DISI Compression Results

[cpolly69]

I am

[shpankey]

So if I'm understanding you guys right, I should be smoking pretty bad? I mean, if my rings are so worn or whatever that I can only produce 130 psi in each cylinder, would that mean a lot of oil blowby and therefore smoking?

Which if that's the case, then I'm really stumped as I have VERY minimal smoking only at idle and it's actually pretty hard to see. Most times I can't see it, but can smell it some. The thing is though, even that smoke didn't start until I installed the OCC just recently. Other than that I have never smoked and even with that, it's so light you can't really see it most of the time.

Also if I'm understanding you right, I should be consuming oil? That is something I can say definitively that doesn't happen. I do not use a single drop of oil! I also use very high quality synthetics. Currently have a fill of Redline 10w40 synthetic in it.

Knowing all of this, anyone have any ideas what might be causing me the super low 130psi [150 wet] compression on all cylinders?

[aaronc7]

I just am still surprised as to why my cylinder 3 was the highest compression- if I labeled cylinders 1/4 the way other way around, then 3 would be my lowest... just double checking.

[Lex]

shpankey, yours is a very odd case. Do you have a catless exhaust? Do you have oil residue in the valvacover vent going to your intake?

[shpankey]

I did put a test pipe in, which removed one cat. But that's as far as I've changed the exhaust. No other changes to it other than that.

I'll check again but I haven't noticed any oil there Lex.

[Lex]

I have an 08.5 and I've had a test pipe for .... well ever ... and it has never smoked with 16k miles on the clock now.

Also never had any oil in the intake but the motor's still young. Only bolt-on I don't have is the DP and I plan on keeping it that way on the stock turbo.

[cpolly69]

meh get a catted full dp - you will be ok - i went 2 times around and have this now - i'm happy with it and no smoke.... and that's still on the same turbo that was smoking before from the extreme pcv imbalance

[shpankey]

My car doesn't always smoke and when it does it's barely. I have to bend down to the pipe and get real close to tell if it even is. But I can smell it sometimes when in the garage. But it didn't even start smoking like that until I put on the OCC. I've had the test pipe on since the beginning and it never caused any smoke issues.


p.s. I meant to mention this earlier. But my oil dipstick smells like gas BAD BAD. Like I'm sniffing straight fuel. I just put this oil in last weekend. Redline 10w40. Should it smell like fuel this bad already? Maybe this has something to do with my cars issues.

[cpolly69]

unfortunately you are describing compression leaking from the combustion chamber into the other areas of the engine that hold oil - when compression gases are getting mixed in with the oil the oil will change colors very quickly after a change & can smell like gas..
what strikes me as odd about your situation is the way that you have low numbers across the board - usually when it's fail it's just 1 that is much lower then the rest.... that's usually what happens when you have a head gasket leak...

[jwdp54]

my post from 12/19/09
car at the time had 22k fully bolted, meth and stock ecu

Originally Posted by jwdp54 i got mine checked on sat. not sure what to think about the results.. 1-145 2-145 3-140 4-145

i had mine done again today

car now has 27k, have been stock since 23k

145 145 140 145

[shpankey]

Did you have them do a wet test too?

[jwdp54]

all i did was warm up the car then pulled the plugs and came up with the same numbers from 4 months ago. not sure what you mean by wet test.

[shpankey]

After you do your test like you did normally. Add a teaspoon of some 30 weight oil into the plug hole and restest. If you are having leakdown issues, your number will go up a fair amount (for instance my normal test was 130, when I added the oil it was 150, which indicates a real problem).

[turboneil]

just did mine and it was 185 for all 4.... and thats with 21k hard miles.

Sent from my Droid using Tapatalk

[superskaterxes]

what kind of compression loss should one see from a leaking injector seal? just how much is missing?

[Lex]

Originally Posted by superskaterxes what kind of compression loss should one see from a leaking injector seal? just how much is missing?

Probably not much. Combustion pressure is MUCH higher than just compression. If the seal was leaking under just compression, you'd hear/feel it all the time with the motor on. Did you ever get around to testing your motor?

[superskaterxes]

Originally Posted by Lex Probably not much. Combustion pressure is MUCH higher than just compression. If the seal was leaking under just compression, you'd hear/feel it all the time with the motor on. Did you ever get around to testing your motor?

right before i went BT i tested 180's across the board. i thought my friends injector seals were done but his compression was low on all cylinders so i wasent sure exactly how that would be affected by injector seals. doesent the piston rise up above the injector or no?

[Lex]

Nope, piston is always below the injector.

[08_ms3_gt]

did a compression test tonight;

2008.5 mazdaspeed3, 35,000 miles (literally)

cylinder pressures:

(pass side)
cyl 1 - 182psi
cyl 2 - 177psi
cyl 3 - 175psi
cyl 4 - 178psi
(driver side)

b/c i was doing the test alone, i'm actually pretty sure all of the pressures were around 180-185. the reading was declining before i even got from the inside of the car to the engine.

