Lost compression in 2 cylinders

[FalconVFR]

ok so i have a dilemma, and thought i would ask everyone their opinions... my car (99 alero gls 3.4) died last week... was driving fine, then sputtered for about a second, then died... no other warning signs... so i take it to a shop, and they run a compression test, and show that cylinders 5 and 6 are both running about 75lbs, when the rest are about 150lbs... so my first thought is head gasket... but they tell me that those cylinders are directly across from each other... (not on the same bank)... now while i know its still possible for both head gaskets to go at the same time, it seems kind of a remote possibility... from what he could tell without tearing it apart, there doesnt seem to be any valve or lifter damage, but he freely admitted thats just a best guess on his part... he did note that the lower intake manifold was leaking as well... he said it probably wasnt worth the cost of fixing, as its got 156k miles on it... so i towed it back to my place, and there it sits... i guess what i want everyones opinion on, is it worth me tearing into it on the weekends or something, or does it sound like theres more serious problems, and i should just sell it as is? could the leaking manifold gasket cause a loss of compression on 2 diff cylinders?

a little extra info: i drove this car about 50 miles round trip every day to work, with no problems.. mostly highways... its never overheated (including when it died), but did have a tendancy to run a little hot, just under the 3/4 mark... because it did run a little hot, i was always checking my coolant level, and it was just fine... no leaks either... i didnt see any smoke out the back before it died, but i was also a little preoccupied trying to get it off the road with no power steering or brakes... the car did start ticking pretty bad a couple months ago, so i did the seafoam fix, which worked like a charm, ticking went away and hasnt been back since...

ive heard horror stories of the LIMG on thes engines, and i can only guess that the headgaskets would probably be worse... if it was just one bank, id feel alot more comfortable with tearing into it, but seeing as how its both sides, well, maybe an engine swap would be easier... ive done plenty of work on engines before, but mostly smallblock chevy and fords... and none with fuel injection...

thanks in advance for any advice... you guys have always been really helpful to anyone who needs it on this forum...

[AZFire316]

The risk you run with getting another engine is you may get one that has the same issues or may soon there after. Damn GM and their cheap gaskets in that period! Claimed my 3400 at 159K.

[JLw7123]

It is not that hard to replace the headgaskets it is just takes a long time if you are doing it for the first time. My headgasket is leaking i am going to replace it this summer.

[TxAlero]

Headgaskets sound scary but I did them and If I can do it you can! LOL

[Lucalare]

Get it running and check your coolant for bubbles, and also check your oil for coolant (drip some on your hot exhaust manifold and see if it boils). Bubbles in your coolant would be exhaust gasses and oil boiling on the manifold means that coolant is leaking from the coolant passages into the oil passages. Either of those are a sure sign of a shot head gasket.

[zzyzzx]

Searching around the internet, I see head gaskets as a common problem for this. Also, consider the possibility that you have has low compression in one for some time and never really noticed it until the second one went.

This person had low compression and found cracks in the head when they took the head off and scrubbed it. With pics!http://www.therangerstation.com/forums/showthread.php?t=35008

You should be able to fix this yourself if you have another car to drive for a few weeks, and it's worth it if you like the car and have a place to fix it.

[Cliff8928]

Does it actually run? I wouldn't rule out a snapped camshaft, it's known to happen on the cams with the pressed on lobes.