Need help. My 2002 Z06 (w/ 45,709 miles) engine stopped running while driving. The engine became a bit louder then stopped running and had to pull off to the side. I had just filled up with cheap 91 octane (CA car), might it be water in the tank from cheap gas? I had to call a tow truck to get home.

After getting home, I barely got it started and when I did the idle was VERY rough, and sounded bad. I checked for codes and came up with "P0106 MAP/Barometric Pressure Circuit Range/Performance Problem".
-So far I have changed out the MAP sensor with difficulty and the help of my daughter's small hands. No change.
-Disconnected the battery and cleared the codes withe the OBD II.
-Disconnected the MAF sensor while Running the engine and the engine died. Checked inside all three sensing wires were in place.
-Cleaned throttle body and put in a new air filter.
-Made sure all wires were fully seated on spark plugs. Changed out wires and plugs three weeks ago, using iridium AC Delco plugs and Accel wires. Torqued plugs to correct specs using anti-seize and electrical grease on wires and plugs.
Four weeks ago I started getting a "P1416 Port air circuit malfunction/(air) system bank 2", and just kept resetting it, maybe reset it four times.
-Ordered a new AC Delco fuel filter and will change it out as soon as I get it in the mail (autozone and pepboys did not carry or stock).

Need some help, I am out of ideas.
-

 

DO NOT START THE CAR ANYMORE TILL YOU CHECK FOR VALVE SPRING FAILURE. With the way it died and the rough idle please check if a spring broke and you start you could drop the valve and your done!!!(if it didnt already happen)
do a search on here on valve spring failure

Steve

 

machz800ps, is giving you very good advise.
Your car's year, fits right in the bad batch of valve springs, that made it past quality controll @ the engine plant.

Do not turn your motor over!
Good luck.

 

Thank you so much for the advice. I took off the coils and valve covers to find the driver's side (4th from the driver forward) spring is broken. They are the yellow springs many are saying are the bad ones. It appears the valve retainers are still in place. I have not tried to take it apart yet.

Thank you so much for the help, glad I don't have to buy a new engine!

Any advice on the type of springs I should buy to replace all of them?

 

If your running the stock cam, I like the Manley, NexTek springs.
Part #221428-16
1.311" Single
Inst. 150 lbs @ 1.800"
Open 355 lbs @ 1.200"
Coil Bind 1.085"

I have a stock 03 Z.
That's what I replaced my original springs with, over a year ago.
You will be able to use your stock retainers, & locs, with that set up.

Oh by the way, replace all of the valve springs.
Good luck.

 

Thank you will check them out!

 

If your doing this job your self, look to pick up a Crane , or (knock off)valve spring compressor tool, that allows you to change out two springs at a time.

 

Yes will be doing it myself. Will buy a compression checker, modify and hook it to air to keep valve in up position. Already have a spring compression tool from changing out springs on my old 1990 corvette.

 

Glad to help, I dont know a lot about the clearance with a broken spring but make sure you have not bent a valve or damaged a piston (you may have to pull the head to check, but i am not for sure . Hope its just the spring which is very possible

good luck
steve

 

I changed the springs using the BT racing stock replacement (from Colorado Speed on this forum) their customer service was great. I bought new rods and a rocker bearing rebuild kit. Took me a few weeks (working on the weekends) but it all came together fine. The car is running fine now. Thank you all for the advice and help.

 

I am looking to swap the springs on my 03Z in the near future. You happen to have any tips, or what tools would I need aside from wrenches etc and recommend any places to get them from?

Thanks.

 

 

Get the valve spring compressor for LS1/6 engines (I bought the Proform on eBay $75.00) made things easier especially for the cylinders closest to the firewall.
www.youtube.com/watch?v=-I85URitTdM

I'm really impressed with the springs from Colorado Speed 888-592-6661
-BT Racing LS Platinum SK001 $289.00

While I had the valve springs out I decided to change out the Pushrods as well.
-BT Racing Chrome-molly PR7400 $90.00

I also bought the upgrade bearing kit for the rockers (pressed the bearings out myself and put the new ones in using a vice and the right sized sockets). The stock ones are garbage, just hope they don't fall apart on you after changing the springs, you will have to take the rockers off again as well as flushing if not drop the oil pan.
-Comp Cams LS Retro-Fit 13702 Trunion Upgrade kit $129.94

I used compressed air (100 psi) through spark plug hole to keep the valve up while I took the springs off (get a good magnet for the valve retainers). I used the air hose from a compression checker kit (well worth buying $40.00 Autozone), make sure it fits spark plug hole (it will have adapters).

You will need an 8mm socket to take off the rocker bolts. This is usually a 1/4 inch socket. Buy a 3/8 drive socket so you don't keep breaking them by loosening the 22 ft lbs of torque.

If you haven't changed out spark plugs and wires in a while, this is a good opportunity to change them out. You will probably damage the wires when you take them off. I bought spark plug wire plier from Autozone $10.95 for the tight space. Use electrical contact grease for the wires and plugs.

To turn the engine I jacked up the rear and put on jack stands. I put it in 5th gear and spun the tire to be able to position each pushrod correctly to install the rockers. Make sure to keep track of each rocker to reinstall them in the same place you took them off.

Don't forget to use Assembly Lube when you install the pushrods and rockers.