CrossThreadedSparkPlug Turned into Cylinder Head Replacement

[OldsmoBeast]

Hey y'all...

 

Okay so I did a tune-up today...got new AC Delco Professional Platinum Plugs and new wires...car runs smooth....but my #5 plug was having difficulty threading in the plug....pretty sure it cross threaded, so I pulled it out and threaded it back in and it'll tighten up and then pop back out...I'm having difficulty explaining it but basically it won't tighten all the way it'll just pop back out...I tightened it as much as I could and then when I got the car running I could hear the pressure escaping from that cylinder... I'm pretty sure it has something to do with that plug... I'm hoping this doesn't result in an engine fire!!! What should I do?!?

 

Help!

 

YK

[sonyman87]

lol you striped the hole.. over torqued.. i could only imagin if it got loose enough while running.. heavy on the gass might shoot out like a bullet. :shock: not sure though.. definatly get an oversize fitting or fine some kind of replacement threading

[sl3196]

I did that once. You have to get one of those rethread kits and tap the hole. Not sure on the size.

[95 3-4]

Napa will sell you a helicoil rethreading kit for $12 or so, be precise you only have one more chance and shes junk :!:

[maybe2fast]

have a shop hela coil it for you. to risky to do your self. one shot thing

[5speedz34]

Do what is said above, or just get a new head, or maybe its time for a engine swap.

[Brian P]

Do what is said above, or just get a new head, or maybe its time for a engine swap.

 

Do you recommend engine swaps when people run out of gas too?

[5speedz34]

Do you recommend engine swaps when people run out of gas too?

 

No, lol, I was just saying.

[terryk2003]

Do what is said above, or just get a new head, or maybe its time for a engine swap.

 

Do you recommend engine swaps when people run out of gas too?

 

hell yeah...L67...

 

anywayz...back to the problem @ hand...i would deff. prolly take it some where and have em heli coil it...OR you could do it yourself if you wanted too, but like was said before...its a 1 shot deal... :?

[GP1138]

Well, it's not as much of a one shot deal as you think... I did the same thing on my old 2.8. I basically didn't torque one plug down enough, and it ended up popping out. I let it cool like an idiot, and next day, I couldn't get the plug back in, not for the life of me. So I went and got a helicoil kit.

 

It's fucking hard to do unless you have the right extensions and BE PATIENT. I can't stress that enough. It's definitely not impossible, but I recommend you be careful when you do it, because you're going to get a few metal shavings in your engine. I'm not sure how to avoid that, but I honestly didn't care at the time, as I was late for work by an hour with my boss and coworkers pissed, and the car was a part of my job (delivered pizza).

 

It shot out again a couple times, and the last time it happened, I just didn't care anymore, and torqued and torqued the tap until it would move no more. Did the same with the plug. It stayed in until the engine fell out the bottom of the car.

 

Basically you'll get a tap with a spark plug socket sized/shaped top, which you're supposed to re-tap the hole with. You have to be careful and patient when first threading it in, but when you feel it catch, you're going to have to put some ass into it. If it doesn't appear to be going straight, STOP and try again, or you could really fuck things up. After you get the hole re-tapped, you'll have little spacers that thread onto your spark plug, which fit into the hole you just tapped. There will probably be around 4 of them, all different sizes. Use the one that is just under the size of the spark plug's threads, and make sure it goes in all the way, because the top of the spacer's threads have ridges meant to keep the helicoil/spacer in the actual hole.

 

It's definitely not impossible, but if you're too unsure, it might be a good idea just to let your mechanic do it.

 

Or, if you're really desperate, you can just go out and buy a junkyard head.

 

This is pretty much what it looks like. Tap is on the left, spacers are on the right.

[95 3-4]

grease on the tap is about the best way to keep ALL of the metal shaving from going into the cylinder, or I suppose a helper could hold a shop vac wand right next to the work

 

I would say if you dont fell confortable doing it, take it to a mechanic shop and let them do it, I cant see it costing a whole heckuva lot and there should be no reason for the head to come off

[OldsmoBeast]

Sounds like fun times.....did I mention that this was on the BACK of my engine? the #5 on the 3100 is the biggest pain in the ass....its the farthest one towards the driver's side and on the back...closest plug to the driver...

