Accretion in plug hole wall of M271 engine
05-06-2017, 11:37 AM
#1
Newbie
Thread Starter
Accretion in plug hole wall of M271 engine
Hello, everyone. I live in Japan and have read this site, and thank you for many meaningful information. I am starting to walk the way of DIY with a little troublesome Mercedes.
Would you tell me what this black deposit (Figure, red allow) ? I found it in No.3 plug hole when I replaced spark plugs after I experienced arrhythmia of engine while running highway and warning sign (Engine check), P0304 code appeared. It was very firm and I could not even scratch. I couldn't find engine oil or coolant in plug hole. Replaced plug had tendency of burned, shamefully this had to be first time to replace plugs,,,,,
I am also worrying about low LCC temperature (60-70 degree Celsius) and plan to replace thermostat. Must I replace spark Plug Hole Seal or other gaskets ?
My car info: W203(WDC203042) C200 Kompressor, 2003 model (maybe).
About 45K miles, never have been replace engine gaskets.
Best regards.
Would you tell me what this black deposit (Figure, red allow) ? I found it in No.3 plug hole when I replaced spark plugs after I experienced arrhythmia of engine while running highway and warning sign (Engine check), P0304 code appeared. It was very firm and I could not even scratch. I couldn't find engine oil or coolant in plug hole. Replaced plug had tendency of burned, shamefully this had to be first time to replace plugs,,,,,
I am also worrying about low LCC temperature (60-70 degree Celsius) and plan to replace thermostat. Must I replace spark Plug Hole Seal or other gaskets ?
My car info: W203(WDC203042) C200 Kompressor, 2003 model (maybe).
About 45K miles, never have been replace engine gaskets.
Best regards.
Last edited by runmercedes; 05-07-2017 at 02:14 AM. Reason: Mistaken writing
05-06-2017, 09:31 PM
#2
Super Member
First, Welcome to the forum!
Second, are you using Google Translate?
"Accretion" and "arrhythmia" are giveaways. Especially, the word "arrhythmia".
It's important for a few reasons. A big reason is so that I know to use easier to translate words and sentences, and to avoid common "phrases/sayings" that don't translate very well.
For example, I like to say "that engine is a boat anchor". That means "That engine is broken. And, it is not worth the cost to fix that engine" - so get another engine - either used or rebuilt.
On to the tech!:
1) The valve cover has gaskets that seal the valve cover from the spark plug hole. The gaskets can leak after time. Also, some mechanics do a poor job putting the gaskets back, and the gaskets leak.
You are looking at the stock gasket - the round part. There may be some silicon sealant also that a mechanic used in the past to make sure that the gasket seals.
2) How long have you had the car??
3) What is the HP rating for your engine. There were over a dozen M271 variations made. The engines vary by HP, heads, super charger pulleys, pistons, etc.
4) In the future, also list what the error code means. No one mesmerizes every error code. Most people have better things to do than to search on stuff, because the poster didn't include important information.
For others, P0304 means - misfire. So, that M271 engine "could be a boat anchor". The engine would need a new/rebuilt head. So, it would definitely be fixable! But, the cost of repair is often greater than the "value of the vehicle". Since there is a very limited market for used M271 engines, then I can sort of say "the engine is a boat anchor".
Actually, I was looking hard for justification for using that phrase.
Fwiw, I jump on my car, and even offered over the "book value", even though I knew that it likely needed a new head. I knew the repair cost, possible upgrades, desired maintenance items, etc, even before I looked at the car. And, the cost of the car, is actually a good deal less than the additional budget I had planned on for maintenance and upgrades. Plus, I planned on replacing the head anyways - regardless of the shape of the engine in the car I bought. Because of the caking on the intake valve faces. And, imho, with the right maintenance plan and upgrades, I can see an M271 engine going 200K+ miles and 30+ years.
Heck, my Mustang GT 5.0L V8 is already over 30 years old. And, imho, it's one of the most reliable cars on the planet today!
5) The M271 engine has a number of cheap/poor design features. These were done to reduce cost.
a) The cheap POS timing chain a a BIG problem for many/most of the older cars. At 45K, I don't think that is the issue with your engine - YET!
b) The "built in catch can" in the valve cover is minimal. It's likely "okay" for ~150K - ~200K miles for the lowest power M271 engine (least amount of supercharger boost).
For the ~190HP versions, imho, it's very inadequate.
