Overheating.. LIM and ? on head gasket

Been reading some of the post on this site.. there is a lot of helpfull info.
So a thanks before hand. and sorry for the long post, but it is detailed.

Here it goes.. and I have told her to get rid of it, so let me know otherwise, if after fixing the LIM and posibly the head gasket for the 2,4,6 cyl.
Compression test.. all start strong so not ring, valve, or strong indication of blown head gasket.( read on for head gasket ?) not water in the oil. and with weather hard to determine if blowing fluid (steam) exhaust.. ( i think it is but minimal)
cyl 1 175#, 3 175# , 5 175#,
cyl 2 155#, 4 155#, 6 135#. (should i replace with this variance i do not like # 6 cyc readings)

My girlfriend picked up a 1999 Olds Alero.. 3.4L V6, she has had it less than one month.

After testing and replacing oh.. just about everything in the cooling system. I would not have even thought about the LIM gasket.. and even beating my head on the grown, cutting my hand on small tight places. yelling, you know how it goes when stumped.

Few days ago, car got hot.. and of course like most women, keep on driving vehicle after it overheats.. not running hot, but overheats.

I could not locate any source of loss fluids, Replaced thermostat.. same problem, flushed system, the Dex-Cool brown junk was in the resovior and THIS HAS ME PUZZLED. what appears to be a wad of cotton material.. collected about a golf ball size compressed.. Noticed vapor leaking out of front middle head bolts. ( between 2 & 4 cyl) *** great blown head gasket..*** but still not make sense since what caused it to over heat i have been unable to identify.,

finally replaced, thermostat, flushed system, radiator cap, and even water pump.. pump was cheap,. 22.00.. (amazed on how easy with so little space)

Symptoms.. overheating while driving, idle temp ok.. (did catch it shoot up to just under H; thought did not have system full, bleed out, ) not blowing hot air out of heater.. this was sporadic.. inlet heater hose was hot, return cold. great plugged up heater core flushed out again, no change and flow fine.

Thought was only head gasket, (before compression check, bud had my compr tester) ran the Bar's Leak head gasket repair (did not want to tear into her engine) well leak out of 2 head bolts stopped.. thought was in the clear.. NO ...

Flushed system, no more cotton coming out.. still no leak in head bolts.. no sign of lost fluids..

but bubbling on resovoir and finally cought veh blowing out the resovoir tank.. is this from the lower intake manifold gasket blowing exhaust or pressurizing system to blow out the surge tank.

The engine looks like it has be opened up before, maybe for LIM, i do not know..

So for you experts.. from reading post here, the LIM gasket has to get replaced. and is Felpro ok, then just use prestone extended life.. ?

I guess i need to replace head gasket(s) or can i get away with this and retest compression after engine is at operating temp, and then skirt some oil in # 6 to see if pressure come up if operating temp does not ???? but if testing cold one head to the other should not have such a variance.. ?
spec show min 100# for compression test per cyl at normal operating temp. max variance 30% so withing in spec.. expecially for side by side cyl else can go down to 117# 175-30% that is a big variance ..
or does the LIM cause this variance in compression..?

and if i do have to change head gaskets.. do i need to replace head bolts and what are the new/revised torque specs,, (found this is a mfg prob as well, torque specs being off from mfg and cause svc prob, recall, svc memos?

fused and relays, working for cooling/heating system, if the vehicle is overheating/ LIM or blown head gasket, blowing exhaust in radiator system, if cooling system is running vapor and not fluid, this would cause heater not to work, inlet hose hot, return cold only vapor going into heater core and not fluid.. does that make sense???

sorry again for being so long.. but this model engine has jacked up problems..
Ron

Sort of hard to see and understand what you are sayng but here are some answers.

When you run a compression test basically you are testing piston rings, head gasket seal and valve guide seals. Normally bad LIM gaskets will not show up on this test but may affect the test a few psi. It is possible bad LIM gaskets will cause blown head gaskets if the problem is not detected soon or resolved. Compression on the 3.4L usually hovers around around 150 psi + for each cylinder.

Fel Pro makes good gaskets and can be used instead of the improved GM version. Cylinder head bolts are torque to yield TTY and should be replaced if you plan on doing cylinder head gaskets. Using Prestone Extended Life coolant is fine since it is Dexcool compatible.

UIM/LIM bolts can be reused. Just clean off old threadlocker.

The LIM bolts do have a new torque pattern and specs.

Diagonal bolts may require a crows foot to tighten.

Tighten

1. Tighten the vertical lower intake manifold bolts (1) to 7 N.m (62 lb in).

2. Tighten the diagonal lower intake manifold bolts (2) to 7 N.m (62 lb in).

3. Tighten the vertical lower intake manifold bolts (1) to 13 N.m (115 lb in).

4. Tighten the diagonal lower intake manifold bolts (2) to 25 N.m (18 lb ft).

The revised cylinder head bolt torque and pattern is:

44 ft-lbs, then additional 95 degrees.

Torque sequence:

Top bolts..... .5, 3, 2, 8
Bottom bolts.. 7, 1, 4, 6


BTW - Although cylinder 6 compression is alarming and lower compared to the good ones it is not out of tolerance.

thanks for the info, especially on the torque specs.. shop manual and az, have not check napa.. but torque specs dif on az, repair manual( w./out update i am assuming) and yours.. i thought the 95deg final TTY was for 2001 or newer..

The figures I provided are out of the current GM TSBs and GM Techlink data. The LIM data is applicable to all 1999-2004 Oldsmobile Alero with the 3400 V6 Vin "E" and to 2000 and up Vin "J" 3100 engines found in other GM cars. The cylinder head torque data is definitely applicable to 2000 and up and should be applicable to 1999. But you could double check. Be careful and don't be too reliant on Autozone, Chiltons or Haynes data. Plus the GM 1999 Alero FSM specs if available are more reliable.

The extra 90 to 95 degrees on cylinder head bolts has been standard on these engines for years and a carry over from the 3.1L Vin "M" which was 33 ft-lbs plus additional 90 degrees.

thanks again.. i remember reading torque specs change from 99-00...
and since i have read 3 dif specs, not sure which one is most current and from GM tech updates...,
gave a good new year..

Red Raider.. thanks for the prev info.
question for you.. just tore down the engine.. looks like LIM and Head gaskets have been replaced before.. however the idiot did not torque everything down(a strong assumption based on loose loose bolts on heads and LIM..
Since the head use TTY bolts.. if they were reused, would or could that cause the outside head bolts only to be say at 45ft ib or less, inside seemed pretty tight except one?
also, the rest of the LIM bolts were all loose, and YES the intake was sucking up most of the water, and blowing out the rest once coolant not sufficient to cool vehicle.
and the front head gasket looked completed different than the back one.. different material and stamps were also different both in bad shape..
will have back together tomorrow..
have a good one.