2000 sl engine codes 0507(hi idle) and 0301(cyl 1 misfire)

I have 1.9L sohc 5 speed manual transmission 2000 Saturn SL with about 162k miles. It has been an economical car.

I am not a mechanic but decided to see if I could solve this problem. Engine codes have been 0133 (ho2s slow response bank 1 sensor 1) as well as the 507 and 301 mentioned above.

So far, I have done the following items one at a time in this order:

1. replace spark plugs
2. replace idle air control valve
3. replace o2 sensor in front of the catalytic converter

I have not changed the spark plug wires.

Since replacing the o2 sensor I have not received a 0133 code.

I usually get 2 507 (hi idle codes) for each 301 (cyl #1 misfire). Sometimes I only get hi idle codes.

At cold start the car goes to about 2000 rpm and comes back to about 1400rpm. When warm the car will idle about 1500 to 1800 rpm.

When shifting to a higher gear the rpm increases to about 2300 when I push in the clutch. If I keep the clutch in the rpm will slowly decrease.

The fuel economy has fallen off from the low 40's to the mid to upper 30's.

My Haynes manual says the idle air control is preset at the factory and does not need to be set unless the throttle body has been replaced or someone changed the setting. Since I have made no changes I have not tried to manually set the idle.

The idle seems to be rougher. I have looked for an air leak or vacuum leak but did not find anything obvious. The manual indicated a rough idle or misfire could be caused by a worn timing chain. I have never had the chain replaced. But, the troubleshooting section makes no mention of what might cause a high idle condition.

Any suggestions would be most welcome.

Randy

Your intake manifold gasket needs to be replaced. This is a common problem on the SOHC cars in the third generation. Take some brake cleaner to the gasket near Cyl #1. You should hear a difference in the idle.

Its a medium level DIY job. Basic tools and the manual is really all you need.

I'd check the ETCS electronic temp control sensor. Not sure when they went to the brass ended sensor. But they have been know to cause problems

I'd check the ETCS electronic temp control sensor. Not sure when they went to the brass ended sensor. But they have been know to cause problems

the high idle codes and the misfire code are classic symptons of an intake manifold gasket leak.

However, replacing the Engine Coolant Temperature Sensor (ECTS) can never hurt as a precautionary step. The OP's sensor is resin tipped which cracks from the coolant sending false data to the PCM. The new ones are brass (changed at the factory in late 2001) and will not crack. $17.50 at the dealer

the high idle codes and the misfire code are classic symptons of an intake manifold gasket leak.

However, replacing the Engine Coolant Temperature Sensor (ECTS) can never hurt as a precautionary step. The OP's sensor is resin tipped which cracks from the coolant sending false data to the PCM. The new ones are brass (changed at the factory in late 2001) and will not crack. $17.50 at the dealer


I have seen previous threads that talked about the ECTS. According to the door sticker, my car was manufactured in Nov 99 so it presumably has the old style sensor. In looking at the manual I think I can replace that item.

I can certainly spray brake cleaner on the gasket as a test to see if the idle changes. I will read the manual section regarding the manifold gasket replacement. However, that may be beyond my abilities.

If it seems the manifold gasket needs to be replaced, is that the right thing to do with a 2000 SL with 162k miles?

I would like to drive it another year or so. I use Castrol hi mileage oil and it uses a quart about every 1500 miles.

Thanks Randy

I have seen previous threads that talked about the ECTS. According to the door sticker, my car was manufactured in Nov 99 so it presumably has the old style sensor. In looking at the manual I think I can replace that item.

I can certainly spray brake cleaner on the gasket as a test to see if the idle changes. I will read the manual section regarding the manifold gasket replacement. However, that may be beyond my abilities.

If it seems the manifold gasket needs to be replaced, is that the right thing to do with a 2000 SL with 162k miles?

I would like to drive it another year or so. I use Castrol hi mileage oil and it uses a quart about every 1500 miles.

Thanks Randy

One additional question-

If the intake manifold gasket is leaking, is it likely to completely fail soon or could it last awhile?

The ECTS sensor is a snap to replace, a deep well socket is needed. I think its a 13mm. While you're doing that check the connector they have a corrosion problem.
No way to tell when a gasket will go completely AFAIK.

P0507:
The idle speed on DOHC and SOHC 1.9L engines is controlled by the PCM via an idle air control (IAC) valve. The IAC valve consists of a 2 coil stepper motor that moves a pintle valve in and out from the seat controlling the amount of air bypassing the throttle plate. The powertrain control module (PCM) controls the IAC valve by supplying ignition voltage or ground to any of the four circuits of coil A or coil B. When one circuit of a coil is supplied ignition voltage, the other side is supplied ground. Coil A and coil B are independent of each other, however both must be functional in order for the valve to move correctly. The IAC position is measured in counts, which can be read on the scan tool. When the engine is turned OFF, the IAC is retracted 80-100 counts allowing for maximum air during a restart. After the engine is started, the motor position command is based on ECT and throttle position (TP) sensor values. DTC P0507 sets when the actual engine speed is 200 RPM or more above the desired idle speed.