It IS good to know that I can fix this....just not too excited about the pain in the ass i'm about to experience....

 

EDIT: as for taking the head off.... I HAVE been considering swapping a LIM/UIM off of a 3400, it wouldn't be too hard because the heads on my car are the same as a 3400's heads...I could theoretically grab a head and do that...but it's a lot of work and money for right now... never know...

 

Thanks guys!

 

YK

[Brian P]

if you remove the DIS, alternator, AND tilt the engine with a suitable tool, you'll have gobs of room

[OldsmoBeast]

if you remove the DIS, alternator, AND tilt the engine with a suitable tool, you'll have gobs of room

 

If by 'with a suitable tool' you mean 'by parking facing downhill on your driveway', then I think we're in business... I don't know many other tools for effectively tilting my engine....

[Brian P]

that would work

By tool, there is a tilting tool made by Lisle (pretty sure it's them) since you can't use the 3x00 dogbone mounts to hold the engine forward. You could also unbolt or remove the upper mounts and use a ratcheting strap mechanism to hold it forward. Or get a dogbone and bracket from a 2.8/3.1 and make that your "tool". Either way, but just removing the DIS and alt should be plenty enough.

[OldsmoBeast]

that would work

By tool, there is a tilting tool made by Lisle (pretty sure it's them) since you can't use the 3x00 dogbone mounts to hold the engine forward. You could also unbolt or remove the upper mounts and use a ratcheting strap mechanism to hold it forward. Or get a dogbone and bracket from a 2.8/3.1 and make that your "tool". Either way, but just removing the DIS and alt should be plenty enough.

 

Wicked, thanks.... I'm gonna stop by NAPA or Crappy Tire on my way home from school tomorrow and check out one of those heli coils....

 

By the way...if I DO mess up the "one-shot" helicoil wonder as everyone seems to imply.... Couldn't I just get a j/y head anyway? I wouldn't have to replace the whole engine because i messed up a head...anyway...

 

YK

[terryk2003]

yeah...if you messed it up, you could just get a head...but, be careful and dont mess it up, and you won't have to worry bout it!

[OldsmoBeast]

Napa will sell you a helicoil rethreading kit for $12 or so, be precise you only have one more chance and shes junk :!:

 

NAPA wants $60 Canadian for this kit... the only other place with anything similar is Partsource (owned by Crappy Tire) and they want $54 for a VERY crappy knock off... so looks like I'm going to drop the $60 tomorrow for the good kit...and pray to God I get it right...and then if that doesn't work, I'll grab an Alero 3400 head with the LIM/UIM from my local yard for $150 (If I pull them, of course) and some gaskets from crappy tire and that'll be that.

 

YK

 

PS: I swung by the dealership parts desk just out of curiousity to ask how much a new head would cost.... any guesses? They said "A cylinder head for that vehicle will cost you $958.00 Canadian"... what a joke.

[Brian P]

yup, thats why the reman companies are in business!

[OldsmoBeast]

Woo alright so I messed up the Helicoil crap....looks like I'm grabbing a new head....

 

So tomorrow i'm going to the j/y and I'm getting both 3400 heads, and the LIM/UIM/TB/EGR and whatever else I need off that 3400... So tell me, what do I need for this head replacement and what should I grab off the 3400 for the LIM/UIM swap....keep in mind my car already has (stock) the same heads as a 3400 due to the addition of roller rockers.

 

Thanks

 

YK

[CuttySup]

When you guys say "torque them down," I hope you don't mean with a torque wrench!

