[myhighlander]

I have 550 miles on my 08 highlander now. About a week into having it, I noticed that on cold starts once I put the car into drive and accelerate, there is a sounds that really makes it sound more like a 4 cyl. instead of a 6. Kind of a faint fluttering or knocking sound from the engine. I hate to use the word "knocking" but it's just really hard to explan. All I can say is that my 6 cyl. sounds just like the 4cyl RAV 4 we test drove before deciding on the Highlander. Anyone else notice this?
Also, there's sometimes a popping felt and heard from the steering, once again only on cold starts and if the car isnt warmed up for atleast 3-5 mintues. As soon as I make that first turn I can feel this faint pop in the steering. I dont know if I'm just being paranoid, I turned in an 05 Chevy Trailblazer to get back into a Toyota. I HATED the Chevy, too heavy for me. I love the way Toyota's drive and ride but I'm wondering if the sounds I'm hearing are normal w/ Toyota's or if the dealer should take a look at it! Of course it will be my luck that the dealer wont hear what I'm hearing. :ugh3:

 

[summerwind]

The "it sounds like a diesel" when accelerating when cold per Toyota is normal

The popping sound may be the intermediate steering shaft and should be checked out.

 

[neax]

When cold, I have the same sound from the engine.

 

[jwall]

Same here on the engine noise. The colder it is, the more pronounced. Dealer says, 'they all do it', so..............

The steering on the other hand sounds like it needs to be looked at.

 

[az-scoob]

nobody warms up their cars before driving anymore? thats like climbing out of bed and sprinting around the block immidiately, who would do that? just my $0.02

 

[jwall]

I have 550 miles on my 08 highlander now. About a week into having it, I noticed that on cold starts once I put the car into drive and accelerate, there is a sounds that really makes it sound more like a 4 cyl. instead of a 6. Kind of a faint fluttering or knocking sound from the engine. I hate to use the word "knocking" but it's just really hard to explan. All I can say is that my 6 cyl. sounds just like the 4cyl RAV 4 we test drove before deciding on the Highlander. Anyone else notice this?
Also, there's sometimes a popping felt and heard from the steering, once again only on cold starts and if the car isnt warmed up for atleast 3-5 mintues. As soon as I make that first turn I can feel this faint pop in the steering. I dont know if I'm just being paranoid, I turned in an 05 Chevy Trailblazer to get back into a Toyota. I HATED the Chevy, too heavy for me. I love the way Toyota's drive and ride but I'm wondering if the sounds I'm hearing are normal w/ Toyota's or if the dealer should take a look at it! Of course it will be my luck that the dealer wont hear what I'm hearing. :ugh3:

Since the Rav 4 uses the same engine, I wonder if they have the same issues?
I may raise some eyebrows here, but a $30k plus car shouldn't have issues like engine noise and rattle/pops from the dash.

 

[DeWat]

There are some older posts either here, or over at TundraSolutions that talk about this concerning the tapping (sound like valve tap when a vehicle is low on oil). I remember the bottom line being that it was supposedly the fuel injectors that were the culprit until they warmed up. My wife's 05 Avalon does the EXACT same thing. I have no problem if it does turn out to be "normal", and not destructive. But since it only happens until the engine is warmed up, I can't help but wonder if there is a long term effect.

DeWat

 

[jwall]

Exactly, DeWat.
I know this has been discussed before and probably beat to death, but injectors seems to be the most common answer. My problem is I can't get a dealer to tell me definitively what it is. My dealer is pretty vague, "There's a lot of pumps, injectors and so on". Pumps? Being an old school guy, it sounds like lifters/valves etc. or some kind of device in the exhaust manifold or pipe that acts like a heat riser because I only hear it on light acceleration. But what the Hell do I know?

I guess I can only take solace in that 'they all do it', but as you say, long term damage? And it's just plain annoying.

 

[jobo]

You think this may be the famous gm piston slap that reared it head sever years ago. I had a tahoe that I go rid of for this slap. Usally only lasted a very short period after cold start. Just a thought.

 

[jwall]

You would hope not as many have heard it on older models and you would think if it was something big like piston slap, it would have been fixed by now.

I just don't know.

 

[jobo]

Engine noise

I have 550 miles on my 08 highlander now. About a week into having it, I noticed that on cold starts once I put the car into drive and accelerate, there is a sounds that really makes it sound more like a 4 cyl. instead of a 6. Kind of a faint fluttering or knocking sound from the engine. I hate to use the word "knocking" but it's just really hard to explan. All I can say is that my 6 cyl. sounds just like the 4cyl RAV 4 we test drove before deciding on the Highlander. Anyone else notice this?
Also, there's sometimes a popping felt and heard from the steering, once again only on cold starts and if the car isnt warmed up for atleast 3-5 mintues. As soon as I make that first turn I can feel this faint pop in the steering. I dont know if I'm just being paranoid, I turned in an 05 Chevy Trailblazer to get back into a Toyota. I HATED the Chevy, too heavy for me. I love the way Toyota's drive and ride but I'm wondering if the sounds I'm hearing are normal w/ Toyota's or if the dealer should take a look at it! Of course it will be my luck that the dealer wont hear what I'm hearing. :ugh3:

Go to www.pistonslap.com and see if any thing here sounds like your problem. Hope not. Advise if you think there is a comparison.

