robbyk

Wdtony,

Have you asked your local Lexus dealer what is the fee for a diagnosis?. I know you are waiting on money but I think Lexus charges something like $125 to tell you what is causing the noise. You are still doing the right thing and that is trying to diagnose it yourself to save a few bucks. But you don't want to start replacing parts without knowing the cause, in the long run you may end up spending more money by replacing parts you didn't need to replace.

I am with you, I am extremely picky when it comes to engine noises.

wdtony

Thanks, I will call and ask them. If they could precisely pinpoint the exact cause, I wouldn't mind paying $125. I don't want to pay them for a guess. I'll call tomorrow.

jfelbab

Just wondering what type and grade of oil is in the vehicle and how long ago it was changed. Did the noise begin soon after an oil change? I might be tempted to change the oil again with a 100% synthetic using the viscosity suggested in the manual. I know that Lexus has been going with a thinner semi-synthetic blend recently and maybe your engine has some issue with it. An inexpensive option to try.

wdtony

Called the dealer today. The service dept. would not give me a quote about the diagnosis. I asked repeatedly but the only answer they gave was whatever the cost, it would be deducted from the cost of the repair. Also the guy told me they couldn't guarantee they would diagnose it but they'd do the best they can. Ugh,

@jfelbab: I bought the suv in September and the oil was changed then. Also I just changed the oil again about a month ago. For the entire life of the vehicle the oil type has been synthetic blend 5W-30 and I have all records which shows this. Full synthetic might be better but I have a feeling it also might not make any difference with this specific issue.

fastnoypi

have you attempted a top end cleaning? Oil deposits from normal blowby can hang valves open if there is enough crud buildup.

wdtony

No, I haven't. I would like to. Do you have any information about how this is done?

wdtony

I checked the oil today and the level was perfect as usual. BUT, I found some very very small grainy metallic specs on the end of the dipstick. I repeatedly cleaned and repeated to see if I could get more out and there was a tiny amount every time.

These pieces were very small, smaller than pepper but I could feel them if I rubbed them between my fingers. I am not happy with this find. I don't ever remember finding little metal bits on the dipstick before.

I may have to drop the oil pan and inspect the oil carefully. Any thoughts?

wdtony

I checked again today but found no more metal flakes on the dipstick.

fastnoypi

I've been able to do it 2 ways using fish air tubing.
Use the tubing to draw the top end cleaner from a container. I use an empty water bottle so i can see the level.

The 2 spots you can connect the other end of the tubing is either through the brake booster hose or your pcv breather hose.

Pinch the tubing and have someone start the car. Release the tubing so it will suck up the cleaner at little sips at a time. If you suck up too much cleaner, the car will stall.
I typically do about a cup to 1 1/2 cups at a time, then shut the engine off for the cleaner to soak. Then highway drive till all the smoke goes away.
Be prepared for billows of white smoke from your exhaust.

wdtony

If I do this, will I need to change the oil and filter after the process is finished?

btungate

Any results wdtony I read this thread with high hopes to find an answer I also have the same noise. Please update with any progress. Also fastnoypi what top end cleaner were you using.
Thanks

fastnoypi

yes it is good practice, any blowby during the top end cleaning will contaminate your oil a little bit when done with a solvent. You can also do it with hot water to internally "steam clean" your intake valves.



I typically use Seafoam or splurge and use GM top end cleaner. In the event I don't have either on hand i use hot water.

*note..doing the steam cleaning method with water...the engine has to be up to operational temperature so the hot water will steam up when it hits the valves. Do not shut off the motor when using water.
PRACTICE control sipping up your choice of cleaner with a top end cleaner FIRST.
In the case of sipping up too much liquid, it is easier to restart the car with the top end cleaner than getting the plugs wet with water and waiting for evaporation.

wdtony

I haven't done anything yet so I have no update. My wife is pregnant so we are trying to save every penny right now. When I get a few extra dollars together I will focus back on this issue. I will probably do this right before changing the oil next time. I absolutely plan to do a lot of top end work but putting it off for now.

The sound is still there and has only gotten a bit louder (perceived) since we bought it 8 months ago.

One question I have is: When the top end clean has worked for others, did the sound (before the clean) only occur at certain points/times and diminish at other points/times. Or was the sound always present no matter how long the engine ran?

wdtony

Sorry so long for the update. Tax refund came back so now I can continue troubleshooting.

Took it to the dealer and at first the sound would not occur so I left it overnight and then it could be heard distinctly. The technician said he couldn't pinpoint exactly what the sound was but he believed it was top-end and rear bank (or bank 1 which means the cylinder head in the back).

Lexus wanted around 1700 bucks to fix it and stated that they could NOT guarantee that it would be fixed. So I opted out of that.

So I decided to do the job.

So I spec'd out all the front bank lifters and they were all at the upper end of spec (intake and exhaust). Then I finally got to the back bank (bank 1) and found 2 exhaust valve clearances out of spec. They are only out .002 inch out of spec so I am not sure if that is the issue. All other valve tolerances are in spec. BTW, these 2 valves are both exhaust, cylinder 3 so they are both for the same cylinder.

Anyway, parts are ordered and should be arriving today. Hope to have the car back together tonight or tomorrow. Plugs, PCV valve and valve covers needed replaced anyway.

Also, the technician said that the "grit" I found in the oil change might be normal since I am using a synth blend oil with detergents. So hopefully this is a top end sound and the grit/shavings are unrelated.

Will follow up with a conclusion when the car is back together and running again.

jbl-1985

wdtony, a little more insight here.

1) I mentioned before that my 05 RX has a slight noise like yours but not nearly as loud. I was once concerned but then I just agreed to ignore the noise. The interesting thing is that my uncle has a new '15 LS460 and it makes the same kind of sound at idle too. Again, not as pronounced, but there nonetheless. After hearing it from his car, I have no interest in chasing it down in mine. "Let it be" is my motto on that one.

2) I mentioned in an earlier post as well that my 2000 ES had a high pitched ticking noise (obviously not the same engine) and I couldn't ignore that noise anymore. The video below shows what I heard, and I did take it in to get fixed. It ended up being a failed lifter on exhaust valve #3, and the noise you hear in the video is now completely gone. I tried all of the oil additives on this problem and none of them worked.

The noise you hear on your car seems to to be a lower pitch or thunk and is different from the noise on my car - I would not suspect a lifter for that reason.