Anyone replaced Mk7 glow plugs yet?

Seen a P13D4 code a couple of times since the spring (cylinder 3 glow plug). Winter is coming so I'm finally trying to eliminate the problem, which might mean replacing the glow plug.

Sure enough after taking the engine cover off, there's a bunch of debris around the glow plug sockets, probably stashed there by some critter :/

I'd like to test the connection and the plug itself, but the newer harness doesn't look the same as tutorials I can find online. Anyone know about these new plugs and how to safely remove them? I don't want to just start yanking on them unless that's the right thing to do...

Is there a recommended interval for changing them? I don't see it on the VW Schedule.

no preventative replacement schedule, replace when codes are stored. But if you really wanted to stay on top of it, I'd say every 200K, but it prob depends on how many short trips you make vs long highway runs.

Glow plugs if replaced should always be replaced as a set, not singuliary.

They would be covered under the 11/162k warranty anyway.

Had a Glow plug (cylinder3) replaced under warranty by dealer at 36k miles.

740GLE said:

no preventative replacement schedule, replace when codes are stored. But if you really wanted to stay on top of it, I'd say every 200K, but it prob depends on how many short trips you make vs long highway runs.

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Thanks!

thundershorts said:

Glow plugs if replaced should always be replaced as a set, not singuliary.

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Why?

I have only ever replaced failed glow plugs, never working ones. I may have been doing it wrong for 20 years, but it hasn't caused a problem.

Simon

As gp's age, the resistance changes so if you change one only, it will heat at a different time/rate/temp to the others. My guess is that they are NGK,s which are very good. Think VW doesn't use Bosch ones anymore cause they made some stinkers.

The new glow plugs also have a pressure sensor built in, don't they?

Yes, all the CR engines have Bosch glow plugs with built in cylinder pressure sensors.

They are quite expensive, I certainly wouldn't be replacing them all at once. The connectors are very fragile, too.

But what about how they age?!?!?!?!

I'm prob gonna get rid of those junk bosch units and pick up some good NGKs, waiting 2 seconds for GP is too long for me.

I think Bosch, Bremi, and Beru are the only ones that make these that fit the CR engines.

The pre and post glow would be determined by software, not the plug itself.

thundershorts said:

As gp's age, the resistance changes

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Not in my experience. My ALH has one glow plug which was new 3 months ago, one that's been in there for 5 years, and two which have not been changed during my ownership (10 years) - they might well be original. They all read the same resistance, within 0.1 ohm.

Wife's ALH is similar, all but one plug changed over the years as they failed, all read within 0.1 ohm of each other today.

Our cars have a random mix of Bosch and Beru plugs, perhaps it's NGKs that go wonky with age?

Simon