DISI Compression Results

[Ziggo]

no other symptoms, though it might have just occurred. The car leaned out after I fixed that exhaust leak, I stopped the first pull at 4.5k but I was at 23psi and 13afr.

I don't have a leak down tester, maybe I will pick one up soon.

[Dano]

Originally Posted by Ziggo no other symptoms, though it might have just occurred. The car leaned out after I fixed that exhaust leak, I stopped the first pull at 4.5k but I was at 23psi and 13afr. I don't have a leak down tester, maybe I will pick one up soon.

I can send you my OTC tester if you want, PM me.

[Dano]

Originally Posted by atvfreek @Dano; those PU pistons are just as fragile as the gen1 pistons. They do not like heat and power. Every summer we see more and more ring land failures. And they far trump the amount of rod failures we used to see

Roger that. I was just thinking with aftermarket heat management like a fan controller, you might be able to stretch the useful HP range they can survive. Its a crap shoot for sure and not worth the gamble when rebuilding.

[mrQQ]

I'm really not sure if one pull could do that.

[stockms3]

I've forgot to warm up the engine and it was too late because I had everything out so I ended up testing on cold engine.

80k/stock k04 some smoke after long idle.

1. 180
2. 180
3. 156
4. 165

Retested 3 & 4 wet and both were right on 180....FML

I will redo again tomorrow on warm engine.

[Tokay444]

180 on a cold engine seems high.

[Jtaylor]

Originally Posted by stockms3 I've forgot to warm up the engine and it was too late because I had everything out so I ended up testing on cold engine. 80k/stock k04 some smoke after long idle. 1. 180 2. 180 3. 156 4. 165 Retested 3 & 4 wet and both were right on 180....FML I will redo again tomorrow on warm engine.

Up your idle to 900 and say goodbye to that smoke

[stockms3]

Did compression today again on a warm engine....numbers were exactly the same as cold.

1. 180
2. 180
3. 156
4. 165

Wet test brought the lower numbers to 180, however, I've discovered low coolant and a little milk on my oil cap. Last summer I had water pump and coolant replaced. I don't think it could be a headgasket since oil dramatically improved those bad cylinders.

Thoughts?

[stockms3]

I posted this in local section and just figured I would share in case anyone is wondering.

Performed a leak down test today.
Cylinder/gauge1/gauge2/%between gauges

1. 90psi/88psi/2% leaking
2. 90psi/86psi/4% leaking
3. 90psi/46psi/ SHIT LOAD(abt 46%) LEAKING coming out of the PCV/Oil fill hole
4. 90psi/79psi/12% leaking

My cylinder 3 is fucked. Most likely going forged.

[jack_hammer]

Originally Posted by stockms3 I posted this in local section and just figured I would share in case anyone is wondering. Performed a leak down test today. Cylinder/gauge1/gauge2/%between gauges 1. 90psi/88psi/2% leaking 2. 90psi/86psi/4% leaking 3. 90psi/46psi/ SHIT LOAD(abt 46%) LEAKING coming out of the PCV/Oil fill hole 4. 90psi/79psi/12% leaking My cylinder 3 is fucked. Most likely going forged.

I made light of it in your other thread, but that sucks. Sorry to hear.

[mrQQ]

900 miles after rebuild with SP63 10.5:1 pistons the compression is 195 in all 4 cylinders.

[IMASA]

Did a compression test today just to make sure everything is gonna be fine when I install my BNR S3. 84k kms on the motor.

1. 180
2. 180
3. 180
4. 180

Looks like I'm good to go.

[LatinKraze]

Just tested today again with a working gauge (previous HF gauges all read 120 across the board)

Fully bolted (minus Ex/Int Mani) on BNRs3v1 for the last 20k miles...going forged next year

Left to right 168, 165, 170, 173 with 118k Miles.

[r3d]

Looking at everybody's number, I don't feel so bad now.
At 120k I got:

1-170
2-181
3-175
4-170

[England15j]

@35700
1k on BT
1- 189
2- 185
3- 180
4- 186

[Gr8Speed]

100K miles, cold wet test

210
200
195
205

I'm thinking compression gauge is a piece of shit (vatozone) but the consistency is what matters anyway.

[sidekick]

Originally Posted by Gr8Speed 100K miles, cold wet test 210 200 195 205 I'm thinking compression gauge is a piece of shit (vatozone) but the consistency is what matters anyway.

Cold wet test as in engine cold and you added oil? Do a hot test with no oil to get a real idea of compression.

[Gr8Speed]

Originally Posted by sidekick Cold wet test as in engine cold and you added oil? Do a hot test with no oil to get a real idea of compression.

Shouldn't the heat increase my compression reading? Correct me if I'm wrong.

[ABolewski]

1: 150
2: 150
3: 145
4: 145

Yay.

[5doorsoffury]

Just got my otc comp tester in the mail. 32k tuned since 9k
201
199
199
197

[Cevaes_64]

175 70 175 175... 24800 Miles in FL

Car has been at he dealership for 2 weeks with a blown Cylinder #2 trying to get a replacement engine under warranty =(

[sidekick]

Originally Posted by Gr8Speed Shouldn't the heat increase my compression reading? Correct me if I'm wrong.

