Spark plugs look terrible

So i recently replaced my plugs at 120K miles, I'm assuming this was the first time they've been replaced as the maintenance interval is around 110-120K. I definitely was not expecting them to look this bad though, I've had several Audis go up to the 160-200K mile mark and their plugs never looked so bad. Even the PCV valve looked pretty bad...

Is this normal or could it be an indicator of a larger issue?

 

Looks fine for 100k.

That one cylinder may have an issue but I wouldn't sweat it majorly.

 

Normal. Mine had 135K on them.

 

They're worn but fine.

 

Phew! I figured it's fine since the car runs great but I needed some confirmation

 

Looks like that one got water in the plug tube.

 

If that's the case i would notice it kinda when doing an oil change, no?

 

To me (NOT A MECHANIC), they look like 120k mile spark plugs. Mine looked pretty similar when I replaced mine.

 

Some moisture could have gotten in and just sat on top of the plug-hence the rust. Water eventually evaporates. Not a big deal at all.

 

PCV valves always have residue in them because of blowby. Clean it out and make sure it opens and closes properly. One end should not allow air through while going the other way does.

 

Or replace. Cheap.

 

Yup, replaced it since it was pretty cheap to buy and easy to replace.

 

Does the PCV valve freely "rattle?" If so it is probably working. They look bad pretty quickly since the job they do involves crankcase vapor transport. Carb cleaner can be used to clean/free a used valve, but I'd replace it since they are cheap and are high "value."

 

Should i be seeing an increase in mpg after replacing plugs and pcv? Because I'm not seeing a change at all...

 

Probably not 4R was adjusting enough on its own.

 

No. Not measurable. These plugs are made so well they work at near maximum efficiency even with 100k+ miles.

 

No, the rust looks like it’s where the boot goes on.

 

Bingo!

Nope, it doesn’t enter the engine itself. It just sits in the spark plug well.

It should evaporate. The coil boot has little vents built in. But I got water in mine after I stupidly used a pressure washer on my engine. Even though I thought I did it as briefly as possible, and from a distance, water got into the #6 well. Water stayed in there for probably a month until it got into the insulator or the coil and the cylinder started to miss.

This is what my plug looked like after it sat in water for the month until it started to fail.



If there was indeed water in the OP’s spark plug well, it should look different than all the others. It’s untreated steel, so the moisture will cause surface corrosion pretty quickly. In my case, electrical arcing probably made it look worse.

 

Now you have me worried because I did wash the engine bay once (kept the plastic engine cover on and used minimal water). I feel like I won't stop thinking about it now until i take it all out again and check the spark plug wells

 

I guess I don’t see any reason to worry now. If it never caused the old spark plug or coil to fail, you’re golden… especially since you already got new plugs. The corrosion in the plug well isn’t something I’ve worried about either, since it’s going to be dry and hot in there anyway (as long as you don’t pressure wash again). It’s not going to rust away. Your plug has rust on it, which says to me it was in water, and then it dried. Compare it to mine, which is just a cruddy mess, with no rust.

Now that I think of it…. if you absolutely feel compelled to check anything, and you’re losing sleed, you could look at the boot at the top of the coilpack. It’s got tiny passages along the edges near where they seal against the valve cover (presumably there to let vapor/moisture escape if it ever got in there). You could check them to see if the pressure wash packed mud or dust into them and plugged them up. They are tiny, so you have to look for them.

But honestly, I’d let it ride and not mess with it anymore. I dont like to repeatedly disconnecting those coil harnesses (or anything else), unless there is a real need to. It be worse to accidentally damage one chasing a theoretical problem.

 

I’ve got one of those long grip retrieval tools and I like to put a piece of rag wet with isopropyl alcohol to clean out those tubes when doing a plug change.