The problem is oil coating the intake valve seats, and causing "misfires". The other issue is that MB makes their misfire detection very sensitive (more than required by US OBD-II/smog laws).
Note that all gasoline engines get oil in the intake system!
For non boosted engine, it's minimal and "no effects" are really "seen".
For boosted (supercharger, turbo) engine, the oil in the intake system can be an issue.
For Direct Injected engines, imho, if it's a boosted engine, then today, the owner can likely forget about getting 150K+ miles from that engine, without some valve service. (There are a number of suggested "mitigations" to solve this problem. We'll see how well they work, and if the manufactures see the additional part cost worth it to get longer engine life.)
In other words, this is not anything new to people that really know engine design and mechanical engineering. In fact, it's been very well know for 50++ years.
So...,
You may have oil/"caking" on the intake valves seals causing misfires.
However, you must first check the timing chain and the timing chain adjusters.
Or, you could have the $17 hose vacuum leak.
Or, you could have a bad injector.
Or, you might have an intake manifold leak.
There are a lot of possibilities!
So, you can not just look at the misfire error code, and say the problem is "part-xyz". You'll need to do more testing and checking.
Good Luck!
Second, are you using Google Translate?
"Accretion" and "arrhythmia" are giveaways. Especially, the word "arrhythmia".
It's important for a few reasons. A big reason is so that I know to use easier to translate words and sentences, and to avoid common "phrases/sayings" that don't translate very well.
For example, I like to say "that engine is a boat anchor". That means "That engine is broken. And, it is not worth the cost to fix that engine" - so get another engine - either used or rebuilt.
On to the tech!:
1) The valve cover has gaskets that seal the valve cover from the spark plug hole. The gaskets can leak after time. Also, some mechanics do a poor job putting the gaskets back, and the gaskets leak.
You are looking at the stock gasket - the round part. There may be some silicon sealant also that a mechanic used in the past to make sure that the gasket seals.
2) How long have you had the car??
3) What is the HP rating for your engine. There were over a dozen M271 variations made. The engines vary by HP, heads, super charger pulleys, pistons, etc.
4) In the future, also list what the error code means. No one mesmerizes every error code. Most people have better things to do than to search on stuff, because the poster didn't include important information.
For others, P0304 means - misfire. So, that M271 engine "could be a boat anchor". The engine would need a new/rebuilt head. So, it would definitely be fixable! But, the cost of repair is often greater than the "value of the vehicle". Since there is a very limited market for used M271 engines, then I can sort of say "the engine is a boat anchor".
Actually, I was looking hard for justification for using that phrase.
Fwiw, I jump on my car, and even offered over the "book value", even though I knew that it likely needed a new head. I knew the repair cost, possible upgrades, desired maintenance items, etc, even before I looked at the car.
And, the cost of the car, is actually a good deal less than the additional budget I had planned on for maintenance and upgrades. Plus, I planned on replacing the head anyways - regardless of the shape of the engine in the car I bought. Because of the caking on the intake valve faces. And, imho, with the right maintenance plan and upgrades, I can see an M271 engine going 200K+ miles and 30+ years. Heck, my Mustang GT 5.0L V8 is already over 30 years old. And, imho, it's one of the most reliable cars on the planet today!
5) The M271 engine has a number of cheap/poor design features. These were done to reduce cost.
a) The cheap POS timing chain a a BIG problem for many/most of the older cars. At 45K, I don't think that is the issue with your engine - YET!
b) The "built in catch can" in the valve cover is minimal. It's likely "okay" for ~150K - ~200K miles for the lowest power M271 engine (least amount of supercharger boost).
For the ~190HP versions, imho, it's very inadequate.
The problem is oil coating the intake valve seats, and causing "misfires". The other issue is that MB makes their misfire detection very sensitive (more than required by US OBD-II/smog laws).
Note that all gasoline engines get oil in the intake system!
For non boosted engine, it's minimal and "no effects" are really "seen".
For boosted (supercharger, turbo) engine, the oil in the intake system can be an issue.
For Direct Injected engines, imho, if it's a boosted engine, then today, the owner can likely forget about getting 150K+ miles from that engine, without some valve service. (There are a number of suggested "mitigations" to solve this problem. We'll see how well they work, and if the manufactures see the additional part cost worth it to get longer engine life.)
In other words, this is not anything new to people that really know engine design and mechanical engineering. In fact, it's been very well know for 50++ years.
So...,
You may have oil/"caking" on the intake valves seals causing misfires.
