Hi All,

I have a question regarding my '86 SE V6.
Up to 2 weeks ago I had been hearing a "rata-tata-tat-tat" sound from the engine. Well, I took it to the Pontiac dealer, they checked it over and said it was a split cross-over pipe. It was going to cost $400 to fix so I declined. Now it gets interesting...

Last night I was driving on the highway and the engine just started making the loudest, most horrific noise. I got it home fine as I thought the whole pipe must have just broke apart while driving. This morning I checked it out to find one of the back spark plugs completly blown out of the block!! It was just hanging on by the wire. Now I am kind of concerned that part of the plug, the "gap" and threads, may still be down in there as they aren't on the plug. I'll get the deck off tomorrow to look into that.

So my questions are:
1) Is it likly that the noise was the spark plug all along and not the crossover pipe? A shoddy mis-diagnosis?

2) That somehow the technician was back there goofing around and maybe put some pressure or something on the plug boot and caused it to loosen?

3) What the heck causes a plug to just blow out of the block anyways???

Thanks for the help,
Scott

It probably rusted through, is the lower part of the spark plug still in the head?

Could have been a mis-diagnosis, the plug may have been the leak and noise. Tough to say.

I had one break off in the head, here's the thread and how I got it out.
https://www.fiero.nl/forum/Forum2/HTML/011773.html

[This message has been edited by Tigger (edited 10-21-2001).]

That sure is a god awful noise isn't it? I had that happen to me on my T-bird. But get this, there wasn't anything actually wrong with the plug, it just somehow unscrewed itself and fell out! The next day I found it hanging by the plug wire!

-Marlin

[QUOTE]Originally posted by Tigger:
[B]It probably rusted through, is the lower part of the spark plug still in the head?

Yep, I think so. My plug looks just like yours and my story is the same as SteveJ's... it's a hell of a sound!!

So how do I go about this EZ-Out operation?
Is WD40 as good as using the Liquid Wrench?
Is using this anti-sieze better than gerase for my new plugs?

The thing I wonder about is I just replaced these plugs last Winter... sure didn't take long for them to rust.

Thanks for the help,
Scott

This seems to happen a lot with Fieros. Someone told a similar story about six months ago and about 5 people had gone through the same thing including me. Take it slow and get a good bite with the ease out and you should have no problem. Good luck!

I make spark plugs for a living. Did the shell actually rust and break, or did the insulator pop out of the shell. I'm curious. Were these the original plugs?

Banzai !!!!!!!!!!!

If the plug broke at the top of the threads,,,, that's very often a sign they were over tightened.

Antisieze on the threads is best but be carefull. The antisieze makes it easier to over tourque the plugs.

As long as the threads aren't siezed, they should come right out. Don't drive an extractor any more than absolutley needed or you could expand the thing and make it tighter.

------------------
11-Sept-01, The day the world as we knew it ended.

Banzai, the plug is less than a year old.
AC Delco straight from the dealer.
It just popped out of the shell. It was not rusted at all. I took all my plugs out today and there were others which severly rusted, but not this one.

This was indeed the cause of the "rata-tat-tat" noise... not the cross-over pipe as the dealer suggested. I'm going back tomorrow to get a refund on their "service fee" for the shoddy diagnostic.

I got the plug out with a standard spark-plug socket. Came out real nice but the electrode was missing! I stuck a magnet down in there to try and retrieve it but no electrode. **Note to self --> never stick a magnet down there again!! You may not be so fortunate to get it back out next time! End note**

I put the new plugs in and started it up and ran it just fine. So I have no idea what happened to the electrode. Vaporized I suppose.

It's conceivable that the plug was over-tightened. But maybe it was just a bad plug.
The mystery continues.

Thanks everyone for the help and suggestions,
Scott

That is so bizzare. The guy I bought my fiero from said the same thing happened to him. However, he was doing 120 mph when it shot out. Those d*m Gremlins.

Wouldn't one of those fancy telescopic (similar to a radio antenna) with a magnet on the end work? I've got a fancy screwdriver with one in the end that holds the hex bits.

Hope the electrode was blown out the exhaust valve.

Another friend mentioned that it would probably get sent out the exhaust so I figured what the heck... start it and roll... if it blows then it blows.

I also thought of one of those magnetic telescopes, but it was like $5. We Fiero owners are cheap bas**rds!

At least I have "one of those stories" now.

Scott

First thing I did when I got our Fiero was change the plugs & wires. Was surprised when I got two of them out whithout a socket, and the other two weren't much tighter. Changed them again the next year, still weren't real tight, but guess a duke won't quite blow em out. Must have something to do with the exanding and contracting of the cyl hd. Don't know.

I was goofing around on a minibike before and had a spark plug shoot out while I was riding it. I had just put the spark plug in and I had made sure it was good and tight. The spark plug was fine and I put it back in.
It did make me nervous because the spark plug was right between my legs. The engine was horizontal 3hp Briggs and Stratton. I didn't know that mini bikes could have gremlins too. I learned never to doubt those buggers.

Did anybody say what the problem is?.......It is a stopped up converter!!! The back pressure caused the crossover pipe to split then went into the cylinders and blew out the plug! Better fix ASAP! That is the root cause of a fire!! TRUST ME ON THIS!!

[QUOTE]Originally posted by revin:
[B]Did anybody say what the problem is?.......It is a stopped up converter!!!
>>
Yikes!! I was afraid of something like that. Better get it into the shop today!