DTC Parameters
DTC P0507 will set if actual engine speed is 200 RPM or more above the desired idle speed when:

• The condition exits for longer than 10 seconds.

• The vehicle speed equals 0 mph.

• The TP angle equals 0 percent.

• The barometric (BARO) is greater than 70 kPa.

• The ignition voltage is between 9-18 volts.

• The intake air temperature (IAT) is greater than -25°C (-13°F).

• No ECT, exhaust gas recirculation (EGR) pintle, manifold absolute pressure (MAP), misfire, vehicle speed, or TP sensor DTCs have been set.

• The desired idle speed is within 650-875 RPM.

• The ECT is greater than 60°C (140°F).

DTC P0507 diagnostic runs continuously every 17 seconds when the above conditions have been met.

DTC P0507 is a type B DTC.

Diagnostic Aids
Important: If DTC P0508 or P0509 is set, diagnose that DTC first. A diagnosed IAC valve circuit may have caused this DTC to set.

To locate an intermittent problem, use a scan tool to command different idle speed RPM (650-875). ENGINE SPEED should match the DESIRED IDLE SPEED within 200 RPM.

IAC terminal resistance:

• A to B: 40-80 ohms

• C to D: 40-80 ohms

• All other combinations should be open.

Use the following flowchart for possible causes of high idle speed.

Did you mean P0130:?

The oxygen sensor 1 (02S-1) is an electrical source that responds to oxygen content in the exhaust manifold. When the sensor reaches approximately 316°C (600°F), it produces a voltage based on the difference in oxygen between the atmosphere and exhaust gas. The powertrain control module (PCM) sends a bias voltage (391-491 mV) on the signal line which is pulled up through high resistance. When the O2S-1 is cold, it produces no voltage and has extremely high internal resistance. The internal resistance of the sensor is much greater than the resistance of the bias pull-up resistor. However, when the sensor heats up, it produces voltage that overrides the bias voltage. This voltage is read by the PCM to determine a rich/lean O2S-1 signal used to adjust injector pulse width. Under normal conditions, low sensor voltage means high oxygen content/lean air-fuel mixture and vice versa. Normal sensor readings will fluctuate between 10-999 mV. DTC P0130 sets when the O2S-1 signal is not consistently fluctuating out of the 300-600 mV range necessary for closed loop fuel control.

DTC Parameters
DTC P0130 will set if O2S-1 voltage is not fluctuating outside 300-600 mV when:

• The condition exists for longer than 49 seconds.

• The engine run time is greater than 1 minute.

• The engine coolant temperature (ECT) is greater than 60°C (140°F).

• The throttle position (TP) angle is greater than 7 percent.

• No cam (camshaft), crankshaft position (CKP), ECT, exhaust gas recirculation (EGR), evaporative emission (EVAP) purge solenoid, fuel trim, IAT, MAP, misfire, system voltage or TP sensor DTCs have been set.

DTC P0130 diagnostic runs continuously once the above conditions have been met.

DTC P0130 is a type B DTC.

Diagnostic Aids
Important: An intermittent open in the signal or ground wire, as well as an inactive sensor, will not set this DTC.

The most probable cause for DTC P0130 is contamination. Check for obvious contamination (oil, fuel or engine coolant) by removing sensor. Identify and correct the cause of the contamination if contaminated. Replace the O2S-1.

Thanks for the details regarding P0507 and P0301.

I had noted that P0507 only occurred when I was at 0 mph. That is one of the criteria before it can be set.

Randy

I sprayed brake cleaner around the gasket near Cylinder 1 and the idle moved up about 400rpm. I repeated several times with the same results.

I also talked with my mechanic. He chuckled a bit about my efforts but was good natured about it.

He uses a water hose to test for gasket leaks but confirmed the test.

His estimate to replace the gasket was $250. In looking at the manual I don't think I have the skills to do it myself.

But, I have learned some things in getting this far.

Thanks for all the advice.

Randy

I sprayed brake cleaner around the gasket near Cylinder 1 and the idle moved up about 400rpm. I repeated several times with the same results.

I also talked with my mechanic. He chuckled a bit about my efforts but was good natured about it.

He uses a water hose to test for gasket leaks but confirmed the test.

His estimate to replace the gasket was $250. In looking at the manual I don't think I have the skills to do it myself.

But, I have learned some things in getting this far.

Thanks for all the advice.

