Morning all,

Bit of advice please. I’ve got a ’97 4.2SC which has clocked up nearly 52,000 miles over the past two years, (now at just over 103,000) and all seems to have been going well…until now. I seem to have developed that dreaded judder when accelerating, or putting the car under load at low speeds. Now I assumed that this would be the gearbox as has been covered many times in this forum. However, the indy guys I use (RCV in Kent – brilliant team by the way), don’t seem convinced by my fullfat self-diagnosis. No errors are showing on diagnostics, and when they took her down the road with a laptop connected, the only issue to come up was a very slight misfire on two of the cylinders. Not enough to effect performance though. The judder doesn’t always happen (love an intermittent fault ), and disappears when cruising normally.

The suggestions so far are to flush the gearbox, and/or replace the coil packs for the two offending cylinders. Since both a fairly pricey treatments and neither one could resolve the problem, I just wondered if anyone had any other ideas.

Thanks in advance. Life is what happens while you�re making other plans.

A '97 super-charged? Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Sorry, that'll be a 2007 SC! Less haste more speed  Life is what happens while you�re making other plans.

Think I'd be sorting this miss fires first then go from there.

My td6 had an occasional judder when releasing the brake from a standstill and it turned out injector number 1 was failing.

Like you, my initial thoughts were gearbox but lukilly it wasn't

I have a L322 TD6
A few years back I had a nightmare of expense not helped by the work done by "specialists"
The car would shudder rather severely similarly to yours.
The transmission failed around this time and the shudder was still there after a full rebuild so the tranny shop took it to a so called RR specialist who advised that the trouble was in the transmission.
3 times this went on with the tranny being torn down and rebuilt leaving nothing to chance.
I could not work on the car as I had a back operation but as soon as I could I diagnosed it using my FAULTMATE checking "cylinder speed".
Now all cylinder (pistons) must operate at same speeds or the crank would break but what that reading actually tells you is the cylinder firing force.
I wont go through all that happened but I fitted new injectors and the moment I started the engine I new the problem was gone.
It has been as sooth as I could ever hope for since that day.
What the effect of out of balance firing forces was that the engine was not firing smoothly when the transmission reached lock up speed thus causing the shudder.
I would fix your engine issues before doing anything else.
My problem started through some very bad diesel fuel.
Whey these cars do not have a water trap in the fuel system is beyond me.

Thanks guys. Just been speaking to an independent gearbox specialist who knows the ZF transmission very well. He is betting it's the torque converter, something which I know has also been covered on the forum quite a bit. But I take your points Paul and uteman, just trying to minimise the frustration and expense.

As an aside, I've been quoted a TC replacement at £1,277.00. Anyone care to offer an opinion as to whether this is good or not.

Thanks. Life is what happens while you�re making other plans.

I had a shudder when driving my car, thought it might be the torque converter, certainly felt like it. Before looking to change I found a front brake caliper sticking, changed both front calipers problem resolved. Might be worth a look.

Totally agree ref checking brake callipers, had the same on our '03 4.4 M62 two years back. Though it was gearbox, but turned out to be front left calliper sticking. I'd also sort that misfire as well.

My old Dad was a mechanic and he always instilled into me to check the simple stuff first, you just might save yourself a whole bunch of hassle and money! Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

Thanks gents. Brakes should be fine as these were just serviced and had new lines front to back...the issue was there prior to this so think brakes can be eliminated. I’ll tackle the misfire first then, although it’s not even perceptible unless the diagnostic laptop is attached. Thanks for the advice. Life is what happens while you�re making other plans.

You may well be right, almost certainly are, but it costs nowt to check and just because brakes have been serviced (whatever that actually means, new discs, pads?) won't stop a calliper from starting to stick. Dead simple to check, take it for a run then when it's had a bit of a judder, pull in somewhere and see if one of the front wheels is hotter than the other. Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

Don't know if this will help but I had a slight misfire on my 4.4 about 18 months ago, it was traced to the battery being weak. Once a new battery was fitted, never experienced it again. Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)

Well, problem finally sorted

After taking the old girl to a friendly gearbox specialist (Auto Gearbox Specialists in Hailsham, East Sussex), they diagnosed it as the torque converter. In case anyone is suffering the same, I cannot praise the service from these guys enough.

Next is to tackle that slight miss fire! Life is what happens while you�re making other plans.