 

[jwall]

The more I listen and hear it, I don't think it's piston slap, IMO

 

[PaulW]

nobody warms up their cars before driving anymore? thats like climbing out of bed and sprinting around the block immidiately, who would do that? just my $0.02

There's no reason to warm up a modern car before driving it. Just let the revs get too high before it's warm. If anything, letting it idle is detrimental since oil pressure won't be as high.

 

[jwall]

Go to www.pistonslap.com and see if any thing here sounds like your problem. Hope not. Advise if you think there is a comparison.

Thanks for the link, jobo.
Under GM's definition, the noise may not be piston slap as there is no oil consumption or smoking and it runs like a rocket.

There were some links and I ran into this one on the 4 runner fourm and this post:

"Pistons rock as they cross TDC where the thrust load from the rod angularity shifts from one side to the other. This makes noise. Harmless, but it is the source of piston slap in most all situations.

To prevent this, pistons are designed with long, tapered, flexible skirts so that they can be fitted very tight in the bores when the bore and piston is cold. The taper of the skirt and flexibility of the skirt then prevents scuffing when the piston is hot. Also, the piston pin in OEM production pistons is always offset to one side....it is NOT in the middle of the piston. By offsetting the pin in the piston, artificial thrust load is created to control the piston "rocking" as it crosses over TDC.

Unfortunately, all of the above control techniques, common in past model engines to the extreme, create excess piston mass, cause friction and cost power and fuel economy. With the desire to build in as much power and free-revving capability and to improve fuel economy as much as possible thru friction reduction these design features are pushed in the other direction on modern engines.

Piston pin offset has been reduced over the years to a bare minimum today to reduce the thrust load generated and reduce friction. Pistons have been lightened up considerably by shortening the skirts. This creates less rotating/reciprocating mass which is good for power, free revving capability and fuel economy. Light weight pistons are great but the skirts, by necessity, are short making it hard to make them both strong and flexible and the shorter ckirts make them more prone to rocking.

Unfortunately, when the performance or fuel economy oriented pistons are run cold they are very prone to "slap" until they warm up to operating temperature.

The piston designers and development engineers are always treading the fine line between piston slap cold and friction and power/fuel economy loss when the engine is warm.

It is possible that you are hearing piston noise from an engine that is on the "high limit" for piston clearance so that it makes some noise cold. The good news is that the condition is harmless and that engine is probably a little more powerful (due to less friction) than a "quiet" counterpart. The bad news is that...it makes noise cold."

So when a dealer says "They all do it" he probably has no choice because they sure won't say, "Yeah, it's piston slap, but a good one"

I know what injector tick is and that doesn't bother me and it's really hard for me to discern lifter/valve train noise from the so call piston slap (knock). I don't hear it at idle, only on light acceleration when cold.
I probably will have my dealer listen to it. This also brings up another topic (unpopular), oil. Brands, types? I know that oil won't help a piston slap, but some are better than others quieting valve action? How soon can one use synthetic?

Any comments will be appreciated.

EDIT:
I just talked to two different dealers, not my local one and they both confirm the above except that true piston slap is MOVEMENT in the cylinder whereas the noise in the Highlander is mainly caused by the short piston skirt. FWIW: Both did recommend synthetic oil though.

So.... They really do 'all do it' and that's just how they are.

 

[jwall]

Update:

Just an update.
When I had the HL in for the whining noise, (bad transfer case)
I left it overnight so they could check the ticking noise I hear.
A technician (not a service writer or somebody on the phone) actually heard it and said it is the injectors pulsing.
CASE CLOSED.

summerwind was correct all along.
You're the man, summerwind! :thumbsup:
Thanks.

 

[MikeyB]

Thanks for the link, jobo.
Under GM's definition, the noise may not be piston slap as there is no oil consumption or smoking and it runs like a rocket.

There were some links and I ran into this one on the 4 runner fourm and this post:

"Pistons rock as they cross TDC where the thrust load from the rod angularity shifts from one side to the other. This makes noise. Harmless, but it is the source of piston slap in most all situations.

To prevent this, pistons are designed with long, tapered, flexible skirts so that they can be fitted very tight in the bores when the bore and piston is cold. The taper of the skirt and flexibility of the skirt then prevents scuffing when the piston is hot. Also, the piston pin in OEM production pistons is always offset to one side....it is NOT in the middle of the piston. By offsetting the pin in the piston, artificial thrust load is created to control the piston "rocking" as it crosses over TDC.

