Henryv

Ok so I was driving, then all of a sudden I hear this weird noise coming from the engine. Was this horrible loud ticking, noise like something was hitting the fan or something was loose in the engine. I was worried but the thing still ran so I just kept driving but as I got close to home it started to get alot worse and started to smell like something was burning so I babied it off the highway and as soon as I could I pulled over and parked to take a look under the hood. It's night now so I poked around a bit and saw that something broke because I saw gas spewed on the underside of the hood and around some of the other things. Then I saw the coil pack. The damn thing blew off the cylinder! It totally got ripped off the screw holding it down and had the cylinder exposed, still with the spark plug in it , or at least I think its there, couldnt see, and gas all around that area. What the hell happened here?!?!?! What could have caused this and is it expensive to fix? I'm worried because it looks like an expensive fix. Anyone have any input? I'm going to have it towed tomorrow to get it checked but I'd like to know what happened and how expensive it will be to fix. Damnit, I feel like . I'm just glad I was close to home when it happened.

edit: Also prior to this, the runner was vibrating with a rough idle but I couldnt figure out the problem. Never threw a cel though, even when the coil pack blew up. I googled up coil pack blowing up and seems like the other's had the same thing happen. Vibrating under idle, then coil pack blowing up. I just hope that I didnt do too much damage to it by driving it a bit after it blew up because right when I heard the noise from the engine it didnt smell but after a bit it started to stink. Probably went about a mile or so after it blew because I had to get off the highway (no shoulder).

MTL_4runner

This could really get expensive because if you stripped the threads for the spark plug, you are going to need to helicoil it for reuse and that requires removal of the head unless you are willing to risk any damage from aluminum chips that come from the retapping process. Look at the plug that blew out very carefully and if you can see threads from the head attached to the plug....trouble!

Did you do the plugs yourself or does someone else do them?

Henryv

Oh man, not what I wanted to hear but thanks for the reply mtl. I didnt get a chance to check it out much last night because it was dark but am about to go take a look at it in a bit. Unfortunately, I did the plugs myself so I cant blame anyone else and have them eat the bill. It was months ago though and didnt have the vibration till lately so I didnt think they were the problem. I actually thought it was the airaid mit with a leaky hose or something simple like that because it happened around the same time of installing the mit but I replaced it with the stock intake and the vibration was still there. Stupid thing is I was gonna check the plugs out this weekend provided it didnt rain. Too late now. If I do have to have them helicoiled, how much to they have to tear down? Would it be wise to get my timing belt and water pump done now too since they have to go in anyway? I wasnt going to do it till I hit 90 (I'm at about 75 now), but if they have to tear down the same parts I might as well do it now. Its gonna be a helluva bill :cry:

edit: Just went to look at it. Plug and the part connecting the plug to the coil pack blew right out of there and is nowhere to be found. Looked down the cylinder and it looks pretty bad in there. I'm surprised I dont have a dent in the hood. Is there any way the thing could have blown out and slipped into the cylinder? At least theres probably some pieces in there. Sigh, this sucks.

MTL_4runner

Any chance you can post a pic of what is left and of the plug hole in the cylinder head?

epic37311

LMOA I was just about to post that and you beat me to it MTL.
Some footage would have been crazy.
Back to the topic. Fist I ever heard of something like that

4RUNR

Link?

Something doesn't sound right here.

mt_goat

I have heard that you can helicoil spark plug threads without taking the head off.

mt_goat

Here is where I saw it: http://www.4x4wire.com/forums/showfl...fpart=all&vc=1

Henryv

Well, I meant that they also had a vibration before one of the coil packs blew up. Just dropped it off to be checked and the guy said that the plug probably wasnt torqued enough, which caused the vibration and the plug blowing out. Stupid mistake's gonna cost me, just dont know how much yet. Won't know til tuesday. Took some pic's but couldnt get one clearly down the cylinder:
Ripped pack right off the screw

Best I could get of the hole. Its hard to get a good shot in there

Bottom of pack

4RUNR

That's what I was getting at. The coilpack had no more to do with this 'accident' than the hood. It's probably a DIY job since the only casualty seems to be the coilpack. New coilpack + sparkplug.

