HELP PLEASE...VN V6 Manual

[05 VZ SS]

help....my vn v6 5 spd manual is doing strange things....all of a sudden there is a lot morer movement in the engine...and the acceleration seems to miss under 2000 revs...after that its fine....Started it out of the blue...clutch is near the top...could this be the problem?..it idols fine though...and you can really notice the movement...Engine mounts were changed about a year ago..I put fuel in a few days ago, tuesday, and it started today, Friday...Any ideas on what to check?

[Pretender]

It's obviously missing down low which could be either electrical or fuel system related, unfortunately. I say unfortunately as it can take time to pinpoint the exact cause.
When a V motor misfires(or doesn't fire on all cylinders properly) you do get a lot of movement and most engines will appear to idle OK until put under load.
Check your leads first then check for any vacuum leaks including the intake.
It really could be many things including an injector not working through either a blockage or an electrical problem, crank angle sensor, failing coil or DFI module. Have you replaced anything lately?
Sorry not much help but someone will tell you what to check and how to check it very quickly.

[05 VZ SS]

hey..thanks...Have changed nothing lately...only thing i chnaged lately is thicker oil...went from 10-40 to 40-70..but did it a month ago...Could that have done anything?

[timbra_88]

Tiny chance that the oil would do that, only if its REALLY thick. My mate had a problem where if u punched it from idle, it'd sort of sputter a bit and then rev up, it wouldnt do it if you just revved up slowly. If yours is doing this its your leads. A sure way to tell is go out to the car at night in the dark, pop the bonnet with the engine running and look along your leads for any tiny sparks arking out from the leads, if so, change your lead, but id say thats the problem anyway. Tim

[Pretender]

No the oil should not make a difference.
If you have a mechanic you use he/she will be able to perform a diagnostic check which may tell you exactly what it is (or not as there are a lot of posts relating to incorrect codes showing up).
Do the basic checks first like make sure the leads are all connected properly, look for any loose or bare wiring, loose hoses etc. Check the the radiator whilst the engine is running (remove the cap first if you have one) to ensure you are not losing or have lost coolant etc.
It is also a good idea to loosen the bolt that holds the wiring socket on the DFI module (8mm I think) then pull the plug out slightly and push it back in firmly and retighten. Sometimes helps as it cleans the contacts. Same with the fuses in the engine bay and the crank angle sensor connector(to the left of your air/con compressor you will see a wire running behind the Harmonic balancer), just pull out or apart and push back in.
If you don't find anything I would suggest getting a diagnostic check done or search this forum under "diagnostic(s) + check" as there are lot's of posts on performing your own check.
Or just wait as someone with the know how will reply to this post.

[samuels]

No the oil should not make a difference.
If you have a mechanic you use he/she will be able to perform a diagnostic check which may tell you exactly what it is (or not as there are a lot of posts relating to incorrect codes showing up).
Do the basic checks first like make sure the leads are all connected properly, look for any loose or bare wiring, loose hoses etc. Check the the radiator whilst the engine is running (remove the cap first if you have one) to ensure you are not losing or have lost coolant etc.
It is also a good idea to loosen the bolt that holds the wiring socket on the DFI module (8mm I think) then pull the plug out slightly and push it back in firmly and retighten. Sometimes helps as it cleans the contacts. Same with the fuses in the engine bay and the crank angle sensor connector(to the left of your air/con compressor you will see a wire running behind the Harmonic balancer), just pull out or apart and push back in.
If you don't find anything I would suggest getting a diagnostic check done or search this forum under "diagnostic(s) + check" as there are lot's of posts on performing your own check.
Or just wait as someone with the know how will reply to this post.

believe it or not oil does make a difference,it may well of started this problem,especially if it was thicker,40-70 what sort of noise did it have in it for you to use that oil cruzey? thats getting close to diff oil
but like everyone has said check electrical and fuel systems,how old are your plugs,have you got an ohm meter,check your leads,if they are over 17 ohms they are buggered....

[05 VZ SS]

Hey guys....I checked the plugs on Saturday arvo and they were buggered....Replaced them and the problem went away...Thanks for your help guys..

Samuels - Started using thicker oil as it was disappearing through the rings..The thicker oil seems to have stopped this...however, next oil change might drop back to 25-70 and see what happens....