Randy

I would replace the gasket even with 160K miles on the car. These cars (if treated right) can last well over 250K. To me its a good investment and worth the money. Look at your manual and see if its a doable job for yourself. As i said before its on Medium difficulty and only you know your limits :)
Goodluck!

Intake Manifold
REMOVAL & INSTALLATION
1.9L SOHC Engine
Before servicing the vehicle, refer to the precautions in the beginning of this section.
Properly relieve the fuel system pressure.
Drain the coolant system.
Remove or disconnect the following:
Negative battery cable
Air cleaner fresh air hose
Positive Crankcase Ventilation (PCV) valve hose
Fuel line from the rail
Throttle cable from the throttle body
Throttle cable bracket nuts
Fuel injector electrical connectors
Throttle Position (TP) sensor electrical connectors
Idle Air Control (IAC) valve electrical connectors
Manifold Absolute Pressure (MAP) sensor electrical connectors
Exhaust Gas Recirculation (EGR) valve electrical connectors
Heater hose from the intake manifold outlet
Position the wiring harness over the brake master cylinder
Remove or disconnect the following:
Intake manifold support bracket bolt
Label the vacuum line for proper assembly
Drive belt
Power steering pump
Upper intake manifold bolts
Evaporative Emissions (EVAP) canister purge valve solenoid vacuum hose
Brake booster vacuum hose
Lower intake manifold bolts
Intake manifold
To install:

Thoroughly clean all gasket mating surfaces. Be careful not to damage or score the aluminum surface. If replaced, use Loctite® 290, to seal the new PCV valve inlet tube into the manifold.
NOTE: Refer to Section 1 of this manual for the intake manifold torque sequence illustration. The illustration is located after the Torque Specification Chart.


Install or connect the following:
New gasket and manifold. Torque the nuts in sequence to 22 ft. lbs. (30 Nm).
Power steering pump. Torque the fasteners to 27 ft. lbs. (38 Nm).
Drive belt.
Heater hose and install the manifold support bracket bolt. Tighten the bolt to 22 ft. lbs. (30 Nm).
Lubricate the male ends of the fuel lines with a few drops of clean engine oil, then connect the fuel supply and return lines.
Fuel line(s) in the retaining bracket. Torque the mounting screw to 36 inch lbs. (4 Nm).
Throttle cable to the throttle body and attach the accelerator cable bracket. Torque the bolts to 22 ft. lbs. (30 Nm).
Reposition the wiring harness and connect the wiring and vacuum hoses to their original locations. The harness leads to the TP sensor and EGR solenoid must be routed between the intake manifold runners.
Negative battery cable
Fill the coolant system.
Prime the fuel system by cycling the ignition ON for 5 seconds and OFF for 10 seconds a few times without cranking the engine.
Start the engine, check for leaks, and repair if necessary.

My '99 SW! had the gasket go.
I chickened out doing myself, but looked in when the tech was working on it. He had the upper motor mount off. I assume that this would allow easier access to the lower intake manifold bolts, by rocking the engine.

Well, after looking at the manual, I decided the intake manifold gasket replacement was beyond my abilities.

So, I took it to my local mechanic. This is the same one that chuckled at my diagnostic efforts. But was impressed at the help from members of the Saturn forum.

The cost (labor and gasket) was $225. So far I have only driven it home from the shop but the idle is about 1000 rpm after warming up. That is about half of what it had been.

I have not yet replaced the temperature sensor but that should be within my capabilities.

It will take a tank of gas to see if the fuel economy returns to the low 40's where it had been.

Once again thanks for your comments and ideas.

Randy

Well, after looking at the manual, I decided the intake manifold gasket replacement was beyond my abilities.

So, I took it to my local mechanic. This is the same one that chuckled at my diagnostic efforts. But was impressed at the help from members of the Saturn forum.

The cost (labor and gasket) was $225. So far I have only driven it home from the shop but the idle is about 1000 rpm after warming up. That is about half of what it had been.

I have not yet replaced the temperature sensor but that should be within my capabilities.

It will take a tank of gas to see if the fuel economy returns to the low 40's where it had been.

Once again thanks for your comments and ideas.

Randy

Im about to under go the same opertion (intake manifold gasket) and will posting a how-to for it soon. Sorry I couldt do it for you earlier. However I may be able to make for it. Heres a video for how to change your ECTS.

http://www.youtube.com/watch?v=JC0U53w_Htk
Video Provided by Richpin :)

Thanks very much. I watched the video and believe that is within my capabilites.

Randy

I checked my gas mileage for the first time since the replacement of the intake manifold gasket.

Most of my driving is highway. Mpg was 42.7 which was back to the normal range of mpg.

Now, given the economy and cost of gas, I hope the SL will last several thousand more miles.

Fantastic! Happy driving!!