Yeah, that's kinda where I'm headed. I'm completely stock and always used whatever oil the dealer put in it as they did all changes up to 100K. OCI's were not always good so I think I may be paying the price for it now. There's an outfit on ebay that sells refurbished motors (all kinds) for $3K plus a core deposit. I don't have time to rebuild my motor since it's my DD.
I changed the pcv and the turbo and still get through the same amount of oil so it must be rings, ringlands or valves. Low compression in cylinder 4 will be checked with leak down this weekend.

Barely over that will get you a built shortblock from @SPEEDPERF6RMANC3; just sayin'

Thanks but I'm looking to keep it stock. My DD with a 70 mile daily commute so I need it to be very reliable......not that I am saying his built blocks are no good.....just figure that staying stock is the most reliable. Besides that, I can't afford to rebuild my head etc.

Gotcha... Just putting it out there. IF your head were good you could get a block built with upgraded rods and OEM pistons; should be completely reliable and have good power potential for the future.

Of course if your head isn't good that doesn't matter.

Thanks. I'll keep it in mind. Hopefully the leak down will reveal all this weekend. A qt of oil every 200 miles is getting to be a bit much, plus I have CEL P0401 now which will fail CT emissions when the time comes. Anyway, if I have a cracked piston, ringland etc I imagine it's only a matter of time before Zoom Zoom Boom. I've already done about 20,000 miles or more with it burning oil like this, I magine the cats are toast by now.

@maisonvi;

Are you staying out of boost? I noticed that blowby is reduced if you don't punch it all of the time. Do you still have both cats installed? My motor went like that for 7,000 miles and I was still able to save my cats.

Yeah, I’m completely stock.
I boost here and there and usually when I do I get a cloud of black smoke and misfires.
I attended an install meet with the CT Nator guys a few weeks ago and we pulled the plugs, they were caked with white deposits. So, we put new plugs in and this weekend I pulled them to do compression tests and they were almost as bad again – maybe 4 thousand miles on them.

So, I’m totally stock, have a rebuilt KO4 in it as well as a new PCV valve. I burn a quart of oil every 200 miles. I did compression tests yesterday at a Nator BBQ and got the following results…..cylinder, dry test, wet test.

1 / 180 / 200
2 / 180 / 210
3 / 185 / 200
4 / 200 / 205

We tried to do leakdown tests but for some reason the tester wouldn’t work properly…..either that or it was operator fail ;-)

One thing we did notice was that the plug in cylinder 4 came out very easily…it was loose. Also, the end of the plug socket had about a 1/8” wide ring of oil on it. One of the guys also said he saw a lot of junk on top of the piston.
My guess looking at the numbers is that 4 is already seeing a lot of oil so the wet test made no difference.

One of the guys from the NY Nator who was at the BBQ suggested a catch can to see how quickly it filled up. I had another thought on this and wanted your opinion.
Rather than buying a catch can could I just disconnect the hose that connects the PCV to the IM, block the IM hole and see what pukes out of the PCV ?
With the oil consumption I’m seeing I doubt it would be long before it was obvious that I was pushing oil through the PCV (if that’s what my issue is).
If I didn’t see evidence of that then I could switch my attention to the valves.

Thoughts ?

I assume your valve cover gasket is ok.....I havent taken the valve cover off in a while but i think you have a gasket that goes around the spark plug holes in the valve cover.

New dry test yesterday on warmed up engine when replacing spark plugs.

#1 - 193
#2 - 192
#3 - 180
#4 - 195

If you look at my older post in this thread, these numbers are about 10 psi HIGHER than my last test.

In August of last year the numbers were:


#1 - 180
#2 - 180
#3 - 172
#4 - 180


No change in engine mods. Same compression gauge used. Same testing technique of testing with all four plugs removed and cranking engine until needle stopped rising, same differential on #3 cylinder.

The only explanations I can offer is that I am now running Rotella T6 5w-40 oil instead of Mobil 1 5w-30 and perhaps I had the engine warmer this time. Maybe someone else has an opinion. I know the car did not magically get better compression, ha ha.

