GGGB Posted January 1, 2013 Share Posted January 1, 2013 Hey Guys/Gals: I have a 2001 ls430 with 187K miles. I am having my first issue with it. My engine light came on with a code of p0325. My ls430 was very sluggish with SIGNIFICANT hesitation, rough idling and a decrease in gas mileage down to 15mpg. The same day I noticed a red triangle with the exclamation mark in the middle came on when I turned the corner. I immediately pulled over & checked my oil. It was low…less that the half-way to full. I normally changed my oil every 7500 miles with mobil 1. But; I missed my last oil change—I was laid-off and have had a hell of a time getting back to work so I totally forgot for the first and only time. So it has been about 10K miles since my last oil change! Uggggh! There is no evidence of an oil leak. Also, for the past month I have not been using premium, either. Trying to cut corners. I added oil—mobil 1 and added 7 ounces of Lucus upper cylinder and fuel injector cleaner to a fall tank of gas as was recommended on this forum. This is the first time using an additive. The next day I got an oil change with regular oil. (On Tuesday, I plan to get another oil change using mobil 1 again.) This appeared to correct the problem for about a week then the light came back on again. Today I noticed another problem: After I start my car, put it in drive and gently press the gas, I hear a motorized whirling sound for about 2 seconds. The sound is very similar to the sound of a robot moving, like on the movie Terminator. This sound is repeatable—meaning I can turn the engine off and restart it and when I step on the gas, the noises occur. I will be taking my vehicle to my mechanic on Tuesday. I’d like to go with some basic understanding of the potential problem. Any Ideas on what’s going on? Did I blow my engine? Quote Link to comment Share on other sites More sharing options...
James Horning Posted January 1, 2013 Share Posted January 1, 2013 Left bank knock sensor , electrical code. Check for rodent damage , single wire to sensor. Or the harness is just brittle and dried out . Both sensors are under the intake manifold . Quote Link to comment Share on other sites More sharing options...
curiousB Posted January 1, 2013 Share Posted January 1, 2013 I have been running regular fuel for 3+ years on my '04 LS430, just rolled over 125k miles. No issues. Last time I checked the engine was still under the hood. I wouldn't go crazy doing a bunch of back to back oil changes. That is just throwing money away. You say you just did a change then wait normal interval before doing it again. Regular vs synthetic is a passionate debate here but that debate has nothing to do with your current issues. Once you cut over to synthetic it is not a death sentence to do a regular oil change before you go back to synthetic. The issue here is the possible loss of oil not the oil type. Prior poster suggested wiring to the knock sensor. Unfortunately its a bit of a problem to get to it. So before ripping out the intake manifold I would: Burn down the current tank of gas to near empty. Just normal usage don't make a special trip to throw the gas away. Fill with premium fuel from a Tier 1 gas vendor (I prefer Shell), preferably a fairly active gas stop (means fuel is turning over frequently). Since you must have an OBDII reader reset the P0345 code Monitor the oil level to see if it is holding Throw a piece of cardboard down and park in the same spot in your garage each day. See if an oil leak develops after several days of parking in the same spot. After your next long drive (over 15 minutes) in the evening (i.e. dark outside) take a look at the catalytic converters just after stopping. See if one or the other is glowing red. That could suggest an ignition problem in one or more cylinders dumping gas into the exhaust system. Don't stick your hand down there. Its hot! ouch... I believe your model has coil over plug ignition so you won't have the very common bad coil problem the earlier model LS400s were prone to have. Its also unlikely more than one CoP went bad at the same time (so losing one cylinder in 8 wouldn't likely make the dramatic performance hit you are seeing). I would look to common components on the ignition system. Maybe the crank position sensor is faulty, loose connector, or out of alignment. When were the plugs changed last? They are good for 100k miles so unlikely they suddenly woke up faulty. But it may be just time to replace them and its cheap/easy to do. A faulty knock sensor needs to get fixed but you can relax and go through a logical order. It might be the intake manifold has to come out to replace a sensor or a wire but try the easy stuff first. You can do that on you own. Maybe you get lucky and just find you had some bad gas and there is no big oil loss. Good luck. Hope your work situation has improved. Quote Link to comment Share on other sites More sharing options...
GGGB Posted January 2, 2013 Author Share Posted January 2, 2013 James thanks for the reply. Today, I cleaned my MAF and replaced an air filter. My MPG went way up to 19.8! No hesitation at all. All was well. Drove around a few hours and no engine light came. So I think I keep driving and see. Quote Link to comment Share on other sites More sharing options...
GGGB Posted January 3, 2013 Author Share Posted January 3, 2013 Drove my vehicle to/from work today and logged the highest mpg ever-- 21.8!!!! My engine light/P0325 did not come on. So far so good. Quote Link to comment Share on other sites More sharing options...
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