Piston rings gone bad, shop to blame, or cars age??
11-18-2011, 12:56 PM
#1
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Piston rings gone bad, shop to blame, or cars age?? I just bought my 2001 trans am ws6 last december from an old woman who garage kept the car and had it regularly maintained. The car ran like a top. I of course wanted to do some upgrades. The car was bone stock, i did full suspension on it and got a baseline dyno for it. it put down 312rwhp and 325rhtq in July. I put headers on it, and a cold air. A month ago i had a shop in town put in a cam, and 36lb injectors and do a tune. The car pulled 347rwhp. Did a compression test and it was down on all 8 cylinders. 145-155 on 5 cylinders and 160-175 on 3 cylinders. What cause the piston rings to go down so fast and all of them at the same time??? I only ran it at the track once. My guess is the fuel/air mix is jacked up and washed down the walls and burnt out the piston rings. I did a leak by test and it was good. Its also backfiring which could be due to fuel/air mix. The shop owner says hes not responsible at all, the tune and timing is "spot on"HELP?? Thanks.
11-18-2011, 01:10 PM
#2
Say what? You don't know what you're talking about, customers like you make it tough on good customers. !st of all if the fuel tables are all wrong why didn't the cats die????????
Maybe you need a brain transplant....go see a doctor!
Maybe you need a brain transplant....go see a doctor!
11-18-2011, 02:14 PM
#3
if a compression test shows that any of the cylinders are leaking, a cylinder leakage test can be performed to measure the percentage of compression lost and to help locate the source of leakage. a cylinder leakage test applies compressed air to the cylinder through the spark plug hole.
1) make sure the engine is at operating condition
2) remove the radiator cap, oil filler cap, dipstick, air filter cover, all spark plugs
3) rotate the crankshaft with a remote starter button so that the piston of the tested cylinder is at TDC on its compression stroke, this ensures that the valves of that cylinder are closed.
4)insert the threaded adapter on the end of the tester air pressure hose into the spark plug hole
5) allow the compressed air to enter the cylinder
6) observe the gauge reading
7) listen and feel to identify the source of any escaping air
The tester measures leakage from 0% to 100%
less than 10% is good
between 10 and 20% is acceptable
20-30% is worn engine
above 30% definite problem
100% bad!!!!!
leakage sources, if you hear air escaping in these areas you can pretty much figure where its coming from
Radiator - faulty head gasket, cracked head, cracked block
throttle body - damaged intake valve
tailpipe - damaged exhaust valve
oil filler or dipstick - worn piston rings
find the source of the leak first before jumping to the conclusion that the rings are bad, it could be something else, you never know. its good to rule it out. I really think the injector change with an improper tune prematurely wore out your rings as the fuel mixture was too rich, indicated by the backfire. too much gasoline mixture means the spark isnt burning all the fuel on the compression stroke throwing it into the exhaust system which ignited the unburnned gases from the temp.
hope this helps
1) make sure the engine is at operating condition
2) remove the radiator cap, oil filler cap, dipstick, air filter cover, all spark plugs
3) rotate the crankshaft with a remote starter button so that the piston of the tested cylinder is at TDC on its compression stroke, this ensures that the valves of that cylinder are closed.
4)insert the threaded adapter on the end of the tester air pressure hose into the spark plug hole
5) allow the compressed air to enter the cylinder
6) observe the gauge reading
7) listen and feel to identify the source of any escaping air
The tester measures leakage from 0% to 100%
less than 10% is good
between 10 and 20% is acceptable
20-30% is worn engine
above 30% definite problem
100% bad!!!!!
leakage sources, if you hear air escaping in these areas you can pretty much figure where its coming from
Radiator - faulty head gasket, cracked head, cracked block
throttle body - damaged intake valve
tailpipe - damaged exhaust valve
oil filler or dipstick - worn piston rings
find the source of the leak first before jumping to the conclusion that the rings are bad, it could be something else, you never know. its good to rule it out. I really think the injector change with an improper tune prematurely wore out your rings as the fuel mixture was too rich, indicated by the backfire. too much gasoline mixture means the spark isnt burning all the fuel on the compression stroke throwing it into the exhaust system which ignited the unburnned gases from the temp.
hope this helps
Last edited by senor_camaro; 11-18-2011 at 02:39 PM.
11-18-2011, 02:51 PM
#4
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how many miles on this engine? judging from the compression I want to guess that it is in the 100k?
Alot of things can cause lowered compression. Do you know it is the rings for sure?
And no, the tuner is not responsible for that. Had you said that the engine poped while on the dyno or something like that, then posted the tune and it was found to be jacked, then yeah he would be at fault.
Alot of things can cause lowered compression. Do you know it is the rings for sure?
And no, the tuner is not responsible for that. Had you said that the engine poped while on the dyno or something like that, then posted the tune and it was found to be jacked, then yeah he would be at fault.