Valve cover gasket is ok, no leaks anywhere. I drop absolutely no oil on my garage floor.

Just a guess here but maybe the T6 makes the rings seal better.

How many of you guys actually pull the fuel pump relay and wait for the car to die before checking compression?

Never did that once.

Me neither. Just push and hold the gas pedal to the floor - that disables the injectors. Apparently it's a built in system to clear flooded engines but it works for compression tests as well.

^^ Exactly.. I once did it by pulling the fuel pump relay, now I just slam the gas pedal.

ring gaps just lined up for the previous test, or were closer.

Carbon buildup = smaller combustion chamber = higher compression?

Maybe. Did not think of that and would have thought that any changes in carbon deposits in the combustion chamber or on top of the pistons would not be enough to account for that. Dunno.

I just think it may be the built in margin of error in the cheap Actron compression gauge I have. If I checked it again tomorrow, it might be somewhere between the two readings above. I guess the important thing is to compare cylinder-to-cylinder on the same day. Both sets of numbers are pretty good. I need to continue to watch cylinder #3 , which is a bit lower than the others, as so many other people are experiencing. Down maybe what 6-8% compared to the average of the others?

When Omar checked my compression right after it was built, he got around 180-190 across the board; when he referred to the manual it directed him to pull the relay, etc. When he did that he got 210 on all four.

I'd be interested in an explanation for that....

Unless ya'll cranked it longer/harder.

Threw P0302 CEL which is cylinder 2 misfire. Pulled and replaced plugs, swapped coil packs and did a compression test. Got the following

125
80
155
155

I'm looking for a used block to build :boggled: I knew it was coming just thought it would take a little longer.

He told me that he didn't know why it was higher....but that the procedure clearly states to pull the relay and let it die before performing the test. Makes no sense to me either. I don't understand how it would be higher, but he said it was.

Just doesn't seem right to hit the "like" or "thank" button. Kinda that awkward situation. We feels for ya, butt, ya gotta pay when you wanna play. :knockedout:

I would say its better to have low compression than a hole in the block and messed up head :) much less $$$ needed for rebuild

I plan on trying to reproduce his results when I get a chance. I also can't see what the purpose is, or how it would produce higher compression. The only thing I can think of is that it prevents fuel from entering the combustion chamber, but so does putting the pedal to the floor.

Do a leak test because you also COULD have a leaking injector seal that causes compression lose... If you hear air coming from under the intake then that might be your issue and not a blown motor...

take it from me guys. ALWAYS pair a leak down test withy our compression tests. that way you know you're seeing the big picture.

We tried to on my MS6 this weekend but for some reason we couldn't get it working. I'm planning on trying again with another tester.

"We don't pull no stinking relays." Just hold the go pedal all the way down to the floor and it cuts off fuel flow to the cylinders.

What's the name of that movie? Badges? We don't need no stinking badges!
Edit: blazing saddles haha love it

A little more back story. The car idles fine, fresh oil (rotella) smells like fuel after less than 200 miles, No smoke unless I load the engine up. I am going to buy a leak down tester tomorrow. I was thinking maybe my head gasket cracked between the 1 & 2 Cylinders?

just got mine back from the shop with these results...

170
165
150
177

opinions? im looking to tune the car asap but want things running as well as i can get it before.

I would do another test with the engine hot and do a wet test to see if that 150 goes back up, especially if it is #3 . 27 PSI difference is more than 10% and is cause for concern.

fuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

I highly reccomend a proper leakdown test as well.

Sent via blown passenger side speakers.

Compression test last year was 180 on all 4 cylinders. Did anyone 2 days ago and got
180,180,150,180.

Add a teaspoon of oil in cylinder 3 and it popped back up to 180.
That's pretty much a sign of cylinder ring right? I'm guessing theres no way it's the injector seal =\

That does appear to be a fried ring or cracked ringland.

Sent via blown passenger side speakers.

Stop doing comp tests without leak downs!

