Daignosis Engine Noise
11-02-06, 06:18 AM
#1
Driver
Thread Starter
Daignosis Engine Noise
Engine Diagnosis Hours: Tech(s):29
Customer Notes Engine Loud At Star-up During Cold Temp
Operating As Designed Per Lexus Area Field Technical
Specialist Perform Audible Inspection. Comparison Was Made Between This Vehicle And An Es350 With Approx 800 Miles. Minimal
Difference In Sounds Between The Two Cars.
No Repair Attempt Made.
Job # 1 Total Labor & Parts
I have Deisel, Clacking, Knocking first 5-10 minutes after all cold starts.
Is this diagnosis right.
With about 20% of ES350 owners experiencing this problem.
Has anyone ever found out what causes this?????????????
Customer Notes Engine Loud At Star-up During Cold Temp
Operating As Designed Per Lexus Area Field Technical
Specialist Perform Audible Inspection. Comparison Was Made Between This Vehicle And An Es350 With Approx 800 Miles. Minimal
Difference In Sounds Between The Two Cars.
No Repair Attempt Made.
Job # 1 Total Labor & Parts
I have Deisel, Clacking, Knocking first 5-10 minutes after all cold starts.
Is this diagnosis right.
With about 20% of ES350 owners experiencing this problem.
Has anyone ever found out what causes this?????????????
Last edited by nyardich; 11-03-06 at 02:45 AM. Reason: Any Fixes
11-02-06, 06:42 AM
#2
Lexus Champion
Engine Diagnosis Hours: Tech(s):29
Customer Notes Engine Loud At Star-up During Cold Temp
Operating As Designed Per Lexus Area Field Technical
Specialist Perform Audible Inspection. Comparison Was Made Between This Vehicle And An Es350 With Approx 800 Miles. Minimal
Difference In Sounds Between The Two Cars.
No Repair Attempt Made.
Job # 1 Total Labor & Parts
I have Deisel, Clacking, Knocking first 5-10 minutes after all cold starts.
Is this diagnosis right.
Customer Notes Engine Loud At Star-up During Cold Temp
Operating As Designed Per Lexus Area Field Technical
Specialist Perform Audible Inspection. Comparison Was Made Between This Vehicle And An Es350 With Approx 800 Miles. Minimal
Difference In Sounds Between The Two Cars.
No Repair Attempt Made.
Job # 1 Total Labor & Parts
I have Deisel, Clacking, Knocking first 5-10 minutes after all cold starts.
Is this diagnosis right.
Been there done that and the answer is, NO, it is not normal. Since I have not heard your car, ask a few friends and family simply if for the money you spent that seems normal to them after you drive them in your car from a stone cold start. See what they say first before deciding anything more.
11-02-06, 07:23 AM
#3
Pole Position
Join Date: Oct 2006
Location: IL
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Valves or Piston Slap????
Noisy engine? It might be "piston slap"
by Jim Kerr
Knock, knock, knock, knock. No it's not the neighbour at the door. It's the disturbing sound of piston slap coming from your car or truck's engine. Is it a problem? Maybe - it depends on whom you talk to. During the last couple of years, I have had hundreds of inquiries about piston slap. Let's look at what causes the knock, and why it is much more common now than in the past.
In simple terms, piston slap occurs when the piston is forced rapidly against the side of the engine cylinder wall. The more clearance between the piston and cylinder wall, the louder the knock. Controlling piston slap is a complex process. Too little clearance between the piston and the cylinder wall and the parts will score and fail. Too much clearance and you get a knock. It doesn't help that usually the piston and cylinder are made of different materials and have different expansion rates.
Several features are used in piston design to reduce slap. To keep the piston close to the cylinder yet allow room for expansion, the piston skirt (the part that slides against the cylinder) is tapered - it is bigger at the bottom than at the top. The top of the piston expands more, where the extra clearance is, because of higher heat at the top of the piston. The bottom always remains close to the cylinder.
Pistons are also made oval shaped. The large part of the piston is close to the cylinder, while there is clearance on the smaller sides. As the piston expands, heat is transferred into the smaller sides, so the piston becomes more round. Thus, the large sides of the piston always stay close to the cylinder and piston slap is avoided.
There are several other piston features to counter piston slap, such as offsetting the piston pin position, but I think you get the idea. Too much clearance between the piston and the cylinder and we hear that Knock, knock, knock.