However, you must first check the timing chain and the timing chain adjusters.
Or, you could have the $17 hose vacuum leak.
Or, you could have a bad injector.
Or, you might have an intake manifold leak.
There are a lot of possibilities!
So, you can not just look at the misfire error code, and say the problem is "part-xyz". You'll need to do more testing and checking.
Good Luck!
Last edited by RedGray; 05-06-2017 at 11:43 PM.
The following 2 users liked this post by RedGray:
Lubo2018 (08-05-2020),
runmercedes (05-06-2017)
05-07-2017, 12:16 AM
#3
Newbie
Thread Starter
Thank for your reply, Red Gray! I must apologize to you because of unclear English,,, I used online dictionary, for I don't have intelligence of Google,,, If I had !!
When the car signed the Engine Check Light, its engine shaked at high revolution(>2500 rpm) and showed unstable engine revolution. Dearler man told it belongs to emergency mode, after misfiring the ECU stopped the cylinder( NO.4). I understood my car was 3 cylinder car at that time. After that, no the same symptom has appeared.
About the points you have mentioned,
1) I see and feel relieved. I never restored or even opened the engine head, so I didn't know liquid gasket was used in maker factory. The deposit (is it right ?) must have been there since my car born in South Africa (Right handle w203 saloon was made there).
2) My wife bought In 2004, recently it has been my duty to maintain the car,,,
3) 163HP. Code 203042 may be helpful,,,
4) Dealer man told me P0304 means "misfire of No.4 cylinder", I confirmed it in Haynes manual also.
5) Many information, thank you. Fortunately( or unfortunately) ,my car is not so strong version. And it will be more 20 years to run so long distance. I suppose the cars in U.S. run as much as they like. Many signals, and many cars, so my car has repeated stop and go.
I have new quetions,
a) M271 engine have supercharger as booster, but does not have injection, is it right ?
b) what is "$17 hose" ? one of breather hoses (2710160481, 2710181282, 2710181482, 2710181582)? In Japan it is famous that they tear and break, my car has been routinely experienced and replace few years ago. Very high cost wages,,,
It is difficult to write in bulletin board because of technical terms, abbreviations, unique sentence like "drink beers" (In U.S., every DIY needs alcohol? ) not only beyond wall of different language. But your reply relaxed me at first, thank you very much.
Best regars,
When the car signed the Engine Check Light, its engine shaked at high revolution(>2500 rpm) and showed unstable engine revolution. Dearler man told it belongs to emergency mode, after misfiring the ECU stopped the cylinder( NO.4). I understood my car was 3 cylinder car at that time. After that, no the same symptom has appeared.
About the points you have mentioned,
1) I see and feel relieved. I never restored or even opened the engine head, so I didn't know liquid gasket was used in maker factory. The deposit (is it right ?) must have been there since my car born in South Africa (Right handle w203 saloon was made there).
2) My wife bought In 2004, recently it has been my duty to maintain the car,,,
3) 163HP. Code 203042 may be helpful,,,
4) Dealer man told me P0304 means "misfire of No.4 cylinder", I confirmed it in Haynes manual also.
5) Many information, thank you. Fortunately( or unfortunately) ,my car is not so strong version. And it will be more 20 years to run so long distance. I suppose the cars in U.S. run as much as they like. Many signals, and many cars, so my car has repeated stop and go.
I have new quetions,
a) M271 engine have supercharger as booster, but does not have injection, is it right ?
b) what is "$17 hose" ? one of breather hoses (2710160481, 2710181282, 2710181482, 2710181582)? In Japan it is famous that they tear and break, my car has been routinely experienced and replace few years ago. Very high cost wages,,,
It is difficult to write in bulletin board because of technical terms, abbreviations, unique sentence like "drink beers" (In U.S., every DIY needs alcohol? ) not only beyond wall of different language. But your reply relaxed me at first, thank you very much.
Best regars,
Last edited by runmercedes; 05-07-2017 at 02:26 AM. Reason: Mistaken
05-07-2017, 04:56 AM
#4
Super Member
I think you did a very good job in the translation.
You can see if Google Translate makes things easier for you:
https://translate.google.com/
On to the Tech:
1) I see and feel relieved. I never restored or even opened the engine head, so I didn't know liquid gasket was used in maker factory. The deposit (is it right ?) must have been there since my car born in South Africa (Right handle w203 saloon was made there).
As long as the hole for the spark plug does not have oil leaking into it, then that gasket/sealer is fine.
