[gt_cristian]

Hi guys,

About a month ago I took out the spark plugs to check the gaps at 50K miles. After I put everything back on, about the same time, I started having a subtle exhaust gas smell and/or unburnt fuel smell when the engine was cold.

I also started noticing a strange metalic grinding noise when starting the car remotely. But when I was starting it manually, I was not getting that noise. So I figure out why. Cold weather here triggers the Rear Defog and Heated Seats to turn on automatically when I remote start the car.

If I start it manually, and I turn on the Rear Defog, the same clicking noise happens. So there is something there.

As for the bad smell, it seems to come from the ignition coil pack. I inspected the rubber boots and spark plugs, I did not see a problem.

Any thoughts? I bought a new set of spark plugs that I will try to install. I will also put some silicone grease on the boots to make sure they slide in properly.

Thank you for any ideas on this!
Cristian

 

[gt_cristian]

So it seems I did not tighten the spark plugs well enough last time I checked them becase 3 of them has brown residue at the base of the ceramic portion.



Nonetheless, I am still getting the same grinding/clunking noise when I turn on the heater, ac, rear defog, high beams. The more of these ON at the same time, the easier it is to hear the grinding noise. This is where the grinding seems to be coming from:

 

[jblackburn]

While those certainly put more of a load on the serpentine belt/engine at idle, it would strike me as odd that the sound's coming from the timing chain/camshaft sprocket area.

The serpentine belt tensioners on these engines have been known to fall apart or just stop holding tension on these cars, which will usually result in a chirping belt or something of the sort. If you have definitely ruled out that as the source of the noise (try listening around with a paper towel roll or something that you can point at things to isolate the source of the noise, I think the timing chain/tensioners would be a powertrain warranty claim. This would be the first I've heard of on the 1.4T.

 

[gt_cristian]

I think you are right! The belt tensioner looks like it is causing this issue.

I found this video that shows exactly what I am hearing.

https://youtu.be/5NvaIquhYoA?t=30s

In the comment, that user is saying he replaced te tensioner pulley as well. I am trying to see if this is covered by the Power Train Warranty, but it seems it is not covered.

I just hit 80K miles, would this be a good time to change the drive belt as well?

Thank you for your reply on this!

 

[jblackburn]

Not a powertrain coverage but the tensioner itself isn't too hard to change.

It would be a good time for the belt. That does require removal of the top engine mount & support of the engine from below (a piece of wood on top of a floor jack will do the trick).