Toledo TDI Loss of Power

[matz]

Hi,

First of all, I've had a look at the other thread about low power but the characteristics of my problem seem a bit different.

We run a Toldeo TDI 110 W Reg. Going down the motorway today, suddenly the car feels like the brakes have come on. All the power has gone and the engine is gutless. It still drives but theres no pulling power at all. Parked up for 2 hours, drove the car and it was fine for about 4 miles then = gutless again. Drove for 6 miles like this, parked up to buy a newspaper switched off for 2 minutes, got back in and the car drove fine; I would have expected it to lose power again shortly after this.

Any ideas whats causing the loss of power? It seems to happen after about 3 or 4 miles, ie when engine is hot but recovers temporarally after a restart.

Any ideas gratefully received

 

[sssstew]

sounds like a limp mode sort of problem, something like an overboost maybe causing the engine to go into limp mode, thus reduced power. These should be logged by the computer, so if u can find someone near with VAG COM and get them to plug in and see, if not then you will have to pop to a dealer to plug into their machine.

Then if there are no faults found then start looking at other things, but really its a check on VAG COM or dealer computer first, could save a lot of troubleshooting.

 

[prc]

Exactly as Stew mwntions. The is going into limp mode, so you need to look at the faults that have been logged.

 

[thewez]

Hi, try the plug that goes into the MAF. That could explain the on, off of the problem. Might be the MAF dieing but that is more of a slow process.

 

[matz]

OK, thanks everyone for the replies, I'll get the car booked in this week sometime.

My wife used the car today a few times for short trips all with no problems.

In addition to the reply about the MAF here, someone else has suggested it may be the MAF Sensor. They said to test this = unplug the sensor and drive whilst unplugged. The engine will be smoky and run rich but if it runs ok with no problems with the plug disconnected then the MAF needs replacing.

To do the above, I'm assuming what needs disconnecting is the multi plug that goes into the component within the large flexible hose from the air intake box?
.
Does any of this make sense?? If its possible this is the problem and the test works, it'll save me a trip to the dealer perhaps?

btw the car has done 90K

Thanks again

 

[matz]

A little bit more info. hopefully; Took the car out tonight and it was ok for the outward trip (about 8 miles) On returning, I gave it some stick and with lots of smoke in the rear veiw mirror, it lost power again. Parked up and switched off then started up straight away and it was ok. Drove the rest of the journey (about 5 miles) without using much power and the car was fine all the way.

It seems to happen when accelerating hard ( about 4000rpm) and sustained. Driving gently its no problem.

So, perhaps not a "limp home" problem????

 

[sssstew]

it could certainly be a limp home problem, sound so me like it still might be overboosting at somepoint, so something is not functioning right when you give it beans which is causing it to go into limp mode.

 

[prc]

it could certainly be a limp home problem, sound so me like it still might be overboosting at somepoint, so something is not functioning right when you give it beans which is causing it to go into limp mode.

Agree with Stew except it could also be under-boosting...

Any difference of +-200mbar and it will go into limp mode. My old ibiza had this problem.

 

[matz]

Thanks for replies so far

Rang a local fuel Injection place today who have the necessary computer to hook the engine to and they have quoted me £45 for the test + approx 2 hours work @ £38 hour to diagnose the fault, leaving me with the choice to let them go ahead and fix or hand the car back and I make my own arrangments.

From where I'm standing, it looks like I have litle choice but to go ahead with this to get to the bottom of the problem.

Unless unplugging the MAF sensor shows up thats faulty. (which I'll try later)

 

[prc]

Thanks for replies so far

Rang a local fuel Injection place today who have the necessary computer to hook the engine to and they have quoted me £45 for the test + approx 2 hours work @ £38 hour to diagnose the fault, leaving me with the choice to let them go ahead and fix or hand the car back and I make my own arrangments.

From where I'm standing, it looks like I have litle choice but to go ahead with this to get to the bottom of the problem.

