I have a 99 Z24 2.4 and just recently, my car begin to stutter and hesitate slightly upon acceleration. Now it has gotten much worse. It idles roughly and hesitates almost every time I accelerate. The car will actually start up very quickly, but if i dont immediately give it gas it dies. After stopping (i.e. at a red light) when I put it in gear and give it a little gas it starts to stutter very badly and if i dont mash down on the gas it will die completely. After running for a few minutes, although the idle is quite rough, it wont die at idle. It only seems to want to sputter and cut off when i try to accelerate a little (then i have to really give it gas to keep it running). It also seems to have random drops or lags in power at cruising speeds.
I dont know why the aforementioned is happening, but i figured spark plugs would be a simple start. When i pulled out the outer spark plug on the passenger side, it had oil on the threads (Just that one spark plug had oil on it). I also noticed (before i even touched the spark plugs) that there was oil sitting on top of the block between the camshaft housings. And all the old spark plugs were a very dark matte black.
The car is a manual and has around 200,000 miles on it, but it has never given me problems like this before.
Are these two problems related? Does anyone know the cause? ANY help or input is greatly appreciated. thank you
HI,
First off, no, ther should not be oil down in the spark plug thread area. Most likely you have a leaking valve cover gasket and the oil is puddling in that spot, get some new gaskets and reseal it.
The oil CAN cause a misfire. Either by redirecting the spark to the head and / or by causing the rubber boot to decompose and leak high voltage. I'd clean it all up, put in new plugs, put on new wires and get a new gasket on, chances are you'll run better.
Dave
yeah, i'm definitely going to finish the spark plug change. And the camshaft housing does seem to be oil stained slightly so i'll look into changing that gasket and go from there. Thanks for the response, Dave.
The oil pressure sensor is in that same area and is commonly known to leak.
ok, thanks tom and dave - and have any of u got the camshaft housing (valve cover) off a 2.4 before? and is it really necessary to take off the timing chain, case, power steering pump, fuel rail, etc.? (these were all taken off in the haynes manual)
Randell Rainey wrote:ok, thanks tom and dave - and have any of u got the camshaft housing (valve cover) off a 2.4 before? and is it really necessary to take off the timing chain, case, power steering pump, fuel rail, etc.? (these were all taken off in the haynes manual)
yes, you have to pull the cams to do those gaskets, my bets on the oil pressure sensor.
ok, i did the spark plugs and the seafoam and its still running bad (it doesnt cut off though). I think i'll try the coils next. And, tom, i've searched the forum and the haynes manual and i dont see anything about the oil pressure sensor for the 2.4; do u know where it is?
Right above #4 cylinder sensor coming out of cylinder head at a rearward angle.
oooh, u mean the "oil pressure switch/sending unit"? - i def see that as a possible leaking candidate and its much easier to get to
Yeah your right, it's a switch.
do u now of any way to test the ignition system on the 2.4? i think mine might be faulty, but i changed the coils and got no difference. wat about the module and housing?
The housings go bad frequently also. The module not so much.
yeah i read about that - i was thinkin of jus replacin it n seeing if that helps ... but i really wish there was a way to test those things
You can test the resistance between the terminals of the housing. The four holes where the coils go to where the four plug connectors attach. Resistance should be less than an ohm.
