dunnojack

i've also noticed that there are more quieter ES's than mine.
Makes me wonder..... there might be a mod that Lexus is not telling us that can quiet down the engine..... maybe a simple twist of a nut, or a small part replacement.

Spill it, Lexus.

garsarno

My diesel / knock now lasts for 1/2 hour+. Going in for first free oil change next week. Will see what excuse service guys say...

terryes

During speedweek at Daytona, the subject was cars, cars, cars, and the group that I was with received quite an earful from some pretty good mechanics and drivers. Here is one point that MAY or MAY NOT help you with your noisy engines --- and possible some other problems you are experiencing as well.

((Please note: the ES350s in my nieghborhood (four now) exhibit NO problems, so I am only going on what has been posted here))

Try occasional full throttle accelerations.

This keeps the carbon cleaned out of the combustion chamber and is important due to the tight squish volumes between the piston and cylinder head. Todays engines are designed to promote good in-cylinder mixture motion (combustion) but it has the down side of providing a ready place for cabon build-up to touch the piston -- CAUSING NOISE. Simply put, they say you will hear a rythmic, piston slap-like noise when the engine is cold. Very prominent and very annoying. The said the CAUSE could be excessive carbon build-up, causing the piston to contact the carbon on the head --- which causes it to rock in the bore and "SLAP". They also said this is much more evident when the engine is cold and the pistons haven't expanded to full diameter yet.

They also said it's a simple and EASY FIX for this problem --- A few good "WOT" (wide open throttle) accelerations will clear the carbon out. They also provided a lot of in-depth technical jargon (which are in my notes) -- for another time.

WOT's: After you warmed up your car, get on a relatively quiet Interstate/Freeway, place you transmission in 2nd or 3rd gear (depending on how fast you want to go, and how strict the POLICE are) and take the car to 55 mph. Then press and hold the throttle wide open, hold it for a few seconds and then let completely off the throttle (do not use your foot brake). Leave the ES350 in 2nd (or 3rd) so that the engine brakes the car and creates some pretty dramatic over-run conditions at high vacuum levels. Let the car slow to 50mph or so and then repeat the WOT a few times. If you notice some "clouds" behind you during this operation, your system is being cleaned out.

The boys also pontificated on what could cause cabon buildup:

1. Driving in city traffic for extended periods. Start and Stop.
2. If your transmission/engine is caused to lag or hesitate (see another thread on this subject).
3. Crappy GAS. Manufacturers recommend a specific grade of gas for a purpose.
4. Oil pressure on cold high RPM operation. If the system is overpressurized with cold (jelly like) lubricants, other "THINGS" may occur as well !!

So, the simple point is ---- if you have thousands of miles on your car and it starts/runs quietly KEEP DOING WHAT YOUR DOING.

Lex13

Thanks for the tips terryes. I'll be sure to watch out for the noise and remember to apply these tips if needed. I do have one question for you though. As for your "Location", what the heck is "fk"? Maybe my geography is not up to par, but I'm stumped on this one.

ES350Bob

That run the heck out of it might work for cars with miles on them, but the common diesel engine noise complaints from members are from day one or near day one of taking ownership and could not be as a result of built up carbon buildup.

LexBob2

terryes, there are 4 ES350's in our relatively small residential area, including mine. I've talked to 2 other owners and they both report their cars are problem free, like mine. Neither mentioned any unusual engine noise. One of the guys is a little older (still working tho), so I don't know if his comments can be trusted.

terryes

If what you say is true, these complainers knew about the DIESEL noise before they left the parking lot after purchase.

If that is true I have nothing to add !!!!

LEX --- FK is an inhouse joke around here.

ES350Bob

Spend some time reviewing the diesel engine noise threads and you will see people did not know when they left the parking lot of the dealership.

