Compression tests. 4.2 S4 Section 2003-2009

New Tech notes Compression test motor or drive lin
#1

I don’t have time to post some of the results I have collected. This is the section for the addition of any of the test results people have gotten or seen for the 2003-2009 Audi S4 4.2 chain driven motors.

If anyone has any or seen any information posted please feel free to populate

please include

Year of the S4: Example 2004 B6
Motor size: OEM 4.2
Mileage: example 130,000+

Audi lists there “NEW” specs on the 4.2@203=14 bar After break-in the acceptable levels should be 185psi anything over is steller. Anything under 130 or 9bar is known as too low or in need for repair.

You really don’t want to see a Difference between Cylinders = max 20psi

See video here
http://audirevolution.net/videos/150/4.2-audi-compression-test.

Compression tests should be done after the motor is up to operational tempiture

I will delete this post soon. Im going to update the original post to include

Here is a quick reference on what side of the motor your compression tests are from.

The motor firing order is 1- 5- 4- 8- 6- 3- 7- 2 Keep in mind unlike other motors our TDC is referenced with the #2 cylinder

http://audirevolution.net/addons/albums/images/473024769.jpg

Ieatfishburritos, the 2nd coming..
#2

Ill add a little data. The 11.1 compression B6/B7 S4 is going to have a compression raito of 185 new After break in 180s-160s is great

Here is a

B7 S4: 2006
motor: oem 4.2
Mileage: 98,000

Cyl1 - 140
Cyl2 - 145
Cyl3 - 130
Cyl4 - 150
Cyl5 - 145
Cyl6 - 145
Cyl7 - 150
Cyl8 - 155

Not in great condition. This was a car where the owner didn’t change the oil -6000 he went the 10,000 route. A major no no if you ask me.

The car still ran strong even tho it was down on compression

#3

B6 S4: 2004
OEM 4.2L
~70k miles

Cyl #1: 165 psi
cyl #2: 166 psi
cyl #3: 155 psi
cyl #4: 168 psi
cyl #5: 161 psi
cyl #6: 157 psi
cyl #7: 159 psi
cyl #8: 162 psi

Oil changed with lubro moly ~3k miles

#4

Collected data.

B7 S4: 2006
OEM 4.2:
Mileage: 78,000

2006 w/ oil consumption (1 qt/500 mi). Currently at 78

Cyl 1: 150
Cyl 2: 170
Cyl 3: 148
Cyl 4: 170
Cyl 5: 177
Cyl 6: 170
Cyl 7: 147
Cyl 8: 150

#5

B6 S4: 2004:
Motor: 4.2
Mileage: 136,000

Comp test results prior to installing SC

Cylinder 1: 170
Cylinder 2: 170
Cylinder 3: 165
Cylinder 4: 175
Cylinder 5: 170
Cylinder 6: 175
Cylinder 7: 170
Cylinder 8: 170

#6

Last week I threw in new plugs and did a compression test after having the blower for ~15k, almost no variance at all between pre & post blower install so that was good to see.

Anyhow

B7 S4: 2005.5 (bastard child)
Motor: 4.2
Mileage: 97000

C:1 = 149
C:2 = 150
C:3 = 153
C:4 = 169
C:5 = 165
C:6 = 162
C:7 = 179
C:8 = 166

Not stellar, but well within acceptable range I guess.

Oil: Motul Xcess 5W40
OCI: every 5k since 50k
Owned: Owned car since 39k and 4 years ago as of yesterday

#7

Year of the S4: 2006 B7 S4 MT6
Motor size: OEM 4.2
Mileage: 68,000+ miles

I’ve been having some smoke on startup issues, which in turn is causing my car to consume oil (no smoke while driving). Before starting my engine pull, I did a compression test. The numbers aren’t stellar, especially for a car with 68k, which I have owned since 30k and have taken very good care of. JHM says it could be possible that the cylinder walls are warped, but they don’t see the compression getting worse as long as I stay on par with oil changes.

This is the same car that ran 12.86 a few months ago, and still is running like a raped ape…lol Before my issue I had almost zero oil consumption, so it was hard for me to stomach having these issues. I’ll keep everyone updated when the engine gets torn down.

cyl #1: 140 psi
cyl #2: 145 psi
cyl #3: 140 psi
cyl #4: 145 psi
cyl #5: 150 psi
cyl #6: 150 psi
cyl #7: 160 psi
cyl #8: 165 psi

*Also had oil on #3 and #8 plugs…pretty sure it’s valve guides or valve stem seals.

Update: Engine is almost out, removed my JHM IM before the pull considering it has a $300 powder coat job and I don’t want it scratched by chains. Upon inspection of my intake valves I noticed #3 and #8 have a few valve tops with oil on them, which is making my seal or guide assumption correct. Most of the valves are very clean, but a few have some carbon build up near the edge where they seat, which I am also hoping may be causing the lower compression numbers.

Engine will be out this weekend, and I should know more by next weekend.

#8

Saw this in a members information.

Year: 2005
Motor: 4.2
Mileage:104.5

Cyl #1: 140
Cyl #2: 165
Cyl #3: 150
Cyl #4: 150
Cyl #5: 145
Cyl #6: 140
Cyl #7: 145
Cyl #8: 150

With fresh oil it does not rattle on cold start at all. When the oil gets near 1500 miles it starts to rattle every cold start.

#9

I recently sold my 2005.5 bastard B7 S4 that was consuming excessive oil at about 92,000 miles (although the consumption started at around 60k). By excessive, I’m talking 1 quart every 500 miles or so. The car is gone, but I figured I would make a post anyhow.