In the past, the sound of piston slap meant trouble. Worn cylinders, damaged piston skirts, or cracked pistons were common causes, and all meant expensive repairs. Now things have changed.
Engine designs have changed to make them more compact, lighter, with less internal friction, and higher revving. To do all this, piston design had to change, and some of the major changes are shorter piston skirts and straight piston skirts. The short, straight skirts allow the piston to rock more in the cylinder, and we hear it as piston slap.
Closer manufacturing tolerances have helped reduce piston clearances and slap, but some engines need more piston clearance to allow for piston expansion. During the first few minutes of operation, the piston can expand several thousandths of an inch, yet clearances are typically in the one to two thousandths of an inch. Fortunately, the cylinder also expands, or we would find pistons seized.
On vehicles built in the last decade, piston slap that occurs for a few seconds on cold start is quite normal. My own vehicle, with only 30,000 km on it has piston slap for about 5 seconds when first started on a below freezing winter morning. Service information from General Motors states "A cold Piston knock which disappears in 1.5 minutes should be considered acceptable". From experience, I have found that piston slap that occurs only during cold starts and lasts only for a minute or less causes no problems. Just don't place a load on the engine until the pistons have expanded and the clearance has been reduced.
Speaking of clearance, we normally find piston to cylinder clearance in the .0005 inch to .002 inch range. A human hair is typically about .002 inches thick, so you can see the clearances are very small. Some manufacturers are using special coatings on piston skirts to reduce friction. This enables them to reduce clearances even less and prevent piston slap. Ford V8 overhead camshaft engines use coated pistons; so does the Corvette Z06 high performance engine, as well as other manufacturers.
A good example to show the advantages of coated piston skirts is the Corvette. Clearance specifications for the coated pistons are from minus .001 inch to plus .001 inch. You read correctly; minus clearances! The piston is actually larger than the cylinder on the skirt sides of the piston. That coating has to be slippery! As the engine warms up, expansion in the cylinder block gives more clearance.
The correct engine oil can help reduce slap. Good oil takes up some clearance and is not easily scraped off the cylinder wall during cold starts. Sometimes, changing oil brands or viscosity can reduce a cold start piston slap.
If you suspect your piston slap is excessive, then there is an easy method to locate which cylinder has the problem. Before starting the engine, remove one spark plug wire and short it to the engine block. When the engine is started, that cylinder has less pressure pushing the piston sideways. If the knock changes, or is gone, then that is the cylinder with the problem. If the knock is still there, try another cylinder at the next cold start. It takes a little time, but it is much better to locate where the problem is before disassembling the engine.
So is piston slap a problem? Not for most engines built in the last decade and if the noise is there only for a few seconds during cold start. If the knock is in an engine of older design, the knock continues, or it is there during acceleration, then engine work is in the future. The worst part about piston slap is trying to explain that a cold start knock on newer vehicles can be normal, especially when you try to sell your vehicle!
Noisy engine? It might be "piston slap"
by Jim Kerr
Knock, knock, knock, knock. No it's not the neighbour at the door. It's the disturbing sound of piston slap coming from your car or truck's engine. Is it a problem? Maybe - it depends on whom you talk to. During the last couple of years, I have had hundreds of inquiries about piston slap. Let's look at what causes the knock, and why it is much more common now than in the past.
In simple terms, piston slap occurs when the piston is forced rapidly against the side of the engine cylinder wall. The more clearance between the piston and cylinder wall, the louder the knock. Controlling piston slap is a complex process. Too little clearance between the piston and the cylinder wall and the parts will score and fail. Too much clearance and you get a knock. It doesn't help that usually the piston and cylinder are made of different materials and have different expansion rates.
Several features are used in piston design to reduce slap. To keep the piston close to the cylinder yet allow room for expansion, the piston skirt (the part that slides against the cylinder) is tapered - it is bigger at the bottom than at the top. The top of the piston expands more, where the extra clearance is, because of higher heat at the top of the piston. The bottom always remains close to the cylinder.
Pistons are also made oval shaped. The large part of the piston is close to the cylinder, while there is clearance on the smaller sides. As the piston expands, heat is transferred into the smaller sides, so the piston becomes more round. Thus, the large sides of the piston always stay close to the cylinder and piston slap is avoided.
There are several other piston features to counter piston slap, such as offsetting the piston pin position, but I think you get the idea. Too much clearance between the piston and the cylinder and we hear that Knock, knock, knock.
