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gifted-tulip

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Everything posted by gifted-tulip

  1. Steve thanks for your thoughts. Glad to hear its not serious. Does any engine damage occur during the time the valves are taping? I thought of using 1 qrt of 10w-40 in my next oil change but this may be to conservative. I usually change oil every 4000 miles. I looked at the exact time the car was parked before starting it. The time was actually 8 full days. I will try to avoid leaving it parked that long in the future...plan to keep it under 5 days. I have a question assuming proper maintenace, what is a reasonable life expectancy of this 4L engine.? Does the A/C compressor need any service at any time?
  2. Guys, Occassionally after parking my car for 5 - 7 days,I hear valve taping sounds coming from the engine. Is this a major concern? The car has 191000 miles on it at present. The taping is loudest when the engine first starts then gradually disappears over 30 to 45 seconds at idle. The engine is working normally most of the time. I would appreciate your help. Is there anything I can do? I use 5w-30 80% synthetic oil in it and 5w-30 is the recommended oil by manufacturer.
  3. I suggest replace both pre cat oxy sensors at the same time even though it seems like an unnessary expense. The light may be coming on because the signal from the two sides is different now that you have put in one new sensor. I have a 1998 ls400 and when I replaced both pre cat oxy sensors the light went off and has never come on again. The pc software however is the professional way to get the definitive answer.
  4. I forgot to add a note to the previous post. You can reach me directly at < Art_helen@sbcglobal.net > I only entered this info because my internet skill is rather soft and sometimes I cant find my own posts.
  5. I have a 1998 Lexus LS400 with 191000 miles. I am just doing the 190,000 mile maintenance on it...new timing belt,water pump,brake pads, brake rotors,tires,and four wheel alignment..new battery,and change of differential, automatic transmission, Brake and P/S fluids and antifreeze. The brake fluid was only slightly discolored (pale yellow)but no leaks found anywhere. I also checked the NGK iridium spark plugs--they are like new and do not need changing. The engine air cleaner and battery are only a few months old. I just put 4 new Michelin Primacy tires on it. There is no vibration or noise in the steering system. The antislip differential works like new and all the interior dash and lights are working. It has a 6 CD disc changer that is working normally. I would like to know what you think this car which is now ready for another 100,000 miles is worth today. Any siggestions.? I think the 1998 LS400 is probably one of the best cars Lexus ever built.
  6. I will only address only one code, namely...P0420 on your code analyser at this time. Note: The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. Is your check engine light on? This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system. Symptoms : The main symptom to the driver is the illumination of the MIL (malfunction indicator lamp). Check-engine-light. You will likely not notice any drivability problems, although there may be symptoms. For example, if the substance inside the catalytic converter is broken or failed, it may be restricting the exhaust which will result in a feeling of reduced power output from the vehicle. Causes: A code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for A damaged or failed oxygen sensor (HO2S)needs replacement. Even new ones can be defective although this is unlikely. The Downstream oxygen sensor (HO2S)wiring was damaged at installation or was connected improperly The engine coolant temperature sensor is not working properly. Is there proper coolant in the coolant reservior? Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe. Do you hear any abnormal sounds under the hood, under the car,or at the back of the car? Retarded spark timing The oxygen sensors in front and behind the converter are reporting too similar of readings Leaking fuel injector or high fuel pressure Cylinder misfire Oil contamination Possible Solutions: Here are some suggested steps for troubleshooting a P0420 error code: Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required. Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady). Inspect the downstream heated oxygen sensor (HO2S), replace if necessary Replace the catalytic converter Overall probably the biggest mistake vehicles owners make when they have a P0420 code is to simply replace an oxygen sensor (H02S). It is important to do proper diagnosis so you're not wasting money replacing parts unnecessarily. I strongly recommend that if you need to replace the catalytic converter that you replace it with an OEM unit. Second choice would be a high-quality replacement part. There are many stories in forums where folks replaced the cat with a cheaper aftermarket one, only to have the code return shortly thereafter. good luck.
  7. where did you take your lexus for repair.? What did they say? Have you had the problem resolved? I am so sorry to hear about your Lexus dealer experience. You should report your experience to Lexus corporation headquarters. It may bring about some real changes at your local Lexus dealer. Also, remember to give your experience with the local dealer to your local"rating your experience" web site. I hope the issue is now resolved. You can send me a direct email at anytime <art_helen@sbcglobal.net> but then no one else get the benefit of your experience. That is why the Lexus club is so valuable. It shares your experience with many other owners.
  8. If your check engine scanner reads 242 degrees, the coolant temperature is way above boiling. The engine temperature should be 160 - 180 degrees F. when warmed up. Maybe your coolant fluid is low in coolant reservoir. Let the car engine cool down completely 2 - 4 hrs. and then check coolant level in coolant reservoir that is close to coolant radiator Have you checked whether your coolant reservoir is filled to the proper level? After filling the coolant reservior, start the engine and let it warm up at idle and then do a diagnostic code check again. If the temperature is still above 180 degrees, you may have a faulty thermostat or cooling fan or fan belt problem that needs replacement. Secondly your starting problem may be due to faulty fuel pump or a plugged fuel filter in gas line. I would suggest replace the fuel filter first to see if this fixes your problem. Then have mechanic check fuel line pressure at the engine. Maybe you have dirt in your gas tank and you need gas tank removed and cleaned of all debris.
  9. I would suggest you take your Lexus to a Lexus dealer if possible for code check. Sometimes a simple fix can be as simple as a new gas cap. I agree with guru member above, it is highly unlikely that all four oxygen sensors went bad at the same time. I really doubt the diagnosis made by your shop. Go and get a Lexus dealer opinion if possible. MY engine light came on on my 1998 Lexus LS400 and a code diagnosis of one precatalytic oxygen sensor was made by the Lexus dealer. They recommended that I replace both right and left precatalytic oxygen sensors. After I replaced both right and left pre-catalytic oxygen sensors ..the engine light went off and has not come back on in 25,000 miles of driving. Maybe it was unnecessary to replace both Right and left side Oxygen sensors as I did but it sure has solved my problem completely.
  10. Which "OBD II" tool would you recommend as the best tool for diagnostic use on 1998 Lexus LS400?
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