I recently used 10-30w from 5-30 on my g35 2003 because somebody told me it could help a little with oil consumption. But now (a week later) the car has a "misfire in cylinder #1". Spark plugs has been changed recently (4 or 5 months ago) and I just changed the ignition coil on that cylinder. I am going to change the oil back to 5-30 to see if that makes any difference.
Idle is perfect but the sound pf the exhaus is really thick and loud. What do you think? Thanks (mods ztube ground kit)

 

Oil would have nothing to do with it misfiring. No need to change back. Of course going from 5w30 to 10w30 is really not gonna help with oil consumption anyway. That is a VERY slight difference in weight.

Pull that plug and inspect that the gap is correct, and switch the coil with another cylinder and see if the problem moves. If it does, then its your coil. I would suspect the coil if its an aftermarket.

 

I just installed a new sparkplug and coil on that cylinder and still the same, fast start good idle, loss of power and car shakes. Spark had a little oil. Any suggestions?

 

Wait, it happened before and after the new plug and coil?

 

Yes, and the sound of the exhaust is like thick loud sound. Engine soon blinks If i use the car. I dont know what else to check..

 

By blink do you mean you have a CEL or SES light on? If you have a light on connect a scanner to the OBD II port and read the code.

 

Done that at autozone "p0301"

 

But you said the plugs were changed ~5 months ago and you just got this..? You need to pull the plug and check the gap and whether or not its fouled. If its not the plug or coil you have serious probs. Like compression probs.

 

Change the coil boot

 

have you checked if you have spark?

 

So yesterday I changed ignition coil #1 and sprk plug too. Today I used the car went to autozone and now the scanner reads misfire on cylinder 3. I dont know what to do.

 

Cam sensor. its not throwing a code (yet). this sounds like a load issue.. which makes me think cam sensor...

Or you '*seafoamed*'' it or ran ''*engine restore*'' (oil compression \ thickener) .. or the guy helping you put 'engine restore' in it.

https://www.google.com/search?source...69i57.6831j0j1

 

Well I have never put seafoam or engine restorer on the car and nobody has worked on the car except me.

 

Excellent... has cylinder 2,4,6 ever miss-fired ? if not I lean very heavily towards the passenger side Cam sensor being your issue.

 

Also a issue I personally had was a open pcv, and to much oil spraying the plugs. lead to caking on cylinder 5,6 which leas to massive ping and extreme engine retardation .. which 'could' feel like a spark miss under load. have you looked at the plugs to see if they are more than normally dirty / oily ?

you could do the following. sit over night, fire it up, give it 10 seconds to oil up, rev it to 5000rpm for 10-15 seconds and shut down .

pull the 1,3,5 plugs.. check for WET oil. (wet as in you can or need to wipe it off).