Tdi 170 engine woes

[Steve220]

Hi all,

2006 Audi A4 2.0 TDi 170 S-Line, 75k miles - Full Audi service history, ecu software up-to-date, not applicable for injector or loom recall.

An ongoing issue that seems to be getting slowly worse. The car used to stutter or surge, as in shakes the car for a split second if cruising at low speed around 1500-2500rpm. It usually coincides with the outside air temperature being about 14 degrees C or higher - the car showed no faults on VAGCOM.

More recently I've started to get a problem where the car seems to be holding back on power. Usually there's a good rush of solid power when you accelerate but its started to become hesitant, like the turbo isn't even spooling! I've tried a lower gear and given it the revs and it will surge back to power and accelerate properly. It feels almost like an intermittent switch of power on and off repeatedly. I do a lot of long journeys in the car and sometimes after a few hours of driving the engine light will come on showing:

000665 - Boost Pressure Regulation: Control Range Not Reached
P0299 - 006 - Short to plus - intermittent

001137 - Exhaust Pressure Sensor 1 (G450): Implausible Signal
P0471 - 006 - Short to plus - intermittent

I drove the car this afternoon to work and the whole journey felt like I had no turbo at all! Tried the lower gear trick I did last time and it felt like I've only got half power. What isn't helping is the rocker cover gasket is blowing AGAIN (I've replaced it with a genuine audi part 4 times this year) and dumping oil all over the EGR and DPF making a horrid oil burning smell. What I will mention is that the whole thing seems to be intermittent in itself. Some days it will act totally normal, then there will be days like today when its an absolute pig! A month ago I stripped the inlet system right down and poured a bit of oil out of the intercoolers and cleared up all the pipework, inlet manifold, EGR and turbo has no lateral movement.

Any help or advice would be greatly appreciated!

Regards,
Steve

 

[carlcall]

Hi Steve....have you had a quick read of my thread http://www.audi-sport.net/xf/threads/does-the-2-0-tdi-brd-170-have-a-diverter-valve.275351/ as it looks like I was having similar problems to you but without the error codes.

Mine was occasionally hesitant before I had it remapped and had that awful....sometimes it would happen when I had the cruise control on, but with a slight increase/decrease in speed it would go.

I would check that the valve is holding its vacuum or if it's actually working at all. Either pop the pipe off it and push the arm into the valve, place your finger over the hole and see if it returns back either a little amount which means it's not leaking or it fully returns which means it's goosed.

Or the second option would be to pop over to a local garage and ask them if they could just check the vacuum on the valve and that if it's faulty how much would they charge for the replacement.

It's easy enough to do yourself and cost around £23 for all the parts including gaskets......and whilst it's all apart give the Manifold, EGR and Anti Shudder Valve a good clean.

 

[mm707]

Same symptoms as mine had, changed the vacuum unit on the inlet manifold, fixed.

There's a diaphragm inside which splits.

 

[SDHA4SLine]

Hi Steve....have you had a quick read of my thread http://www.audi-sport.net/xf/threads/does-the-2-0-tdi-brd-170-have-a-diverter-valve.275351/ as it looks like I was having similar problems to you but without the error codes.

Mine was occasionally hesitant before I had it remapped and had that awful....sometimes it would happen when I had the cruise control on, but with a slight increase/decrease in speed it would go.

I would check that the valve is holding its vacuum or if it's actually working at all. Either pop the pipe off it and push the arm into the valve, place your finger over the hole and see if it returns back either a little amount which means it's not leaking or it fully returns which means it's goosed.

Or the second option would be to pop over to a local garage and ask them if they could just check the vacuum on the valve and that if it's faulty how much would they charge for the replacement.

It's easy enough to do yourself and cost around £23 for all the parts including gaskets......and whilst it's all apart give the Manifold, EGR and Anti Shudder Valve a good clean.

If it is the vacuum actuator we seem to be having some sort of epidemic

 

[carlcall]

If it is the vacuum actuator we seem to be having some sort of epidemic

 

[soldier4313]

Feel your pain Steve had issues with my power for months and finally after changing the egr then vacuum actuator it seems to finally of sorted the problem.

 

[Steve220]

Wow! Thanks for the replies guys. I'll look into it! Although I have tested the swirl flap actuator on the inlet manifold and it does work, but I suppose it could have split and should be working better!

 

[carlcall]

Mine was moving but only moved about 5mm but returned back to the original position as soon as I stopped pumping.....this is how much it should move and stay in the retracted position until to release the vacuum.

 

[Steve220]

Guys, I think I may have found my problem! Tried doing a vacuum test on it, by sucking on the pipe, lots of air movement but no movements of the actuator. If I blew then there was full resistance.

Does anyone know the part number of the actuator?

 

[carlcall]

The part number is 03G129061C

I was going to say you can't do it by just sucking on it......but I went and tried it and you can. it takes quite a bit to do it though.

I would also get the replacement gaskets for the manifold, EGR and anti shudder valve as they all have to come off and it's an ideal time to get Mr Muscle out.

Here's a list of what I ordered but the rubber gasket for the EGR to Anti-Shudder was out of stock so I just used a trick I've known about to make it swell up again.....2 parts IPA to 1 part brake fluid. let it soak for a few hours, pull it out and place it on some kitchen towel until the IPA evaporates for a few more hours. It opens the pores in the rubber and fills them full of oil to keep them supple once again.

The resistance you have when blowing could be the split sealing itself back up on the piston.

 

[Steve220]

Silly question, are you getting a vacuum feed to it on idle? I've got nothing.

 

[carlcall]

No nothing on idle....

 

[Steve220]

I owe you all a beer should we ever meet! Changed the actuator and it now pulls like a train again! No silly stutter!

Pulled the old actuator apart and there was a tear in it. Thanks again!

 

[carlcall]

PM us all your address and we'll be around weekend!

Glad it's all sorted now Steve.

 

[soldier4313]

Glad it's sorted buddy know how you feel I spent 3 months renewing most things and finally the actuator was the problem.

 

[CarbonMike]

Glad it's sorted buddy know how you feel I spent 3 months renewing most things and finally the actuator was the problem.

Same here.... new thrust sensor, maf sensor, inlet off, pair of vac actuators & then finally gave up.

Today, I found out it was due to a perished air filter that had got sucked into the air box pipework lol also found out my car seems to have DTM springs on too?