[Qwik6]

Originally Posted by aaronc7 Pull all plugs... connect gauge to one cylinder. turn car on. push ghes and clutch all the way in...crank until the gauge is not rising anymore. you can have a friend check it or set it so you can see it from inside the car, then read the number, release the pressure in the gauge to reset it...and repeat. My battery sucks so I hooked up jumper cables to another run that was idling while I did it. Or hook up a battery charger or something.

Thanks. trying this tomorrow

[Lex]

Originally Posted by 08_ms3_gt did a compression test tonight: pass side cyl 1 - 182psi cyl 2 - 177psi cyl 3 - 175psi cyl 4 - 178psi driver side b/c i was doing the test alone, i'm actually pretty sure all of the pressures were around 180-185. the reading was declining before i even got from the inside of the car to the engine.

Post year of car and miles as well.

[FreeFlyFreak]

Originally Posted by Lex Post year of car.

Apparently Lex's detective skillz are not as sharp as I may have thought.......
Let me give a clue:

08_ms3_gt

[Lex]

Originally Posted by FreeFlyFail Apparently Lex's detective skillz are not as sharp as I may have thought....... Let me give a clue: 08_ms3_gt

Still no mileage and could be an 08.5 Mr. FreeFly

This was also a general comment as I think there's value in knowing the age of the motor when looking at compression.

[08_ms3_gt]

thanks for noting that - i've updated it. see above.

[DaleNixon]

Sorry for the OT, but what is this COBB fix for the PCV? Are you talking about installing an OCC? Or did Cobb come up with something else?

[8.5MS3]

Originally Posted by Mikey95hd That's not good...zoom-zoom boom...

go away, he was sarcastic and is pushing almost 400 on the stock bottom end

[Lex]

You really have no idea what you're talking about. So just do everyone a favor and move on or stop posting before you do some reading.

I'll give you a hint. In DI applications, the gas does not come into contact with the back of the valves where the "deposits" form as is the case with your 1997 T-bird. If you hate this car so much, go back to driving your T-bird because right now you're really starting things on the wrong foot.

Originally Posted by Mikey95hd Try running Chevron gas, it has a cleaner techtron that will help get rid of deposits on the valves, my old 97 T-Bird, passes smog with 130,000 miles, don't run ARCO gas, that stuff is crap, and COSTCO gas is good too, love that sweet crude...

[8.5MS3]

^^wow^^

[Lex]

If you can't figure it out do some reading. It's one of the most documented issues here. Now GTFO of my thread.

Originally Posted by Mikey95hd Just seems the gas you use cause deposits, I love my MS3 just can't figure out why my 2007 smoked for 6,000 mile before they finally replaced my TURBO, isn't this a known problem on the first model year? A friend had his replaced at 18,000 miles, and now has 68,000 with a cam problem, he and a few others work for Lexus.

[Doc]

go and have a read mate, and stop cluttering up this thread........

[8.5MS3]

sigh, go read some fuckin threads and stop clogging up good ones.

POWERTRAIN is 5yrs/60k

you cant clean the back of the valves with fuel injector cleaner if theres no fuel in the air when it goes past. please stop bitching and go do some reading.

[Doc]

thread cleaned up...

[djuosnteisn]

[JumpingJackson]

How big of an effect would popped injector seals have on a compression test / leak down test?

[aaronc7]

probably not much since mine only leaked at 15psi or above... it depends on bad the leak is i guess, but unless its a huge leak, its probably not enough pressure to affect results.

[Lex]

Originally Posted by JumpingJackson How big of an effect would popped injector seals have on a compression test / leak down test?

If they leak under dry compression they will definitely give you issues while driving.

[Qwik6]

Got around to testing mine this morning when I changed spark plugs.

2006 Mazdaspeed 6

Close to sea level. 30 feet I believe.

72,000 miles

19psi daily driver. Damn near fully bolted. Synthetic oil since 32k miles.

Cyl 1 - 192psi
Cyl 2 - 192psi
Cyl 3 - 192psi
Cyl 4 - 192psi

All were 192psi dead on. Engine was heated up. Actually drove the car 10 miles before I came home to pull it apart.

[shpankey]

wow. lucky dogs!!

[Lex]

Great compression for the mileage. Must take care of it well!

Originally Posted by Qwik6 Got around to testing mine this morning when I changed spark plugs. 2006 Mazdaspeed 6 Close to sea level. 30 feet I believe. 72,000 miles 19psi daily driver. Damn near fully bolted. Synthetic oil since 32k miles. Cyl 1 - 192psi Cyl 2 - 192psi Cyl 3 - 192psi Cyl 4 - 192psi All were 192psi dead on. Engine was heated up. Actually drove the car 10 miles before I came home to pull it apart.

[Jarods7920]

190
190
190
190

11k built engine. Minor boltons for another week. 440 ASL. Engine was warm.