DISI Compression Results

[Black Metal]

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 I knew it was coming just thought it would take a little longer.

[btstarcher]

Originally Posted by CosmicArkie I'd be interested in an explanation for that.... Unless ya'll cranked it longer/harder.

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.

[CosmicArkie]

Originally Posted by Black Metal 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 I knew it was coming just thought it would take a little longer.

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.

[MPS_Fan]

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

[btstarcher]

Originally Posted by CosmicArkie I'd be interested in an explanation for that.... Unless ya'll cranked it longer/harder.

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.

[qtrmile beast]

Originally Posted by Black Metal 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 I knew it was coming just thought it would take a little longer.

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...

[Tokay444]

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.

[Mandinca]

Originally Posted by Tokay444 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.

[MSMS3]

"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.

[Dizzy Turbo]

Originally Posted by MSMS3 "We don't pull no stinking relays."

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

[qtrmile beast]

Stinking Badges - YouTube

Stinking Badges - YouTube

[Black Metal]

Originally Posted by qtrmile beast 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...

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?

[Pseudonym]

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.

[himurax13]

Originally Posted by Pseudonym 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.

[Pseudonym]

fuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

[himurax13]

Originally Posted by Pseudonym fuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

I highly reccomend a proper leakdown test as well.

Sent via blown passenger side speakers.

[xtasy]

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 =\

[himurax13]

Originally Posted by xtasy 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.

[Tokay444]

Stop doing comp tests without leak downs!

[JTMS3]

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!

[Lex]

Originally Posted by xtasy 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 =\

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

[Pseudonym]

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?

[shopety2012]

Originally Posted by Pseudonym 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"?

[Pseudonym]

Originally Posted by shopety2012 Who is "they"?

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

[shopety2012]

Originally Posted by Pseudonym 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?

[Pseudonym]

Originally Posted by shopety2012 like your average mechanic? or a performance shop? or like service department of a dealer?

efi logics. performance shop that caters to subarus mostly.

[Tokay444]

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

[[R]usty]

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.

[Mazdazilla6]

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

[Little John]

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

[Tokay444]

Originally Posted by Mazdazilla6 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

What did the leak down say?

Originally Posted by Little John 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?

[Mazdazilla6]

Originally Posted by Tokay444 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.

[Lex]

Originally Posted by Tokay444 What did the leak down say? What did the leak down say?

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.

[Tokay444]

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.

[mtosofsky]

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.

[atvfreek]

Originally Posted by Lex 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.

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.

[nycMS3]

09 MS3 with 50k miles

195 - 192 - 190 - 190

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

[[R]usty]

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

[theurgy]

Nice numbers!

[maisonvi]

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.