In the past, the sound of piston slap meant trouble. Worn cylinders, damaged piston skirts, or cracked pistons were common causes, and all meant expensive repairs. Now things have changed.
Engine designs have changed to make them more compact, lighter, with less internal friction, and higher revving. To do all this, piston design had to change, and some of the major changes are shorter piston skirts and straight piston skirts. The short, straight skirts allow the piston to rock more in the cylinder, and we hear it as piston slap.
Closer manufacturing tolerances have helped reduce piston clearances and slap, but some engines need more piston clearance to allow for piston expansion. During the first few minutes of operation, the piston can expand several thousandths of an inch, yet clearances are typically in the one to two thousandths of an inch. Fortunately, the cylinder also expands, or we would find pistons seized.
On vehicles built in the last decade, piston slap that occurs for a few seconds on cold start is quite normal. My own vehicle, with only 30,000 km on it has piston slap for about 5 seconds when first started on a below freezing winter morning. Service information from General Motors states "A cold Piston knock which disappears in 1.5 minutes should be considered acceptable". From experience, I have found that piston slap that occurs only during cold starts and lasts only for a minute or less causes no problems. Just don't place a load on the engine until the pistons have expanded and the clearance has been reduced.
Speaking of clearance, we normally find piston to cylinder clearance in the .0005 inch to .002 inch range. A human hair is typically about .002 inches thick, so you can see the clearances are very small. Some manufacturers are using special coatings on piston skirts to reduce friction. This enables them to reduce clearances even less and prevent piston slap. Ford V8 overhead camshaft engines use coated pistons; so does the Corvette Z06 high performance engine, as well as other manufacturers.
A good example to show the advantages of coated piston skirts is the Corvette. Clearance specifications for the coated pistons are from minus .001 inch to plus .001 inch. You read correctly; minus clearances! The piston is actually larger than the cylinder on the skirt sides of the piston. That coating has to be slippery! As the engine warms up, expansion in the cylinder block gives more clearance.
The correct engine oil can help reduce slap. Good oil takes up some clearance and is not easily scraped off the cylinder wall during cold starts. Sometimes, changing oil brands or viscosity can reduce a cold start piston slap.
If you suspect your piston slap is excessive, then there is an easy method to locate which cylinder has the problem. Before starting the engine, remove one spark plug wire and short it to the engine block. When the engine is started, that cylinder has less pressure pushing the piston sideways. If the knock changes, or is gone, then that is the cylinder with the problem. If the knock is still there, try another cylinder at the next cold start. It takes a little time, but it is much better to locate where the problem is before disassembling the engine.
So is piston slap a problem? Not for most engines built in the last decade and if the noise is there only for a few seconds during cold start. If the knock is in an engine of older design, the knock continues, or it is there during acceleration, then engine work is in the future. The worst part about piston slap is trying to explain that a cold start knock on newer vehicles can be normal, especially when you try to sell your vehicle!
11-02-06, 07:34 AM
#4
Lexus Champion
Valves or Piston Slap????
Noisy engine? It might be "piston slap"
by Jim Kerr
On vehicles built in the last decade, piston slap that occurs for a few seconds on cold start is quite normal. My own vehicle, with only 30,000 km on it has piston slap for about 5 seconds when first started on a below freezing winter morning. Service information from General Motors states "A cold Piston knock which disappears in 1.5 minutes should be considered acceptable". From experience, I have found that piston slap that occurs only during cold starts and lasts only for a minute or less causes no problems. Just don't place a load on the engine until the pistons have expanded and the clearance has been reduced.
If you suspect your piston slap is excessive, then there is an easy method to locate which cylinder has the problem. Before starting the engine, remove one spark plug wire and short it to the engine block. When the engine is started, that cylinder has less pressure pushing the piston sideways. If the knock changes, or is gone, then that is the cylinder with the problem. If the knock is still there, try another cylinder at the next cold start. It takes a little time, but it is much better to locate where the problem is before disassembling the engine.
So is piston slap a problem? Not for most engines built in the last decade and if the noise is there only for a few seconds during cold start. If the knock is in an engine of older design, the knock continues, or it is there during acceleration, then engine work is in the future. The worst part about piston slap is trying to explain that a cold start knock on newer vehicles can be normal, especially when you try to sell your vehicle!
