New monte carlo Z34 owner
#11
12-15-2009, 06:25 PM
Welcome to the forum. When I had the P0300 code, changing the plugs and wires fixed the problem. Avoid bosch plugs, go with ac delcos or autolites. When you do the plugs, ignore what the emissions sticker says about the plug gap. Gap them to .045 or your car wont run. The sticker is a missprint, the owners manual has the correct gap for the LQ1. While you have the plenum off to do the plugs, it would be a good idea to replace the valve cover gaskets. They are known to leak around the holes for the plug wire boots. Its not hard to do once you have the plenum off.
#13
12-15-2009, 07:46 PM
Well you have multiple codes so you cant just single out a problem. Your missfire code should be solved with new plugs and wires. Your other codes are an unrelated problem with different solutions.
#14
12-15-2009, 08:41 PM
Welcome to the MCF family. I agree about the tuneup 1st. But a relatively inexpensive exhaust pressure test will check your cat' out. Most shops charge about $30 to do the test, at least around here. AutoZone will test the codes and let you clear them, for free.
#17
12-16-2009, 02:26 AM
ok well i guess when i go to pick up the car tomorrow i will have the cat and the tune up done. the guy i bought the car from told me that he thinks that it had a problem with the EGR VALVE. Do you guys think that has anything to do with the problem?
#18
12-16-2009, 03:27 AM
The tune up is the first thing you should do to the car, get the codes clear and then worry about the EGR/Cat. As far as the EGR, SOMETIMES cleaning it helps but if the valve's stuck you may be better off getting a new one. Also, clean the EGR passage in the intake manifold since it's probably clogged up as well.
#19
12-16-2009, 03:07 PM
Since you have the 3.4 DOHC, check the engines timing belt. They are known for breaking. The lower intake gaskets are also known to go bad on these engines. It could actually cause of the codes you are throwing. Take a can of carb cleaner, and spray in around the intake manifold. If the idle changes, you have leaky intake gaskets. They are actually pretty easy to change and not that expensive.
Take the timing belt cover off, and see if there are any little black hair looking things in there. If there are, its little pieces of you timing belt. You should change it right away. I had a 94 Lumina Z-34 with the same engine in it.
there was a debate a while back if these engines are interfering or not. Interfering refers to if the timing belt breaks, the pistons come up and hit the valves bending them. Non-interfering is there is enough clearance between the pistons and valves, so if the belt breaks, they wont slam into them. I wouldn't take a change on it though.
Take the timing belt cover off, and see if there are any little black hair looking things in there. If there are, its little pieces of you timing belt. You should change it right away. I had a 94 Lumina Z-34 with the same engine in it.
there was a debate a while back if these engines are interfering or not. Interfering refers to if the timing belt breaks, the pistons come up and hit the valves bending them. Non-interfering is there is enough clearance between the pistons and valves, so if the belt breaks, they wont slam into them. I wouldn't take a change on it though.
