Stuttering issue!! Gearbox/torque convertor or engine miss? Please help
 

Hi, just bought an 02 4.4i auto sport. Hi there, It stutters under gentle acceleration and the revs go up and down a little when driving steady. I have also noticed poor mpg. I have no dash warning lights at all? Does this sound like i need a tc? It doesnt have any problems in sport mode for some reason? I had oil on my sparks but since replaced rocker cover seals and new sparks but still the same problems. I have just bought the car in the last few weeks and i am gettin frustrated with this! Also, forgot to mention it is lpg converted/duel fuel but i experience the problems on both gas and petrol. This is making me think its a gearbox issue. I would be very grateful if you could share any opinions. Thanks, Gavin

mine does the same thing....rpm throttle 'oscillation' like a misfire every 2 seconds. That's the torque converter locking/unlocking. The slight shudder under normal acceleration. I also have seen about a 0.5 mpg decrease. My transmission does all this plus it prematurely locks the TC under harder acceleration so I get this sudden rpm shift while accelerating hard. No codes. There is likely some pressure and solenoid issues in the valvebody causing some of this. I have resorted to installing a new transmission in the very near future. I have 143k miles and if I do the TC, likely sooner or later the trans will need replacement as well so I figure I'll do both now. My transmission shows none of the typical signs of wearing out.

i think you will find most people here will agree with me and likely have been in our shoes. it's unfortunately one of the most failed components on X5s and costly. Good luck.

My '02 4.4i has been doing the exact same thing for some time now. Hasn't gotten much worse. I've been told by a few people on here and elsewhere that it's the torque converter most likely. That and the transmission are original with 132K miles. It actually shifts perfectly and also shows no signs of wearing out.

I actually haven't noticed a real decrease in fuel mileage but then again, I don't keep that good of track to notice a .5-1 MPG drop.

Is there a definitive way of telling that it is the tc?? I was experimentig again today and noticed that there is no problem at all with this when it is in sport mode (triptronic shifting). When it started to stutter i kept the throttle steady and switched it to sport mode and no shudder? What about everyone else? Would the tc not have problems in both modes?

I have researched and apparantly you can get your tc reconditioned for as little as £200?

My car shifts as it should and isnt that much of a problem tbh but i would rather have it sorted!

I also read that there is some stuff available on the web to add to the trans fluid, and it can cure this problem with the tc? Would it help to do a fluid change? I dont think mine has ever been done?

O and what mpg should i be expecting from 02 4.4i auto sport?

I never thought of sport mode and light acceleration at the same time. When it's in sport mode, I'm having fun.

Driving normally I average 17-18MPG according to the computer but a lot of that is highway commute.

I'm wanting to replace my torque converter soon. I'd rather pull a transmission and pay for a new converter than ignore it for too long and have it take out the transmission too. There's definitely a cost ratio to consider.

I wouldn't add a thing other than approved fluid to a ZF. Eff that, too temperamental and expensive. Which is typical German stuff really.

Anyone ever used dr.tranny shudder fixx? Alot a people swear by it! I have done a LOT of research into the tc problem that i have and some say that a fluid change helps alot?

Look,
I had my tranny rebuilt and even after that it was shuddering,not in a sports mode,because TC has a different lock up "program".
Had tranny reworked under the warranty and shop rebuilt the TC again,but this time the right way.
My advise,if you get the TC replaced,why don't you do a whole tranny overhaul,like swapping the old friction discs.It won't cost much more,but will make your tranny good for much longer.
Or get rid of your X.
One more thing,ask your shop or if you DIY for an OEM branded filter and right fluid,otherwise you'll get into troubles,been there and know what I say.

Keep in mind that :
1. It wouldn't be a good idea in a first place.
2. These gear boxes don't have a dipstick,so,do you want to bother yourself under the X ?

The X5 has different pressures for the TC lockup when in sport mode vs normal mode. When i first noticed the issues, it was only in normal mode, sport mode was fine because it maintains higher pressures in the valvebody. After a few months, I'm getting issues arising in sport mode, like the shuttering. Also, you will likely notice that cruise control eliminates the throttle oscillation (misfire feel) because cruise locks up the TC so the trans is not locking/unlocking trying to maintain speed. If I'm in cruise, all issue pretty much disappear. I have a 4.6is and I was getting consistently avg 16mpg but now i'm around 15.4, same driving habits.