Noisy engine? It might be "piston slap"
by Jim Kerr
On vehicles built in the last decade, piston slap that occurs for a few seconds on cold start is quite normal. My own vehicle, with only 30,000 km on it has piston slap for about 5 seconds when first started on a below freezing winter morning. Service information from General Motors states "A cold Piston knock which disappears in 1.5 minutes should be considered acceptable". From experience, I have found that piston slap that occurs only during cold starts and lasts only for a minute or less causes no problems. Just don't place a load on the engine until the pistons have expanded and the clearance has been reduced.
If you suspect your piston slap is excessive, then there is an easy method to locate which cylinder has the problem. Before starting the engine, remove one spark plug wire and short it to the engine block. When the engine is started, that cylinder has less pressure pushing the piston sideways. If the knock changes, or is gone, then that is the cylinder with the problem. If the knock is still there, try another cylinder at the next cold start. It takes a little time, but it is much better to locate where the problem is before disassembling the engine.
So is piston slap a problem? Not for most engines built in the last decade and if the noise is there only for a few seconds during cold start. If the knock is in an engine of older design, the knock continues, or it is there during acceleration, then engine work is in the future. The worst part about piston slap is trying to explain that a cold start knock on newer vehicles can be normal, especially when you try to sell your vehicle!
The duration of knocking tapping lasting longer than a minute and a half, certainly longer than 30 seconds, that and this part from the article.
"or it is there during acceleration, then engine work is in the future."
It is present and HOW!!!! during acceleration when you have this as a concern.
11-03-06, 02:48 AM
#5
Driver
Thread Starter
Do u know of anyone with this cold start noise that has found a fix.
Approx 20% of ES350 owners have this cold start problem.
I can't believe no one has discovered a fix.
Nick
Approx 20% of ES350 owners have this cold start problem.
I can't believe no one has discovered a fix.
Nick
11-03-06, 03:08 AM
#6
Lexus Champion
The fix is likely valve work as my other car should have been, diagnosed three different places as valves. Nobody has posted that their engines were fixed that I am aware of on here.
Since your car started this with so many miles on it, 8,000 I believe you said, it is important that you find a very reputable garage in your area and let them hear it from a cold start drive and list their findings. Remember, cold start and drive immediately.
Either have that service center call your dealer svc. manager and discuss findings with him or take a copy of the findings with you to dealer service.
Most important just hang in there and get it resolved.
11-03-06, 08:03 AM
#7
Don't know if this means anything, but my car only gives the diesel sound when I have giving it gas during the first few mins of operation on cold starts. If I am going 15 mph in drive and not pushing the gas pedal, it is quiet. Once I accelerate, the noise starts up. Once I let off the gas, it stops.
Is this what others are experiencing?
Is this what others are experiencing?
Trending Topics
11-03-06, 09:08 AM
#8
Lexus Champion
Don't know if this means anything, but my car only gives the diesel sound when I have giving it gas during the first few mins of operation on cold starts. If I am going 15 mph in drive and not pushing the gas pedal, it is quiet. Once I accelerate, the noise starts up. Once I let off the gas, it stops.
Is this what others are experiencing?
Is this what others are experiencing?
Yes and no....it is loudest to point heard in the car during acceleration, yet, once heard several times at loudest you can then pick it out from rest of engine sound at idle. One I had heard the sound at it's loudest I could pick it out from rest of sound.
If you had this you'd know it because the first thought you'd have the very fisrt time you heard it is the engine is going to die and it needs to go back.
For me that was the am of the first day I owned it on my former car. It was as though you knew it needed to be on a flat bed tow truck as if driving it further would damage it further.
11-03-06, 09:28 AM
#9
At 5K, I will have Lexus check mine out and I will try to take a ES350 loaner to compare. No doubt, Bob, mine is no where near as bad as your previous unit was. Honestly, if I did not read these posts, I probably would think nothing about it. But, it is good to check everything and get it documented.
11-03-06, 09:40 AM
#10
Lexus Champion
At 5K, I will have Lexus check mine out and I will try to take a ES350 loaner to compare. No doubt, Bob, mine is no where near as bad as your previous unit was. Honestly, if I did not read these posts, I probably would think nothing about it. But, it is good to check everything and get it documented.
And please, anyone very familiar with hydraulic lifters jump on in and add to or correct what I posted. That is my understanding from svc. dept and the 2 independent opinions I got focusing on valves but put in my layperson's terms not as good or nearly the detail as a mechanic could explain it all.
