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Help: Survey Of Lx470s With Cold Engine Knocking


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Hey everyone,

I seem to be having a problem with Lexus and the tech assist department. Can any owners post some documentation please.

99 LX470 with 75,000 miles.

Started last winter in Colorado. Engine knock when started in cold temps. Sounds like a diesel truck....ie knock, knock, knock....lasted for 30 seconds or so. We didnt leave the truck outside that often...but the noise was worse the colder the temps. I really noticed it when I had to move the truck in the driveway after a cold start....it sounded like a diesel. on accel....knock, knock, knock.

Ok, winter 2002 there were no abnormal noises heard...45k on the odometer.

Ok, winter 2003 it sounded like this with around 60k on the odometer.

10 degrees....it would make noise even at idle on start up.

20 degrees....less noise but could still hear it.

30 degrees....hard to tell, but if you put it in gear and loaded the engine it would knock.

Ok, fast forward to this year winter 2005 in Oregon with 75k on the odometer.

30 degrees...much, much louder knock....same knock as last year just louder at a warmer temp. Also, the knock will last for 2-3 minutes...or if you drive the truck it sounds like a constant knock, knock with engine speed. You can hear it outside, inside and all around the truck. Stand fifty feet away and listen as the truck takes off. Yes, you hear it just like a diesel truck taking off.

40 degrees....less knock noise that 30 but its very clear and lasts for the same 2-3 minutes.

50 degrees....I heard it this week on a cold start. Put the truck in gear and moved it in the driveway....there it was the diesel knock noise.

So, the trend is getting worse and I made the appt to have it looked/listened to. I had to leave the truck overnight. Got the call...and Lexus techs said could not duplicate. Ok, leave it again....same response. 3rd day I come to pick it up and take the techs out on a 49 degree morning. I start it, put it in gear and there is the knock. Two techs heard it....jumped out and listened. It lasted for about 2 minutes and the techs said they would have to call tech assistance. I told them that the noise was about a 3 on a scale of 1- 10 because it was farily warm that morning. Ok, now the round and around with Lexus customer service. Tech assist says its piston noise and normal. Lexus customer service says that the dealer is saying its normal piston noise. .....round and around general passing the buck.

So, I come to find out that the Tundra/ Sequoia group have been having this problem for a couple of years but on a much higher/ louder scale. Nothing is mentioned in the Landcruiser circles....nor here in the LX40s circles. These are different engines than the Tundra and should not have this clearance issue with the pistons.

Bottom line, noise is wear...and its getting worse. And, its not several pistons...it is just one piston. The knock is one piston, period.

There it is gang, if you can document your LX age, mileage and climate that would be great. Oh, and if your hearing any abnormal knocking when you put the truck in gear and or take off from a cold start. My argument is simple....if this is normal, then any number of similar aged/mileage LX470s will have this noise. Simple, right? Well bring me some trucks that make the noise.

So, post if your having the noise and/or if your not having any noises.

__________________

Cheers,

Dave Hall

99 LX470....special knocking diesel model. We were thinking about a new GX470 but forget it now.

92 SC400

00 LS400

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Is this the problem with the exhaust manifold crack? Theory being that the heat expands the manifold and closes the crack after it warms up. They should have a recall since it seems to happen alot or at least cover it under the drivetrain warranty.

I have a very faint tick and it goes away after 2-3 min. No where near the sound of a diesel.

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Nope,

I was hoping that mine was the manifold. No dice. What are your specifics? age/mileage and location. Does it get cold where your at? and does the LX sit outside from time to time?

The best way to duplicate the knock noise is as follows...

1. Start engine cold with outside temps below 40 degrees.

2. Put truck into gear

3. Power brake the truck just so the rpms get to between 1000 and 1100. If the pistons are rattling...you will hear it as a distinct knock, knock, knock...that will go away after 30 to 120 secs.

Thats it....any other questions?

=====================================================

Is this the problem with the exhaust manifold crack? Theory being that the heat expands the manifold and closes the crack after it warms up. They should have a recall since it seems to happen alot or at least cover it under the drivetrain warranty.

I have a very faint tick and it goes away after 2-3 min. No where near the sound of a diesel.

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No solutions yet on the Tundra/Sequoia boards. I have heard of Toyota looking to replace some engines. Nothing concrete yet.

Bottom line, this is not a nuisance or subjective issue. One piston is making lots of noise....noise is wear, the noise is getting louder and louder each year, the wear is getting more and more. Lexus does not want to fix it because it will cost lots of money. I dont care about the Lexus bottom line...nor the Toyota bottom line. If it is out of spec....its out of spec. If its normal there should be other owners having the same noise.

