Please Help me 3100 95 Grand Prix!

[95grandprix3100]

Hey Guys I'm new on the site even though I've been reading it for awhile. I need some serious help. I bought a '95 GrandPrix last winter and it drove fine for about 10,000 miles and then some of my cylinders stop firing. Went to the spark plugs and wires first to check up on if i was getting a spark. Turns out the spark plugs were all corroded because of a headgasket going bad. One spark plug was jammed into the head because the idiots i bought it from threaded it in wrong and forced it. After chatting with my mechanic i decided I'd try and do the head gasket work myself and get the sparkplug drilled out while i was at it. Bought the book and thought i did everything right but ran into a lot of problems along the way including 3 exhaust manifold bolts that broke of in the head, 2 of which i had drilled out. I also somehow lost a gasket ring to the heads which holds the headgasket in place. My buddies at the mechanic shop didn't have an extra so they just cut an old head bolt to hold it in place for me. I'm having problems to where my car is seriously lacking power, my temp gauge on my dash isn't working and my coolant is filling up and then emptying in the resevoir-which im told has to do with a bad headgasket. Im told I may have installed it incorrectly. Can anyone help me?

[60dgrzbelow0]

This is one of those times where, in spite of all your noble efforts to do this repair and replacement yourself, everything may have gone against you. If the head was already damaged, cracked or warped, removing the broken-off bolts and installing a heli-coil kit to fix the Gollywogged spark plug hole would make for a nice fit for your spark plug, but if the new gasket is insufficient to overcome any existing warp or propagated cracks, getting coolant leaks and losing compression and power would follow.

Also... using a cut-off bolt instead of the hollow-mild steel small cylinders that act to align the gasket/head configuration might turn out to be a bad idea. Once the head and new gasket are bolted and torqued back down, if the engine temp was transmitted to this odd steel bolt and made its length expand, it might generate enough pressure to push inside the area between the block and the head... and lever them apart enough to make the new gasket fail.

Try calling around to some local junk yards and getting a used head. Sometimes, machine shops keep heads in stock that were either not picked up or finished for one reason or another. A few phone calls might lead you to a re-built one for cheap and after getting one more new head gasket to finish the repair...you will back on the road in no time! (They might even have a few of those gasket alignment items on hand, too.)

Good Luck with getting things put right again...

[no_doz]

dont piss with it any further-find a 3400 van & get the heads, upper intake manifold, lower intake manifold, & throttlebody, then do a minor port/casting cleanup as well as gasketmatching & install the stuff with some good metal felpro gaskets.

if you do-your hp, reliability, & efficiency will be increasing very nicely

[95grandprix3100]

thanks guys that may help a lot, I've heard alot about the 3400 or 2000+ 3100 head swap and had considered it decided since this was my first real engine work that i would back off on doing any special stuff, however if my heads are junk I don't see why I wouldn't want to snag a 3400 top end. That requires a new ECU tune though, Correct? That can be pretty costly and being an 18 year old in the middle of his sport season im looking at very very limited funds. To be honest I really would like to see this car run again before we get too far into our crappy michigan winters. BTW The bolt cut to size to align the head gasket was taken out, the rings used to hold the head gasket in place during tightening surround the head bolt thread locations. My mechanic buddy cut a notch in the top so i could remove it with a magnetic flat head screw driver once the other bolts were in place.
The main thing i'm confused with is what exactly did I do wrong? 60dgrzbelow pointed out that I may have warped heads, but my car was running great previous to that so how could they warp? I did spend a really really long time doing the work( 4 months to be exact...yeah I can hear the snickers already) but I was really quite busy that entire time and took a couple weeks off to work on friends eagle talon and my girlfriends POS Ford Probe.
I have a few theories as too what i may have screwed up on such as I stupidly first tried to start it with the spark plug wires in the wrong firing order which resulted in some loud belching noises-could that wreck the new headgasket? Or my theories include that i didn't bother having the top exhaust manifold bolt drilled out of cylinder 5(the front two cost $45, and i was assured that it "wouldn't matter that much") also when i put the LIM on i only used one thick bead of RTV on the heads and didn't fill in the depression on the LIM too, are any of these viable reasons as to why it is running the way it is? (sorry about writing a book here guys-haha) Thanks for all your help!

[robertisaar]

you can swap large port 3x00 parts on a 95 and be safe, but it won't be ideal. not to mention the 95 PCM is worthless(untuneable) anyway. if/when you get to that point, either obd2 or obd1 swap.

