Z400Racr90

So on my way home yesterday after the gym...windows down taking it nice and easy in a 25mph zone. Then i was like hmm i wonder if my rearend is still making noise so i put the windows up, radio all the way down, and heater fan off. Then out of no where comes a very loud tapping...I can't believe that at the exact time i was trying to listen to something a lifter or pushrod or rocker decided to take a **** on me. So anyway...very restless night because being 17 this car is my life and my only reliable sourse of transportation. Get home after schol today and start the car, trying to decide exactly what it is and the noise goes dead silent so im like cool, then i notice my engine swaying side to side and the rouhg idle.great i lost whatever cylinder was the problem. Try taking the car back to my house (i was at a friends for his garage) and the car runs horrible under 1800rpm and the SES light is flashing. So now im stuck, all the work will be done by me, i grew up around cars, hell i built my first engine a 4g63-t when i was 13...But i wanted to know if anyone has had the same experience so i can be more exact about what im getting into and order the parts before i dive head first into this project. Anyhelp would be greatly appreciated.

Ben

SparkyJJO

iTrader: (11)

SES light flashing is probably due to misfiring. When my lifters went bad (5 all at once!) it started off just making noise at startup that would go away after a few minutes to running like crap at start and SES flashing because it was misfiring badly. I assume the noise was still going while it was running bad?

I have the V6 but I imagine it'll be similar on the LS1, you gotta take the intake off to get to the lifters. I don't know much more than that since I had a shop do my lifters. Spent a fortune doing that instead of doing it myself but I had no time or place to do it

Z400Racr90

i am pretty sure the intake and heads must come off to get the lifters out of an ls1

98mysticZ

iTrader: (11)

pull codes then pull the valve covers if it looks like its going mechanical and inspect the rockers.. and springs... and u can loosen the rockers and pull out all the push rods its easier then pulling the heads for now just make sure all is well there then dig in... and heads must come off to pull lifters

transamws6_97

iTrader: (5)

yeah flashing ses means you have a missfire. could be as simple as a fouled plug or burnt wire. start with the easy stuff first.

waterbug1999

iTrader: (3)

HAve you pulled all the codes???

On my 04 5.3L Z71 I had misfies and the engine would almost die when at idle and shaking very bad as I could feel the truck swaying.

Well, it ended up being a bad O2 sensor going out. It would sense a lean condition and dump more fuel causing the misfires. Something to look into.
My buddy had EFIlive and we could tell it was the O2 as the % was not right. Changed it and all was good and the light went away after a few starts... Just a suggestion.

mikenews

iTrader: (9)

+1 definite misfire..code should be 301, or 302..and so on I believe

01WS6/tamu

iTrader: (37)

Pull codes, it will have a misfire code in it for sure. See which hole or holes are the offender. Check for spark, fuel injector pulses. Grab a compression gauge and throw it on the above noted cylinders with misfire codes if it has spark and fuel. This will tell you if you need to look further. Pull the valve cover off, look for broken spring, dropped valve etc. If nothing is visible push down on the end of each rocker arm by the push rod. It should not move at all or a thousandth or so downwards. If you can push down easily then you have a problem with a lifter. Pull the pushrods to make sure there is not one that is bent. Have to pull the heads to change lifters.

ae13291

iTrader: (8)

yea sounds like a misfire! maybe a coil or two died out on you, the car will run really rough if its more then 1 cylinder that out, scan the ses codes asap b4 you damage the cats from the misfire and unburned fuel

Z400Racr90

Dont have any cats with the offroad y pipe. I know it is a misfire but i believe its def. valvetrain related due to the noise beforee it happened. I wish it could be something as simple as a fouled plug or wire but i dont have that kind of luck...

1sick'98WS6

iTrader: (19)

definately pull both valve covers off, check pushrods.... happened to me bent in 3 places

01SSRMS

iTrader: (7)

still worth pulling the codes if it is a valvetrain problem. should point you to the problem cylinder or bank.

Z28Fistergod

iTrader: (10)

I suggest waiting until you find out what is wrong before you order the parts, buying unneeded parts can get expensive quickly. Getting the head gaskets now wouldn't be a bad idea, but if you get aftermarket lifters your still going to have to wait on shipping anyway.

ae13291

iTrader: (8)

start off with the simple things first man! maybe could be a busted rocker also! drain your oil and check for metel or needle bearings