Since we did one on my PU this weekend as it has burned a qt of 5w 30 in 2500 miles I figured I throw up our findings. Compression test was done with two different testers for accuracy and right after driving 100+ miles to @silvapain;s house so plenty warm.

First test:
Cyl 1= 192
Cyl 2= 192
Cyl 3= 195
Cyl 4= 195

Second test: (within 5 mins of first test)
Cyl 1= 190
Cyl 2= 186
Cyl 3= 190
Cyl 4= 190

So my concerns went down somewhat but when i went to put the hotpipe (fmic) back oil residue was present with the finger test but not visible at first glance. Poor ko4.... Also after spending some time yesterday looking at shit underneath I found a small amount of buildup at the crankcase but nothing on the undertray. RMS leaking was the diagnoses from my fellow Nator IL gearheads.

Figured data is data, whether good or bad but internals seem healthy with just under 47K of miles put on them.

Sent using stupid fucking Swype!

Do you have oil in your intake from the valve cover vent tube?

id originally took the car in to get a leak down test but they didnt do it saying it was pointless since i had a compression test done. fuuuuuuuuuu

also, the car was running very lean according to the mechanic after inspecting the spark plug. they found that the gasket around the bpv was fucked and replaced it. could any of this help in me getting that 150 in cyl 3?

Who is "they"?

the shop i took it to to have the tests done.

like your average mechanic? or a performance shop? or like service department of a dealer?

efi logics. performance shop that caters to subarus mostly.

So in others words they've never done a compression test before, since those subby guys never take their plugs out.

Did my first compression test with a brand new craftsman compression tester (old one doesn't seal). I beat the shit out of this car and I currently have 42000 hard earned miles. I've been wanting to do one for a while now but I've been busy.

Car was not 100% warm so I'm expecting slightly higher numbers on a warmer car.
Dry only
1 - 175
2 - 174
3 - 175
4 - 172

Very happy with the results. Car runs perfect so I expected no less. Also checked the plugs (they have 10K on them) and they're very clean and gap is spot on.

I gotta say this MZR engine is holding up damn well.

Got out of class and did a compression test after going to get gas and back to my dorm. Pretty satisfied with my numbers at 15k running Pennzoil Ultra 5w-30.

1= 180
2= 175
3= 179
4= 180

Just did a test on my motor after finishing my break in.(1000) miles!

It wasnt very warm.
1=180
2=180
3=180
4=180

Will do another test when i have the motor warm

What did the leak down say?

What did the leak down say?

I don't have a leak down tester but I'll try to go somewhere this week to get a test done.

If the compression numbers are good, there is no oil in the intake and no smoking/oil consumption on startup, accel, decel then I wouldn't jump on a leakdown.

knowing what i know now, with my motor, i honestly would only do a compression test SECONDARY to a leak down from now on. So much more vital information to be had from a leak test.

Figure i'd throw in my numbers. Did a test yesterday just to see how healthy the car is. Car is a 2008 with 60200 miles and fully bolted with e85 and meth. Car has been raced a bunch of times and driven aggressively sometimes but i baby it plenty and maintain it well. Numbers were 188-183-183-190.

I agree with this. Leak down does tell a lot, but of the car isn't using oil or blowing oil out the dipstick, valve cover etc, you can trust the compression test is accurate.

09 MS3 with 50k miles

195 - 192 - 190 - 190

Mods:
SRI, OCC, EGR Delete, Injector Seals, AP + Nishan tune ;)

Swapped plugs this morning so I decided to do a compression test while I'm at it. Car was at operating temperature.

1 - 182
2 - 180
3 - 181
4 - 180

:fest30:

Nice numbers!

08.5 MS3 with 84K on the clock.

135
137
135
135

Thinking the gauge was off. (cheap one I borrowed) Car runs like a champ, so I figure its ok. I would like to do a leak down at some point.

At least they are consistent. If they were all 170 except one at 135 if be worried. Looks like a bad tester.

My thoughts exactly.

Sent from my XT907 using Tapatalk 2

190-190-180-190.

With more cranking 200-200-190-200.

Pretty much the same as they've been for the last 30k miles.

