My car becomes seriously slow when in hot weather?

[Dylan Johnson]

I have a 2005 2.0TDI (140) and in the morning its fine the turbo is there, but ive noticed coming home from work when its been hot recently its SERIOUSLY slow the car goes nowhere and struggles to get past 3k revs its like the turbo is not working at all.

 

[Gazpot0111645]

All cars will produce less power in the warmer weather. Its a fact that warmer air is less dense than cooler air. Bring on winter...

 

[mitsiboyblue]

I have a 2005 2.0TDI (140) and in the morning its fine the turbo is there, but ive noticed coming home from work when its been hot recently its SERIOUSLY slow the car goes nowhere and struggles to get past 3k revs its like the turbo is not working at all.

It sounds like the turbo's 'VGT mechanism' is sticking from high carbon deposits and some corrosion. Ive had exactly the same problem and it involved a full strip and clean of the turbo. Afterwards problem gone and hasn't ever returned.
Dave O


Sent from my SM-G930F using Tapatalk

 

[Dylan Johnson]

It sounds like the turbo's 'VGT mechanism' is sticking from high carbon deposits and some corrosion. Ive had exactly the same problem and it involved a full strip and clean of the turbo. Afterwards problem gone and hasn't ever returned.
Dave O


Sent from my SM-G930F using Tapatalk

Yeah, it has to be this because it really is like an on off switch, with all this hot weather some days it works but most days it doesn't. Just in the afternoons though, mornings is fine. Can you clean the turbo yourself or is it a professionals job?

 

[Daveyonthemove]

I took a friend out for a spirited drive in my S3 today, and he was blown away by the power, but it felt much slower and down on power.
This was at 3pm, probably the hottest part of the day. The temp gauge read 28.5 but the paint was too hot to touch and the leather felt hot enough to burn. I imagine it was down to heat soak.

 

[Gazwould]

Higher intake temps , less oxygen .

But this sounds like VNT turbo under boost , any fault codes ?

 

[mitsiboyblue]

Yeah, it has to be this because it really is like an on off switch, with all this hot weather some days it works but most days it doesn't. Just in the afternoons though, mornings is fine. Can you clean the turbo yourself or is it a professionals job?

Ok let me explain something....
All turbo's get hot, xtremely hot when in operation so just because we're having hotter weather at the moment 30'C + is not really anything to do with the lack of water molecule content of cooler more densor air for this level of power loss discribed.
If the turbo has a partially seizing VGT mechanism from carbon build up the raised daytime temperatures at the moment could be sufficient enough to cause metal expansion of the turbo and hold the mechanism from moving thats when the turbo has almost zero power from start up in the afternoons.
Staring the engine cold from over night the turbo mechanism and casting sizes will be relatively smaller inside so will not to be affected as much by carbon trap. This allows the mechanism to move and operated as normal until the mechanism becomes affected by heat soak.
When stuck these mechanisms will probably take a shock or impact on the external control rod to get it moving again, much more than the strength available from vacuum or servo unit controlling it.
If your mechanically minded and have the tools to remove and confidently strip and rebuild the turbo then go for it, but they are not straight forward and patients is required due to access being limited at the back of the engine. Drive shaft could also be an obstruction and may need to be removed. This is a full days worth of lab for a professional mechanic/technician like myself just to give a time scale on work involved.
Dave O


Sent from my SM-G930F using Tapatalk

 

[mitsiboyblue]

Ok let me explain something....
All turbo's get hot, xtremely hot when in operation so just because we're having hotter weather at the moment 30'C + is not really anything to do with the lack of water molecule content of cooler more densor air for this level of power loss discribed.
If the turbo has a partially seizing VGT mechanism from carbon build up the raised daytime temperatures at the moment could be sufficient enough to cause metal expansion of the turbo and hold the mechanism from moving thats when the turbo has almost zero power from start up in the afternoons.
Staring the engine cold from over night the turbo mechanism and casting sizes will be relatively smaller inside so will not to be affected as much by carbon trap. This allows the mechanism to move and operated as normal until the mechanism becomes affected by heat soak.
When stuck these mechanisms will probably take a shock or impact on the external control rod to get it moving again, much more than the strength available from vacuum or servo unit controlling it.
If your mechanically minded and have the tools to remove and confidently strip and rebuild the turbo then go for it, but they are not straight forward and patients is required due to access being limited at the back of the engine. Drive shaft could also be an obstruction and may need to be removed. This is a full days worth of lab for a professional mechanic/technician like myself just to give a time scale on work involved.
Dave O


Sent from my SM-G930F using Tapatalk

Yes.... are there any warning lights on or DTC codes Present in the ECM?

Sent from my SM-G930F using Tapatalk

 

[Retroman]

Hotter weather (and thus thinner air) shouldn't make a noticeable difference to the performance of a normal car. The MAF sensor will be taking both air quantity and temperature measurements to relay to the ECU. The sticking turbo is far more plausible. Personally, I would first stick some turbo cleaner through the system to see it that helped - Forte do some good stuff which is liked in the trade. Secondly, make sure you are using the correct low ash (Audi approved) engine oil.

https://www.ebay.co.uk/itm/Forte-Ad...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[ch1z64]

Now here is a thing you could get done either b4 you strip down what you have to strip , me personnally i would do it b4 . Your car is an 05 and do you thing it has had a carbon clean in all those 13 yrs probably not so to stop the build up off Carbon it might be something you could cosider doing as a 3, 5yr plan starting soon .

 

[Umaar]

Hotter weather (and thus thinner air) shouldn't make a noticeable difference to the performance of a normal car. The MAF sensor will be taking both air quantity and temperature measurements to relay to the ECU. The sticking turbo is far more plausible. Personally, I would first stick some turbo cleaner through the system to see it that helped - Forte do some good stuff which is liked in the trade. Secondly, make sure you are using the correct low ash (Audi approved) engine oil.

https://www.ebay.co.uk/itm/Forte-Ad...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

Cheapest way to clean the turbo is 2 bottles of forte turbo cleaner and 1 bottle of forte advanced diesel treatment in a full tank of fuel. Quite a lot of reviews on Amazon from BKD owners having resolved the issue you’re facing using this method.


Sent from my iPhone using Tapatalk

 

[Gazwould]

Naa , cheapest is £3 Mr Muscle , however not as easy to apply as the B6's 1.9 .