How to Fix Limp Mode on a 1.9 TDi for £4.50 - Mr Muscle VNT Clean

After having some trouble recently with the Passat, I've made a quick video just to demonstrate an easy fix that may work for anyone else with a similar issue.

After harsh acceleration, the car would go into what is known as limp mode. If the ECU detects a fault with the car (such as over boost in this case) the cars computer will shut off the turbo completely and reduce throttle by 50% effectively giving the car around 40bhp. This is enough to get home safely.

After plugging in VDCS, I was able to determine the trigger of the limp mode being an over boost. Over boost in 1.9 TDi engines typically occurs due to stuck VNT vanes inside the turbo, that continue to boost after throttle has been released, thus triggering a safety response from the ECU in order to protect the engine.

These vanes become sticky or stuck due to years of carbon build up from the exhaust, but can easily and affordably be addressed using a strong grease remover such as Mr Muscle, conventionally used to remove stubborn grime from ovens.

This may save you from the expense of a brand new turbo, so is always worth giving a try before biting the bullet on an expensive repair bill.

2m x 3mm silicone tubing at £0.50 per meter
1 x Mr Muscle oven cleaner at £4

This took around 2.5 hours from start to finish.

Thanks for watching.

[honestpeteify]

Good morning Coathanger.
I watched and followed your advice except I never removed the FAULT CODE, I ended using all of the Mr Muscle in a 3hrs 20 mins later. Done a EGR delete in.
Started the car & let it warm up, did as you said at 3/4000 rpm & then drove the car at 60mph for a 5 miles to given the ECU time to reset it self..
Thank you, great video & very easy to follow. Most importantly you have help me save ££££'s
SPOT ON 👍👍👍

[vladmarius]

Did this on my 1.9 TDi Passat . No Limp Mode anymore, a more responsive acceleration. Thank you mate !

[rayvon]

I used this same technique on my egr / inlet manifold on my seat altea xl 1.9 tdi. Had the emission service centre warning, which when I plugged in my code reader threw up the P0104 egr insufficient flow error. Mr Muscle worked like a charm.

[jaycee]

Just did this on a 2008 2.5 TDI VW Touareg.. very easy to get at the egr cooler, the nuts and hex bolts are right on top ... just take it easy and dont snap or strip them ... As soon as I can evaluate the results I'll post here ...



OK ... Initial update .. same day
Power is smoother across the entire rev range .. quicker pick up, more gradual, no big catapult effect after an initial lag .. It just go's ..and keeps going .

Very happy so far ... easy job really .. I did deviate a little from the guide here .. halfway through I used a screwdriver and a piece of wood to keep the actuator open for 30 mins .. My thinking was that It would expose even more areas to the solvent ..

After warm up ... ( dont rev the nuts off a cold diesel engine ) I took it for a short, energetic drive.
Holy moly the amount of black soot / carbon that came out of the exhaust was like a smoke screen ..
I assume this was the residue that had been removed by the solvent getting blown off ... It cleared within 30 seconds.

[deemybutt]

No wonder homebase are having to close stores to survive :)

Nice detailed vid, my 1.9 is slightly older do engine layout different

[golfgti]

Quick fix definitely going to use this in future cheers dude

[stuartcox]

1K on the likes bro, you are welcome and thanks for the tutorial

[obviouslytwou]

I'm going to do mine but going to take turbo off. And also do the air intake. After deleting my EGR valve completely. As I've just blocked the pipe and I soon will be capping of exhaust feed but leaving old egr there after cleaning and welding or bolding egr valve closed. Cheap fun and simple

[yuriperiotto]

How do I know the tube hasnt gone into the engine?

[jamiehawkes]

Happening on my vw sharan TDI happens to them all eh that looks like a straight forward job i can do at home no biggy fme nice video dude ty

[Tyler-fubl]

Have this happening on my car, instead of oven cleaner could I just use seafoam? Heard it is great on carbon

[raffaelle]

it saves me money, thanks for the upload

[adamlowe]

Archoil AR-6400D works well to prevent refouling. I run a bottle through every 1000 miles or so. Supermarket diesel contains more biofuel and causes a lot of soot problems especially on modern cars

[jamdbw]

It's work, and work very nice. Instead mr.muscle you can use caustic soda (NaOH) but if you make too strong mix caustic soda with water, just keep it in turbo not more like 10 min, because this can demage rotor in turbo. If you use this be careful with hands, face and eyes. Regards

[laszlokerekes]

Does this actually work???? Drive a 2016 skoda octavia vrs 2.0tdi and now my car goes into limp mode if I go above 2000rpm in 4th or 5th gear, tried to regenerate the dpf but couldn't clean it perfectly

[lucaottaviorovesti]

Hai già tolto i collettori di aspirazione x caso devi levare la turbina oppure No? Grazie

[rasheedserrt]

I have a question. Why the EGR clogging up? Is that when you always drive slow?
And if you have a heavy foot, is there a chance that it break with carbon?

[Merseydiver]

Sorry, what do you mean by N20 engaged?

[michaelbolt]

Im jealous of your access to the turbo, on my galaxy it’s buried

[No.Handle]

Thank you for the video I’ll need to try this.