[OldsmoBeast]

Today's Update: Okay well its Saturday and I have a big date tonight...so I couldn't get THAT much done... but I did wake up a little early this morning and hit the yard, spent a good hour working on that 3400... I got the details on the engine, its a 99 3400 from a Montana, was swapped into an Alero and went kinda wrong....anyway, I was told the top end was good. I pulled the Plenum and Lower intake manifold but I left the fuel rail and injectors, cuz I figured they're the same as the ones on a 3100. I was going to continue and pull off the heads, but I was sooo cold....its snowing here and I've had a long week...so I think I'll continue my j/y mission tomorrow. Anything I should know while pulling the heads? anything else I should grab while I'm there?

 

Help me out fellas!

 

Thanks,

 

YK

[DiscoStudd]

This was a hot topic over at 60 Degree V6.com . I think they still have an article posted on how to do the 3400 Top end swap. One of the major points that sticks out in my mind is that you have to tap the "heater pipe" hole on the front head so your car's "screw-in" type heater pipe will thread into the 3400 head. The 3400's used a "press-in" type heater crossover pipe, hence no threads cut in the head...

[OldsmoBeast]

This was a hot topic over at 60 Degree V6.com . I think they still have an article posted on how to do the 3400 Top end swap. One of the major points that sticks out in my mind is that you have to tap the "heater pipe" hole on the front head so your car's "screw-in" type heater pipe will thread into the 3400 head. The 3400's used a "press-in" type heater crossover pipe, hence no threads cut in the head...

 

Do you mean in the LIM or in the actual head?

[DiscoStudd]

I couldn't find the write-up on the site, but I did manage to save a copy of it to my hard drive last year. Here's what it says:

Page 1

3100 to 3400 Top End Swap

 

One of the most popular modifications right now is the 3400 top end swap onto a 3100. The 3400 (along with the 2000+ 3100s) have much larger runners than the 94-99 3100, thus allowing for increased airflow into the engine. Stock 3400 plenum and manifolds also benefit little from increased PnPing, although gasket matching is recommended. Also, if you plan on installing a 62mm TB with this combo, you will need to port out the plenum opening to match the 62mm TB size. With that all said, let's get to the procedure!

 

Preliminary Steps

 

There are a few things that need to initally be done before attempting this swap. To save time (and possibly even money), do these steps first before tearing into the engine.

 

1. First of all, I recommend 97 3400 parts from the minivans (Venture, Silhouette, etc). This way, people with a 96-99 3100 won't have to worry about any EGR issues. Also, if you are buying new from GM, they are cheaper than the 00+ units. Why? Who knows... Here are the part numbers and prices for the units:

 

Upper Plenum : 10234990 [$126.08]

Lower Manifold : 24508396 [$61.04]

These prices are from GMPartsDirect.com. Dealership prices will most likely be higher.

 

2. Once you get the parts, you will need to make a couple modifications to the lower manifold. The first thing is the heater coil pipe fitting. The 3400s use a pressure fitting, whereas the 3100s use a screw in fitting. This is easily fixed though. You will need a 1/2"NPT pipe tap. Just tap out the coolant pipe hole. Be careful when doing this. You don't need to go all the way down either. I did this on my first manifold, and ended up getting the tap stuck inside the thermostat housing. I attempted to back the tap out, only to destroy all the threads that I had just created. If you get about 3/4 of the way down, you should be fine.

 

3. The next step is more of an observation step, although action may need to be taken. I found out the hard way that regular stamped rockers will fit the 3400 lower manifold. This is due to the larger runner size reducing the distance between the manifold and the rocker. I have included several pictures below which illustrate what to look for. If your lower manifold DOESN'T have the grindings from the factory as seen in the pictures, you will need to add them. So goto the next step... If your manifold has the stock grinding, you can skip the next modification.

 

4. If your manifold doesn't have the ground down areas from the factory, you will need to grind these areas down. NOTE: This should only be required for those people not having roller rocker heads. I will mention this again during the actual installation phase, but make sure you check clearances with a feeler gage before final assembly is done. Even after I ground down the manifold the first time, I had to go back and grind somemore becuase it was still touching. With that said and done, I used a die grinder to grind down the areas shown. You will most likely have to get down ~1/16" to 1/8" in order for everything to clear. Take your time while doing this and don't try to do too much at once. I have already talked with 1 person that sent the grinder bit through the runner . There should be 4 areas to grind down.