MTL_4runner

This is very bad protocol and can be quite risky.
You certainly can do it, but you are running the risk of damaging something with the retapping.
Even with loads of grease on the tap, some shavings will get in there.
Only way to prevent this is to remove the head, insert the helicoil (or insert) and reinstall.

MTL_4runner

If the sparkpulg just wasn't tight enough and vibrated out, you should still run a tap through the threads (you don't have to take the head off for that) to make sure when the plug came out, it didn't bugger the last few thread turns. Trying to force threads in aluminum is very bad because it galls up easily. If it did vibrate out, you are in luck and you may just have to pay for a new spark plug and a coil pack.

Be sure to retorque all the pulgs to prevent this from happening again.

mt_goat

Did you read what engnbldr had to say about it:

">>>*One trick we use is to set up a shop vaccum, (Having a friend nearby with a 2nd set of hands is a real asset here...)

The vaccum will draw out most of the shavings, even though they are pretty much harmless, they just blow out the exhaust when you start it..

The real problem is with the late EFI engines...They run very close to stoichiometric, which means high heat compared to a carb rig..

The steel threads act like an insulator and change the thermal transfer from the plug to the head, this is all that cools it..This is due to the thread pitch, spark plugs and helicoils are only around 75 to 80% thread contact, this leaves little air pockets around the threads..Lots of folks don't realize this, and just how close these engines are to hot spots even when tuned normally..

When we install a helicoil set or theadsert inhouse, we always suggest a one heat range drop in the spark plug for that cylinder to avoid detonation...*EB "

NorCalVP

A friend of mine on TTORA had something similar happen to him. But it wasn't the plug, There is an insert in the head that has the spark plug threads. this piece came out, and had a very similar result to yours. So just installing a plug thread repair kit may not do it.

Go to TTORA.com and ask for BigBabBob. he'll give you the nitty-Gritty on what had to be done to his truck.

Henryv

Crap. Just got a call from the stealer. They couldnt get the plug in even with the coil and said that its totally stripped. They say I'm gonna need a new head and its gonna cost me around 3-4 grand. I'm gonna check around and get a second and third opinion from independent shops but I wanna know what you guys think. Can I just unplug that one cylinder and drive it a bit without causing any harm? I want to get it out of there but dont know if i need to get it towed out. How much should this cost normally? I'm still hoping that when I bring it somewhere else they will tell me something different but I'm not holding my breath. This sucks.

aowRS

Christ. You can probably find two decent 3.4 engines for $4,000. Get your truck out of that dealer's hands. That is highway robbery and they know it.

Andreas

Henryv

Well I figured that since people were doing whole engine swaps for that much. Just want to get a ballpark figure so when I go elsewhere I can get a gauge of how much is normal. Gonna go get it after work but still want to know if its ok to drive it out.

91Toyota4x4

You can drive it but it's probably gonna shoot gas all out under the hood like before.

MTL_4runner

You can drive it fine as long as you disconnect the fuel injector for that cylinder first, otherwise you risk spraying gas all over the engine compartment and the whole truck could go up in flames (not worth it!). If you don't want to do that I would have it towed back to your house.

As far as the pricetag for a new head, I would start pricing used engines from the junkyard.
A used engine should be about $1500-2000 with decent miles and then I would sell yours as is running on ebay.
Just be honest about what happened and I am sure someone will buy it because it runs (or sell it for parts).
You could look for a used head, but it would probably need to be rebuilt anyway (not worth the agrivation in my book).

dwh91102

fisrt let me start by saying henry I'm sorry to here about the truck, what a freak accident. 2 get that truck the hell away from the stealer, what a joke 3k. Take the veh to a independent shop have them pull the head and take it to a machine shop, if they can't repair it they will let you know, and you'll have to look for a used head, and get it machined (few hunderd bucks), and as you said go ahead and get your timing belt changed.. Mtl not to flame you but your talking about him getting a whole engine, and have it put in...your breaking his pocket book dude. His motor only has 75k thousand mile on it. Your telling him to take it somewhere have the engine pulled, and go buy a new one, when the only problem with his motor is a damaged head. Not everybodys pockets books are so deep