2.0 tdi judder when hot

[foxylad]

Hi All,

I have a 2006 A3 2.0 tdi 140 Sport. It doesn't have a DPF. It has done 57k.

The car runs fine from cold and starts perfectly. The problem only occurs when the engine has heated up (20 mins or so into a journey).
When the revs are between 1500-2000 and I try to accelerate it judders, almost like there is a misfire about to happen, and kangaroos. If I put my foot down it pulls through it and seems fine at higher revs. It will also sometimes die when pulling away from stationary. Again, only once the engine has heated up.

About 3 weeks ago I put a bit of redex (1/4 bottle) into the fuel tank. I don't know whether this is pure coincidence, but its better for you to have all the facts.

I changed the fuel filter, thinking it might be that, but it doesn't seem to have made any difference.

I am now looking at changing the glow plugs, which is a bit more of an expense.

I just wanted to see what you thought it could be? Obviously I don't want to go spending money on glow plugs, if it is more likely to be injectors or something else??

Any thoughts will be greatly appreciated!

Cheers,
Chris

[UVB]

Is this definitely engine related or could it be drivetrain? If it could be the latter, worth checking your cv joints as mine had a similar sounding weirdness which proved to be split inner boots.

[foxylad]

Is this definitely engine related or could it be drivetrain? If it could be the latter, worth checking your cv joints as mine had a similar sounding weirdness which proved to be split inner boots.

It definietely feels engine related to me because it really feels like it's misfiring, but thanks, that's something to check.

I have it booked in for a diog on monday at a VW/Audi specialist near mine. £20 + vat for a scan which I thought was really good!

The guy from the garage said it could be something like a coolant temp sensor, which sends signal to ecu.

What do others think?

Cheers,
Foxy

[Geraldy212]

Foxy, don't bother with changing the glowplugs. They have nothing to do with your current concerns. Glowplugs are only used when starting the engine, and yours is starting fine. The VCDS scan should easily show-up what is giving a problem. The coolant sensor is a likely culprit. Let us all know what the scan shows..... thanks.

[foxylad]

Right, I've had the scan on it now. He hooked it up to the VCDS as soon as I got there and there was only 1 fault code showing - Engine Speed Sensor. He cleared the fault code, took it out on a run and the symptoms were the same for him, feeling like its misfiring and sometime dying when pulling away from a standstill. He then hooked it back up to the VCDS, but it showed no fault codes the second time. He said to me that sometimes a fault has to happen several times for the code to register.
He has said that I should drive it for another week and let it do it again to get the fault to register and then take it back in to scan again. He said he would most likely change the Engine Speed Sensor.
Just wondering if it an easy job to do myself? Apparently you have to have the oil filter housing off, and then the sensor just unbolts. What do you think?

[dansansome]

How long ago did the fault start happening? Surely by his logic the code would have already registered. Is he likely to charge you for another scan?

[foxylad]

It's been doing it for about 6 weeks now. When he scanned it first time the fault code was there. He cleared it & took the car on a run & then scanned it again, but the code never came back. So he said give it a week or so & scan it again.
I'm hoping he won't charge me again!

[mikey2012]

What did he say the fault was when it came up before he deleted it. As the computer isn't loging a fault it may mean that it is purely a mechanical fault.

Have you had a cambelt change recently?

Try disconnecting the coolant temp sensor when the engine is hot and give it a run.