My Saturn is Sick.
Tuesday morning on the way to work, the service engine soon light came on. Then it started flashing. About the same time I noticed the car was lagging, sputtering at idle, and started to have a bit of a knock.
Uh oh. I got to work (the whole 2.3 miles it is) and didn’t think much of it. Until I tried to go home for lunch. The car was shaking… the SES light flashing… I plugged in my ODBII reader, and pulled three codes off the engine computer. P0128, P0301, P0154.
I babied it home, where I put it in the drive way, and I took Kylene’s car back to work.
My 2003 Saturn L300 has 99,950 miles on it. It’s on the original timing belt, and the original set of spark plugs. It’s also on the first thermostat.
That’s not a bad run.
So about those codes…
P0128 – Temperature. The car isn’t warming up as fast as it should. I’d noticed this last year when it got -really- really cold. This year, it’s been happening more frequently, and although the car used to be warm by the time I got out of the neighborhood, lately it’s just been warming up by the time I get to work. It doesn’t cycle much either, and I’ve noticed a decrease in fuel economy (from 27 to about 23mpg, on highway). I think the car has been running in “open loop”.
P0301 – Cylinder #1 is misfiring. I’m not getting backfires, but it’s misfiring. You can smell fuel in the exhaust.
P0154 – The exhaust O2 sensor before they catalytic convert is giving bad / strange readings. Probably a result of the 301, unspent fuel in the exhaust, which will eventually cause damage to the cat.
After some lurking and some posts on the saturnfans.com forums, I’ve had a couple of former Saturn techs to take care of the 301 and 128’s first. A new thermostat and housing was $30 — that’ll fix the 128. The 301 is likely spark plug related, since it’s the original, OEM set of plugs on the car.
Spark plugs and a thermostat? Oh yeah. I can do that…. well… I think.
GM must hate their customers. Yes, my V6 3.0L engine with plenum coated intake manifolds DOHC, and ignition coils looks darn sweet when the hood is up and the engine is clean. Heck, it’s inherited some of the engine from the corvette. But.. it’s a bear to work on. You have to remove the entire intake manifold and throttle body to get to anything of importance. Plugs? You’ll be taking three layers off the engine, draining some of the coolant. Thermostat? Same three layers come off, then you remove the top radiator hose, re-position the oil dipstick, get our your 9″ 3/8″ ratchet extension, and remove the thermostat from the engine block.
I convinced myself, that for $350 of dealership labor fees and nearly 200% markup on parts prices that I could do this and rule out a lot of ‘what if’ / diagnostics on what’s wrong with my engine. Who knows, maybe I’ll have the confidence to try the timing belt & water pump replacement if this does solve the problem. That’s an $1100 job at a dealership, and getting to the plugs and thermostat give me expirence in ripping the engine down more than half-way to to the where it has to be in order to change the timing belt.
So for the last few days, the car has been sitting in the garage, the electric heater has been warming it up, and Thursday I made a run to the part store on the way home from work to pick up a few tools (torque wrench, E-socket set, throttle cleaner, de-greaser, plugs, thermostat, etc…
