AU Fairlane 5.0L Vibration

wazza69 · 20-08-2007, 06:36 PM

Hi Guys,
I recently bought a Series 1 AU Fairlane. It has a vibration in the motor around 1200RPM. Now I've searched all the forums, and came across some things to try, this is what I've done:

Replaced Spark Plugs (NGK Iridiums)
Replaced Leads (and checked each one's resistance - all were fine - around 4 ohms)
Cleaned the throttle body
Cleaned the ISC Valve
Reset the ECU

and it's still got the vibration! Any ideas on anything else to check before I send it in for someone to look at - maybe its the injectors or something...

V8falcons · 20-08-2007, 10:00 PM

Quote:

Originally Posted by wazza69

Hi Guys,
I recently bought a Series 1 AU Fairlane. It has a vibration in the motor around 1200RPM. Now I've searched all the forums, and came across some things to try, this is what I've done:

Replaced Spark Plugs (NGK Iridiums)
Replaced Leads (and checked each one's resistance - all were fine - around 4 ohms)
Cleaned the throttle body
Cleaned the ISC Valve
Reset the ECU

and it's still got the vibration! Any ideas on anything else to check before I send it in for someone to look at - maybe its the injectors or something...

Is the vibration @ 1200rpm in netual,or taking off?

harmonic balancer,or uni joints maybe.

wazza69 · 20-08-2007, 11:28 PM

both neutral and driving, but much more noticeable when driving.
I'll look into the harmonic balancer, thats one of my 'could be stuffed' options...

BLACKAUXR8 · 21-08-2007, 12:25 AM

I did my harmonic balancer and you would know if it was broken the whole car feels like theres an earthquake in it. I have a friend who's fairmont was doing this turned out to be that 2nd gear was rooted in the auto and the motor was running in limp mode. It was a chic though and she had no idea on what was going on. she didnt even realise the car wasnt going into 2nd or 4th

wazza69 · 21-08-2007, 12:36 AM

Haha no the gearbox changes gears fine. Sometimes when I put the boot in, it backfires too... it only vibrates around 1200, above that its ok, so I'm guessing that rules out the harmonic balancer... I might change the fuel filter and see what happens.

BLACKAUXR8 · 21-08-2007, 02:00 AM

you could have one of you cats on the way out? when you put the boot into it the exaust fumes can puch the broken bits up so it flows then at low revs they block it again. I also had this happen to mine when it fully collapsed you could put your foot down and it would go fine then other times you can put your foot down and it would shake and gargle and back fire. Easy way drop the pipes of at the front and shine a torch up the cats.

wazza69 · 21-08-2007, 02:25 AM

cool, another one to add to the list! Thanks mate i'll check it out.

wazza69 · 30-08-2007, 06:07 PM

Well I had a call from the injector place, they checked all the injectors and they were fine, they did tests on the cylinders, and no 7 is playing up, however all the leakage tests showed up fine - so they're thinking it may be the camshaft... which means money, which sucks for me!
Getting my mechanic to look at it asap, and see if it really is the camshaft. If so, may as well put a bit extra cash in and put a better cam in hey ;-)

stavros68 · 30-08-2007, 06:43 PM

most likely a harmonic, does it mis under load?? i had the same problem thought it was the auto looked at the harmonic and saw the rubber trying to part company

S3SR · 31-08-2007, 11:22 AM

if you only recently bought it wouldnt the roadworthy certificate cover it?

sorry im not all clued up on this stuff, but id look into it

wazza69 · 31-08-2007, 04:20 PM

It misses a little under load, but doesn't vibrate like it does around 1200rpm. I bought if off a mate - private sale. He thought it'd just be a tuning issue, as did I!

wazza69 · 16-09-2007, 10:34 PM

All fixed, it was the Harmonic Balancer! Happy days...
Another problem however - there's a box in the front left mudgard in front of the wheel just behind the plastic protector, and its ticks quite loudly - not a steady ticking, but all over the place (rhythm wise), any ideas what this is??

wazza69 · 16-09-2007, 10:42 PM

Just did a quick search, seems like its a common problem - its the purge valve. I'll wrap it up in sponge & cable tie it and see if that fixes it

peterban · 17-09-2007, 12:27 AM

I don't think you are supposed to clean the throttle body on the V8's as they have a special coating on the inside of them.

wazza69 · 17-09-2007, 02:48 AM

yeah??

howesy · 17-09-2007, 06:55 AM

Quote:

Originally Posted by peterban

I don't think you are supposed to clean the throttle body on the V8's as they have a special coating on the inside of them.

I was always told the same about the coating and to avoid using throttle or carby clean but was also told that WD40 on a rag was the best and safest thing to use on those throttle bodies. I either use a very soft dry cloth or the WD40 every once in a while and it works a treat and keeps the idle fine.

wazza69 · 17-09-2007, 01:38 PM

I just found the throttle body clean for the 6 thread and assumed the 8's would be fine to do it too as well... too late now, I've done it!