'93 SC2 Engine Problem
 

I bought an SC2. When I first talked to the owner he made it sound like the engine was junk but I went and looked at it.

It runs and drives ok. But runs rough, engine light is on and is "low on power" from what previous owner said.

Previous owner said he bought the car and shortly after 2 valves were "burnt". So he had a new head put on as well as a new timing kit.

After which it ran and drove good for him for about 3-4 months and now the new engine problem.

He said that cylinder 2 had low compression and cylinder 3 had no compression as of now.

It only has 98k miles.

I also noticed a good amount of oil on top the valve cover. Like where the spark plugs plug in and around the valve cover bolt. Not sure where this is coming from.

The car DOES NOT overheat, no matter how long you drive it.
(That is saying a lot having 2 people learning to drive on it, that have never drove stick before)

Was thinking of doing a compression test myself just to see what its at now.


Any ideas?

indeed do a compression check on it...zero compression in a cylinder is never good.

also -- read and post those codes

https://www.saturnforum.com/forum/sho...ght=paper+clip

I gotta second the suggestion!;)

Yep. Hopefully it's just valves and not a cracked piston or broken rings. I'll third the compression test. Do both a dry and wet one.

Compression should be done, and it sounds like who ever did the head used some after market cam cover set. Use GM only the aftermarket crap is known not to last long on S-Cars. Also check the PCV valve.

Well, here's what I found out. When you pull the middle 2 spark plugs (2&3?) it doesn't change what the engine is doing so I'm assuming those cylinders are either dead or barely functioning.

Oil smells "chemically". Assuming its gas that is going into the oil from those 2 cylinders. But what would cause these dead cylinders.


Previous owner said he had a new head put on and drove it a couple months and now lost compression. Think the new head burnt some of its valves?

Another thing, 2 of the bolts that hold the valve cover down (the two between the cams towards passenger side) seem to be stripped out. They will not tighten down, thus allowing oil to leak out.

Also, person following me said "when going through the gears it blows blue smoke out the back"

One last thing: I pulled the engine codes and I got
26- QUAD-DRIVER (QDM) ERROR
32- EXHAUST GAS RECIRCULATION (EGR) CIRCUIT
43- ELECTRONIC SPARK CONTROL (ESC) CIRCUIT


What do you think?

do the compression test and verify cyl compression or lack thereof.
Post compression of all cylinders

Do not worry about chasing codes until you determine whether the engine is salvageable.

Didn't know you could run an s car on 2 cyls (I've done it on 3)

Monday a friend of mine with a newly purchased 1982 Corvette, a one owner low mileage car, and I drove over to an upholstery shop to get an estimate on having the seats upholstered. My first comment before the car had gone a half a mile was this is running bad.
His response was, it runs faster than my Hybred so it seems o.k. to me.
The car quit before we got home.
Loose battery connection caused ignition and/or fuel injection problems.
Fix loose connection, car starts runs a whole bunch better.
I am a car guy and a good mechanic. He? on the other hand is a wanna be car guy and knows how to put gas in it.
I personally fail to understand how a four cylinder car can potentially have 2 cylinders dead and still be described as runs and drives o.k., which points out that a subjective interpretation of a condition in many cases is a misinformed opinion.
Something is dead wrong and the suggestion is to get done or do it yourself, a compression test. Something needed to diagnose the operation of your engine.
There is an opinion assumed that you know what one is or have the capability of doing it yourself.
I do. I have the tools.
I takes about 20 min. and it helps to have a second person to help you.
Or. Find some one to do it.
But I am a car guy and a passable shade tree mechanic.'
Your error codes could be generated and the operative word is
COULD BE
not is,
generated by one or more cylinders are not capable of working for what ever reason. They do not identify the reason but are one more indicator as to something is wrong.
Burning oil, thus the blue smoke out the tail pipe also indicate a problem. That in conjunction with the error codes point at a problem. They also point at the need to obtain a compression test which will give a clear indicator on the need to do additional work.
You ask what I think.
My answer is?
You need to obtain some in depth diagnostic work, such as a compression test.
But it is beginning to sound like no matter what some one told you about the engine in that car, something serious is wrong with it which is going to require a decision on your part as to what to do with the car and it's engine.
And considering the age of the car and the cost of repairing it the solutions range from replacing the engine to replacing the car.
And anything at this point in time is nothing more than a guess.

ok.

Compression test:
#1- 155
#2- 160
#3- 0
#4- 150

Did dry test on all 4 and those were the results.

So I did a wet test on #3 and it was still 0. Assuming some valves are effed??


Also, the spark plugs looked pretty old and nasty.
These spark plug had 2 ground electrodes is that normal?

#1- small amount (compared to other plugs) of deposit on center electrode.
two grounds electrodes were both black. Looked like carbon. Pretty normal

#2- Thick white build up on center electrode that could be chipped off. Also, a build up on one of the two ground electrodes. Looked almost burnt.

#3- thick oily gummy deposit

#4- Very thick white build up around center electrode, that can be chipped off like chalk- End of center electrode was black


And yes the car runs like garbage but for only running on two. It runs pretty dang good.

You have a dead cylinder. Sounds to me like one or the other of the valves is stuck open. This won't let the cylinder build compression to fire the air fuel mixture. Either that or you have a dead wire or coil. Start with the easy stuff first. Replace the plugs and wires and then check for fire on the plug before you install it. If it's firing put it in and see how it runs. Get a can of seafoam and run it thru the crankcase and then change the oil and filter.