HELP 5.3 Turbocharged Compression?
03-17-2015, 09:46 PM
#1
HELP 5.3 Turbocharged Compression? I've been having problems with the car since purchase about a month ago.
Just did a compression test.
#1 - 162
#2 - 165
#3 - 160
#4 - 170
#5 - 165
#6 - 160
#7 - 150
#8 - 166
What do you guys think? I'm still in the tuning process as well.
Just did a compression test.
#1 - 162
#2 - 165
#3 - 160
#4 - 170
#5 - 165
#6 - 160
#7 - 150
#8 - 166
What do you guys think? I'm still in the tuning process as well.
03-17-2015, 10:00 PM
#3
04 5.3 stock bottom end
243 heads stock
arp studs
ls9 head gaskets
comp cams dual springs
custom grind boost cam 114lsa
mpt70 turbo .96 ar
KY turbo kit 3in down pipe
50mm bov
41mm waste gate
80lb injectors
fast fuel rails
ls6 intake smooth and painted
performabuilt 4l60E stage 2
3600 edge converter
sphon front k-member solid motor mounts
sphon torque arm and sway bar
Founders panhard bar
sphon 1.5 drop
stock 10 bolt 3:37 gears from motive
e85 twin granatelli 340 fuel pumps in tank
243 heads stock
arp studs
ls9 head gaskets
comp cams dual springs
custom grind boost cam 114lsa
mpt70 turbo .96 ar
KY turbo kit 3in down pipe
50mm bov
41mm waste gate
80lb injectors
fast fuel rails
ls6 intake smooth and painted
performabuilt 4l60E stage 2
3600 edge converter
sphon front k-member solid motor mounts
sphon torque arm and sway bar
Founders panhard bar
sphon 1.5 drop
stock 10 bolt 3:37 gears from motive
e85 twin granatelli 340 fuel pumps in tank
03-18-2015, 08:04 AM
#5
When I first got the car it would run fine around town, but when it would hit boost it would just fall on its face. Now I know a lot of that has to do with the tune, and I'm getting that worked on now.
Last week it really started acting up. Barely idles, dies a lot. Rpm is really jumpy.
Last week it really started acting up. Barely idles, dies a lot. Rpm is really jumpy.
03-18-2015, 09:26 AM
#6
Log it to see what's going on. Verify pcm inputs good/stable as expected.
03-18-2015, 03:09 PM
#7
Odd the #7 is so low too. Shouldn't have a 20psi spread between numbers.
My 2008 5.3 was 190-200 cranking compression with 243's and ls9 gaskets. With the Isky tripple 12 cam about a 1/2* advanced form the card.
Threw it in "dot to dot" the first go around and I saw very low compression and poor performance like your seeing. My crank key was way off. When I put the degree wheel on I was almost 8* retarded from the card "dot-to-dot"
This was also on a cheap harbor freight compression tester so who knows how accurate those numbers really are. I'd say your on the low side for cranking compression though. Did you do the test with the eng warm and TB open?
My 2008 5.3 was 190-200 cranking compression with 243's and ls9 gaskets. With the Isky tripple 12 cam about a 1/2* advanced form the card.
Threw it in "dot to dot" the first go around and I saw very low compression and poor performance like your seeing. My crank key was way off. When I put the degree wheel on I was almost 8* retarded from the card "dot-to-dot"
This was also on a cheap harbor freight compression tester so who knows how accurate those numbers really are. I'd say your on the low side for cranking compression though. Did you do the test with the eng warm and TB open?
Last edited by Forcefed86; 03-18-2015 at 08:39 PM.
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03-18-2015, 05:08 PM
#9
I wouldn't sweat those compression numbers. If it's bugging you, warm it up good and do it again. I bet it comes out different.
Read the plugs too. Might tell something.
But as was mentioned, you need to data log the car. It should be very revealing
Read the plugs too. Might tell something.
But as was mentioned, you need to data log the car. It should be very revealing
03-18-2015, 05:25 PM
#10
Odd the #7 is so low too. Shouldn't have a 20psi spread between numbers.
My 2008 5.3 was 190-200 cranking compression with 243's and ls9 gaskets. With the Isky tripple 12 cam about a 1-1/2* advanced form the card.
Threw it in "dot to dot" the first go around and I saw very low compression and poor performance like your seeing. My crank key was way off. When I put the degree wheel on I was almost 8* retarded from the card "dot-to-dot"
This was also on a cheap harbor freight compression tester so who knows how accurate those numbers really are. I'd say your on the low side for cranking compression though. Did you do the test with the eng warm and TB open?
My 2008 5.3 was 190-200 cranking compression with 243's and ls9 gaskets. With the Isky tripple 12 cam about a 1-1/2* advanced form the card.
Threw it in "dot to dot" the first go around and I saw very low compression and poor performance like your seeing. My crank key was way off. When I put the degree wheel on I was almost 8* retarded from the card "dot-to-dot"
This was also on a cheap harbor freight compression tester so who knows how accurate those numbers really are. I'd say your on the low side for cranking compression though. Did you do the test with the eng warm and TB open?
