Cold Start Diesel Engine Noise
11-21-06, 08:56 AM
#1
Driver
Thread Starter
Cold Start Diesel Engine Noise
Has anyone ever got cold start engine noise"Clicking, Clacking, Diesel like noise that seems to go away after warm up fixed or reason explained. 03/06 build.
I'm frustrated dealer won't admit problem.
It's cold here in Ohio and happens everytime cold start.
I never heard of anyone getting this fixed.
Mine is really loud.................................
Nick
I'm frustrated dealer won't admit problem.
It's cold here in Ohio and happens everytime cold start.
I never heard of anyone getting this fixed.
Mine is really loud.................................
Nick
Last edited by nyardich; 11-21-06 at 09:00 AM. Reason: update
11-21-06, 09:04 AM
#2
Lexus Champion
Has anyone ever got cold start engine noise"Clicking, Clacking, Diesel like noise that seems to go away after warm up fixed or reason explained. 03/06 build.
I'm frustrated dealer won't admit problem.
It's cold here in Ohio and happens everytime cold start.
I never heard of anyone getting this fixed.
Mine is really loud.................................
Nick
I'm frustrated dealer won't admit problem.
It's cold here in Ohio and happens everytime cold start.
I never heard of anyone getting this fixed.
Mine is really loud.................................
Nick
It doesn't need to be cold am for this to happen, happens here in my state too middle of summer and yes plenty of people on here have this annoyance at various degrees of intensity.
Try getting a completely independent opinion from an outfit not affiliated with either Toyota or Lexus dealer.
11-21-06, 11:05 AM
#3
Driver
Thread Starter
Nick,
It doesn't need to be cold am for this to happen, happens here in my state too middle of summer and yes plenty of people on here have this annoyance at various degrees of intensity.
Try getting a completely independent opinion from an outfit not affiliated with either Toyota or Lexus dealer.
It doesn't need to be cold am for this to happen, happens here in my state too middle of summer and yes plenty of people on here have this annoyance at various degrees of intensity.
Try getting a completely independent opinion from an outfit not affiliated with either Toyota or Lexus dealer.
According to poll 16 to 20% have this problem.
Nick
11-21-06, 11:10 AM
#4
Lexus Champion
I believe the prior diagnosis of valves myself, it isn't normal for any car to knock and tap like that, unless it's an ES350 it seems, at least according to Lexus it is normal, though that is not pointed out to you till after you own it.
11-21-06, 11:35 AM
#5
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I'm going to add the following article again... IMO this is normal operation on cold start especially considering the metalurgical makeup of the various components in our 3.5s... This should be occurring at any cold start, regardless of it being 95* or 10*, however it will be more pronounced the colder it gets because metal continues to contract as it cools.
I agree, it is annoying.
I do not agree that it is the heads/valves/timing chains... The 3.5 uses hydraulic valve lifters that continously adjust valve lash. Further if you look at the schematics for the 2GR-FE engine, the pistons are minimally skirted allowing them to rock within the cylinder, this would especially be true at cold start as the pistons have not expanded to match the cylinder sleeve... The tolerance is tight given the fact the pistons are coated to minimize scuffing and also to try and combat cold start knock... It is minimized, but not completely eradicated, therefore Toyota/Lexus will keep telling you it is normal... The noise is not the injectors nor is it the valves, but these are instead simple explainations for simple people.
More on Piston Slap
GS Forum and Piston Slap
Engine Diagnosis 101
http://www.pistonslap.com/
Try a Product Like This.... Anyone???
Court Dismisses Piston Slap Suit
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!
________________________________________________________________
Bob Weber
Oil type has nothing to do with piston slap
Published October 15, 2006
Q. You have written about the diesel-type noise found in gasoline engines called piston slap but I don't recall you writing about the cause. Also, would a certain type of oil help this condition?
D.S., Tinley Park
A. To understand piston slap, we must know what a piston looks like. Envision a soup can with metal ears extending below. Those are "skirts" on a piston.
When the piston ascends in the cylinder, it is pushed against the cylinder wall by the piston rod. As the piston begins descending, it is forced against the opposite wall. As this occurs, the skirt slaps the cylinder wall and makes a noise. Unless it is severe, this usually causes no harm. Your choice of oil has no effect on piston slap.
I agree, it is annoying.
I do not agree that it is the heads/valves/timing chains... The 3.5 uses hydraulic valve lifters that continously adjust valve lash. Further if you look at the schematics for the 2GR-FE engine, the pistons are minimally skirted allowing them to rock within the cylinder, this would especially be true at cold start as the pistons have not expanded to match the cylinder sleeve... The tolerance is tight given the fact the pistons are coated to minimize scuffing and also to try and combat cold start knock... It is minimized, but not completely eradicated, therefore Toyota/Lexus will keep telling you it is normal... The noise is not the injectors nor is it the valves, but these are instead simple explainations for simple people.
More on Piston Slap
GS Forum and Piston Slap
Engine Diagnosis 101
http://www.pistonslap.com/
Try a Product Like This.... Anyone???