55k miles on the motor.

My build starts this winter. Striving to come out of the gate in the spring.
It's gonna be tough though.

I'm quite impressed and how the motor has held together. Original VVT, clutch, block. Modified and heavily tested on since before it had 10,000km. Always pushing it a little more each time. When/if it lets go, it's certainly done its job.

I hear you on that one, Lex.

76,000 miles here. 205-210 psi in every cylinder. No oil consumption and no blow-by issues.

Original clutch, VVT (no noises), everything.

Must be a GenWon thing :)

@Lex, be proud to have such a good engine. Mine took a shit at only 19k miles... That makes me sick!

Never had blowby or oil consumption issues either. I am religious on the maintenance and modify/tune smartly as I am sure you do as well but some do seem to be built on Wednesday.

That is an early and I must say an unusual failure.

I too am religious on the maintenance and I strongly believe that is the reason it is in the excellent condition that it is today even 4 years later.

Since day one I have done a carbon cleaning treatment with Seafoam almost every 3,000-5,000 miles and religiously clean parts that accumulate dirt, carbon, etc...

I am always taking a peak inside the cylinder and the pistons are and have always remained very very clean.

I think maintenance is 100% key to longevity and an all around healthy engine.

It can be a bit of extra work but its a nice way to spend a Sunday for an hour or two with some music :)

This is unusually rare in my part of the world. ;)

I have 47k with 8k of them with my 3071 @26 psi running a 3/9 mix of e85/93. Have been getting a TON of oil from my valve cover to my TIP. Added oil catch can according to jbr instructions with check valve and it helped a little but the problem still persists.

Here are my results.
Dry test: 1) 150 2) 150 3) 170 4)150
Wet test: 1) 200 2) 200 3) 215 4) 200

Good bye rings.
Inb4 @Tokay444; "yea but what's your leakdown?"

Haha yea I figured

81000 miles, I'm at sea level(Florida), the car is completely stock.
All cynlinders would jump to 210( +/- 2) then taper down to 180(+\- 2)and hold it on all cylinders.

If your gauge doesn't stick at the highest registered reading, it's faulty.

24k, tuned (20 psi)on e85 at 9k .
I ran my etune every day.
195-193-193-193
Matco tester

190, 190, 182, 190. 92,000 miles. Original K04. Never smoked even running catless downpipe since the first year. Scrupulous maintenance. Synthetic oil exclusively, initially Mobile 1 5w30 then switched to Rotella T6. Mazda oil filters. K&N cone on my Mazdaspeed/AEM CAI.

I drive the shit out if this car. There is not a day that goes by that does not see some WOT to 6,000 in 3rd or 4th, nor a week that does not see some three digit mph.

This is a stout engine. Only time the dealer has seen this car was for the VVT warranty fix and the idiots misdiagnosed that. Got that done and a new timing chain and it was making the same noise when I picked it up. Turned out to be the idler pully, which I then replaced myself. Still runs 13.2 quarters at 107-108 despite my shitty 60 ft launches. This is a 12 second car with a good driver.

Just did my first compression test of the new motor today. Used a brand new craftsman compression tester. I have 1,030 miles on the engine. During my engine breakin period I used SuperTech 10W40 oil during breakin period. Today i'm going to change the oil to Rotella T6 5w40. Could the weight of the oil cause my compression to be low in #3 ? Could the rings need more time to seat since i only have 1030 miles on the engine? Lastly should this be a major concern right now or should I just change the oil and monitor the compression over the next month?

#1 - 188
#2 - 180
#3 - 165
#4 - 185

Leak down.

The motor should be broken in by now. I would do a leakdown test as suggested.

I haven't really gotten into any boost yet, maybe 11psi max over these 1,000 miles. I haven't even gone WOT yet. So I went out for a drive and did 3-4 WOT pulls, was pretty scary at first but also a blast getting into boost. Last time I went WOT I went ZZB so it was a little intimidating to do. Anywho i'm hoping this will help seat those rings since i haven't put much pressure to them yet. I did hit 20psi and flowed 410g/s so i have a feeling i'll be moving some major air as i start tuning. Hopefully what i just did i'll see a little better compression in #3 . Results to come shortly!