 

5. The final step in the preliminary phase is the EGR adapter plate. It is once again only for those having a 94-95 3100 initially. For more info on the EGR adapter, check out the EGR Adapter Procedure.

 

 

With all that said and done, its time for the installation, right? Well, almost... at this time, you might want to do other modifications to the manifold and plenum. This could include gasket matching the runners, porting out the plenum for a larger throttle body, or possibly even painting or powercoating the pieces. All of that is up to you. For info on doing such items, check out the how-to areas. Not all of them are actually covered, but some basic PnP info is, which can then be applied to the manifold and plenum. If you still have some questions, I would prefer you bring it up on the 60DegreeV6 forums, but I will also try to answer any emails I recieve.

 

Page 2

3100 Intake Manifold Removal

 

 

Instructions

 

Removal of the Upper plenum

 

1. Relieve fuel system pressure

2. Remove your air cleaner assembly (stock, CAI, etc..)

3. Remove the EGR assembly from the plenum. Unplug the EGR plug and set the EGR aside.

4. Disconnect the following electrical connectors:

 

* Spark plug wires

* Throttle Position Sensor (TPS)

* Idle Air Control (IAC) valve

* Injector Harness

* MAP Sensor

 

5. Disconnect the following vacuum lines:

 

* Vacuum modulator

* Fuel Pressure Regulator

* Brake vaccum pipe

* PCV

 

6. Undo the ICM from the upper plenum. If removing lower manifold as well:

 

* Unplug 3 electrical connectors

* Remove remaining bolts from ICM brakcet and remove from engine. You will also remove the EVAP canister purge solenoid at this time.

 

7. Remove the MAP sensor from the upper plenum

8. Undo electrical connections to the alternator (1 plug and 1 bolted wire) and remove alternator.

9. Remove 12 (6 for 3400) bolts from the upper plenum (7mm wrench)

10. Remove the upper plenum from the engine

 

 

Removal of the Lower Manifold

 

1. Drain and recover coolant

2. Remove the serpentine belt

3. At this time, it is necessary to support the engine in some way, either with a jack and block of wood under the oil pan or an engine hoist

4. Remove upper engine mount

5. Undo power steering pump (3 bolts accessible through the pulley) and set off to the side. It is not necessary to undo any of the fluid hoses from the pump.

6. Undo coolant bypass line from water pump

7. Remove radiator hose from thermostat housing

8. Undo thermostat housing (This can just be set of to the side with the bypass line still connected)

9. Remove valve covers

10. The fuel rail can be done 2 ways:

* Ensure injector harness is unplugged

* Remove fuel lines from fuel rail. Fuel will leak out of the rail, so be prepared to have a rag ready to keep the fuel spread to a minimum. OR

* Remove fuel rail from lower manifold and set of to the side. To do this, undo the 2 bolts holding the rail to the lower manifold. Then carefully pry the injectors out of the lower manifold. This can be done with a screwdriver or small pry bar gently lifting up on the rail in the vicinity of each injector. Once all are undone, set the fuel rail off to the side (limited by the fuel lines)

 

11. Remove 8 lower manifold bolts

12. Remove lower manifold from engine

 

 

If replacing the lower manifold gaskets at this time:

 

1. Loosen rocker arm nuts

2. Remove pushrods. IMPORTANT!! Keep the pushrods organized. They must go back in the same position that they were removed from.

3. Remove lower intake manifold gasket

4. Clean off all of the gasket mating surfaces (including the gap between the heads on the block). Ensure all old RTV is removed from all of the surfaces.

5. Clean off any excess dirt, oil or other materials before reinstalling new gaskets and RTV

 

Oops, I said the heater crossover pipe was in the head. It's in the manifold :oops: ...