That is why if you review Vandam's thread... preparing for arrival...you will see where CL members created a complete checklist before accepting delivery, one item on the list is to help them avoid getting one with diesel engine knocking tapping--be sure you cold start the car and drive it first from a stone cold start to rule this out.

garsarno

What gets my interest is the "tight squish volumes between the piston and cylinder head" comment. The cold oil viscosity must play a role in this. That's why I'm thinking Mobil One synthetic oil's viscosity when cold flows freer than regular oil, hence it gets to the squish areas faster, coating them with oil better and maybe eliminating the knock tap noise.

osokuko

Have a question. Looking under the front driver and passenger seats of my new car I found 3 black vents coming out from under the carpet under each seat. There obviously heater ducks aimed to warm up the rear passengers feet. The reason I’m asking this question is because I thought they were not there on my 07/06 car. Or maybe I’m becoming a victim of older age. Notice I didn’t say old. Lol

terryes

You just like the sound of the word squish, don't you.

Actually I checked with my neighbor to see if he remembered anything being mentioned about using synthetic oil. He ran a blank as I did. The only thing we both remember is, "use what the manufacturer recommends and you can't go wrong". NO ONE said not to use other products.

For what it's worth. I redline both my M-45 and ES350 about once every ten days, and they are very quiet. Like other people have said, you can hear the garage door open and closee, but you don't hear the cars starting up and pulling out.

LexBob2

My 4/06 car has them. They're pretty far under the seats, and kind of hard to see.

osokuko

Thanks, I don't know how I could have missed them before. Maybe because of the Black interior. Anyway took a picture.

ESsearch

garsarno - The squish area is inside the combustion chamber, as you stated between the cylinder head and the top of the piston. Oil has no bearing on this. If there is oil inside the combustion chamber, you've got big problems and you would see black smoke coming out of the tailpipe.

The oil type or grade might have some effect on the noise, although not because one flows "faster" than another. I believe the ES calls for 5w-30w, which means at cold temperature it will flow like a 5 weight oil. That is very thin oil and would be very free flowing. After warm up, it progresses to the equivalent of a 30 weight oil, which again is a lot lower viscosity than what we used to use years ago (i.e. 20w-50w). I actually would be curious if a thicker oil would not actually cushion the parts more and lessen the noise? Just a thought.

As a former mechanic, I have been inside many engines. I do not believe this "rev it up and blow it out" theory for modern engines. It used to be called a poor mans tune up back in the 60's. That was when engine tolerances were a lot more loose and even then it was for cars with 70,000 plus miles on them. On the ES issue in particular I think it is not a sound theory because it would take several thousand miles for any significant carbon to build up.

FWIW - My car is more noisy when cold than warm but I would hardly call it a diesel noise. Some of you might, noise is very subjective. Regardless, I don't feel it is that big of an issue and I also believe it is not damaging at all. I suspect it is the nature of the thermal dynamics and tolerances of this engine design. There could be a variance in the tolerances that would cause one engine to be louder than another.

Pete

ES350Bob

Pete,

From your former mechanic perspective it would be great to get your opinion on this diesel engine noise.

First note: dunnojacks recording is what most with the diesel engine sound would describe to you as their typical idle sound whether the engine is cold or fully warmed up.

BUT: Add workload stress to the engine when from a cold start as in putting it in drive and what you hear inside the car is VERY different than dunno's shared experiences so far and a different noise than his recording sound contains.

If you have ever cranked a boat trailer's wheel up or down to hitch or un-hitch the trailer from tow ball it is like that cranking sound where the teeth are making noise only a MUCH duller quality of tone rapid thumping/knocking sound and it lasts for the first 5 minutes/5 to 7 miles +/- of driving the car until it reaches hot. It is so loud you can hear this knocking inside the car and it is a noise above the sound of the otherwise acceleration sound whether cold engine or hot engine without this knocking. I see garsarno has indicated his is lasting up to half an hour now not just the typical first 5 minutes of driving.

Cold engines are noisier than warmed up ones, but this is something above and beyond a cold engine as it warms up. To get an idea, start your car cold, accelerate it and imagine a sort of rythmic knocking sound on top of the normal acceleration sound like the handle end of a butter knife rapidly against a dull metal object.