DD knock rattle? I'm lost

[thefridge]

ok im really in need of help here my 2002 ws6 is a daily driver and my wife is starting her new job soon so i cant drive hers to work anymore,
ok here goes
ive got a sound a code and loss of power and it shakes all through the pedal and shifter.
sound is like a rattle/knock this is in idle and speeds up with rpm
code is p0300
what i have done,
put 93 in it ( i ran 87 for a month or so bc of $)
pulled valve covers, springs, and everything there looks ok to me,
pulled plugs, 2 of them were extremely more worn than the others, i cant remember now which cylinders they were but i know they fire right after each other in the sequence,
so i replaced the plugs, and finnaly put my long tubes on that have been sitting in the garage for a year,
anyway started car up after everything was put back together and the sound is still there, drove it arround the block and noticed the lack of power,
so that is what i have done, please if some of you ls1 gods out there got something i can do, or if you know a thread that can point me in the right direction please let me know thanks in advance

[pajeff02]

First recommendation is to go outside tonight, open the hood in a dark location and start the engine. You'll be able to see right away if you have spark jumping around from a cracked plug or bad wire. Next step is to inspect the wires to ensure that they are properly seated -- you should hear/feel one "click" on the plugs and two "clicks" on the coil packs. With headers, wire positioning is critical so that you don't melt a boot or burn a wire, so take a look at that as well, especially if you see spark jumping around. Misfire can also be the result of a lean condition caused by fueling issues. Chevron Techron fuel system cleaner is fairly reasonable and does actually work -- add one bottle to no more than 12 gallons of fuel. Changing the fuel filter and then checking fuel pressure at the rail are also recommended if the problem persists.

[SMWS6TA]

In addition to what Jeff posted above, I'll ask the other stuff:

Does it feel like engine knock? or something else?

When's the last time you cleaned the MAF?

Front O2's - have they ever been replaced? They are good for about 75,000 miles after that they start to loose reliability.

CATS - have they ever been replaced? You could be on the edge of them been clogged.



It may be none of these, but they still can effect the idle/mpg/HP.



Running 87 for a month won't hurt you, it just doesn't give you peak HP. I've run 87 in times of tight money myself. No shame.

[thefridge]

I'm not sure what it feels like honestly, maf never cleaned it idk how 02s never done them, but when I took them out they are pretty black, cats are no longer installed as of 2 days ago, is there anyway I can test plug wires? I have a multimeter.

[pajeff02]

Grab a can of CRC Spray MAF cleaner from the local parts store and follow the instructions. Do you have access to a scanner that allows you to watch live sensor data?

[SMWS6TA]

Here is a ist of what a code P0300 may mean that one or more of the following has happened:

Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s) - in your case does not apply
Stuck/blocked EGR valve / passages - in your case does not apply
Faulty camshaft position sensor
Defective computer


If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.


If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, check the coils (a.k.a. coil packs).

I've also heard in other cases the problems were faulty fuel injectors.


Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.




I would focus on the plugs & wires first. If you have no idea when they were last change I would just change them.


Black O2's - could mean several things, mostly you are running very rich. But if you just did headers you will till you get a tune (recommend Frost).

[thefridge]

How do I check the coil packs? And I have a scanner I borrowed from my buddy and it has a feature that's called data logging not sure what that is, replacing the fuel filter here in a few mins, and can those things you noted about the code, can those cause the rattle
/knock I have

[pajeff02]

If it is a bad coil pack, your code will usually isolate the cylinder and not be random. If the wires are on, the plugs aren't cracked or arcing, and the harness connections are intact, I would be looking at fueling and things that affect fueling such as the O2 senders and fuel pressure.

[SMWS6TA]

does his data logger have an ability to print off the data? If so post.


Like Jeff said above the code will give you the cylinder (ex. P0301 = this means the misfire is coming from the #1 cylinder) In your case it is random.


I don't think it's the Coil packs. They are really good on the LS1. It is rare for one to go bad.

Clean the MAF like suggested?

I didn't see it posted or asked - are you using a K&N filter?

If so many members have reported having issues effecting the MAF. The oils that is used to clean the filter gets on the MAF and will cause reading errors.



Knock - you are saying you have a knock code or you feel like you have one?

[thefridge]

Cleaned the maf and replaced fuel filter, still there, and it's kinda like a rattlly knock , and I cannot tell where it's coming from, yes I hear it, and I'll check with him on how to use that scanner I know it's a high dollar one

[SMWS6TA]

I almost want to say do a video and post link on youtube

[thefridge]

. Video of the sound it's more prominent on top and passenger side

[SMWS6TA]

last time I heard that I was thinking push rods but it turned out to be a clogged CAT.

[thefridge]

No cats and do you have a write up to check push rods?

[thefridge]

With that sound is anyone thinking something bad like a main bearing? As there any other symptoms to a main bearing failure?

[robs98mysticZ]

if it were possibly a bent pushrod you just pull valve covers, then rockers ect, pull pushrods from head lay it on a flat surface (ie. table)...then roll it you will know if its bent...if i am missing anything someone chime in

[thefridge]

Yea I'm going to pull the push rods today and check that off the list.

[thefridge]

Update
None of my push rods are bent,
So as of now I have checked the followoing
Maf cleaned
No cats
New fuel filter
Push rods rockers and springs all good
New plugs
(not wires waiting on $$) but wouldn't wires give me a specific code not P0300
P0300 code
reset PCM

Plan on
checking injectors( is there any way to actually check them?)
Checking pressure at the rail


Also something I noticed today
The noise doesn't start until about 20 to 30 seconds after a cold start

[pajeff02]

Sounds very strange...

Other stuff to potentially check - could be a collapsed lifter or an exhaust leak. Is it really erratic or is that just the sound in the video?

[robs98mysticZ]

[QUOTE=pajeff02;2783477]Sounds very strange...

Other stuff to potentially check - could be a collapsed lifter or an exhaust leak.

header bolts are an easy check off too