Unless unplugging the MAF sensor shows up thats faulty. (which I'll try later)

Or try to find someone with VAG COM at a place near you..

 

[matz]

Just had a chat with a guy at Turbo Technics who has told me that from my description of the symptoms he is saying that it is almost without doubt a sticking turbo.

He then proceeded to tell me the bombshell news that since 2 weeks ago these variable nozzle turbos cannot be repaired AT ALL. No spare parts are now available and the only alternative if you have one of these Turbos and its failed is a brand new one at £1000 inc VAT!!!!!

I hear what is said about putting the engine on a VAG COM computer but he is adament that the Turbo is faulty from my description of symptoms and that testing the engine is throwing good £££ after bad.

Any comments?!

 

[prc]

Yes, it could definitely be the VNT sticking. This happens alot on car that do alot of city miles. What sticks is the vanes the rest of the turbo itself is probably fine. There's a VNT link in the tdi faq that shows you the internals.

This will throw up 1 or more fault codes, which is why I wanted to see what faults where being logged. If you find someone close or get the shareware version of VAG COM on your notebook with an OBD cable you could see what they where.

 

[Stu B]

Is there no one on here that is in your area that could have a coffee with you & do a quick VAGCom check with you........ Surely someone is in your area, from our forum./...

 

[matz]

ok, thanks PRC. I've found an independant turbo specialist that will test the car on the Bosch equivelant of the VAG COM for £56 ins. He says too that its probally a sticking Turbo; something to with something sticking in the wastegate chamber or soemthing like that and that its something they can ease and clean.

Sorry to be pedantic, but is this Bosch equivilant equipment going to do the same job as the VAG COM you mention? All the diesel and fuel injection specialists round this way use it including a VW/ AUDI independant thats highly rated.

 

[prc]

Sorry to be pedantic, but is this Bosch equivilant equipment going to do the same job as the VAG COM you mention? All the diesel and fuel injection specialists round this way use it including a VW/ AUDI independant thats highly rated.

I should actually work better than VAG COM (not better, just a better sampling rates). But as Stu mentions there should be someone local, who will do it for free.

 

[matz]

Thanks for all your advice PRC. I don't mind paying £56 but if anyone pops up here that will be a bonus. I'm north of Bristol btw.

 

[bugulls]

mine did exactly the same run limp then was ok when i restarted it found out it was a small hole in the boost pipe from the turbo to the intercooler replaced the pipe and het presto no problems since

 

[prc]

mine did exactly the same run limp then was ok when i restarted it found out it was a small hole in the boost pipe from the turbo to the intercooler replaced the pipe and het presto no problems since

Yep, I've seen this happen as well. Full load and car goes limp due too big a pressure drop.

 

[sssstew]

for £56 you could buy a ODB cable and download the free version of vag com, in fact for about £43 actually.

And yep sticky vanes and hole in the dodgy vacuum pipes for the system are all possible, you can try working the VNT mechanism by hand to tyr and loosen it and also lube it, there is some stuff about this on the tdiclub.com forums, maybe do a search.

 

[matz]

Took the car out tonight and gave it a blast with the MAF sensor unplugged. The car drove fine. Plugged it back in and under hard acceleration the power dropped off like before. Double checked all this by unplugging again, another hard drive and the power was there.

Seems like its the MAF sensor after all and that the Turbo is ok?

I wonder how the power given by limp home mode is defined. Maybe I gave the impression that the power was down more than it actually was. It still drove and accelaerated but had lost all its ooomph!!

In limp home mode, does the car really crawl?

Anyone know whether the MAF breaks down into componets that fail, giving my above problems. Europarts have quoted £120 to £160 in response to me asking how much a MAF sensor was for the car. I'm wondering whether I need to spend all this to fix it.

For peace of mind, I'll probally get the car hooked up to get the fault codes read anyway in the near future!