So, here is the poll. If you have some noise...speak up and be counted. If you hear no noise....speak up and be counted.

Thanks

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Jocigar,

Thank you and exactly the information I needed. If ever we needed the actions of a community such as this...it is now. This should not be the normal condition in a 65k vehicle. I have read all the horror stories about GM and the ongoing problems. Ford on the otherhand has fixed this problem and replaced thousands of engines. I dont think this is a rampant problem with the LX/Landcruiser and hope to come to the table with 100 owners and no problems. That will make Lexus listen.

And a side note. Sure, when started there can be some cold engine noise...for a few seconds...say 15 seconds. But, when the noise goes on and on for minutes and minutes and you start driving the car and can hear the noise. That my friends is excessive wear and your pistons are paying dearly. Go read the MIT article on it.

Cheers

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I recommend you try and correlate the degree of knocking over the years with the engine oil weight. If you run lighter weight oil, such as 5W30, the knocking will be gratly reduced. I wouldn't worry about the noise.

Jocigar,

Thank you and exactly the information I needed.  If ever we needed the actions of a community such as this...it is now.  This should not be the normal condition in a 65k vehicle.  I have read all the horror stories about GM and the ongoing problems.  Ford on the otherhand has fixed this problem and replaced thousands of engines.  I dont think this is a rampant problem with the LX/Landcruiser and hope to come to the table with 100 owners and no problems.  That will make Lexus listen. 

And a side note.  Sure, when started there can be some cold engine noise...for a few seconds...say 15 seconds.  But, when the noise goes on and on for minutes and minutes and you start driving the car and can hear the noise.  That my friends is excessive wear and your pistons are paying dearly.  Go read the MIT article on it. 

Cheers

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I've got an 04 GX470, with the exact same engine and transmission as the LX 470. I've seen no mention of any engine knocking problems on cold starts in any of the Lexus boards that I follow. Mine only has a couple thousand miles on it, but I started it after it sat outside in below zero temps for about 5 hours on Christmas Eve, and it started right up and was as quiet as can be.

I havn't even had my first oil change yet, so it still has the factory fill oil in it, which according to the owners manual is 5W-30.

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Thanks for the feedback everyone. Keep the replies coming! From this and other lists it does seem that the knock is not a normal condition with these vehicles. I do need additional responses to make the numbers more reliable.

Check out my thread on the Landcruisers forum. Lots of good input and feeback there....

http://forum.ih8mud.com/showthread.php?t=30084

Thanks again,

Dave

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  • 2 weeks later...

A number of manufacturers are having similar problems GM has a bunch in their Suburbans.

Some Piston slap IS normal on really cold start--the question is "How Much is Normal?'

<_<

One thing that can/will make it worse is varnish building up on the wrist pins or in the piston ring grooves.

Try adding 1 pint of Marvel Mystery Oil to the crankcase and run it a full change cycle to see if it improves it. MMO will gently soften varnish without hurting anything.

It only take 0.004" of piston skirt clearance at normal room temp to sound real loud when temp is 30F.

If it knocks at operating temp--it is too loose. If it is quiet at operating temp it may be OK. :unsure:

You should not ever be able to hear it inside the vehicle windows up. :cries:

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Tex,

I agree completely. Some noise is ok on a real cold start. The problem is....mine is rapidly getting worse and its just one cylinder not a series of knocks.

Oh, you can hear it in the cabin, outside the truck, across the street and down the block. I think of a real cold start as 10 degrees or below.....not 50 degrees. What do you guys think?

This thinks knocks at 50 degrees. :censored:

===================================================

A number of manufacturers are having similar problems GM has a bunch in their Suburbans.

Some Piston slap IS  normal on really cold start--the question is "How Much is Normal?'

  <_<

One thing that can/will make it worse is varnish building up on the wrist pins or in the piston ring grooves.

Try adding 1 pint of Marvel Mystery Oil to the crankcase and run it a full change cycle to see if it improves it. MMO will gently soften varnish without hurting anything.

It only take 0.004" of piston skirt clearance at normal room temp  to sound real loud when temp is 30F.

If it knocks at operating temp--it is too loose. If it is quiet at operating temp it may be OK.  :unsure:

You should not ever be able to hear it inside the vehicle windows up.  :cries:

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  • 4 weeks later...
Hey everyone,

I seem to be having a problem with Lexus and the tech assist department. Can any owners post some documentation please.

