Loose Spark Plug From The Factory

For my understanding is the techs plug in and read the level, but the reading comes in at a quart low. If you fill it until you hit the overflow, you're good to go.

 

Yes, that is the scan tool method. From what I’ve heard, if you’re <1 quart low, it won’t indicate as being low. I cannot confirm or deny this claim though. I don’t personally trust that method as there’s a number of reports from TW members that have had their fluid checked by the dealer using a scan tool, only to find out later that it was in fact low, albeit not that much, but low nonetheless. For an accurate level check, the transmission must be purposely overfilled with a specified amount, open the overflow plug during a specific temperature window, then measure how much comes out and subtract that from what was added into the system.

 

I know this an old thread but I have to confirm what the OP posted. My son and I just changed the plugs on his truck. One plug very loose and the ignition coils looked exactly like the pictures that the OP posted. Truck now runs more smoothly and the idle has also smoothed out a bunch.

 

Know the build date and build location? I have a mid-year 2021 from Mexico and this is making me want to go check since mine runs kind of crappy

 

Plugs are screwed in by fine folks in state of Alabama. Nothing to do with a region of assembly...shit happens

 

No I don't have that information, but it is a 2008 MT base model. We purchased in a few months back used. It has 90,000 miles on it. What is interesting though, is that the crush washer on the plug that was loose, was not even crushed. Must have been done at the factory. Glad we changed them. Like I said, runs noticeably better. Never heard of this happening before.

 

You say it must have been done at the factory yet. Your vehicle has 90,000 mi on it which is well within range for spark plug replacement recommendation. It is possible they were replaced at one point and just not torqued all the way down.

 

True, however the previous owner gave me all of the maintenance records, and he said he never changed the spark plugs when I asked. Additionally, the plugs looked every bit of having 90,000 miles on them.

 

I had loose plugs too. And a snapped off ACIS actuator door shaft in the plenum. Lots of problems with this truck, three burned out coils, bad fuel pump, etc. They said they replaced three but only two were, when I rechecked everything. Good thing I bought the extended warranty.

Nice, isn't it? I have two coils that still look like this. Cylinder#3's plug was loose and cylinder#4's coil looks the same too:

 

Check your mail for a settlement regarding the Denzo fuel pump recall

 

I did get a post card about that settlement. Everything was ultimately fixed under warranty/recall, and the Stealership paid for the tow, and they gave me a loaner. So I really don't have a claim for uncompensated costs.

 

I changed my plugs at 80,000 miles and found cylinders two and three loose. I had never seen this before. Today at 104,000 miles my truck hesitates then goes into limp mode with check engine light flashing. I shut it down and restart the motor. Check engine light is off. Head back home (which is only a mile down the road )and the same thing happens.when I get home I pull the fault code and the problem was cylinder three misfire. I pulled the coil on that cylinder and the coil was wet with fuel. Checked the plug and sure enough it was loose. I’m positive that it was installed properly. Maybe even on the tight side. I decided to swap coils with cylinder five to see if that cylinder would give me a misfire. It hasn’t happened yet. The problem seems to have gone away. Seems odd that the plugs would loosen on their own. I still need to check the other plugs to see if they’re still tight.

 

You using denso/Toyota plugs? (Iridium for 3rd gens, copper for 2nd gens)

 

Using Denso iridium.

 

At 65k miles and decided to change out my plugs. I heard about the loose plug issue a while back but never investigated it on my own truck. Well low and behold, #2 and #5 were loose. So should I replace these 2 coils or just run them? Haven't had any codes or anything pop up, so maybe just clean them?

 

If you're not throwing codes, just clean them and run them. You can even do an EPR oil treatment if you want.

 

I had to remove a stuck half of a Ford plug
Good times……

 

Very strange. I never got a notice about this, wish I did.

 

Add my 2017 to the list. I did my 65k plug replacement today and #3 was loose. #1 and #5 weren't particularly tight, but didn't show signs of blow-by like #3.

 

You guys got room for 1 more? Changed the spark plugs at 59k since I got quoted $800 at every local dealer. OEM spark plugs were $66 from local Toyota Dealer. Middle coil on the passenger side was brown and the spark plug was very loose. Thankfully all other coils and spark plugs looked great. I would recommend atleast checking the torque spec atleast if you are not close to 60k or even change them before hand.