2003 V8 Spark Plug change (167k originals)

[Good351]

So I picked up a 2003 4Runner Sport V8. It currently has 167k miles. I don't know if the plugs are originals for sure, but the previous owner had not changed the plugs in 50k of owning it. He did do the timing belt at 120k.

I've done plugs on my previous Tacoma's so figured this would be a snap. I got the socket wrench out and tried to remove the first one.. No budge. Tried another and couldn't move it.

So my question is: Do I just get the breaker bar out and crank on them? Use an impact? Is there any history of these plugs freezing to the heads?

 

[asahi4runner]

Try the warm engine trick before breaking out the breaker bar or using the impact gun on it. It's still aluminum after all.

 

[ben550]

Try the warm engine trick before breaking out the breaker bar or using the impact gun on it. It's still aluminum after all.

The V8 is not aluminum, but the heat may help.

 

[Dylan]

Try the warm engine trick before breaking out the breaker bar or using the impact gun on it. It's still aluminum after all.

Yeah, I thought the V8 is cast iron.

 

[asahi4runner]

Sorry you're right I was thinking about my other 4.0. No I just double check the heads are aluminum.

 

[MikeInNH]

Yeah, I thought the V8 is cast iron.

The engine is cast iron..but the heads are Aluminum. The spark plugs are in the heads..NOT the block.

 

[Good351]

Try the warm engine trick before breaking out the breaker bar or using the impact gun on it. It's still aluminum after all.

I'll try them when the heads are still warm.

I've been searching and reading all I can.. Looks like an impact is a no-no, don't have one anyway so no worry there.

 

[montana_jeepn]

The engine is cast iron..but the heads are Aluminum. The spark plugs are in the heads..NOT the block.

I think the first step is to remove the spark plugs from the block and install them in the heads.............

......in all seriousness though, good luck! I still cringe whenever I do any work on an aluminum head. Don't forget the anti-seize when the new ones go in.

There are quite of few articles out there, fortunately I've never had to try any of the methods.

How to Remove Stuck Spark Plugs - AutoRepair.Answers.com

Aluminum head stuck spark plug ? Speed Talk

 

[ebg18t]

......in all seriousness though, good luck! I still cringe whenever I do any work on an aluminum head. Don't forget the anti-seize when the new ones go in.

This is always an interesting debate. Go with the mechanic or the manufacturer..
NGK Tech bulletin advising against anti seize

 

[BlackWorksInc]

The V8 is not aluminum, but the heat may help.

The 2UZ-FE is a Cast Iron Block with Aluminum Heads. Heating them up would not be a bad idea if they are being a pain to come out.

What I would do is heat the engine up, turn it off; turn the spark plugs a hair tight, and then 1/8~1/4 of a turn (how ever much lee-way you get) to loosen them and then use a penetrating oil and let them soak in for about 10-20 minutes and try to loosen it up again. Keep repeating the process until you get them out. Its how you're supposed to do them on the Ford Triton engines that snap their ridiculously and stupidly long plugs all the time.

 

[MikeInNH]

Its how you're supposed to do them on the Ford Triton engines that snap their ridiculously and stupidly long plugs all the time.

I think those are suppose be soaked overnight.

Removing spark-plugs in a hot aluminum engine is an easy way to strip the threads. Warm - maybe...but not hot.

I'd put liberal amount of penetrating fluid down each spark-plug hole when the engine is cold and let it sit overnight. Then try.

This is one reason I use regular nickle plugs and replace them once a year (about 35k miles).

 

[BlackWorksInc]

I think those are suppose be soaked overnight.

Removing spark-plugs in a hot aluminum engine is an easy way to strip the threads. Warm - maybe...but not hot.

I'd put liberal amount of penetrating fluid down each spark-plug hole when the engine is cold and let it sit overnight. Then try.

This is one reason I use regular nickle plugs and replace them once a year (about 35k miles).

The idea was to get the heads hot break the threads loose a fraction of a turn to get the penetrating oil to seep in. The 20 page TSB that details the instructions on removing the plugs (3 pages are for removing the plugs, the other 17+ are for what to do when they break) says about 20 minutes before you try to remove them, if they do not come free you repeat the process until they come out. On a side note its like less than half an hour to get them out if they didn't stick, but the TSB calls for like 3hrs+ labor time NOT including repair time if the plugs break.

 

[montana_jeepn]

This is always an interesting debate. Go with the mechanic or the manufacturer..
NGK Tech bulletin advising against anti seize

I hadn't heard this before. Thanks for sharing!

 

[Dylan]

The engine is cast iron..but the heads are Aluminum. The spark plugs are in the heads..NOT the block.

But the knee bone's connected to the thigh bone...

 

[ebg18t]

I hadn't heard this before. Thanks for sharing!

I didn't know about it till 2 years ago. My understanding is Denso is the same way, but they don't have a published tech bulletin.