Hi, I have a 2014 mii since it's out of warranty I decided to service it myself. Except for the oil filter being extremely hard to remove it was a breeze. 

The same day the car was fine didn't really feel any difference. 
Yesterday a day after the service I started to feel vibration when passing the 3500 rpm to 4000. I could really feel them in the gas pedal. 

I changed: oil (liqui moly 502 certified),oil filter (MAN the only one there was),  spark plugs NGK, air filter. 
I could update with exact models if needed. 

So anyone have an idea what's going on? The only thing I wasn't sure about was how hard to tighten the plugs. By what I understood you tighten by hand and the add one turn?
Could that be the cause? 

Any information would be helpful. 
Thanks. 
 

For the spark plugs I think your meant to torque them to the manufactures specification according to NGK spark plugs. 

 

https://www.ngksparkplugs.com/about-ngk/tech-talk/spark-plug-installation

 

 

After removing the spark plugs to check that the gap is correct on the plugs you will be able to tighten them to the correct tightness.

Thanks for the quick replies, the car is only 2 years old should I still clean the plug housing? If yes what should I use to clean it with? 

Yes you should always clean them before installing new spark plugs, something that sucks the dirt up would be ideal so the dirt doesn't drop into the spark plug socket. 

So what should I use to clean it? 

I'm not too sure, I just know something that's sucks it up would be your best bet, maybe a Hoover would do? Maybe put some paper or cloth over the spark plug holes once they're clean to stop anything else getting in. 

Figured it out! 

Just took another look at the car and I saw that the air filter housing wasn't connected well to the intake. I guess I didn't attach it well. 

Happy it wasn't anything serious! 

 

Thank anyway! 

I have never found the need to use a torque wrench for refitting spark plugs, although you do need to exercise caution with an alloy cylinder head.

 

The plug will have a crush washer. Tighten the plug by hand until it starts to nip the crush washer, then a quarter turn for a new plug or an eighth of a turn for a used plug with a ratchet bar or T bar should be enough to seat the plug securely.

Edited 10 February, 20179 yr by ronime