Court Dismisses Piston Slap Suit
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!
________________________________________________________________
Bob Weber
Oil type has nothing to do with piston slap
Published October 15, 2006
Q. You have written about the diesel-type noise found in gasoline engines called piston slap but I don't recall you writing about the cause. Also, would a certain type of oil help this condition?
D.S., Tinley Park
A. To understand piston slap, we must know what a piston looks like. Envision a soup can with metal ears extending below. Those are "skirts" on a piston.
When the piston ascends in the cylinder, it is pushed against the cylinder wall by the piston rod. As the piston begins descending, it is forced against the opposite wall. As this occurs, the skirt slaps the cylinder wall and makes a noise. Unless it is severe, this usually causes no harm. Your choice of oil has no effect on piston slap.
11-21-06, 11:44 AM
#6
Lexus Champion
Since this lasts for several minutes/miles rather than a few seconds, the above caution and prediction is noteworthy IF one wishes it attributed to piston slap, esp. the ...during acceleration caution...
It is not as loud a sound or as robust a knocking/tapping to involve the piston itself in my opinion and that of several others who listened to my former car.
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11-21-06, 04:05 PM
#8
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I'd love to see the look on their faces! I tell clients and friends that ride in my car the same thing about my transmission flare/slip! I wonder how many of those people run out and buy the ES350?
11-21-06, 04:44 PM
#9
It actually shocked me that she made the comment.
11-21-06, 04:48 PM
#10
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No matter whether the cause be piston slap or something else Lexus can build an engine that is quiet.
I can buy any number of cars with noisey engines but I bought a Lexus for a quiet and sublime ride.
Lexus needs to Fix this issue or sales will fall even if they want to call the sound "Normal".
Pat
I can buy any number of cars with noisey engines but I bought a Lexus for a quiet and sublime ride.
Lexus needs to Fix this issue or sales will fall even if they want to call the sound "Normal".
Pat
11-21-06, 08:00 PM
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No matter whether the cause be piston slap or something else Lexus can build an engine that is quiet.
I can buy any number of cars with noisey engines but I bought a Lexus for a quiet and sublime ride.
Lexus needs to Fix this issue or sales will fall even if they want to call the sound "Normal".
Pat
I can buy any number of cars with noisey engines but I bought a Lexus for a quiet and sublime ride.
Lexus needs to Fix this issue or sales will fall even if they want to call the sound "Normal".
Pat
11-21-06, 08:30 PM
#13
Unfortunately, I have to agree with onsknht. Based on what I've seen to date, Lexus will only produce a TSIB for glaringly obvious issues. Trans slipping and trans death, along with nav unit replacement and brake issues seem to be it so far. I've been waiting patiently for 6 months on a wind noise TSIB and have got nothing. It amazes me the trans issues just keep going. I also know that some ES350's have the engine noise issues, others don't.
Here is my prediction: NO TSIB for Wind Noise or Engine Noise. Period. Dealers have been explaining these two as being 'normal' since Day 1.
The trans\nav\noisy brakes are "in your face" undeniable things and have been (or are being) addressed.
Here is my prediction: NO TSIB for Wind Noise or Engine Noise. Period. Dealers have been explaining these two as being 'normal' since Day 1.
The trans\nav\noisy brakes are "in your face" undeniable things and have been (or are being) addressed.
11-22-06, 05:31 AM
#14
As I said in a previous post, I am also parking our 2004 Lincoln LS with 63,000 miles on it next to the ES350 overnight at the dealership outside in the PA cold and will arrive there when they open up for both to be started. Let them hear which car, upon startup, needs engine work!
11-22-06, 05:37 AM
#15
Lexus Champion
MD..Sharp wife to mention it, or would it be sharp man for marrying her.
Pat summed up my view of this supposed normalcy.
Let them claim it is normal to enough of us, dozens of us on here alone have experienced that claim yet oddly no explanation given for those that do not do this.
Ons and Wanderer..I agree, nothing will be done about the knocking tapping, unless it is at the level of, or worsens and progresses to the level of, cannery works long enough for the owner to get completely disgusted in order to file a Lemon Law complaint, after spending their own money for second opinions.
2007..be happy you missed the "normal feature" of an ES350 of knocking and tapping, it is as bad or worse than dealing with a rattle...you could take your car in for service and demand it comply and be "normal" and have them adjust it so it knocks and taps.
Pat summed up my view of this supposed normalcy.
Let them claim it is normal to enough of us, dozens of us on here alone have experienced that claim yet oddly no explanation given for those that do not do this.
Ons and Wanderer..I agree, nothing will be done about the knocking tapping, unless it is at the level of, or worsens and progresses to the level of, cannery works long enough for the owner to get completely disgusted in order to file a Lemon Law complaint, after spending their own money for second opinions.
2007..be happy you missed the "normal feature" of an ES350 of knocking and tapping, it is as bad or worse than dealing with a rattle...you could take your car in for service and demand it comply and be "normal" and have them adjust it so it knocks and taps.