Vibration issue after remap / tuning box

**skyegtb** · 25-10-2015,06:47 PM

Car - 2001 Allroad 2.5tdi with BDG engine from 2007 Skoda Superb with fully de-catted exhaust.

Hello! The title of this thread is not the best to explain the situation, so here it is in more detail. About 3 years ago I had this car re-mapped by a local company. The guy spent a couple of hours installing and fine tuning the map but the result was a barely noticeable increase in power and torque. I say barely noticeable as I have no proof of any changes, eg. dyno run but the 'butt dyno' told me that there was next to no gains..... Anyway, a couple of months ago I spotted a tuning box on eBay from TDPerformance. I checked the details on their website and saw that it was designed for an AKE 2.5TDI - so I knew it should fit my car (my original engine was an AKE and the BDG I replaced it with was a bare engine, here's the thread: Question 2001 Allroad 2.5tdi AKE timing belt tensioner failure). Anyway, I bought (for £60) and fitted this box and after a few days driving about I felt immensely impressed with the increase in power and torque. The car was totally transformed, mid range power was excellent and even better I started to see 40mpg+ on a longer run. I had never seen much more than 38mpg before.

So, why I am I writing all of this? Well, first off I wondered if there would be an issue fitting a tuning box to an already (supposedly) mapped car. Seemingly there is no issue with this which is good, but unfortunately I have a couple of issues which have appeared since fitting the box. First is that under full throttle hard acceleration the car is noticeably smoky, especially so at night time when a car is behind me with their lights on. Prior to fitting the box the car was remarkably smoke free. I can live with this smokiness but the next issue is more annoying. Under full throttle acceleration from low revs <1300 in 4th and 5th gear, as soon as the boost rises I get a strong vibration coming from somewhere in the rear of the car. I suspected the rear diff but I guess it could also be the prop-shaft bearing, or perhaps it is noise coming from the gearbox or somewhere ahead, but it certainly sounds and feels like it is from the rear... This is what annoys me. Under every other driving condition the car is brilliant, but this vibration in high gears at low revs / full throttle is driving me nuts. It is only there for about 200 to 300 rpms, but now when it happens I always lift off the throttle to stop it happening as it feels and sounds quite unpleasant.

So, after all that long drawn out waffle I need to ask, what do people think the noise is and how do I go about checking out where it is coming from myself? Have other people who fitted tuning boxes suffered similar issues? I have a car lift and can gain easy access to the underside of the car and all components but have no idea what to check.

Looking forward to your advice!

**Doctle Odd** · 25-10-2015,08:37 PM

The "tuning box" is really a way of fooling the ECU into thinking that the engine is colder and adding a little more fuel, this would account for the smoke. Some people swear by them some people hate them. I think the noise/vibration is a separate issue

**ametlib** · 25-10-2015,11:13 PM

Hi again,
Still remember the amazing job you did last time so this one I'm sure will be a walk in the park

. First, if you take the tuning box off, will the smoke and vibration still be present ? vibration yes, smoke yes but a bit better ?

**skyegtb** · 26-10-2015,03:00 PM

Thanks! Yes, the engine swap was rather epic but it was well worth the effort. Also, yes, the next step will be to remove the box and see what changes. I am away from home at the moment but will report back when I have done this. For info, the vibration noise is similar to the vibration you get from quattros when turning at low speed / full steering lock, but at a much higher volume and intensity.

**amiram** · 26-10-2015,03:44 PM

You can start by checking the rear axles, right and left, Rubber Bushings of the rear suspension arms upper and lower, left and right. It is 10 minutes under the vehicle with a flashlight.

**bluezie** · 26-10-2015,10:42 PM

I used to get this same vibration on my 2001 2.5 AKE quattro. It was originally de-catted and rolling road remapped to 208BHP, but since the MOT rules changed I fitted second hand cats, which has stifled a bit of power, and it no longer gets the vibration, which I think is the rubber mounted prop bearing wobbling caused the torque spikes as the car hits boost at low revs. The noise seemed to come from the centre of the car where this bearing is mounted. It always only lasted a for about a second or 2.

**skyegtb** · 27-10-2015,12:55 AM

Hi Bluezie, this sounds almost exactly like my issue. I will get the car up on the lift next opportunity and see what I find. I don't want to take the box off the car unless I really have to as the increase in power would be a shame to lose!

**Jordan christie** · 17-12-2020,03:30 AM

Originally Posted by skyegtb

Hi Bluezie, this sounds almost exactly like my issue. I will get the car up on the lift next opportunity and see what I find. I don't want to take the box off the car unless I really have to as the increase in power would be a shame to lose!

Hi man, this is an old post but this is currently happening to my car right now too I just had it remapped recently and in 4 5 and 6 gear low Revs same thing is happening, did you ever find the solution?
Thanks
Jordan

**skyegtb** · 17-12-2020,01:28 PM

Originally Posted by Jordan christie

Hi man, this is an old post but this is currently happening to my car right now too I just had it remapped recently and in 4 5 and 6 gear low Revs same thing is happening, did you ever find the solution?
Thanks
Jordan

Hi Jordan, yep, very old thread but I still have the car and can confirm after checking and replacing many components the issue is still there even though nothing is showing any wear. I have got used to it and just accept it for what it is. If the tuning box is removed the shudder goes away so presumably the extra torque is causing a problem somewhere, but to date I do not know where. Atleast it seems to have done no damage to the car, it is still trucking along perfectly after all this time!

**Crasher** · 17-12-2020,02:02 PM

In the days when I was doing the first tuning boxes by Hopa (we often did two or three a day!) we had to dial them into the car and if you went too far they didn't like it, especially cars with the VP44 distributor pump. I remember a chap fitted one to a brand new type 8D A4 V6 TDI quattro with the AFB engine in around 1998 and it damaged the pump; Hopa ended up paying for a new pump.