rattling (valves?), decreased gas mileage, oil on spark plug

[Hunter13]

I am new to the forum and wanted to see if I could find out some info. I have this rattling noise from the engine or around. It has about 85,000 miles on it and has always been serviced well and up to date. Even $600 trans change!! I recently changed the spark plugs on my wifes 2005 nissan murano thinking this may be causing the clicking noise and found oil on the back right spark plug. Afterwards it stopped for about a week and started right back. I have read where many muranos have this problem where oil gets to the spark plugs and was wondering if there is a recall for this or a factory screw up. I am wondering if that same housing for that spark plug has oil on it again. (Don't want to go through that headache again!)

I also changed air filter from regular to K&N thinking I would certainly get better gas mileage with the changing of spark plugs and the K&N filter but instead went from 23-26 to 16. Don't understand what the deal is. Any helkp and knowledge is greatly appreciated. Don't want to end up with a money pit ecspecially with the warranty running out at 100,000. Thanks.

J

[Pilgrim]

I can't speak to the other issues, but I don't think the K&N is a factor. It should not reduce gas mileage.

[hookahh]

Wow...I get like 14 MPG (NYC).

[chuck jones]

I agree...there should be no connection between a K and N filter UNLESS you've recently replaced it and oiled the filter...in that case, there are MANY instances wehre folks over-oil the filter and it sucks the excess oil in and has a tendency to foul the sensors. You'r eonly supposed to put a very light coat ofoil on them....but folks seem to think that if a little is good, more is better.

Also, the MO's are famous for leaking head gaskets in the back...I just had my head gaskets replaced after they found oil leaking down the back side of hte engine block...you might ask them about that. You could have oil seeping into the rear plug if that's where you're finding the fouled one....but most head gasket issues push compression or coolant OUT, not suck it in.

I go back to my question about your K and N filter...did you recently change it or oil it? Since this started after you installed a K and N...I always go back tothe last thing I did before the trouble started....I'll bet you over oiled it. Do yoruself a favor....quit reading all the BS about how great the K and N are and go back to a good stock filter....you never hear of folks complaining about fouled plugs when they use a stock filter. I've used both, and the K and N started throwing check engine lights and fouling plugs because of the oil on the filter screen....clean off all your plugs, go back to a stock filter, and sell the K and N to someone else. A K and N filter will NOT increase your gas mileage, give you more power, or make you look more handsome in your rear view mirror. They work in some engine applications but do nothing for a Murano.

Like Hookhah said...I get about 15 mpg around town with my MO', sometimes even less depending upon how quick I am off the line...it's not economical in stop and go traffic and you'll only get about 23-24 on the highway. If you wnat gas mileage, buy a Miata. This is a family car designed for comfort, accessories, extra room, and a nice look....it was never designed to give you 30 mpg.

[mojay]

Recently had motor on 2003 replaced, mechanic now says he can't get motor to fire up.
Any one know what could cause that

[Pilgrim]

Originally Posted by mojay

Recently had motor on 2003 replaced, mechanic now says he can't get motor to fire up.
Any one know what could cause that

I suggest you start a new thread about this.

Thoughts:

- Is there gas in it?

- It takes three things to make a motor run:

Gas
Air
Spark

The failure probably lies in one of these, not more than one. The ECU controls all three.

- You need someone who has a diagnostic scope to check it.