Jump to content
SAU Community

Recommended Posts

Started up my car the other day and it was running really rough........... took it to my wifes uncle who is a mechanic and had a look. said it appears to be running on only 5 cyl............ checked em out and there is definatley a miss in cyl #1.

as we were only at his house couldnt find out for sure what is causing it.........thought i would throw it up here to get peoples opinions on it..

As far as i can tell i have 4 options as to the cause....

spark plug

coil pack

injectors

or the bad one.......a valve..

the car is running just really rough and bad vibration through the whole car..........any ideas?

Link to comment
https://www.sau.com.au/forums/topic/206474-only-running-on-5-cyl/
Share on other sites

firstly try to eliminate all the easy problems first eg spark plugs and test the coils to see if that fixes it.

if it is that then your lucky, if not then you'll have to go about replacing the more expensive bits.

so try the easy bits first

swap spark plugs with another cylinder.. this will cheak sparkies..

pull the coil out and start it without a spark plug.. if it sparks.. its not the coil packs

injectors.. use a multimeter.. get a workshop manual.. and cheak the voltage/amprage

cross all these off.. and then double cheak them.. then find 3 other ways to cheak each part.. then find other things that can cause it.. and as a VERY last thing assume a valve.. because valves dont just shit themselfs for no reason.. broken valves are caused from wrong calculations when shaveing blocks/heads.. or extended periods of very very poor timing settings..

see what can cause damage valves and then diagnose those and see if it realy does lead to broken valves..

An easy way is to go down to repco or supercheap and get a compression tester.. it fits where your spark plug goes.. you disconnect the battery and then crank the engine.. and it will regester the max PSI on a guage.. this can determin if there is a leak within the chamber. Do this to all 6 cyl's

BOM!.. gosh im good! :whistling:

lol... Im really proud of that!

and sorry to complicate things.. but gaskets can also cause a los of preassure that can manifest or appear as though a cylinder has dropped..

keep us updated so we can help

Edited by GTS4WD
I feel sorry for GTS4WD. All that effort and a mechanic takes over... :ermm:
agreed. there wasn't any real point in asking the forum in the end, ask the mechanic next time :D

So your saying I dont do as good of a job as a mechanic!?! :P

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Is there a diameter difference in the stock to Nismo? If so, the weight alone won't be indicative when comparing flywheels of the same diameter, since the radius of the flywheel acts on the moment of inertia with a square factor, where as mass is linear. Roughly going from a 4.5kg flywheel with radius 20cm, to a 9kg flywheel with radius 14cm would see them act the same. This calc is just here to act as a brief numbers comparison and reflects no actual RB flywheel diameters etc. it also assumes even weight distribution (thickness) throughout.
    • It seems this could be due to a restructure/team direction change... Or... You're working with a different category of vehicle... Or you've decided you'd rather be able to play with your own cars again...   I'm hoping the latter...
    • had 4 weeks off over xmas and well did some stuff to the shed and BRZ, well short of is I don't work full time in supercars anymore as of yesterday.........
    • Did you get any down time over Christmas, or have you had any since to play with this? Or have you given up and are trying to get yourself a second hand V8SC instead?
    • A random thought I had just before I hit "Submit on this post". If brake fluid, in a container in my garage that has never been opened goes bad after 18 months, why can I leave it in my car for 24 months in an "unsealed container"... Secondly, some other digging, and brake fluid manufacturers seem to be saying 5 year shelf life... Me thinks there line on 18 months for an unsealed bottle is pretty much horse shit marketing spin. Kind of like how if you drive a car and don't run a turbo timer your turbo and motor will die horribly...   Where I started on this though... Someone (me) started down a bit of a rabbit hole, I don't quite have the proper equipment to do Equilibrium Reflux boiling per the proper test standards. I did a little digging on YouTube, and this was the first video I found on someone attempting to "just boil it". This video isn't overly scientific, as we don't have a known reference for his test either. Inaccuracy in his equipment could have him reaching the 460 to 470f boiling point range in reality. In the video, using a laser temp gun, he claims his Dot3 that's been open in his florida garage for over a year gets to about 420 to 430 fahrenheit (215 to 221c) Doing some googling, I located an MSDS for that specific oil, and from new, it claims a dry boiling point of 460 to 470f. Unfortunately they don't list a wet boiling point for us to see how far it degraded toward its "wet" point. While watching it I was thinking "I wonder what the flash point is..." turns out its only 480f for that specific brake fluid....   As for testing the oil's resistance, I might not be able to accurately do that unfortunately. Resistance level will be quite a LOT higher than my system can read I suspect based on some research. However, I might be able to do it by measuring the current when I apply a specific voltage. I won't have an actual water % value, but I'll have some values I can compare between the multitude of fluids. I'll run some vague calculations later and see if I should be able to read any reliable amount of current. These calcs will be based on some values I've found for other oils, and see how close I'll need my terminals together. From memory I can get down to 1pA accuracy on the DMM. I don't think my IOT Power Tester has any better resolution.    
×
×
  • Create New...