times. Sending a sample to blackstone for some peace of mind. I also installed an oil catch can to see if that helps with the oil in the intake. Early signs show it will.

I have a theory to the scoring on the piston walls. I have a 2nd car that I have been using for work rather then my 4Runner, even though I would still end of taking it to work 50 percent of the time until the gas prices went Sky high. Then I was parking the 4Runner from Monday - Friday and only using on the weekends the last few months. Giving more time to allow the oil in the intake to drip all the way down and soak what ever carbon there was in the combustion chamber. This might have allowed the carbon to loosen up and tumble down onto the cylinder walls. It’s my best guess to all this.

But just to really raise some eyebrows. I have decided to increase the oil weight to 5w-30 by Quaker state. I know this has been discussed on forum before but I decided to give it a try thanks to the 540rat. I will send a sample of this to blackstone as well for comparison. Changing the oil to 5w-30 has decreased the typical 1gr chatter/clatter that they all have. Looking forward to the next oil analysis.

Looks like your 4R is pumping air like a champ, happy to see that. And you bumped up to a 30 weight oil that I know you'll enjoy; I've been running a 30 weight for the last 50k and the 4R sounds and feels really good.

Yes I agree. I’m not one to “feel” an oil change or a cold air intake, but I definitely notice a difference with how the engine sounds/operates with the heavier weight oil.

I just received my oil analysis back from blackstone labs and it appears that I don’t have anything to worry about. See report below.

Attached Images

 

Told you lol

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