This is my first post.  The Orange Exhaust inspection Warning Light on my 2015 Yeti Black Edition Diesel TDI ( mileage 27,000) has started to stay illuminated after start up.  The engine starts well and runs well also it has not had the modification under the recall.  My regular garage used their computer to analyse the situation and the light went off but returned after a few days as they predicted.  They think the problem is that the glow plugs need replacing  but their quoted price is problematic as they say that the plugs can be seized in and the  labour element can be pretty open ended even possibly needing a specialist?  Bit out of my depth in this issue.  Any other owners had this experience.  Any advice.

 

If you garage had anything other than a £15 Ebay OBDII code reader then they would know definitively if one or more glowplugs were outside of limits, find someone with VCDS, it will be much cheaper and painless than relying on the guesses of a garage.

Find a better garage; one that knows how to use a code reader and is able to understand it!

usually glow plug 3!

Hi Nicco

 

The exhaust inspection light comes on to tell you that the vehicle emissions may be exceeding the standard.  This could be caused by a variety of different faults, the fault code(s) will be logged (even if the light goes off again) and can be read/reset.  A proper VAG code reader will often give more detail than a generic one.

 

Modern diesels use the glow plugs for cold starting, but also to reduce emissions by turning them on when the engine is lightly loaded and not producing enough heat on its own.  So their function is individually monitored by the ECU, and a glow plug which draws too much or too little current will be flagged up.  I don't know if the Yeti flags up a general glow plug fault or if it can pinpoint which plug is faulty.

 

Apart from using the ECU and fault code interrogation, glow plugs can be tested in situ.  A simple ohmmeter is better than nothing ( a reading of about one ohm is typical ), but a specialist diesel workshop will have a glow plug tester. This applies enough test current to get the glowplug realistically hot, which can show up intermittent faults that an ohmmeter can't.

 

Assuming you have a faulty glowplug, you need to get it replaced.  It's often advised to replace all of them, on the basis that if one fails the others won't be far behind.  However, as your garage have hinted, replacement can be problematic.  Engine development has led to the adoption of long, slender plugs.  After a few years, these can be seized in place due to corrosion and carbon buildup.  An experienced mechanic armed with the right penetrating lubricant, heat and patience can often succeed in getting them out.  An impatient or ham fisted one can easily shear off the relatively weak hollow top and you enter a world of pain.  At this point, most garages (even main dealers) will pass the work over to a mobile specialist who can drill the plug out without damaging the head, using a battery of special jigs and tools.  This could take over an hour per plug, so the attraction of replacing all of them begins to wane.

 

From the above, you can see that the stakes are high, and you need to be certain that a glow plug really is the cause of your problem before going down the replacement road.  The plugs are cheap enough, it's the labour that's the killer !

^ Yes it does, vcds told me plug 3 - had 'em all replaced!

Edited 4 October, 20205 yr by Frenchtone

I had glow plug 3 fail and the things you read on the net about them being stuck in and breaking made me think twice about replacing it myself.
But I bought one and sprayed WD40 down beside the plug a few days before taking it out, It came out with no problem but you do need a proper socket with rubber insert to grip plug as there may be carbon deposits on the end that need a twist and pull after the threads release.
It came out so easily I did the other 3 without lubrication, much easier than petrol spark plugs.

My local mechanic recommends flooding the area with Plusgas releasing fluid as that is longer lasting than WD40.