Hello friends,
Need your expertise to troubleshoot the sudden misfiles with all driver side cylinders (1-3-5-7). My car is 2004 LX470 with about 220K miles.
Car was still runnable but just couldn't go fast. Drove slowly (~25 mph) to safe place and rest to calm down. After about 1 hour of break, the LX seems back working again, and I could maintain 65 mph to reach my destination at Tuba City. The 2nd day, did some light offroad for about 100 miles without issue. However, when driving to next destination in the afternoon, started feeling the car is getting more and more difficult to maintain the speed like 45 mph, especially uphill. Eventually, right after I found a safe place to pull over on HWY-160 between Tuba City and Kayenta, the engine stopped on itself and couldn't be started immediately after that.
After hours of waiting for AAA to show up, the engine was able to get started, and AAA tow truck didn't want to get me back to Phoenix, and dropped the LX off at Tuba City. Tried to drive the LX for about 10 miles and found it still had no power to maintain the speed. Eventually, my buddy towed me to Flagstaff while the LX kept the engine idling to maintain the steering/braking/light. I knew it's not ideal but at midnight HWY-89 didn't have much traffic. Eventually got another AAA tow truck in Flagstaff to get back Phoenix.
11/2021: Tried to get the shop to replace the head gaskets. However, shop said both heads were warped too badly to re-surface. Eventually, replaced both cylinder heads with rebuilt heads from eBay, including new head gaskets of course.
Since that, had driven for about 2000 miles without issue, and noticed slightly increase on MPG.
The following repair also has been done:
02/2022: Replaced the upstream O2 sensor with Denson one at driver side for code P0134, which was got before the heads replacement
05/2022: Repaired the small coolant leaking on Throttle Body by tapping it in and JB Weld it; Also repaired the cracked hose for "VSV for EVAP". See here for detail.
Just did the leak down test, it seemed all cylinders are in good range at about 15% except for the cylinder 7 is at 25%. However, the cheap kit from Amazon could only do it at 30 PSI.
Checked the timing marks on both cam wheels and crank wheel, and all aligned.
Found 1: The shop installed all the driver side (1-3-5-7) spark plugs super tight! Had to push hardly to loose them.
Found 2: The shop installed all the passenger side (2-4-6-8) spark plugs super loose! Removed them just with my weak fingers without leverage of any wrench.
Didn't do the compression test as I didn't know how to prevent the fuel from injection. Maybe disconnect the crank position sensor?
Before putting spark plugs back with the correct torque to test, anything else I should check?
All suggestion is welcome and appreciated!
Need your expertise to troubleshoot the sudden misfiles with all driver side cylinders (1-3-5-7). My car is 2004 LX470 with about 220K miles.
What happened:
Couple weeks ago, while trying to pass on HWY-89 with floor gas, the LX suddenly vibrated and slowed down regardless how hard pushing the gas pedal. At the same time, CEL turned on (blinking maybe). Pulled over to scan the code, got P0300, P0301, P0303, P0305, & P0307 which basically saying all 4 cylinders at driver side got misfire. Before this happened, the LX have been travelling all the way from Phoenix past Flagstaff as normal. As you may know, I-17 has several big long uphill sections and the LX did it as it should be.Car was still runnable but just couldn't go fast. Drove slowly (~25 mph) to safe place and rest to calm down. After about 1 hour of break, the LX seems back working again, and I could maintain 65 mph to reach my destination at Tuba City. The 2nd day, did some light offroad for about 100 miles without issue. However, when driving to next destination in the afternoon, started feeling the car is getting more and more difficult to maintain the speed like 45 mph, especially uphill. Eventually, right after I found a safe place to pull over on HWY-160 between Tuba City and Kayenta, the engine stopped on itself and couldn't be started immediately after that.
After hours of waiting for AAA to show up, the engine was able to get started, and AAA tow truck didn't want to get me back to Phoenix, and dropped the LX off at Tuba City. Tried to drive the LX for about 10 miles and found it still had no power to maintain the speed. Eventually, my buddy towed me to Flagstaff while the LX kept the engine idling to maintain the steering/braking/light. I knew it's not ideal but at midnight HWY-89 didn't have much traffic. Eventually got another AAA tow truck in Flagstaff to get back Phoenix.
Background History:
After purchased this LX, realized it must had overheating as the heater Tees and radiator was replaced. Also white smokes from the exhaust. Eventually, coolant got into cylinders while parked overnight.11/2021: Tried to get the shop to replace the head gaskets. However, shop said both heads were warped too badly to re-surface. Eventually, replaced both cylinder heads with rebuilt heads from eBay, including new head gaskets of course.
Since that, had driven for about 2000 miles without issue, and noticed slightly increase on MPG.
The following repair also has been done:
02/2022: Replaced the upstream O2 sensor with Denson one at driver side for code P0134, which was got before the heads replacement
05/2022: Repaired the small coolant leaking on Throttle Body by tapping it in and JB Weld it; Also repaired the cracked hose for "VSV for EVAP". See here for detail.
Troubleshooting so far:
Tried to rule out the O2 sensor by changing it back to the old one, still misfires.Just did the leak down test, it seemed all cylinders are in good range at about 15% except for the cylinder 7 is at 25%. However, the cheap kit from Amazon could only do it at 30 PSI.
Checked the timing marks on both cam wheels and crank wheel, and all aligned.
Found 1: The shop installed all the driver side (1-3-5-7) spark plugs super tight! Had to push hardly to loose them.
Found 2: The shop installed all the passenger side (2-4-6-8) spark plugs super loose! Removed them just with my weak fingers without leverage of any wrench.
Didn't do the compression test as I didn't know how to prevent the fuel from injection. Maybe disconnect the crank position sensor?
Before putting spark plugs back with the correct torque to test, anything else I should check?
All suggestion is welcome and appreciated!