[heavymtl]

i'm curious as to (if you put the pushrods back in) properly...also have you made certain that the plug wires are connected to the correct cylinders?...just a couple things to check after

[no_doz]

go OBDI-a running OBDI 60* fwd 6 cylinder from 90-93 vehicle isnt hard to come by, & then you can get a prom programmer from moates.net & tune it yourself or go to wot-tech.com & get one from ben for $60

[robertisaar]

go OBDI-a running OBDI 60* fwd 6 cylinder from 90-93 vehicle isnt hard to come by, & then you can get a prom programmer from moates.net & tune it yourself or go to wot-tech.com & get one from ben for $60

??? on both counts...

you would need a 91-93 3.4DOHC or 93-94 3.1 W-body PCM (16149396). you would also need a few other things, but we'll get to that if the OP gets that far...

and 60 for a ben tune? i always see 90 in the store...

[95grandprix3100]

The pushrods I labeled and made sure to put in the correct places and the wires are on right. Rear bank is 135 and front is 246, correct?

[robertisaar]

1 is closest to the alt 5 is closest to the brake booster, 3 is between them. 2 is closest to the PCM, 6 is closest to the battery, 4 is between them.

[95grandprix3100]

Yeah That's it. Wires were all set.

[60dgrzbelow0]

BTW The bolt cut to size to align the head gasket was taken out, the rings used to hold the head gasket in place during tightening surround the head bolt thread locations. My mechanic buddy cut a notch in the top so i could remove it with a magnetic flat head screw driver once the other bolts were in place. The main thing i'm confused with is what exactly did I do wrong? 60dgrzbelow pointed out that I may have warped heads, but my car was running great previous to that so how could they warp? Or my theories include that i didn't bother having the top exhaust manifold bolt drilled out of cylinder 5(the front two cost $45, and i was assured that it "wouldn't matter that much") also when i put the LIM on i only used one thick bead of RTV on the heads and didn't fill in the depression on the LIM too, are any of these viable reasons as to why it is running the way it is? (sorry about writing a book here guys-haha) Thanks for all your help!

Getting back to the basics...It might be helpful to know how you determined that the head gaskets were leaking via your diagnostics. Did you do a cylinder compression test? Have you removed the heads again since discovering the problem? The answer to the question "How could my heads be warped....etc,..." is simple. Aluminum heads are notoriously easy to warp...even by something as simple as not following an exact reverse torque procedure when unbolting them. If you have removed the heads...its now a fairly simple and inexpensive procedure to examine and measure them by simply using a Mechanics Metal Straight edge and a decent set of SAE feeler gauges. After a thorough cleaning and scraping of old gasket material and detritus, just lay the straight-edge in three directions; corners to corners and directly down the center and determine the largest thickness of a feeler gauge that will slip underneath, For Iron Heads...the acceptable deviation is only .003"...for Aluminum Heads, it is even less... at .002". If the heads are warped... find a machine shop that can heat them and gently bend them back into shape if possible. If they require machining...make sure they take off as little metal as possible to get them "Flat" again. When you re-install them, follow your torque pattern in three graduating stages and use the proper "Stretch Bolt" turn to perform the final tightening of the bolts down properly. You would be wise to spend $30-$40.00 on a brand new set of head bolts as the GM specs are that they should only be used once. Lightly coat the threads and the undersides of the bolt-heads with engine oil to guarantee a smooth tightening action and accurate torque measurements. Don't add anything to your gaskets in the way of any sprays or "Goo" or stick-um of any kind as the gasket has what it needs to seal properly and adding anything else will invite gasket failure. It would be very helpful to your new-found friends and support team in here to see pictures of what you are working on as well. By the way... there is no such thing as a bolt in any place on your engine that holds things together along with others in a set that is dispensable...so having that snapped off bolt fixed means your head will have an even transfer of heat where the lost bolt would allow exhaust gas to escape and give that area an opportunity to overheat...and warp...

[95grandprix3100]

Well guys I know I haven't bothered to update this in awhile but I have great news! I ended up tearing the whole engine apart again and had the heads resurfaced and pressure checked and then put it all back together and it runs great. A oil change, new gas and some fuel injector cleaner later and I'm on the road driving her around again. I ran into a few problems such as the issue where the duralast belt I bought for without ac didn't touch my waterpump to spin it...(really that made no sense, the worst part was I almost started taking stuff apart because I thought I had a faulty thermostat.) That and bleeding it since the upper bleed nut on my 3100 is snapped off caused me some grief. But now my car is happily back to running great. Thanks for all the help!