Unfortunately, all of the above control techniques, common in past model engines to the extreme, create excess piston mass, cause friction and cost power and fuel economy. With the desire to build in as much power and free-revving capability and to improve fuel economy as much as possible thru friction reduction these design features are pushed in the other direction on modern engines.

Piston pin offset has been reduced over the years to a bare minimum today to reduce the thrust load generated and reduce friction. Pistons have been lightened up considerably by shortening the skirts. This creates less rotating/reciprocating mass which is good for power, free revving capability and fuel economy. Light weight pistons are great but the skirts, by necessity, are short making it hard to make them both strong and flexible and the shorter ckirts make them more prone to rocking.

Unfortunately, when the performance or fuel economy oriented pistons are run cold they are very prone to "slap" until they warm up to operating temperature.

The piston designers and development engineers are always treading the fine line between piston slap cold and friction and power/fuel economy loss when the engine is warm.

It is possible that you are hearing piston noise from an engine that is on the "high limit" for piston clearance so that it makes some noise cold. The good news is that the condition is harmless and that engine is probably a little more powerful (due to less friction) than a "quiet" counterpart. The bad news is that...it makes noise cold."

So when a dealer says "They all do it" he probably has no choice because they sure won't say, "Yeah, it's piston slap, but a good one"

I know what injector tick is and that doesn't bother me and it's really hard for me to discern lifter/valve train noise from the so call piston slap (knock). I don't hear it at idle, only on light acceleration when cold.
I probably will have my dealer listen to it. This also brings up another topic (unpopular), oil. Brands, types? I know that oil won't help a piston slap, but some are better than others quieting valve action? How soon can one use synthetic?

Any comments will be appreciated.

EDIT:
I just talked to two different dealers, not my local one and they both confirm the above except that true piston slap is MOVEMENT in the cylinder whereas the noise in the Highlander is mainly caused by the short piston skirt. FWIW: Both did recommend synthetic oil though.

So.... They really do 'all do it' and that's just how they are.

jwall,
A very well written and educational entry. I drive an '03 LX470 (4.7L) w/70K miles that recently began knocking during first minute of cold starting and I suspected piston-slap. The local dealer confirmed it was piston-slap says it's "normal" for these engines and no cause for concern. I don't accept their response, since I know all knocks are bad/indication of major problems. Since I purchased an extended warranty, which requires arbitration when I'm not satisfied w/dealer response, I'm considering this route. Of course this would require dealer-external expert opinions/diagnosis and preparation, which ain't cheap. Whadya you think?

 

[jobo]

Take this thru your BBB. You certainly have the right. Also check old files on the GM piston slap cases. Dont spend any of your monies and keep a written record of everthing. Be sure you take ur vehicle back to the dealer ar lease three more times and tell him to fix the noise if he objects be sure you get copies of his work order or any other papers ,tell them that you want it in writing. Just pester the he.. out of them. I have a friend that ended up with a new Tahoe for just being consistantly there in thier faces. Oh,keep a record of you time spent. Good Luck. I lost an arbratration by being stupid.

 

[toyomoho]

Use a section of rubber hose as a stethoscope and attempt to run down the area of the noise. Piston slap is typically a hollow sounding noise as the piston rocks in the cylinder.

 

[MikeyB]

Take this thru your BBB. You certainly have the right. Also check old files on the GM piston slap cases. Dont spend any of your monies and keep a written record of everthing. Be sure you take ur vehicle back to the dealer ar lease three more times and tell him to fix the noise if he objects be sure you get copies of his work order or any other papers ,tell them that you want it in writing. Just pester the he.. out of them. I have a friend that ended up with a new Tahoe for just being consistantly there in thier faces. Oh,keep a record of you time spent. Good Luck. I lost an arbratration by being stupid.

Jobo,
Thanks very much for the advice/great guidance - I'll follow. Man am I glad I joined this forum. You guys are great. I've just began this journey and have some scattered notes, but will organize/record them w/work orders. BBB is an outstanding recommendation.
Thanks Again, MikeyB.

 

[jobo]

Mikey.Some one is all screwed up. I made no stateMENT that your dealer or any dealer would diasemble your engine once must leSS three time. THE POINT OF RETURNING THREE TIME IS TO INSURE YOUR AND YOUR DEALER HAVE RECORDS OF YOUR ATTEMPTS. tHE POINT IN THIS IS THE SQUEEKY WHEENL GETS THE GREASE,YOU JUST WANT TO BE SURE TO MAKE THEM WRITE IT UP,GO TO TOP MANAGEMENT IF YOU NEED TOO. WHEN SATAN ORGANIZES AN ICE SKATING PARTY IS WHEN TOYOTA WILL PUT OUT AN TSB TO COVER PISTON SLAP TRUST ME COMMON SENSE PREVAILS,TECH JARGON NO GOOD.