I have posted this in the Gearbox section, but since this is no longer a gearbox issue I thought I would get some more traffic in here. I would love to hear some ideas because this is starting to drive me up the wall

1) When I am cruising along in 4th gear at about 1600rpm (90kmph) and the converter is locked up, I am getting a really violent vibration through the car for goes for about 2 seconds, then stops for two seconds, then starts again etc. Like a wave. It's a real deafening deep vibration. DUring this vibration there is a lack of power. I can also get it to this in 3rd gear lockup @ about 65k/hr but it isn't anywhere near as bad.

2) I am also getting a surging feeling in lower gears under light acceleration pulling away from lights etc. Has done this long before the vibration problem appeared but I am now starting to think it is related because it is the same rpm range. See this thread:
ford-v8-f2/au-surging-t83519.html


OK now here is what I know so far - it's not the gearbox. I had it looked over and it needed a few things doing (external cooler, flush, reco converter, 2 & 4th gear had been slipping abit) as the previous owner poorly maintained it, however the particular issue here remains.

It will only do it once the car is at operating temperature. I have checked the Balancer and it lines up with TDC. I have disconnected the MAF and it ran like crap without it so it's not the MAF. Won't be the tailshaft because it is rpm related and not speed related. I am down on power during the couple of seconds of the vibrations so if it's not the gbox it's something with the engine.

I am going to put my old leads and coil packs in and see how that goes, along with new oxy sensors and working 2nd hand TPS but I need some more ideas. Would starvation or over fuelling cause something like this? Any sensors that may cause this?

Check the rubber on the Harmonic Balancer, if it has slipped, timing gets thrown out (lack of power) and counterweight is out of whack (vibration). I had the same drama with my AU, it was a balancer.

Unfortunetely as I said I have checked the balancer with screw driver in cylinder 1 trick and it hasn't slipped as it lines up with tdc.

Just to clarify something else, no stuttering or vibration free revving. Only stutters when working through the gears, or vibrates when locked up.

What does your tacho do during this fault?

hmmm... much driveline slap on the car? Might be a resonance thing.

During the slight surging in lower gears, tacho will surge up and down in a range of about 150rpm e.g. 1850 - 2000rpm. During the vibration in lockup the tacho is steady and is just not pulling along.



There is a fair bit of Backlash in the diff but that usually comes factory standard with Ford anyway. Theres no weird sounds from the diff, just abit of backlash when you get on and off the throttle. Diff oil was changed 5000km ago and mechanic said the fluid in the diff was in suprisingly good condition anyway.

Check your fuel flow and change the filter and as you say change the HEGO's.
Has the CID sensor been out before or has it been moved?
Probably time to get it on a dyno and self test.

the surging you describe happens to my 347 every now and then while cruising in low rpm. I always put it down to the cam/tune. When you accelerate when it does this, the surging gets smaller but faster until it dissapears?

Yes when road tuning with stand alone ECU this goes away with change in timing..
Not sure if it was retarded or advanced ?? But it made it FAR more drivable..
That was with the E303 cam, 110 LSA...

Is the pinion angle o/k and uni joints fine.. Sounds like too much play in bush or driveline ???
Engine / trans mounts o/k ??

Execssive driveline slap doesnt help either...

had something similar in my ltd, didn;t narrow it down till i raised the rear end onto stable stands, chock the front wheels, with someone in control of the car while in gear you can watch the drive line from the side or rear, low revs sure will create an odd reaction in a high gear......

Fuel Filter has been changed 10,000km ago. Always run BP ultimate so I doubt it has clogged up already. By CID sensor I presume you mean camshaft position sensor under the coil packs? Nope, hasn't been touched. How would one go about checking Fuel Flow?




No I wouldn't say it gets smaller but faster. But it dissapears above around 2200rpm. The surging is so slight if you didn't drive the car everyday you wouldn't feel it. More of an issue is the stuttering at around 1500rpm for 1-2 seconds until it powers on. I have had people following me while it has been stuttering and f@rt around and it's not blowing plumes of black smoke. I should also mention while on this subject, on WOT the car pulls like a train to redline and there is no weird noises. All the problems are low rpm.



No movement in the uni joints, that was the first thing i checked. Engine mounts are brand new and the transmission guy would have changed the mounts on the box when he put it back in if there was anything wrong.


I also noticed yesterday, I can get it to stutter and f@rt if I hold it in 2nd gear at about 60ks (2500rpm), at this point if I increase the throttle slightly it will stutter for 1-2 seconds and then power on. I think the reason it is vibrating in lockup is because all engine vibrations / stuttering power delivery isn't being able to be hidden by the torque converter as it is locked up and is magnified throughout the cabin. My theory anyway, makes sense to me

No aftermarket tune?

If not, then can you get hold of an equivalent EEC and see if that's your problem?

It isn't anything as simple as a flat patch on your tyres due to brake lock up etc ???

It's alright guys. I have resolved the problem. It was the oxygen sensors that were creating a very lean mix which I noticed yesterday on the trip computers instant fuel consump. As soon as I got the vibration the instant L / 100km would drop dramatically. Car is running beautifully now. Thanks for all your assistance.