Cracked Head 1991 Saturn

I picked up a beater car and I suspect it has a cracked head. The coolant
looks frothy and there is oil getting into the number 1 and 2 cylinders
(plugs oily). It is vey little oil, but builds up as it sits. The car
stutters at very low load as if compression was zig-zagging up and down. At
full throttle it acts quite well with no noticable smoke (no noticable oil
in coolant or vice versa).

How hard is it to pull the head and repair it? Is there a common crack
point? I know this is a common problem. I'm more interested in knowing if it
just a few hours to pull and JB weld the crack. My worry is, that being a
Chevy, it is hard to do. It *looks* like a primitive engine, but Chevy has a
tendency to put bolts and things at very hard to reach places.

 

(is this a the LL0 or L24? aka SingleCam or TwinCam)

It is not a Chevy and careful with your "primitive" remarks as that is
trolling. No other GM cars use a LL0 or L24. I dont know what engines
you've worked on but I have always found GM cars MUCH easier to work on
than any other maker out there and old Saturns arent half bad. (The new
Ecotecs have are the best)

First off dont go skipping simple diagnostic procedures only to find out
"what you thought" wasnt "what was wrong". 91's have not been known to
crack.(likely you picked up some ill informed crap by a troll in this
group) Do a pressure test on your cooling system. That is by far easier
than jumping right into pulling off a head which to me, doesnt sound
like it is a problem.

It sounds to me that your "Valve Cover" isnt sealing anymore around the
plugs and the oil is shorting out the spark. The frothy coolant you're
seeing is likely Ginger Root put in there by Saturn from the factory. If
you havent changed your coolant in 2 or more years then you are DUE! Get
it done! And be sure to purge the air out of the system.

(Now if you want to see primitive engines look at land rovers crap, or
honda with their cap and rotors.)

 

I wish my Saturns WERE Chevys. Saturn is owned by GM but is an orphan.
Saturn parts are not available from my standard GM parts dealer. I think
THIS is why fuel filters and block heaters are over $100 ea from Saturn.

My understanding was that it was 95 and 96 heads that had the casting flaws
and resulted in cracks. I concur with blah blah, do the simple stuff first
before you go tearing into the head. I doubt that JB weld would be a
reliable repair and would be more inclined to find a good used head and have
a valve grind and guide repair before installation if required. I suspect
that would be cheaper than trying to have the head welded properly.

 

I'm not sure as to the dates but those sound close. It only happened
with SOHC engines. I think it would get stressed at the rockers and
crack. Some bean counter probably tried to thin out to much material.
The fuel filters cost so much because they contain fuel pressure
regulators which alone cost 50 to 75 bucks in any other make. I think
Saturn rates their fuel filter replacements for the S series at 100k
miles or so. Cant recall. As for the block heater failures...I suspect
acidic coolant takes those out.

 

The oil is in the cylinder and mixed with gas. It could be rings or really
bad valve stem seals. If it easy, I can pull the heads and find out. I'm
quite mechanically inclined and this engine is looks easier to work on than
my 3000GT/VR4 or DSM.

 

I do believe the first couple of years where only twin cam

 

Sorry I thought you ment it was getting in the spark plug wells and yeah
just about anythings easier than the cars you mentioned. No real need to
pull the head off just yet because it doesnt sound like the problem.

Check your plugs wires and coil. You may not be getting good spark.

Clean your throttle body and IAC valve. Also clean your EGR and PCV
valve. The pcv is one source of oil consumption. If your rings or valve
train was the cause of the oil loss it wouldnt be the cause of it
running rough at idle unless it builds up a lot of carbon from it.

 

I did the wires and plugs (how I discovered the oil). I talked the guy down
to $1k. After seeing the oil, I guess I was smart to talk him down.

As for the idle, it's perfect. It stutters like bad wires under practically
no throttle/load. If I punch it, it is smooth. My experience with wires is
they start acting up high in the RPMs and move down until they are just bad
under any load.

The emmissions test was 153 PPM HC with a limit of 155 PPM (by comparison,
the GT had 1 PPM with no cat and two old turbos). That means some oil
getting into the combustion, either from a gasket or a crack. I was told the
heads were notorious for cracking.

 

It's dual cam. Didn't know they made a single.

--
Todd Honea

 

Wow. The oil indicates a bad cam cover gasket. $1K is about $900 too much.

That's not really the case. The SOHC heads were bad for a couple of
years, but in general they're no better or worse than most other motors.
Both engines are notorious for oil burning, though - is that possibly
the cause of your high HC readings? I really don't know if that high a
reading is only caused by head cracks or not.
-Rick

 

I cant follow this anymore, I got to make sure... Where are you seeing
oil? On the plug TIPs or in the spark plug WELLs?

I can ground out wires on my 3800 and run smoothly on 3 cylinders at any
rpm range. Different engines = different behaviors. Wires should be
check for arcing and amount of resistance. If you have any wire that is
over 15k Ohms consider replacing it.

Stop worrying about a crack! Have you cleaned out the throttle body?
Have you cleaned or replaced the PCV valve? If not then do the easy
things first. Oil consumption on a Saturn usually comes from PCV valve
or Piston rings. I've never seen consumption from a "crack" and I've
never seen twincam heads crack. Who ever feed you that info doesnt know
Saturns well enough.

 

I will summarize. I bought a beater for a good price. It supposedly consumes
about a quart of oil every month or so. It stutters under a light load, more
pronounced when warm. It doesn't idle badly or accelerate jerky. I first
suspected an ignition problem, so I changed the wires and plugs. When I
pulled two of the plugs on the passenger side, they had oil on the tips and
showed oil fouling. The oil was still on the plugs and smelled of gas. The
doesn't noticable smoke except a puff in the morning. The coolant is foamy
but doesn't appear to have oil in it. The oil doesn't appear to have coolant
in it. I suspect there is a crack in the head near the cylinder crown
allowing oil to get into the cylinder rather than a gasket problem.