Oil on plugs & alternator problem? low MPG's
 

Ok so I have new spark plugs to install but upon inspection I see there is oil on the plug wires. Now I realize this iprobably a leaking valve cover gasket? Or would there be some other cause for that? And it's probably recommended to replace cover gasket so as not to ruin new plugs right?

The next thing is under any amount other than normal electrical load my TI idles low as if losing power. I mean when the Ac compressor kicks on or when I send a window up and it hits the top. I am thinking the alternator is going out and not able to keep up with electrical demands? Again am I right or could there be something else?

The last thing is I am not getting very good gas mileage. For the last month I averaged about 15 to 17. I really only drove from work to home and the store so not a whole lot of time to warm all the way up some times but still I expected better. Could this be due to fouled plugs and needing a fuel and air filter? Also probably a JB engine clean if anyone else uses JB products or a tune up kit applied by vacuum to clean and burn crap out of the engine. Do oil changes affect engine performance on these cars since I will be doing one tomorrow? I only ask because my old car you could feel the difference when it was time for an oil change.

Caliburnes, you are suffering from a very weak and unhealthy spark due to the oil on your plugs. I would imagine you have weak throttle that chokes out up top as well? Oil on the plugs = rougher idle (even for 4 cylinder), poor MPG, unburned fuel, and poor acceleration. When replacing the VC gasket, I would always get new plugs, coils, and clean out the throttle body (of oil), and make sure your vacuum is in order (smoke test).

As for your dip in idle/voltage. The easy guess is a weak ground that probably needs to be cleaned. It's not abnormal for a 15 year old car unless it's really severe
That's just a start.

Ok well I thought the low MPG may have been connected to the fouled plugs. Upon more searching it is common for VC gasket to leak I just didn't realize it had such an effect with proper burn. It must leak bad once it does. I don't have a choking throttle just poor acceleration a slight rough idle to but mostly fixed that with a new ccvv. I have checked my vacuum as well and it seems good to me. That was the first thing I checked for rough idle.

I have new plugs and when you say coils I havn't looked to see where the plug wires go but do you mean the coil or the plug wires?

Well the battery ground looks good to me but the battery is a cheap-o walmart brand. not my choice previous owner put it in it could be that as well. But it is a big noticable drop in rpm while idling and ac compressor kicks on. I guess at most 100 RPM it seems to noticable even for a 15 year old car to me. Are alternators common on these to go? Or are crap batteries a problem for them? Some of the other cars I work on have trouble with cheap batteries not being able to handle proper voltage under load.

Thanks for the repl to by the way. I am really enjoying the ease of repair on this car. And it's fun to work on.

So I had really only looked at the first plug and noticed a little bit of oil. The other three I took some time today to look at and wow they are swimming in oil. And its leaking off the back of the motor from the gasket wow that is certainly the next thing to do. I had ordered the gasket and figured it had the spark plug seals attached to like most of the other vehicles I work on. So now I gotta wait on those before I can make a move.

Replace the valve cover gasket and spark plug gaskets that are part of the valve cover kit. You should be all fine. You can't have oil in the holes and if your wires are wet you most likely have a crappy running car, that is caused by that oil on the spark plugs and wires. Also maybe a CCV valve since that is most likely toast too and not helping with oil control.

Yeah replace valve cover gasket and the spark plug well gaskets as well... Don't use a sealant anywhere except a couple of dots on the half moon areas behind the engine

It sounds like you have some maintance to get caught up on. You probably do need a ccv. This controls pressure in the crank case and if it gets plugged the pressure will find the weakest link to get out, or blow the valve cover gasket. I think on this it's called an upper head gasket but you know what I mean. A bad ccv also decreases fuel mileage as there's added resistance in the crank case. Old oil will also decrease mileage as it creates more friction. As for the power drain when using windows and other 12 volt power things in the car. This can be a sign of a weak battery, have it load tested, or poor ground (pretty hard to find). Sometimes regreassing the window tracks and motors helps. Alternators don't really get weak they either work or they don't work. As for tune up in a can products I have used them before and they do have a place. They are not a fix all however. What I do is with a warm engine so the oil is thinner I will add a can of seafoam let it run for about ten mins then drain the oil while it is still warm. I have also under pressure injected seafoam into the injector rail to clean the injectors. It appears the 318 has an issue with carbon buildup on the injectors. When I did my coolant connectors and had the injector out I soaked them in seafoam to remove the carbon build up. As for plugs I'm guessing I had factory plugs still in my 96 when I got her. and they were pretty bad looking. I felt a noticable power gain when I changed them. Good luck

Hi Everyone I'm Dan and new here.

Recently my 318ti has been getting some really APPAULING MPG figures. In the past I was getting around 32-34 with mixed town and motorway driving, but now she is really struggling to make the 20's. Here are someof the symptoms I have;

When I first start her in the morning (or after a long time) she sounds like she is really struggling to start with little noise from the starter. When she does start she is quite lumpy on idle and the car shakes for the first couple of minutes until she settles down. (The exhaust is also making a "pop, pop, pop" noise at this time too).

In addition to all of this once she has warmed up and say Im sat in traffic a ticking noise appears from near the intake manifold. However, if you blip the throttle to about 1500 rpm it goes away, but will come back again at some point. Funny thing is, i replaced the thermostat and coolant shortly after I got the car (Both Genuine BMW parts) and this noise went away for a while.

Next thing is the wheels and brakes. I have had to replace both front calipers as they were shot. However, neither front wheel spins completely freely, they both have a tiny amount of resistance....does anyone else have this trait or is it just me? There is also a groan when in reverse which sound like its coming from the front wheel(s).

I have had her sent to my local BMW dealer to have any codes read and NOTHING came up ?????? So I'm still at square one as to what i should replace to get her running sweet again. Any and all help would be much appreciated.....

O, one final thing, when driving, if I come off the throttle the speed at which the car decelerates is unnerving. However, if I put her in Neutral (shes a manual) and let her coast, she doesnt seem to slow down any where near as quick, almost as if the engine braking is OTT.

Once again thanks for reading and for any help you can offer.

Check for vacuum leak asap

Hi,thanks for the reply.

I've not long done the Thermostat so checked all the hoses then and all were good....

My only hope is that its either a dirty MAF (which I'm going to clean today).

If not next up is a service including Oil, Oil filter, Air filter, Spark Plugs, and the rocker cover gasket.

Speaking of which, with the gasket do i need to put any sealant on or not ? BMW said no sealant at all, but numerous other websites say to do so ???????