99 LX470 with 75,000 miles.

Started last winter in Colorado. Engine knock when started in cold temps. Sounds like a diesel truck....ie knock, knock, knock....lasted for 30 seconds or so. We didnt leave the truck outside that often...but the noise was worse the colder the temps. I really noticed it when I had to move the truck in the driveway after a cold start....it sounded like a diesel. on accel....knock, knock, knock.

Ok, winter 2002 there were no abnormal noises heard...45k on the odometer.

Ok, winter 2003 it sounded like this with around 60k on the odometer.

10 degrees....it would make noise even at idle on start up.

20 degrees....less noise but could still hear it.

30 degrees....hard to tell, but if you put it in gear and loaded the engine it would knock.

Ok, fast forward to this year winter 2005 in Oregon with 75k on the odometer.

30 degrees...much, much louder knock....same knock as last year just louder at a warmer temp. Also, the knock will last for 2-3 minutes...or if you drive the truck it sounds like a constant knock, knock with engine speed. You can hear it outside, inside and all around the truck. Stand fifty feet away and listen as the truck takes off. Yes, you hear it just like a diesel truck taking off.

40 degrees....less knock noise that 30 but its very clear and lasts for the same 2-3 minutes.

50 degrees....I heard it this week on a cold start. Put the truck in gear and moved it in the driveway....there it was the diesel knock noise.

So, the trend is getting worse and I made the appt to have it looked/listened to. I had to leave the truck overnight. Got the call...and Lexus techs said could not duplicate. Ok, leave it again....same response. 3rd day I come to pick it up and take the techs out on a 49 degree morning. I start it, put it in gear and there is the knock. Two techs heard it....jumped out and listened. It lasted for about 2 minutes and the techs said they would have to call tech assistance. I told them that the noise was about a 3 on a scale of 1- 10 because it was farily warm that morning. Ok, now the round and around with Lexus customer service. Tech assist says its piston noise and normal. Lexus customer service says that the dealer is saying its normal piston noise. .....round and around general passing the buck.

So, I come to find out that the Tundra/ Sequoia group have been having this problem for a couple of years but on a much higher/ louder scale. Nothing is mentioned in the Landcruiser circles....nor here in the LX40s circles. These are different engines than the Tundra and should not have this clearance issue with the pistons.

Bottom line, noise is wear...and its getting worse. And, its not several pistons...it is just one piston. The knock is one piston, period.

There it is gang, if you can document your LX age, mileage and climate that would be great. Oh, and if your hearing any abnormal knocking when you put the truck in gear and or take off from a cold start. My argument is simple....if this is normal, then any number of similar aged/mileage LX470s will have this noise. Simple, right? Well bring me some trucks that make the noise.

So, post if your having the noise and/or if your not having any noises. 

__________________

Cheers,

Dave Hall

99 LX470....special knocking diesel model. We were thinking about a new GX470 but forget it now.

92 SC400

00 LS400

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Have 99 LX470 bought CPO 8/01 18k miles DOFU 5/99 Engine 2UZ-FE. Religous oil changes with mobil 1

Noticed engine knock on cold start at 46k miles. Brought into dealer told them that I thought it was lifter noise. Dealer response: Tech 251 found concern with vehicle as designed. Told dealer that did not beleive this was as designed. As no other vehicle that I owned with this little mileage ever made this sound. Said I would monitor and if got worse would be back at them.

Well, obviously has gotten worse. My wife drives this vehicle most of the time and now with 55k miles on a cold morning here in MSP (10 degrees) engine sounds like a diesel and runs rough for first 45 secs - beyond unacceptable

It reminded me of my 1976 ford van with a 351 V8 that made the same sound starting at 130k miles. The problem - bad push rod. the fix new pushrod. the cost $10.00. put another 70k miles on ford - no noise - car was rusty but trusty sold it for $200.

This sound doesn't make me confident this engine will make it even to 100K. Any data toylexmods can provide would be great.

BTW I use to race motocross on japanese technology - and continue to be pretty confident in it, however Lexus needs to respond more effectively than they have and do a proper diagnoses.

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Have 99 LX470 bought CPO 8/01 18k miles  DOFU 5/99  Engine 2UZ-FE. Religous oil changes with mobil 1

Noticed engine knock on cold start at 46k miles.  Brought into dealer told them that I thought it was lifter noise. Dealer response: Tech 251 found concern with vehicle as designed. Told dealer that did not beleive this was as designed. As no other vehicle that I owned with this little mileage ever made this sound. Said I would monitor and if got worse would be back at them.