Metal expands with heat. Under normal operating conditions, the engine is hot and piston rings only seal properly once the engine is warmed up. Doing a compression test right after driving will give you the best picture of what your compression looks like under normal operation. You add oil to low compression cylinders AFTER doing the test to see if the leakage is at the piston ring or elsewhere in the cylinder.

[Gr8Speed]

Originally Posted by sidekick Metal expands with heat. Under normal operating conditions, the engine is hot and piston rings only seal properly once the engine is warmed up. Doing a compression test right after driving will give you the best picture of what your compression looks like under normal operation. You add oil to low compression cylinders AFTER doing the test to see if the leakage is at the piston ring or elsewhere in the cylinder.

Yeah that's my understanding of it and I figured that if it seals while cold, it should also while hot.

I will redo the test next time I'm working on the car.

[mrQQ]

Originally Posted by 5doorsoffury Just got my otc comp tester in the mail. 32k tuned since 9k 201 199 199 197

that sounds high for stock engine

[5doorsoffury]

Originally Posted by mrQQ that sounds high for stock engine

Yep but before that i had 196 with a matco tester so it is what it is.
I do comp tests every few months.

[Tokay444]

Originally Posted by Gr8Speed Yeah that's my understanding of it and I figured that if it seals while cold, it should also while hot. I will redo the test next time I'm working on the car.

You didn't do it cold.
You did it cold and wet. Big difference.

[[R]usty]

Tested this morning to check if everything was okay after cleaning my intake valves 2 weeks ago. Car was completely warm. Each cylinder was cranked 7 times.

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

Most consistent numbers I've ever had.

[kidlifecrisis]

Bump'd

I started getting some nasty KR (over 5) on my tune which I have been running for about a year now. 3" intake, catted dp, cbe, fuel pump, forge v1, occ, had autolite step colder, switched to itv22, problem started, switched back to autolite, still persists. The car is a 2012, had about 25k when the issue arose.

I threw my maf cal onto stage 2 ots and no more knock at wot (which I'm doing significantly less of since this all started), but when I tested comp, this is what I got...

195
170 (wet was 175)
195
190

What is interesting to me is that the plug on cylinder 2 was MUCH lighter than the other 3. So for some reason that cylinder is running low comp but also much hotter than the rest.

Fwiw the engine, pedals, steering wheel all vibrate somewhat harshly at any given rpm/load/speed. I checked piston height with a 3/8" extension, and cylinders 2 and 3 are identical.

So at this point I'm speculating that it could be a valve issue, or injector seals, possibly both. But I'm still trying to wrap my mind around what could be causing a lean condition in #2 (no CEL however) All were gapped at .026, and rechecked when I tested, still .026

[mrQQ]

I don't think that difference could cause knock.

[speed23]

Maybe an injector issue? causing too lean conditon and knock in cylinder.

[kidlifecrisis]

I threw a half pint of seafoam in a 3/4 full tank this morning, it seems to be running a bit smoother but I'll see how it goes as I burn through this tank. Seems that the low comp could be a symptom of the knock, which itself is caused by a fuel issue

[googlebutt]

Doing my first test, 130 dry test on the nose across the board, tested at a temp of 165. 2008.5 45k miles, no CEL's, no smoke, not eating oil /and runs smooth. Bad gauge?

[Tokay444]

Did you do a wet test?

If there all exactly 130, I would bet the gauge is toast.

[googlebutt]

Originally Posted by Tokay444 Did you do a wet test? If there all exactly 130, I would bet the gauge is toast.

I did not. It's a brand new gauge, I think my engine was a little cold so I'm going to warm it up some more and do the dry test over along with a wet. All my WOT logs look good too hm.

Now that I think about it, the packaging of the tester was kind of sliced up near the extension and gauge, I'm going to go borrow one from Autozone tomorrow.

[BackRoads]

Did mine again today - dry test at 192,500 original miles on the engine: 155-150-150-160. There's life in her yet! Did a leak down test on 4, and got just a little coming through exhaust, nothing past the rings. Overall, pretty happy about it, as we are about to add E85 to my tune on the BNRS3.

[dale_gribble]

New OEM motor, 900 miles, warm (sat for ~30 mins after turned off).

176 - 176 -176 -176

This pleases me.

[[R]usty]

Originally Posted by BackRoads Did mine again today - dry test at 192,500 original miles on the engine: 155-150-150-160. There's life in her yet! Did a leak down test on 4, and got just a little coming through exhaust, nothing past the rings. Overall, pretty happy about it, as we are about to add E85 to my tune on the BNRS3.

Very impressive.

[ledfootrob]

Tested mine a few weeks ago

180 150 180 180

Rebuild in progress, cracked ringland on cyl 2.

[kidlifecrisis]

Scoped the cylinder in question, this is what it looked like.



It looks like a hot spot on the piston? Or maybe some anti seize got in there from when I did the comp test, hard to tell and being the first time I've looked inside a motor I don't have much of a baseline

[googlebutt]

So I posted a while back that the brand new Innova (3614) gauge I used gave me a reading of 130psi across all cylinders. Ordered the Innova gauge with the solid rubber hose (3612) and just got 185 190 190 190. Beware if you buy that gauge.