Help 96 SL-2 no compression

Did you check for a stuck valve? From what you say it began after it sat over night so that would be the most plausible thing to occur.

How would you tell if the valve is stuck and how would you get it unstuck. The shop had the valve cover off and saw nothing abnormal.

There wouldn't necessarily be anything to see if the engine was stopped.

In order to make sure that the valve train is working properly, you need to watch it while the engine is turning (being cranked by the starter, not actually running) and make sure that all the valves move the right direction at the right time.

Having said that... I've never heard of a valve just "getting stuck". The return spring is pretty damn strong. I've heard of valve springs breaking. I've heard of valve lifters breaking, and hydraulic lifters collapsing. (Not an issue on a Saturn, with an OHC engine.) I've heard of valves breaking. But I've never heard of one just getting stuck.

A broken valve spring *should* be visible with the valve cover off. Depending on where and how it broke, though, it might be pretty hard to see unless you're looking in exactly the right place. At least you know which cylinder to look at.

There's another explanation for the problem, too, but you don't want to hear this: broken piston rod.

He will have to watch to see if the valves ride up against the cam on that cyclinder. (Disconnecting the coil pack would be a very wise thing to do since the coild pack wont be grounded.)

Springs on multi valve engines arent very strong as the valve surface area is much smaller. Doesnt take as much to seal. On a SL2 it will be a DOHC engine which will look like this

A broken spring is very possible. It would allow the valve to pull up away from the piston just enough to clear but never fully close with the cam lobe.

From sitting overnight? Eh not likely.

One other test is to pressurize the cylinder with shop air to find out if it blows out of the intake, exhaust, or head gasket. Piston has to be TDC of course.

A broken spring from sitting overnight isn't all that likely either.

Much more likely in my opinion is that either (a) the problem actually occurred as the OP was driving home and he didn't notice until the next morning, or (b) whatever broke, broke the moment the engine was cranked.

I had this happen in the same year and model. It turned out to be a piston with a big piece broke off the top of it.

Ken

May I be so ignorant to inquire what a misfire sounds like/ how you know your engine has done this?

My Saturn is my first car.

My Saturn 'stumbled' in a start up, flashed the SES and then went solid. I had the code checked, and it was something like "engine misfire". After that, everytime the car started rough, stumbled, and the SES light came on, I figured it just misfired.

So all I say, if you hear a stumbling, and see the SES, you might have a misfire.

later,

tom @

You newver mention if the technician perform and cylinder leakage test. He would be able to erify if it is the valves/rings/head gasket/ head leaking. All that can be done without the valve cover taken off.

You newver mention if the technician perform and cylinder leakage test. He would be able to erify if it is the valves/rings/head gasket/ head leaking. All that can be done without the valve cover taken off.