And what is the Verdict Eric? I have high hopes for you as of right now!

Meh, is 15psi going to sway your decision to tear it down again? If it was mine, it sure wouldn't haha. I'd do another compression test just for funzies, maybe a leakdown, then run the hell out of it.

I wouldn't tear it down unless you have other issues crop up such as blowby, KR, oil consumption, lack of power.

I agree, it doesn't make sense to get worried over that small amount, unless of course it continues to deteriorate with more mileage.
I'm OCD about these things though, I'd probably leak down just to know where that 15 psi is going..

This made me sad=[ I followed your build the entire time and marveled at all the parts and that garage. I agree with the others though. Unless you notice some bad sign happening, i'd just enjoy the car as much as possible.

When u do a comp test do you crank all the cylinders the same # of times or keep cranking til the needle stops?

I only ask since I need to crank #3 more than the others

The other obvious question.. was the engine warm or cold?
Did you try adding the teaspoon of oil into cylinder #3 and retest?

No its not going to sway my decision to tear it down again at this moment. Only if things get worse i'll consider tearing back into it but as of now, with such a young engine and I've hardly pushed the limits of it, i'm going to drive it aggressively and monitor oil consumption and what not to see if anything changes. Again I've only hit 11psi boost on a safe tune map for the first 1,000 miles. Just a little bit ago I came home from doing my first WOT logs and hit 20psi so thats the most stress and power the engine has seen thus far.

Agreed! Hopefully I dont get any blowby with everything I've done to it. I'm running dual catch cans (1 sealed and 1 vta) with a DIY perm plate I made and I have my pcv setup just like this. I would assume this setup would provide the most flow of crank case pressure possible.
http://www.permtuning.com/images/PCV...boost_flow.jpg

Did you shit your pants? haha

I'm OCD as well, this is why this stupid compression test is killing me, yet the car is running like a champ and feels amazing with only the base map i'm running ATM.

Engine was very warm, I had just got back from doing 3-4 WOT LOGS and right when I got home I started doing the compression test. Same results as before with no change. I have not added a teaspoon of oil to the cylinder yet, what would that do? Lets say I do add oil to it and i run the test again and compression is up to say 180-185, what does that mean or let say I add oil and run the test and compression doesnt change and remains at 160-165, what does that mean?

I did them all differently, i just cranked it over like 3-4 times each about 2-3 seconds per crank or until the needle stopped moving. I did try #3 a little more and it made no change that I saw.

I may have sharted a bit yes

If you did a wet test (adding oil) and the compression raises significantly, then it indicates a ring sealing issue.
If it doesn't raise significantly, it indicates valves, head gasket, or injector seal.

The issue with wet tests is a lot of people pour way too much oil in there, and the compression DOES go up, but because all the space taken up by the excessive amount of oil actually raises the compression ratio. Therefore the test is inconclusive.

That's why it's important to test every cylinder using the same amount of oil and not just test the "low" cylinder. Then you can compare the differences in each

Thanks for the heads up! I'll do just a cap full of oil in each chamber and run the test to see what results are yielded.

Sounds good, but a leakdown test will tell more, if you are able to do one.

yep a local guy has a tester, i'm going to do a wet test first and then a leakdown test. Hopefully have that leakdown test done before the end of the weekend.

I'm sure you know this, but don't do a leakdown with the oil still there. Burn it off first.

Had some time last night to do a compression test after doing some logs for my tune. Last compression test was about 5000 miles ago. Since then I've been beating the shit out of my car with new tunes and of course a custom tune this whole last month with Lex. Car as of a few days ago has 47,000 hard earned miles.

1 - 180
2 - 177
3 - 180
4 - 177


I'm very happy about these results. This motor has been absolutely rock solid since I got it. :viking:

Yeah, that's awesome. You should be good for a long haul. I'm at 155-ish at 182,500 miles, so there can certainly be longevity in this engine.

looking good guys!