# random misfire



## pbarber55 (Nov 12, 2005)

I am the owner (original) of a 2001 Nissan Altima with 168,000 miles. I just recently changed the plugs for the first time no real signs of problem, just did it. Now the thing is missing terribly at idle. Turning on the AC helps a little but not much. Autozone used their diagnostic tool on it, and it comes back with "random misfire" . OK changed the wires today, no improvement. Any ideas?


----------



## gfriedman (Oct 12, 2005)

pbarber55 said:


> I am the owner (original) of a 2001 Nissan Altima with 168,000 miles. I just recently changed the plugs for the first time no real signs of problem, just did it. Now the thing is missing terribly at idle. Turning on the AC helps a little but not much. Autozone used their diagnostic tool on it, and it comes back with "random misfire" . OK changed the wires today, no improvement. Any ideas?


Does it drive pretty smooth but engine shakes at idle ?

Check your distributor or look for an intake manifold gasket leak

The Gman


----------



## 2000SE (Oct 28, 2002)

What plugs???? 
Use good plugs/wires/cap/rotor and inspect the VC gasket for oil leakage into the plugs. Also, check the spark plug pipes for cracks. Swap the MAF for a known good one.

And, replace the intake manifold gasket :thumbup:


----------



## rps180 (Aug 20, 2005)

It could just be the plugs. Remember, just dropping the plugs on the ground may cause some to go bad. I have had a couple of instances where the plug was bad even when they were brand new. You never know what happened behind the parts counter, so don't assume just because they are new there is nothing wrong with them. Was there any oil on the end of the spark plug wires when you pulled them out of the plug wells? If so, then you got a valve cover gasket leak.
But, do check the condition of the distributor cap and the rotor. If the contacts are black and have signs of excessive wear, replace them. 
You can check to see if the intake manifold gasket is leaking, but in most cases this will not cause a misfire problem but a idle problem. All you need to do is get brake parts cleaner and spray it at the flange where the intake manifold bolts to the head. When you spray at a certain intake runner and the idle changes noticeably, you have an intake gasket leak right there.


----------

