M44 running rough, oil inside cyl2????
 

So I recently picked up an incredibly clean '97 318ic a couple months back. Just over 98k miles now. Took it through DEQ about a month ago and was told it had a bad cam position sensor. But it was still running fine, so I ordered one. A couple days later was coming home from a friends place and it started missing, and died 3 times. Was able to get it home OK. So as soon as I get the sensor, I put it in thinking that would solve the problem. Started it up, it ran fine, got out on the freeway, and then it started missing again. Got it home. Parked it again. Ordered up a Peake code reader the other day (still waiting for it to arrive) but decided today to pull the sparkplugs and have a look.
There is, what appears to be, oil on the plug in cylinder 2. On both the plug connector, and on the end of the plug inside the cylinder! :mad: I'm hoping that maybe it's just thick dirty fuel that collected because that cylinder wasn't firing correctly, but that might be wishful thinking...
Anybody have any ideas :confused:

Well, the valve cover gasket could be leaking on the spark plug and connector causing a misfire...If you look in the sparkplug hole there is a gap a little bit down in there, see if there is a bunch of oil around that...

Could be unburnt fuel on the plug from the misfire...

Thats kinda what I'm hoping for. There is a little collection of what looks like oil in the bottom of the sparkplug well. But could seepage from the valve cover gasket have worked its way all the way through into the combustion chamber? Cause like I said, there was oil all the way up into the socket on the plug connector as well as around the threads and on the tip of the plug. I'm just hoping it's not oil coming up and through from the combustion chamber itself!

It could have gotten on it while you were taking the plug out. It can get pretty deep if the valve cover is leaking bad. My car didn't have the gasket on the #1 plug...was like half full of oil.

I'd suggest getting the valve cover issue fixed first, and as familytruckster suggested that might cause the misfire. It would have to be a lot of oil to do it, but it's possible.

It's a common leak on these cars, and here's how to fix it:
http://318ti.org/forum/showthread.php?t=12007

Good point, I know it wasn't half full, but it probably doesn't take that much to wick up into the rubber socket and start causing misfires. I'm assuming the plug is fouled now anyways so I'll tear into it tomorrow, clean everything up and replace the plugs. If it's running good after that, then I guess I'll be ordering a new valve cover gasket. Hopefully my code reader comes tomorrow so I can run that too!
Thanks for the insight. This engines kinda new to me so I'm not sure of all the common issues with them. It really helps to have these forums around :smile:

Well luckily these engines are quite good. No major issues at all. Welcome to the site by the way. Glad to have more 318ti people!

The problems that are prevalent are due to plastic and rubber parts external to the engine itself. My guess is most cars over 10 years old start to have old rubber/plastic issues eventually.

#1. Is the plastic coolant hose connectors. There's one on the side of the block and one on the back of the head. They have been known to break which causes a major coolant leak and a potential overheat. They are cheap to replace but require a good amount of labor to access them.

#2. Seems to be the valve cover gasket (and associated spark plug hole gaskets)

#3. Vacuum leak.... The main intake boot cracks. The valve cover breather hose cracks. And I've seen a number of vacuum hose leaks that lead to the fuel injectors.

All these parts are rather cheap to replace if you DIY.

Thanks. I do have a '91 318is that I've had for a couple years, but the M44 from my understanding, though very similar, is also a bit different than the M42. And yes, I know exactly which plastic coolant pipe on the side of the block you're referring to. Mine broke in the E30 outside of San Fran on my way from Portland to LA. I was able to shove a smaller diameter hose into the coolant hose then down into the connector and clamp it all together. Got me to LA before it started leaking all over again, then took it to a shop where it cost me $200 to have replaced :eek: But I wasn't about to try to get all the way back to Portland on my Band-Aid fix.
And thanks too for the link to that write up. Very detailed. I've done a valve cover gasket on an old Integra that I had, but I wouldn't have known all of the seals I'd need for this job...

Well today I changed the plugs, and no luck...
I also got my code reader, but all i got was a battery disconnected code, and EWS Input code. Reset those and now no more errors.
But as I was under the hood with my key in the ignition in the "ON" position, I noticed a buzzing coming from the ICV. I fiddled around with the connection and it went away for a sec but then started buzzing again and I couldn't get it to go away after that.
Correct me if I'm wrong, but I'm guessing this isn't normal?
Is this what's causing the very poor running? Even though no code is coming up for it?

i believe if you leave the key in the 2nd notch there will be a buzzing sound coming from the engine bay. well at least thats how its been on my M44 and now S52, i think its the starter or selenoid? something of that matter.

anyway, hope you resolve this soon.
i have a valve cover gasket for the M44, i think it should be the same as the M42.

I know for sure it's coming from the ICV, when I touch it i can feel the buzzing and hear a change in pitch as grab it in different areas...

The ICV will buzz non-stop in key position 2 (on). That's normal. It'll also buzz for a few seconds after the engine is shut-off.

Ok, thanks for the help guys. i'M STUMPED!

So after doing some more research it's looking like a bad crankcase vent valve could also be the culprit for these running conditions. After shutting the engine off I can hear what sounds like a slight whistling for a few seconds follow by a "pffffttt" sound from somewhere in the engine bay.
Is this a normal sound from these engines? I know I've never heard it in my M42...
I still have no codes coming up

I've definitely heard the "pffffttt" sound a bunch, so I'd say that's normal too. Sounds like some sort of air pressure release. Don't think I've ever heard a whistle though.

EDIT: Doubled checked and I do get the air-pressure-release kind of sound for a few seconds on shut-down. It's definitely been doing that for years, so it's most likely normal.