Crushed spark plug electrode? VICS screw failure??

[Myrithel]

I was driving home from work today, and when I got off a small stretch of highway (60mph to 20), I noticed my P5 running like s***. Engine RPM was fluctuating +/- 300 RPM under 1500, and like +/- 150 at under 3000. Really bad idle and driving experience. Lots of vibrations... to the point where the car was visibly lunging if I drove under 2k RPM on any gear under 4th. I figured it was the infamous EGR valve problem (had yet to deal with it) so I drove home the remaining 30~ miles.

Checked the engine code; cylinder one misfire. Pulled the EGR and it was fine (cleaned it), then thought it was the coils and thought to take a look at the plugs just in case.. was in for a surprise. Spark plug one had its electrode basically touching the plug, with lots of little "impacts" all over the electrode and around it. The other three plugs were perfect considering I was driving for over an hour with 3 cylinders.

Something got in the cylinder one and destroyed my plug... and maybe scratched up my cylinder. I remember reading about the VICS screw recall; but it couldn't be, because when I bought the car (used 85k~ miles, over a year ago) I checked with Mazda's VIN recall checker and it came out clean (checked again and same thing). But here's the thing; my VIN falls within a 2005 recall pdf I found..

I'm inclined to believe it was a VICS screw, and that the VICS repair was never done on my car. Can it be?
Is my cylinder damaged?
Do I have any chance to get recall work for my intake assembly, so no additional screws enter the engine? After 11 years from the recall date?


I would love to get my car back on the road by Monday...

 

[Jackie chan]

Stick a magnet down into the cylinder To make sure it's not still in there. Rent a compression tester and pick up a new spark plug. And if you've got till Monday I'd pull the intake manifold and red loctite all the vics bolts. And remove the vtcs altogether. Hopefully the cylinder walls and valves are more or less okay.

 

[i12drivemyMP5]

Usually if this happens there is a loud machine gun type sound while the screw is bouncing around in the cylinder but what other explanation of the electrode being like that is there? Also, there were plenty of cars not listed in the recall that did have this issue. I had already did p&p on intake after removing VTCS and red loctiting the VICS screws on mine before the recall ever went into effect.

 

[Myrithel]

I didn't recall hearing anything unusual from the engine, but then again this was at over 3000rpm, radio on and highway noise.

Since my VIN falls within the recall range, is there any chance that Mazda would replace my intake? I don't really want to put the time into taking it all out.. And then dealing with missing screws or damaged butterflies like I've read about

 

[i12drivemyMP5]

If it hasn't been done according to their system and there wasn't some time limit, I would say how can they refuse?

 

[MrGiggles]

The best way to find out is to call your friendly neighborhood Mazda dealer.. Anything else is just speculation, I don't think there's any dealer techs that post here.

 

[Jackie chan]

They might even give you a motor, who knows. It's worth a shot.

 

[bryan95502]

Had the same issue with my daughters 03 ES. Number one plug had the gap shut. No signs of damage on it. She said she over revved the engine then it started running rough. I pulled the plugs to find the issue with number 1 plug. New plugs and it runs great again. 253k!

 

[Myrithel]

I never heard anything from the engine bay so whatever went in there probably went out moments later (also reviewed dashcam footage and couldn't hear a thing). Replaced the damaged plug and the car drives fine. Don't know about engine damage but hopefully wasn't too chronic considering the VICS screw is brass.

I stopped by the dealer this morning and they told me the VICS recall was done for my car in 2006 (got a printout too). I didn't see any way I could get them to redo the recall work free of charge so I left. My theory is that some dealer did the recall service at that time and maybe didn't torque down a screw or something, or maybe just that the service instructions are so lax that the screw came off anyway after 10 years (FYI car has 95k miles).

Whatever it is, it looks like I'm doing all this myself. Picked up some threadlocker and ordered the intake manifold gaskets from the dealer (coming next week). Since I have no reasonable alternatives I'll be driving my P5 until I have time to do everything (probably next weekend). Here's to hoping that my engine doesn't chew up any more screws in that time...

 

[Myrithel]

Update; took off the intake manifold today.

The only thing that remained of the VICS was the rod. Zero screws, no butterflies.
It all fell off. I shook out 6 screws and 4 butterflies from the lower manifold, all dirty and carbonized. One of the butterflies has both of its holes enlarged but the rest look fine.
I guess I'm pretty lucky that despite all the screws falling out, only 2 entered the engine...

VTCS was fine.
While I'm screwing this thing back together tomorrow (actually later today as it's 3AM - my neighbors hate me), is there anything else worth doing at the same time? I'll be removing the VTCS butterflies and rod, and install a new OEM rear motor mount I was holding on for a few months..

 

[The_big_dill]

Just the rear engine mount if you have the intake off. you can also clean, port and polish the intake while its apart. Acetone is hands down the best for cleaning carbon from my experience.

I'm surprised all screws fell out. My car wasn't part of the recall, but when I took off the intake there were 3 screws missing and 1 of the butterfly valves at the bottom of the intake.

VTCS wasn't part of the recall, thats why they didn't fall off.

 

[Myrithel]

Got everything back together today and the car is running.

Only problem I'm having is that the EGR tube connected to the header is leaking exhaust fumes (I also get a tiny bit of a "dry" sound when accelerating). I then tried tightening the EGR tube nut as much as I could and no dice. Don't know how to fix this, the egr tube wiggles a tiny little bit, and when I tighten the nut, the entire thing screws into the header instead of the nut locking down on the EGR.

I also replaced my rear mount, it was a good thing, checked it off my list, my old one still looked GREAT but now I don't have to think about it anymore. Removed VTCS and used JB weld on the runner holes, and tapped the end M10. No CEL for the EGR leak but only drove 4 miles. Will drive 40 tomorrow.

 

[Jackie chan]

With the egr, keep going until the bung bottoms out. Then you should be able to get the last crank or two on the nut. Get a big cheater bar to help turn it. I always use my jack handle.