11-18-2011, 03:28 PM
#5
I just bought my 2001 trans am ws6 last december from an old woman who garage kept the car and had it regularly maintained. The car ran like a top. I of course wanted to do some upgrades. The car was bone stock, i did full suspension on it and got a baseline dyno for it. it put down 312rwhp and 325rhtq in July. I put headers on it, and a cold air. A month ago i had a shop in town put in a cam, and 36lb injectors and do a tune. The car pulled 347rwhp. Did a compression test and it was down on all 8 cylinders. 145-155 on 5 cylinders and 160-175 on 3 cylinders. What cause the piston rings to go down so fast and all of them at the same time??? I only ran it at the track once. My guess is the fuel/air mix is jacked up and washed down the walls and burnt out the piston rings. I did a leak by test and it was good. Its also backfiring which could be due to fuel/air mix. The shop owner says hes not responsible at all, the tune and timing is "spot on"HELP?? Thanks.
And it shouldn't be backfiring either. Usually the only thing that causes backfiring is something out of time. Ignition or cam. These don't have adjustable ignition by a distributor so it's more likely to be the cam.
But it's also hard to tell by your description what is really going on.
Lastly, it is doubtful there is anything wrong with the rings if its making over 150 psi in compression.
11-18-2011, 04:47 PM
#6
TECH Fanatic
Go see a therapist for anger management.
11-18-2011, 04:56 PM
#7
As for the original question I wouldn't say rings is your problem. If you took a car that was running perfectly fine to a shop and they installed a cam and other performace parts and it is backfiring they definately did something wrong either in the cam installation or tuning. Also 347 hp right off tells me something is wrong and I highly doubt it was the engines fault...
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11-18-2011, 05:12 PM
#8
Agree those numbers are way off, is it smoking at all in the higher rpm range.this is one reason i tell people to go to a shop that has experience with ls motors.not saying shop is at fault but from your numbers posted it leads me to believe something they did isn't right
11-19-2011, 06:29 AM
#10
BS i'm not the shop owner.....what this guy is posting up is complete bs! He doesn't know sheeeet about anything but THINKS he knows. If that tune was rich enough to wash the cylinders down the cats wooooood have died within MINUTES!
11-19-2011, 09:27 AM
#11
The guy is just asking for help because some shade tree shop probably screwed up the cam swap, and now they won't stand behind their work. 347whp is definitely way off from what most cams will make, and I'm sure he paid good money to get these lackluster results. Try to help with a solution rather than being a problem.
11-19-2011, 09:59 AM
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Well, he said he did headers, so there is a good chance he doesnt have cats.
He also didnt say how big the cam was, so a small cam on a mustang dyno could do 347rwhp and not be out of line.
There are a lot of unknowns here and no conclusion can be drawn from the small amount of info that was provided.
He also didnt say how big the cam was, so a small cam on a mustang dyno could do 347rwhp and not be out of line.
There are a lot of unknowns here and no conclusion can be drawn from the small amount of info that was provided.
11-19-2011, 11:02 AM
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Thanks for the advice senor.
Mileage is 96000. The car was dynoed on a dynojet, the same dyno as the first time around as it is the same shop that did the work to it. I am 1000 miles away from my home with all of my tools and my garage, so i am very limited to what i can do. I pretty much have to go by what i see when i go into the shop and what they tell me is going on. The shop did the compression test and the leak down test and from the results the owner told me it was piston rings. I'm also in the process of packing up all of my stuff to go to my next duty station within the next 3 weeks, so without access to my own tools i'm pretty much having to go off of what i am told by the shop. I've never changed out a cam myself, its always been my dad and I and i've also never seen the problems i've had since i brought it to the shop.
The cam specs are: INT EXH
ADV DUR: 277 281
Dur @ .050 228 232
Valve Lift .588 .595
Lobe Sep 114.0
I
Mileage is 96000. The car was dynoed on a dynojet, the same dyno as the first time around as it is the same shop that did the work to it. I am 1000 miles away from my home with all of my tools and my garage, so i am very limited to what i can do. I pretty much have to go by what i see when i go into the shop and what they tell me is going on. The shop did the compression test and the leak down test and from the results the owner told me it was piston rings. I'm also in the process of packing up all of my stuff to go to my next duty station within the next 3 weeks, so without access to my own tools i'm pretty much having to go off of what i am told by the shop. I've never changed out a cam myself, its always been my dad and I and i've also never seen the problems i've had since i brought it to the shop.
The cam specs are: INT EXH
ADV DUR: 277 281
Dur @ .050 228 232
Valve Lift .588 .595
Lobe Sep 114.0
I
11-19-2011, 11:29 AM
#18
is it smokin in the higher rpm range?any smoke at all? if so what color? there is a few really good shops somewhat in your area, i would take the car somewhere else,02form ,there is no reason to act like trash , the op is asking for help , there is no reason to act like a jerk, and there was no need for any f bombs, op good luck man
11-19-2011, 11:49 AM
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It smokes for a few seconds upon initial start up. I haven't been driving it for 4 days due to the backfiring and it just running so rough. I just now went out and revved it and it blows alot of smoke. It looks gray/blueish which is another possible indication of piston rings being shot.
Last edited by adams2001ws6; 11-19-2011 at 11:56 AM.