98 saturn head gasket

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36,515
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ME
compression was 75, 20, 20, 75. Valve timing was good. Valves look good (no burnt holes), but I haven't gotten into them closely. Previous owner says she just got in one morning and it wouldn't start. Did sound funny cranking, like compression really was off. Cyl 3 is wet with oil but 2 is dry. All have flaky carbon buildup on piston tops; cross hatching still visible on cyl walls. Plugs have nothing to say. There's a code for a rear o2 sensor heater and most of the I/M monitors are good, so it wasn't missing. Oil and coolant were where they should have been. Had new looking green coolant (originally dexcool, of course). Gasket had a big tear but I had to reef on the head to pry it off. This might have done it. All fire rings intact. It is showing some "not great" signs of fiber swelling, but I don't know if it's completely done yet. Even if I had the worst piston rings in the world I should have way more than 20 PSI. I'm stumped! I do have a spare head I'll probably wind up sticking on. Thoughts?
 

eljefino

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ME
OOoh, I like this theory. They don't have much tension to begin with!!!! Does extreme heat glue head gaskets down? I've dismantled these particular motors before and they cracked loose way easier. Has an aftermarket rad, BTW. Coolant temp sensor reads normally (they go out a lot.)
 
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22,187
Location
Colorado Springs
eljefino, if you have to pull the motor apart, can you video some of the work and stick it on your youtube channel? If the rings were cooked, wouldn't it affect all of them? I'd think there's something happening between cylinders 2 and 3. Cracked head maybe?
 

eljefino

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ME
Richpin is the king of saturn videos on youtube, so I have to defer to him. My youtube channel is full of people arguing over me doing my stuff wrong, or that a video is full of trickery. Google adsense money is building up though! laugh I was hoping (expecting?) to find a big crack between fire holes in the head gasket, so am stumped. Rings are not a big deal this far into the game. Will report later.
 

eljefino

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ME
The head is still tangled in the injector wires and throttle cable. Will get it fully loose tomorrow and check stuff out. I figure if the head warped though there'd be a trail of fluid in the wrong place.
 
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1,353
Location
michigan
Saturns are notorious for rings getting stuck to the grooves in the pistons ,but you already knew that.that alone would eliminate compression. The oil ring is a joke. Its a wonder anyone gets to 120000 miles unless you have a meticulous oil change record. I hear that you can pop the pistons without removing the block and change rings. Mike the dirty mechanic nearby makes a living slapping these motors back together and selling them. he is a criminal ,but the motors run for 6 months or a year so they can't sue him. New rings , new head gasket and he's got one back on the road in 1 day. are ya sure the cam ain't broke...
 
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13,244
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North Carolina
I'm betting that the head is warped from overheating, the compression of 20 might be the compression shared by the center two combustion chambers.
 

eljefino

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36,515
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ME
Originally Posted By: spasm3
I'm betting that the head is warped from overheating, the compression of 20 might be the compression shared by the center two combustion chambers.
If this were true, and combustion were "short circuiting" above the fire ring on the head gasket, wouldn't that burn that part of the gasket up?
 
Messages
503
Location
McLean, Va.
Head gasket looks fine to me, turn head upside down and with the valve closed plug instahled fluid in chamber does it leak out badly for that little compression. next step would be to check rings with a easy to make single cylinder plate on each cylinder does it leak down badly. the only thing left if these two test show no massive deffects then it has to be camshaft timing. those compression figures are so low it has to be really bad in one of these three things. Head gasket not the problem with this low overall numbers and no massive peices missing.
 
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19,479
Location
Chicago Area
Originally Posted By: eljefino
Originally Posted By: spasm3
I'm betting that the head is warped from overheating, the compression of 20 might be the compression shared by the center two combustion chambers.
If this were true, and combustion were "short circuiting" above the fire ring on the head gasket, wouldn't that burn that part of the gasket up?
I still think it may be the head being warped. It is not burning in the CCs like normal, if at all. And it may not have been torqued properly - another possibility. The internet does not allow a close inspection for me.
 
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