Funny thing... two nights ago I had a dream my engine caught on fire -> then the plug blew, and last night I had a dream I was changing pipes under the car -> probably the catalytic converter. Wonder if my subconscious mind was trying to tell me something?

Thanks for the tip on this... I would have never thought of it myself and the dealer (+ most shops it seems) is about usless in diagnosing anything.

A converter kit + shop time is going to be around $200 I imagine but better than an exploded engine.

Thanks again for this great tip... it certainly has saved the day!

Scott

Now would be a good time to get a free flowing cat! or hollow out the current one.

Revin,

Thanks again for that tip! The cat was totally shredded. I went with a standard replacement cat however. Yes, , I know.
Just don't have the time to fool with the performance stuff right now.

If I'm ever down that way I owe you a beer!

Scott

quote Originally posted by revin: Now would be a good time to get a free flowing cat! or hollow out the current one.

was it cloged??? Come on down!

quote was it cloged??? Come on down!

Well, it was 'bad'. Looked like a pinatta full of confetti in there.

I took it to the dealer and they hooked a vacuum sensor up to the computer and tested the vacuum at different rpm's and it held at the required pressures so they said the cat was good. They never looked at the actual cat itself

When I took it to the muffler shop they got it up in the air, did their usual tapping deal, and determined it was 'bad'. When they got it off there was nothing but confetti in there, it had deteriorated to where it just looked like you stuck a bunch of paper shreddings in there.

So to make a long story short I'm not sure if it was clogged as the dealer said the vacuum test would indicate if it was clogged but I don't see how it couldn't have been clogged considering the insides were totally deteriorated.

Thanks,
Scott

Good catch revin! I never would have guessed that the converter would be the cause. Something new everyday.

Unfortunely the previous owner of my 88GT did not know about the cat. The car caught fire from the exhaust man. receiving a crack. It happened to be right by the wires going into the interior. Melted the caseing around the wires and BAM ! Fire. have someone check out real good for any cracks you might have received with the stopped up cat.
OR after it catches fire ...I will buy it one for $100 like I did my 88GT. ha ha Stay tuned for rebirth pics!!!!!!

quote Originally posted by revin: [B]Have someone check out real good for any cracks you might have received with the stopped up cat. B]

The manifold is in good shape but the shop says there is a hairline crack in the crossover pipe. Would that be enough to cause an engine fire? Does it depend where the crack is? What to do...???

Scott

I don't think the hair line crack in the crossover will start any fires. But it would be good to have it welded or replaced.
Mine had a crack at the end of the manifold going in the last cyclinder in the back, right by the wires going into the interior. Just make sure nothing is near the crack in case of a backfire or a flame shooting out through the crack.

The hairline crack will grow (heat and cool, heat and cool...) and eventually become a small blow torch. Have it welded while the car is apart, 3 donuts, new bolts and some labor. Your cat wasn't plugged but was at one time. Now the bad news... All of the crap that blew out of the cat has lodged in the muffler. It probably isn't totally plugged, but it won't flow as freely as it should either. GL

quote The hairline crack will grow ...Now the bad news... GL

Cripes!! That's just like this car... as soon as I think it is fixed I discover something else to be my problem. Perhaps it is time to trade this baby in. At 54K I shouldn't have so many problems with it.

quote Originally posted by sdvoid: Perhaps it is time to trade this baby in.

Why? So you can run into the same problems all over again?!

quote Why? So you can run into the same problems all over again?!

Oh, I wouldn't get another Fiero. Gasp!!
These things are just too cheaply built. It's always one repair after another after another. I'd go back to foreign cars. At least you get 100+k out of them. I'm at 50k and this thing is about ready for the junk yard.

Scott

sdvoid, Although your car is 54K in miles, it is what 14 or 15 yrs old. The 3 factors that determine the shape of a car are: miles, age and care. Most Fieros on the road today have been neglected so they are in worse shape than they could have been in today. As an example, if your car does in fact have a crack in the Xover pipe and you decide that you don't want to fix it, the likelyhood of secondary effects from the original defect is almost certain. So if you neglect to take care of a problem, it is possible that the car will be in worse shape than if you repair problems promptly as they are found. Granted, the Fiero is probably a touch more sensitive due to the underhood temps back there, but the main cause of problems is the lack of mechanical talent where Fiero owners have them repaired at(inlcuding the dealer). Also, any car that blows out a cat will blow the debris downstream in the exhaust system. It is not a function of brand, 'nationality' etc., but a function of the exhaust system design. Who knows why your spark plug blew out but it is not because it was screwed into a Fiero. So I don't agree that the Fiero is so cheaply built that at 15 it is any less reliable than any other 15 year old car foreign or domestic. This is of coarse only my opinion. Good luck with whatever you decide.

quote the main cause of problems is the lack of mechanical talent where Fiero owners have them repaired at(inlcuding the dealer).

Yes, now that is my problem. I try and keep on top of things but no one seems to be able to give me the full diagnosis. Most shops, including the dealer, are clueless. The Internet forums and mailing groups are better but even then I've been sent running around like crazy based on so many different opinions. With this latest run of problems I'm still nowhere near having it fixed. It's from the plugs to the cat, now to the muffler and then onto the crossover pipe.
And the thing is there will probably be something else wrong with it after that.'
Exasperating... especially since no one is qualified enough to diagnosis it properly.

I keep trying to get to the core cause of each problem I encounter with the car but I have to believe now that the core problem is that it is a Fiero and they were cheaply made experimental cars.

Thanks for letting me vent,
Scott