spark plug diagnosis...need help por favor!

[GeorgeG.]

hey guys, I could use some help from you gear heads. I'm working on my daughters car (no, there will not be pics) and need to figure out what might be causing this. Frankly, the car is at the end of its life(sorta) but needs to last her through college.

Here's the info

03 Altima, 2.5L, 4cyl.
212,xxx miles
it runs rough and sometimes will not start for her (though I can't duplicate it now, go figure). From the way she describes it, it do recall it happening a long time ago back when I use to drive the car. The problem is when you try to start it, it will crank over but not start. Fuel pump engages but it just acts like it's flooded. Sometimes if I would hold the gas pedal down like a carb veh, it would sputter enough to eventually fire up. Other times if I just let it sit for a few hours and come back to try it again, it would fire up. Right now, this is what I can't duplicate.

However, I do know the valve cover leaks oil into # 1 and #4 spark plug tunnels. #4 plug boot actually had oil up inside the boot and on the terminal. I plan to replace the plugs since I have them out and clean out the oil. I'm hoping replacing the valve cover on this car is fairly easy.

Additional notes about the car...

*it's losing coolant internally. She has to add coolant frequently and never has a puddle on the ground. I don't know if that may be the cause for that "rusty" looking plug.
*coil packs 1,2, and 4 have been replaced.
*the CEL light is not on
*tapping the MAF sensor does not change how it idles (found posts online about possible MAF failing)

Thoughts? These are 1- 4 from left to right. TIA

[GeorgeG.]

Well crap.. the spark plug well gaskets are part of the valve cover ($130 bucks!)

[Rick Modena]

I knows that those Jap cars will have a hard time starting if they have a vacuum leak, which is probably being caused by the valve cover leaking oil. Also a hard time starting can be caused by a dirty fuel filter, its cheap and easy to replace and can solve a lot of starting problems.

[racrguy]

If it's losing coolant internally, it's either going into the oil or into the combustion chamber and out the exhaust. Either one of those issues means you need to yank the engine. You need to pressurize the cooling system and find the leak without the engine running.

[Brandon-k]

My fiances 06 was doing the same thing. It was the throttle positioning sensor and some other crank sensor. Both are on the back of the motor and a real bitch to change. Has it died at low speeds on her before?

[GeorgeG.]

not really died, but when she's at a stop, there's been times where, from the way she describes it, feels like it sputters upon acceleration.

I'll probably change the fuel filter while I have it. As far as the coolant, I think it has to be leaking into the combustion chamber. It doesn't have any signs of milky oil on the dipstick. I definitely will not be cracking open the engine though. This car has just about served it's purpose considering I only paid $3200 bucks for it 7 years ago and have since put 140k miles on it since.

I cleaned up two of the coil packs, changed the plugs, sprayed the MAF with MAF cleaner and sprayed the TB with cleaner. I started it up and it seemed to have fixed the problem...but then..... I couldn't take the filthy engine so I power washed the engine bay. I've washed engine bays before but with good results but I guess I was a little too aggressive this time. Now I'm getting a few codes. Two of them are the MAF and IAT sensor readings. The IAT is part of the MAF. I'll let it dry out tonight and see if it corrects itself. I checked the connector and it didn't seem wet so the MAF cleaner may have finished it off. A few online threads led to the MAF, crank sensor, and/or cam sensor being possible culprits so we'll see. The other code was for a cylinder 3 misfire which happens to be the only OEM coil pack left. I'm hoping it just got a little wet.

What about the plug burn patterns...nothing suspicious there? Specifically with #3? Maybe the coil pack has been weak leaving an unburned mixture? There wasn't any codes before I got started today.

[BLAKE]

This car has just about served it's purpose considering I only paid $3200 bucks for it 7 years ago and have since put 140k miles on it since.

In my far-from-professional opinion, this situation is already a win. Sell it before you drop anymore money on it while it still runs and find another beater.