Well, obviously has gotten worse. My wife drives this vehicle most of the time and now with 55k miles on a cold morning here in MSP (10 degrees) engine sounds like a diesel and runs rough for first 45 secs - beyond unacceptable

It reminded me of my 1976 ford van with a 351 V8 that made the same sound starting at 130k miles. The problem - bad push rod. the fix new pushrod. the cost $10.00.  put another 70k miles on ford - no noise - car was rusty but trusty sold it for $200.

This sound doesn't make me confident this engine will make it even to 100K. Any data toylexmods can provide would be great.

BTW I use to race motocross on japanese technology - and continue to be pretty confident in it, however Lexus needs to respond more effectively than they have and do a proper diagnoses.

I had responded to this thread in an earlier post. I finally got my dealer to say that they had several other complaints from LX470 owners recently. they said after speaking with technical people at Toyota that it is in fact piston slap. Other then reassuring me that there has never been a failure of this engine for any reason,no further action has been taken at this time. I said I would monitor and if it got worse they would hear from me loud and clear.

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  • 2 weeks later...

dmichaels,

Glad to see this thread is still getting noticed. I too got the same song and dance of no reported failures of this engine.

My question is this, we all know this is a wear concern and wear will increase over time until it really starts going. Toyota/Lexus are banking that us owners will trade the truck off or sell it before things really get bad and the engine absolutely needs repair.

The problem with this position? Those of us who know whats happening will never own a Lexus again. Period. We have had 5 and will not purchase another Lexus. End of story ;( And we have owned Toyotas for 20 years. Sad day.

Ours knocks at 58 degrees on a cold start up. Its getting worse.

Send me a PM or email at Toylexmods@hotmail.com for some additional tips.

It makes me sad that even Ford stepped up to the plate and repaired the knocking v8 in its trucks.

Cheers to all and good luck with Lexus!

Have 99 LX470 bought CPO 8/01 18k miles  DOFU 5/99  Engine 2UZ-FE. Religous oil changes with mobil 1

Noticed engine knock on cold start at 46k miles.  Brought into dealer told them that I thought it was lifter noise. Dealer response: Tech 251 found concern with vehicle as designed. Told dealer that did not beleive this was as designed. As no other vehicle that I owned with this little mileage ever made this sound. Said I would monitor and if got worse would be back at them.

Well, obviously has gotten worse. My wife drives this vehicle most of the time and now with 55k miles on a cold morning here in MSP (10 degrees) engine sounds like a diesel and runs rough for first 45 secs - beyond unacceptable

It reminded me of my 1976 ford van with a 351 V8 that made the same sound starting at 130k miles. The problem - bad push rod. the fix new pushrod. the cost $10.00.  put another 70k miles on ford - no noise - car was rusty but trusty sold it for $200.

This sound doesn't make me confident this engine will make it even to 100K. Any data toylexmods can provide would be great.

BTW I use to race motocross on japanese technology - and continue to be pretty confident in it, however Lexus needs to respond more effectively than they have and do a proper diagnoses.

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BTW,

The running rough is a key factor. You could be getting some blowby due to excessive piston clearance and ring clearance. Not good

Also, I have said all along just do the proper diagnosis not the song and dance with ears and eyes closed. Hell, I would expect Chevy to do that with a pos 30000 dollar Suburban...not Lexus and a 65000 LX470.

Yep, I dont know how many more winters this thing will last with this slapping. It is loud if left outside....sounds like a rod knocking. Just one cylinder too!

Well, obviously has gotten worse. My wife drives this vehicle most of the time and now with 55k miles on a cold morning here in MSP (10 degrees) engine sounds like a diesel and runs rough for first 45 secs - beyond unacceptable

This sound doesn't make me confident this engine will make it even to 100K. Any data toylexmods can provide would be great.

BTW I use to race motocross on japanese technology - and continue to be pretty confident in it, however Lexus needs to respond more effectively than they have and do a proper diagnoses.

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Did the techs verify that all the cylinders are firing properly? I've had some cases when a spark plug wire was broken internally or loose at the plug connection (on different toyotas). Those were on inline 4 cyl engines, though, and inline crankshafts are naturally balanced. If it happened on a V, I'd suspect there would be some kind of imbalance/vibration. Anyways, it's worth a shot. The only failure I've heard of with the 2UZ-FE (4.7L V8) engine was a blown head gasket, and 99% of the time, that's from poor cooling system maintenance or mixing red/green coolant, which clogs the radiator, causing the engine to overheat. If any of you are in the LA area, I know a good independent Toyota/Lexus mechanic I can refer you to. He drives the LS400 w/ 1UZ engine...same engine, but stroke and bore are larger on the 2UZ.

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  • 3 weeks later...

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