Greetings all. I try to keep my wife's Saturn going. After she complained of low power on hills I did a compression check and thought my gauge was broken but no, the exhaust valves were burnt. No wonder!




Fast forward to new valves, timing chain, etc. and it worked well for over a year. One day it suddenly lost power and slowly died on the highway. It sat outside for 8 months until I had time to drag it inside and have a look. It has spark at the plugs, although maybe a bit yellow in color. Fuel pressure 50 lbs. Compression not great but after sitting for awhile it might just need to run a bit. CPI removed and tests ok. Cylinder head temperature sensor removed and tests ok. Cam chain hasn't skipped. It cranks fine and almost starts but not quite. Any suggestions on where to go from here? Thx, al.

 

How many miles on car/engine?
Have you read it for codes?
Do you have a way to read real time data from the OBD2 port?

While cranking, is it actually firing but not starting or is the engine just rotating? Or does it start, run for a few seconds or momentarily, and then die?

When you turn the key to start, what is the security light on the dash doing? Is it flashing red, solid red, or not lit?

Did anything make a nest in the air intake during the eight month sabbatical?

 

If you don't have a good, blue white colored spark, it's not going to run. Check the coil and the plug wires for corrosion. If corroded, clean them up or replace them. If it's still yellow spark, replace the coil and try it. Have you tried spraying some starting fluid in the intake and seeing if it would run on that? I also meant to ask if the two cylinders you showed the burned valves for were cylinders #2 and 3? Just curious as to why those two side by side and not #1 and 4. Unless all of the exhaust valves were burned and you just showed 2 pics and not all 4.

 

Thanks for your prompt reply Derf. Yes it is actually firing during the start process and almost catches but not quite. With plugs out I can smell fuel and plugs in with some cranking they get wet. The security light comes on when I turn the key to on position, it stays on for a few seconds and then goes out, even during cranking. Saturn has 480,000 kms on it (300,000 miles), which I know is lots but it was running perfectly until it suddenly died. Good point on the nest in the intake -- I've found this in both our vehicles in the past but not now. My cheap code reader isn't showing anything, so nothing real time.

 

Good point on the spark color -- I'll follow your suggestion here. I'll pick up some starting fluid today and give that a try also. Most of the exhaust valves were damaged -- I just showed photos of the worst ones because I hadn't seen that kind of damage before. Initially I was surprised that one badly burned valve looked like it was cut with an oxyacetylene torch until I realized the metal was red hot with high pressure gas going by.... just the way a torch works.

 

Yep, there's nothing quite like using a cutting torch and having a piece of hot slag pop down your shirt. Yowsah!!!

 

I would pull the closest oxygen sensor and see if it starts. I have had cats turn into a ball and completely cut off exhaust flow.

 

300K on an origespecially.engine? Well done.

​​​​​​Per Andy, that's why I was asking if you knew why the exhaust valves burned the first time. If the exhaust has nowhere to go..... especially if it burned them on all four cyls.

How much oil does it burn per 3000mi?

 

No idea why the exhaust valves burned the first time; I've never seen anything this bad on any engine before. If the mixture was too lean the color of the head and plugs should have been different -- the color here looked normal to me. It was going through some oil, perhaps 1/2 quart every second tank full but I wrote that off to articles I had read about Saturn oil control rings.

Last night spraying some starter fluid while my wife was trying to start the engine netted no difference in symptoms -- still almost starting but not quite.

I cleaned up the wire plug contacts and base of the coils. Secondarys showing almost 8K ohms. The spark seems pretty strong with a combo of blue and some red/orange arcing across the coil terminals with wire harness removed. I hadn't thought of blocked exhaust, mostly because it was running 100% with good power until suddenly dying on the highway but then a chunk could have fallen off inside and plugged everything up. Good thought Andy. I took out the exhaust manifold O2 sensor and the compressions jumped up, somewhere around 150 each cylinder so I thought that a blocked exhaust system was it. I ended up removing the catalytic converter and downpipe, and although I could get the engine to start it just barely ran and wouldn't rev up, and after a few seconds finally quit. No codes on the cheap code reader. So, I'm pretty much back where I started :-(. Any other ideas of things to try would be welcomed. Thx, al.

 

I would want to look at live data, code readers really don’t tell you much. If it was running good and quit while driving that is a clue. You have spark but it sound like the timing is really slow if will start but not rev up. I would investigate cam timing even if you have 150 cranking. I have over 260000 miles on my Ecotec and it has all the original timing parts but the engine is clean inside and doesn’t burn oil.