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ArtofOlivia"PocketRocket"
if you haven't tore it down yet....
pull all the plugs.
put about 1-1.5 ounces of oil down the plug hole of #6
take another compression reading.
If the compression stays the same, bad head gasket.
If its suddenly restored or greatly improved, bad rings.
The oil gives a mild seal to bad rings thus sealing them temp for better compression during test. also tends to stay on the rings and such and doesn't blow up to the valves and gasket. This procedure is called a "wet" compression test.
How to make High performance Emissions:
A "true" High flow converter, straight pipe.
Low/No flow EGR valve, block off plate.
Carbon canister and purge valve mod, place in large 30 Gallon can, cover, and place curbside, the city will do the rest.
PCV valve and vent tube, reroute to exhaust to dump where it belongs, on the ground. Or add breathers and let it all free.
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06-10-2009 12:29 AM
# ADS
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it could also be that you didnt alternate the gaps on the piston rings and thats where youre losing compression. check this road out too.
MODS: DS CAI, TCE 65 mm tb, TCE AFPR, TCE LS lifter springs, WOT ported UIM and LIM, 3500 heads, comp cams valve springs locks and retainers, 1393 grind cam, S&S headers, custom 2.5 in catback, flowmaster 80 series , no rez, and to top it all off, an MPR tune. Among misc gauges and appearence things
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Old School KI
Got an update on this Matt? I find it really odd that only 5 and 6 are giving you problems.
Your local OBDII moderator
2000 Grand Am GT w/ WOT parts
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The Pink Car
Anyone guess at sticking valves or not? I would do a leak down before tearing the slugs out of the block.
Got Lope?
3500/3400 Hybrid, Custom Cam 216/240 .050 dur .517/.568 lift 112LSA
Ported, 3 Angle Valve Job, 65mm TCE TB, S&S Modified headers.
Stage-1 Raybestos 4t60e, 3195 PDQ Converter, EP LSD, 3.69FDR
12.67@107.43 Chevy Fest, Epping NH Oct 2010 Nitrous 100shot
2007 Legacy GT Limited 5-speed Turbo... Stage 1 Tune
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Mr. Common Sense
We have already pulled the motor. I must have had a massive misfire on #1 because the ground strap was touching the electrode (!). Spun the motor over and all of the valves look to be moving normally.
Anyway, at last update, the rear head was pulled off (exposing cylinders 1, 3, and 5). Head gasket looked fine, but we were a bit surprised at how much carbon was built up in the combustion chambers. The other head is coming off today. Kinda scratchin' our heads so far......more later.
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The Pink Car
Might have shorted out the ignition system and fried half a coil if your ground strap was touching a plug.
Got Lope?
3500/3400 Hybrid, Custom Cam 216/240 .050 dur .517/.568 lift 112LSA
Ported, 3 Angle Valve Job, 65mm TCE TB, S&S Modified headers.
Stage-1 Raybestos 4t60e, 3195 PDQ Converter, EP LSD, 3.69FDR
12.67@107.43 Chevy Fest, Epping NH Oct 2010 Nitrous 100shot
2007 Legacy GT Limited 5-speed Turbo... Stage 1 Tune
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check the piston rings, excessive blowby could cause a bad afr causing excessive carbon build up.
MODS: DS CAI, TCE 65 mm tb, TCE AFPR, TCE LS lifter springs, WOT ported UIM and LIM, 3500 heads, comp cams valve springs locks and retainers, 1393 grind cam, S&S headers, custom 2.5 in catback, flowmaster 80 series , no rez, and to top it all off, an MPR tune. Among misc gauges and appearence things
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ArtofOlivia"PocketRocket"
how was the fuel pressure? Is computer good? I ask because I've seen comps fail and ground 1-2 injectors that then get stuck open, dumping fuel. Engine still runs, poorly and very rich, but it runs sometimes with a miss.
How to make High performance Emissions:
A "true" High flow converter, straight pipe.
Low/No flow EGR valve, block off plate.
Carbon canister and purge valve mod, place in large 30 Gallon can, cover, and place curbside, the city will do the rest.
PCV valve and vent tube, reroute to exhaust to dump where it belongs, on the ground. Or add breathers and let it all free.
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Mr. Common Sense
Fuel pressure was fine, and the PCM's good too.
Looks like bad rings on both #5 and #6. Headgaskets were fine. A huge buildup of carbon in the combustion chambers for both cylinders. Drained the oil (which had only 300 miles on it), and it was so black (likely from the fuel blowing right by the rings into the crankcase) you'd think it had been in the car for 15,000 miles.
Thankfully, cylinder walls look okay, so putting in new rings and bolting it back together. We'll see......
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Old School KI
I suggest that you mic. those cylinders and check ring gap before reassembly.
Your local OBDII moderator
2000 Grand Am GT w/ WOT parts
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