I tested the compression on the engine and cylinders 1,2,3,4 were all beautiful and within 165-170.

When I moved over to the drivers side bank, cylinders 5,6,7,8 were all low reading between 120-135. These numbers made me want to vommit. Since I owned the car at 45,000miles, the thing was meticulously babied. Im psycho about maintenance and LOVE that feeling when you dump some new fresh oil down the throat.

Why in the world would compression be great on one side and so bad on the other? I have a '97 ford truck with 235,000 miles. She still has perfect compression and doesn’t burn one drop of oil. Why in the world can Audi not figure this out? For a $65,000 sports sedan low compression at these mileages is a joke. I mean, scored cylinder walls, really?

Moral of the story, NEVER buy a car without a compression test.

#10

Year: 2005.5
Motor: 4.2
Mileage:54000

Cyl #1: 140
Cyl #2: 150
Cyl #3: 140
Cyl #4: 150
Cyl #5: 150
Cyl #6: 140
Cyl #7: 150
Cyl #8: 150

Dry test
Done when the engine is cold, lukewarm at best.
Fresh LuquiMoly 5W40 oil. No rattle, no noticeable oil consumption.

#11

Year: 2004
Motor: 4.2
Mileage: 94,000
Oil: Liqui Moly 5w40
Oil Consumption: 1qt loss every 50-300 miles
Issues: Lots of blue smoke pretty much all the time but no CEL. Small amount of oil with silvery froth coming through the PCV

#1 - 130psi
#2 - 140psi
#3 - 130psi
#4 - 140psi
#5 - 130psi
#6 - 130psi
#7 - 140psi
#8 - 130psi

Sending in an oil sample to Black Stone Labs so I have the results for the 95,000 mile service. I think it’s time to test out the old warranty.

#12

Was having some misfire issues so I was moving the coils and had the plugs out to inspect. So did a compression test while I was at it.

B7 RS4: 2008
Motor: 4.2 FSI
Mileage: Just under 65k

Cyl #1: 155
Cyl #2: 160
Cyl #3: 152
Cyl #4: 155
Cyl #5: 162
Cyl #6: 155
Cyl #7: 152
Cyl #8: 165

Oil: Castrol Syntec for first 2 or 3 changes, Motul Xcess 5W40 since
OCI: every 5k since 45k
Owned: Owned car since 45k, 2 years
Oil Burning: About 2 quarts every 5k with the Castrol, nothing noticeable with the Motul (maybe a quarter quart).

#13

2005 b6 s4
warm motor 5-7 cranks x cilinder, battery almost new.
60.000 miles motor

plugs bkr7e perfect
liquimolly 5w40 every 2500 miles.

1-168
2-168
3-167
4-165
5-168
6-164 lower
7-166
8-165

Doing leak down tomorrow
I think the results are ok.
opinions?
Regards

#14

Grabbed this one from another site.

Info on the car:
2007 Audi S4 Avant (Tip)
105,000KM
Dolphin/black

1: 148
2: 150
3: 145
4: 150
5: 148
6: 150
7: 150
8: 150

#15

Another grab

Bought an S4 off a fellow audiziner a couple months ago. Had full service history, looked great, and ran good. Finally got around to checking the compression and what not since it seemed I was losing to much oil, probably about 2-3 quarts over the last 3000 miles. 130k manual

1- 144 PSI
2- 158 PSI
3- 145 PSI
4 - 155 PSI
5 - 155 PSI
6 - 155 PSI
7 - 165 PSI
8 - 175 PSI

#16

any time I see one of these on AZ I grab it and bring it here

Just got car back from dealership. Had compression and leakdown test done to gauge engine health due to visible smoke during engine braking. Car has 79000 miles still under CPO. Burns less than 1 quart of oil every 1000 miles. Here are the numbers, please let me know what you think:

Comp Leakdown
#1 170 7
#2 170 10
#3 165 10
#4 160 10
#5 145 10
#6 145 8
#7 145 25
#8 160 12

They said that during leakdown test #7 was shown to be leaking into the crankcase. Boroscope showed small scratches inside cylinder wall.
I asked the tech what the minimum wear values were, but he was of no help. I am concerned with the leakdown of 25% and wanted to know if anybody had some technical specs from Audi concerning these matters.

Thanks

#17

Year of the S4: 2005
Motor size: OEM 4.2
Mileage: example 120,000

Burns/leaks around a quart of oil between 5k miles oil changes. Two bottles of nitrous ran through so far. Runs good and checked just to get an idea.

  1. 145
  2. 155
  3. 145
  4. 150
  5. 145
  6. 145
  7. 155
  8. 155
#18

Here is some data given by a customer:

“Exhaust tips are black. Oil consumption has gone to like 1-2qt per 200-400 mi. Car still starts right up, without rattle, and drives.”

  1. 145
  2. 135
  3. 130
  4. 130
    5 .155
  5. 150
  6. 155
  7. 140
#19

Here is some data given by a customer:

“Exhaust tips are black. Oil consumption has gone to like 1-2qt per 200-400 mi. Car still starts right up, without rattle, and drives.”

  1. 145
  2. 135
  3. 130
  4. 130
    5 .155
  5. 150
  6. 155
  7. 140
#20

Year of the S4: 2008 B7 S4
Motor size: OEM 4.2
Mileage: 85,000 Mobil 1 0-40 every 5k

Comp Leakdown
#1 170 7
#2 170 10
#3 165 10
#4 160 10
#5 145 10
#6 145 8
#7 145 25
#8 160 12

The car was taking in 1 quart every 1k miles.