11-03-06, 12:00 PM
#11
Driver
Thread Starter
I just got through talking to a friend who works at a Toyota Dealership.
He says the noise we hear is normal. It is heard when engine is cold and most when outside temp is cold like below 50 degrees.
He says this is common complaint of new Toyota Camry's, V6 has same engine as ours.
He says Toyota tells all complainers that it is no defect with engine but is ejectors and it always goes away after a few minutes, or engine is at normal temperature.
I believe him............................................................
Nick
He says the noise we hear is normal. It is heard when engine is cold and most when outside temp is cold like below 50 degrees.
He says this is common complaint of new Toyota Camry's, V6 has same engine as ours.
He says Toyota tells all complainers that it is no defect with engine but is ejectors and it always goes away after a few minutes, or engine is at normal temperature.
I believe him............................................................
Nick
11-03-06, 12:12 PM
#12
Lexus Champion
I just got through talking to a friend who works at a Toyota Dealership.
He says the noise we hear is normal. It is heard when engine is cold and most when outside temp is cold like below 50 degrees.
He says this is common complaint of new Toyota Camry's, V6 has same engine as ours.
He says Toyota tells all complainers that it is no defect with engine but is ejectors and it always goes away after a few minutes, or engine is at normal temperature.
I believe him............................................................
Nick
He says the noise we hear is normal. It is heard when engine is cold and most when outside temp is cold like below 50 degrees.
He says this is common complaint of new Toyota Camry's, V6 has same engine as ours.
He says Toyota tells all complainers that it is no defect with engine but is ejectors and it always goes away after a few minutes, or engine is at normal temperature.
I believe him............................................................
Nick
The deisel engine noise i had had nothing to do with injectors, our cars to my understanding are port injection not fuel injection. In fact the Lexus FTS said he guessed it was timing chain on mine before the drive with him and said cars with fuel injection were noisier.
Also our am temps in summer here are above 72 degrees consistantly and this was middle of summer I got my car so my issue had nothing to do with a temp dipping below or near 50 degrees.
11-03-06, 12:56 PM
#13
Nick, thanks for your input. It may very well make sense since I only get the noise during acceleration and for a couple of mins during cold starts and cold weather. Since my wife drives a Toyota, you have a great point to get 2nd opinions from the service folks over there as well.
11-03-06, 01:05 PM
#14
Lexus Champion
There is a thread somewhere on here where excuses given several members over the deisel engine sound are talked about, the two most often given were timing chain and fuel injection.
Someone pointed out our cars are port injection so the fuel injection excuse doens't apply to our cars. And the timing chain excuse is a no brainer as won't hold for the sound made.
My car and Riley's were both diagnosed as valve problems and coincidentally both had our diagnosis overturned.
My former car---Seperately diagnosed as valves by 2 and also by Lexus svc department as valves as well.
I'd ask Lexus svc manager what the reason is for the noise to see if it matches what your friend at Toyota dealership told you, i see no explanation given by dealer svc manager.
Someone pointed out our cars are port injection so the fuel injection excuse doens't apply to our cars. And the timing chain excuse is a no brainer as won't hold for the sound made.
My car and Riley's were both diagnosed as valve problems and coincidentally both had our diagnosis overturned.
My former car---Seperately diagnosed as valves by 2 and also by Lexus svc department as valves as well.
I'd ask Lexus svc manager what the reason is for the noise to see if it matches what your friend at Toyota dealership told you, i see no explanation given by dealer svc manager.
11-03-06, 01:29 PM
#15
Oh my god! Quit *****ing & buy a $6 mechanics stethescope and find out... Then tell everyone else, so they can confirm it & THEN you can do something about it.
Damn yall are lazy. Sheesh. For real people. You'd think that if all of these people have gone to a dealer & they don't find anything. That suddenly you are going t have a special car where you just drive in, the heavens part & BAM they know what the problem is?
I mean gemmie a break.
http://www.harborfreight.com/cpi/cta...emnumber=41966
Damn yall are lazy. Sheesh. For real people. You'd think that if all of these people have gone to a dealer & they don't find anything. That suddenly you are going t have a special car where you just drive in, the heavens part & BAM they know what the problem is?
I mean gemmie a break.
http://www.harborfreight.com/cpi/cta...emnumber=41966
Last edited by Pheonix; 11-03-06 at 01:36 PM.