[Captain Crawfish]

Coolant being used sounds like a internal issue. Fill it up and sell it before it starts blowing out a bunch of smoke

[SSMAN]

What they said above. Get your daughter in something safer.

[Goku025]

My last car was an 03 altima. It sometimes wouldnt start and sometimes it would die when coming to a red light etc etc. It is the crankshaft position sensor. That part is what is wrong with your daughters car. You change it out, your problems will be solved. I changed it at 150k miles and it made it up to 215k still running strong when I traded it in for an SUV. The only thing that failed were 2 ignition coils and a battery.

https://repairpal.com/nissian-crankshaft-and-camshaft-sensor-recall-492

[jimithing]

Can you do a compression test? Sounds like head gasket to me.

[Goku025]

not really died, but when she's at a stop, there's been times where, from the way she describes it, feels like it sputters upon acceleration.

I'll probably change the fuel filter while I have it. As far as the coolant, I think it has to be leaking into the combustion chamber. It doesn't have any signs of milky oil on the dipstick. I definitely will not be cracking open the engine though. This car has just about served it's purpose considering I only paid $3200 bucks for it 7 years ago and have since put 140k miles on it since.

I cleaned up two of the coil packs, changed the plugs, sprayed the MAF with MAF cleaner and sprayed the TB with cleaner. I started it up and it seemed to have fixed the problem...but then..... I couldn't take the filthy engine so I power washed the engine bay. I've washed engine bays before but with good results but I guess I was a little too aggressive this time. Now I'm getting a few codes. Two of them are the MAF and IAT sensor readings. The IAT is part of the MAF. I'll let it dry out tonight and see if it corrects itself. I checked the connector and it didn't seem wet so the MAF cleaner may have finished it off. A few online threads led to the MAF, crank sensor, and/or cam sensor being possible culprits so we'll see. The other code was for a cylinder 3 misfire which happens to be the only OEM coil pack left. I'm hoping it just got a little wet.

What about the plug burn patterns...nothing suspicious there? Specifically with #3? Maybe the coil pack has been weak leaving an unburned mixture? There wasn't any codes before I got started today.

George listen to me! Go to vato zone buy the crankshaft position sensor 20 or 25 bucks, open hood( it is located about mid way behind block by the firewall) take it out, put new one in, open a beer and enjoy the rest of your day!

[Baron Von Crowder]

check with Nissan, there were TSB's and extended warranty periods on those. It may have expired or you're over miles, but it might pay off.

[GeorgeG.]

I'll look into the crankshaft position sensor...I'll call O'Reilly's and see what they show for my purchase history. I've already changed out one of those "sensors". I don't remember at the moment if it was the crankshaft or camshaft sensor.

I cleared the codes last night and drove it around a bit. I no longer get the MAF/IAT code nor the #3 cylinder misfire. I probably caused the MAF/IAT code when I disconnected the MAF while it was running (I wanted to see if the car would die to rule that part out).

Now I'm getting a really high idle when the car gets to operating temp and the downstream o2 sensor is not reading at all. Both throwing codes. I'm going to check out the o2 sensor and likely replace it.

Once I get it running decent, I think we'll probably get rid of it.

[GeorgeG.]

Finally made some progress. replaced the downstream o2 sensor, erased codes and test drove it. Immediately got a P0507 code for high idle. During my quest for knowledge, I found a couple of threads on some Nissan boards regarding a idle relearn procedure. Figured what the heck could it hurt, it only took 5 minutes. Now it idles nice and smooth (for a car with +200k miles). I'm still not sure what was up with the misfire but it's not doing it anymore. I'll drive it some more tomorrow to make sure before giving it back to my daughter.

So new plugs, valve cover to replace the plug well seals, o2, PCV, and replaced the pcv hose. Either it was already cracked or I cracked it trying to remove it from the pcv valve. Only thing left is to find the exhaust leak and fix that then it's time to dump it. I've never opened up a over head cam engine so the head gasket is not something I want to deal with.

Thanks everyone for the suggestions.