2009 is250, just went to 100k miles last week, i was driving and heard kind of like a rumbling noise, did not pay much attention to it, it was on and off depending on how much gas i give it, so i come to a stop turn the car off, when i get back, push the button and it start and revs pretty high, like a quick burst before coming back down, i continue to drive dont feel anything wrong with the car, except sometimes kind of like a rumbling noise on the passenger side engine, when i get home i stop, turn the car off then turn it back on this time it wanted to start but did not, i try again this time it started but i hesitated like it did not want to start and the lights were kind of dime before finally starting. turned it off and back on again and same thing, wont start the fdirst time, it will crank over but no start but then would start the second time

NO check engine, and basically after its on it will not show any signs of anything wrong, except a slight rumbling noise when i rev it up a bit high but even that noise goes away too. I looked around the engine as i thought maybe something was loose or the air intake hose came undone, dont see or hear anything out of the ordinary.

Anybody have any idea what this could be?

 

Sounds like you might be experiencing a bad battery, or alternator.

Is there any way you can check voltage . While the car is actually on.

 

i can pass by autozone and get it checked, as far as the battery its pretty much brand new, maybe 7 months old.

would a bad alternator cause it to high idle like that at first start?

 

A failing alternator will cause all sorts of electronic issues. Not enough juice to supply all components. By what you are describing dim lights, hard starts.....

 

just got both checked, alternator and battery are good

 

When is the last time you had a tune up on the car?

 

never, i bought the car with 98k miles 2 months ago, its at 100k now, doing the spark plugs soon just been lazy, at first maybe i thought it was a misfire since the plugs never been changed, but would;t that throw a code?

Only thing i have done since i bought it was clean the maf and throttle body about a month ago, and changed the air filter.

 

What I'm thinking was a slight misfire as well. Could be fouled up plugs. Carbon on the valves and what not. The plug change is every 60Kmiles.

Spark plug change on the 250 is not that bad. As long as you have the proper tools. Remember there is a few connectors under the manifold. Do not yank it out with out disconnecting them.

Another is the purge valve hose under the intake. It goes to a hardline coming from the tank.make sure it's off the clip before pulling it off too.

Make sure you have a good hex set for the intake manifold bolts. Always making sure it is properly seated in the hex head.

Fresh set of gaskets. Probably a new PCV valve since the manifold will be off. Last inspect the valve to see how much gunk is built up.

 

well took it to the mechanic, and was told that noise i was hearing was the timing chain. wow, worser news could not be!

they are quoting me 1500+!

so my next question is, how difficuilt is replacing the timing chain on these cars? i have done them before on simpler cars, but one time i had a hell of a time doing it on my lexus is300 because of the vvti cam gear, i had to tow it to a mechanic cuz i got that wrong.

 

Well that sucks. It's going to be an intense job. I also had an Old GS400. I'm glad I didn't have to replace the timing belt on that beast. Got rid of of before I had to do it. At the times I got quoted from and Indy Toyo/Lexus shop was around $1800 including parts.

 

sucks is not the word for this, all the cars i have owned in my life i been so afraid of timing belt issues i change them immediately when buying a car, this is the first one with a timing chain that *supposely* is to last forever with proper maintance, first car i have ever owned with under 100k miles, and its going bad.... smh

 

Yeah you said you had just bought the car? The only other time someone ran into this was. He admitted to not changing the oil frequently. In turn that led to his timing chain problems. If the PO didn't maintain the car it could've well contributed to this.

 

i also was told that it might not just be the timing chain, i.e its ok, but the tensioners might be bad, hence if they are they can cause the chain to skip teeth and that can lead to more engine trouble, which leads me to ask, is the engine on this car interference or non interference?

 

It should be interference. I myself need to check though.

 

ok, so i have taken my car to 2 more mechanics after the first one who said it was the timing chain

the first shop could not figuere it out, they drove the car, looked in and out and could not tell where exactly the noise was coming from or what was causing it since the car was running perfect and no codes.

took it to another shop, this time they spent 2 days with the car, had all 4 mechanics in there shop look at the car in every which angle, and also could not figuere it out, they mentioned that maybe something was loose within the interior since i just had the recall done and to check with lexus.

finally gave in and took it to lexus, after about 3 days get a call from the head mechanic there and he tells me that he is almost 99% sure the noise is from the fuel pump and or housing, that it will cost a bit more as far as the diagnostic charge to get in there and check, but he says you can feel the fuel lines shaking when u accelerate and can clearly hear the noise is resonating from the fuel pump.

Now, the one thing that lexus and 2 of the 3 other shops agreed on is that its NOT the timing chain. Which to me is a huge relief as that job was 2-3 grand.

Lexus is going to send me a estimate later today and let me know how much they will charge me for the job, which of course im not going to do with them i will just take it somewhere else. But i look in rock auto and see they have 2 fuel pumps, one is like 1000 dollars and another is 180.... this car uses 2 pumps, or am i looking at something wrong? Anybody know how hard this job is labor wise at a mechanic shop?