Hey guys, so I was driving home yesterday in the dead of night and all of a sudden what I thought was lifter ticks suddenly got really loud and smoke started to come out of my 99 v6. Thankfully I was fairly close to home and was able to limp the rest of the way back. I did see that it had started to leak oil from the left side of the engine as I faced it.

This morning I went ahead and checked things out in the daylight and was able to confirm that oil is coming out where the spark plugs are and am showing codes of P0300, P0303 and P0306. I've never had to troubleshoot these types of issues before and I'm worried it means I'm going to have to replace the engine or car entirely but can anyone point me to what I need to do to start troubleshooting to confirm? I should have most tools needed, just have never had to troubleshoot this type of issue. I drive about 100 miles a day for work so it's worrying me this means I may need to just replace the car

For some background, oil is still showing as almost to the 2nd dot from when I changed it back in June. Sparkplugs and wires were also swapped out at 307k miles more so as preventative measure and to stop nagging from my maintenance app back in July but prior to that there were no issues and this issues just started last night.

 

Sort of sounds like a sparkplug or two loosened up? That would make loud whooshing/chuffing noises. Maybe a little oil, more gassy.sooty stuff. Although I guess if the valve cover was a little leaky (not unusual at all for a 307K mile engine) there could have been oil in the spark plug holes that puffed out as well.

If you're lucky, they jsut came loose. If you're not lucky, and someone overtightened them when they were swapped, they may have stripped out. I wouldn't worry about that too much until you pop the coils off and take a look.

 

Thanks, after reading a bit, I did go ahead and buy 2 more spark plugs from autozone yesterday. How reliable are those, does anyone know? I know when I first bought them in July from amazon I had read that they should be 2 pronged, which they were along with the ones I just bought yesterday.

 

Whatever is recommended from Toyota is what you should be using

 

HOw reliable are spark plugs from Autozone? They probably sell multiple brands that fit a 4Runner.

And if they came loose, or stripped out, it's almost certainly not the spark plug's fault, that would be an installation error.

Before you start buying part,s you should start looking to see what's wrong.

 

Thanks, I pulled the plug from cylinder #3 and found this. What would cause this other than possibly age of the coil pack? These would have been the original 1999 coils. I went ahead and bought some Denso coil packs from Autozone and swapping those in seem to have worked, although the car is still smoking, burning the unburnt fuel I believe. I'll go ahead and drive it later tonight to get all that burnt out but my next concern is the plastic and metal from the old coil pack still being inside the plug well. When I took out the old one I used a shop vac to try to vaccumm anything out that might still have been on top of the old spark plug but nothing came up, even when I unscrewed the old spark plug. Is the rubber ok to break down on it's own inside the engine like that?

Second concern is, how do I prevent this from happening again?

 

I'd guess that the valve cover is leaking. And filling those spark plug holes up with oil. Which then, over time, lead to shorting the spark current and degrading the plastics on the coil.

I thought perhaps the louder noises meant loose spark plugs, but I guess that's not the case. Which is a good thing.

Valve covers wouldn't be too much of a task, but the driver side is buried under the intake, so you have to take it off. Nothing too difficult, but it will take a weekend day.

 

Thanks, when I did take out the old spark plug it appeared to be completely unthreaded, I felt no resistance when I turned the socket counter clockwise and it just pulled out. The new spark plug went in without issues. Can these back themselves out? I can't imaging I forgot to torque it down and it having ran since July without issues at 100 miles a day, right? I also use locktite blue on these when I put them in normally. Regarding the oil in the well, I seem to remember having done a gasket job within the past 8ish years when I replaced some faulty injectors.

 

I haven't ever heard of anyone using loctite on a spark plug, I really don't think you should be doing that at all. Heat loosens loctite, and sparkplugs run hot, it could be acting both as a partial insulator and, when warmed up, as a thread lubricant.

They can back themselves out if they weren't tightened properly. I tend to do them by feel, but maybe you should try using a torque wrench? I googled the spec, it's 13 ft lbs on a 5VZFE.

When tightening them by hand, you can feel the crush washer start to crush, then the torque ramps up as it get s fully crushed, that's about where I stop.

If oil is in the spark plug wells, there aren't too many other likely sources other than the valve cover gaskets, and the seals around the metal spark plug well tubes. What brand of gaskets did you use? A lot of off-brand/parts store brands use cheap chinesium rubber that seems to fall apart after a few years instead of lasting 20 - 30 years like the originals did.

 

Thanks, I thought it was safe to use blue and to just stay away from red since that's advertised as permanent. For the gasket and seals, I have to look around my emails to see what/where I bought since it doesn't appear in my amazon orders.