2) My wife bought In 2004, recently it has been my duty to maintain the car
That's good.
That means that you did not just buy the car, and that someone sold you the car knowing that there was a very costly repair.
Many/most/all most all new members asking questions about an M271 engine seem to have bought the car, and bough the car without a full Dealer/good inspection. So, they buy a car, then an engine error shows up, they hope/think it is an easy fix, and it is really a $7,000 (US) fix. That's the cost for just replacing a cylinder head. Any other problems, or worn parts, are extra.
That repair cost is above the value of a W203 C-Class car.
3) 163HP. Code 203042 may be helpful
Again, that is good!
At 163HP and 43K miles, it is unlikely that the misfire is from oil burned on to the intake valve.
You can also help to prevent that in your engine buy using a Good full synthetic oil and oil changes every ~5,000KM or 3,000Miles. The good oil and the clean oil, help to prevent the oil from staying on the intake valve and then getting crusty/built-up.
4) Dealer man told me P0304 means "misfire of No.4 cylinder", I confirmed it in Haynes manual also.
That is correct.
5) Many information, thank you.
With a 143HP engine, if you replace the oil as I said above, that will help in the timing chain to last.
There are threads that show how to tell if the M271 timing chain has stretched too much.
*IF* the timing chain breaks, then the engine is worthless/no good. The engine is an "interference design".
So, a broken timing chain will bend the valves, ruin the valves, the cylinder head, the pistons, and the cylinder walls.
a) M271 engine have supercharger as booster, but does not have injection, is it right ?
The M271 engine has a supercharger.
A supercharger gets it's power directly from the crankshaft and the "serpentine rubber" belt.
A turbocharger gets it's power from the exhaust.
There are advantages and disadvantages to both.
The M271 has electronic fuel injection.
It does not have "Direct Injection" where the fuel is injected directly into the cylinder.
That is a newer technology. There are advantages and disadvantages.
As I mentioned, in MY view, the added power and fuel economy are NOT worth it in the engine available today. I buy a car to use for the long term, for many miles, and many years. Until they find a solution to the intake valve oil caking problems, I see the Direct Injection engines as a RISK. Some may last 100K, 150K+ miles. Many have issues before 80K miles. Many dealers have "valve cleaning procedures" to clean the intake valves for some engines. Still, that is not a solution. It is not cheap. And, it works less and less each time that it is done.
b) what is "$17 hose" ? one of breather hoses (2710160481, 2710181282, 2710181482, 2710181582)? In Japan it is famous that they tear and break, my car has been routinely experienced and replace few years ago. Very high cost wages
See #4 below:
You may have the $12 hose problem. The hose costs more, and it takes time/effort (and torx & e-torx tools) to change.
https://mbworld.org/forums/c-class-w...placement.html
"drink beers" (In U.S., every DIY needs alcohol? )
It's a friendly way of saying:
"Thanks, you deserve me buying a beer (or two) for you if we ever meet in person!"
It is difficult to write in bulletin board because of technical terms,
.... not only beyond wall of different language.
But your reply relaxed me at first, thank you very much.
You question showed thought and consideration.
MANY/?most? posts by new members show that they wrote it very quickly with very little thought and didn't care about obvious typing mistakes. And, they don't capitalize the start of sentences. They write run on sentences. They don't use paragraphs.
And I could go on and on and on.
If someone isn't going to spend even some simple/quick effort or time on asking a question, then *I* am not going to spend my time answering it.
I do a good amount of technical writing and technical correspondence. I'm an engineer "with a few degrees". And, I taught for many semesters.
I also decided to stay on the technical side of engineering - not managerial. So, you name it, I often do it when it comes to a product. I've done everything from initial proposal to helping pack and ship an item.
And, I've been doing it since "The dinosaurs roamed the Earth".
So, I can recognize questions that have thought put into them. And, I can recognize questions that someone wrote with very little thought, very little time, and very little care.
For Scanner/sensor data:
You will need a good scanner that shows real-time data to get basic diagnostic information.
There are a number of options.
The best is a "China Clone" of the MB STAR system that runs on a laptop or Tablet. We have ebay for an auction/buying site. Those systems go for ~$1,000 US.
These DAS systems will do a lot besides just showing errors and values.
Such as:
Note: I have not used this company. So, I can not recommend them, or say anything good about them, or say anything bad about them. I listed them as a reference.
V2012.11 MB SD Connect Compact 4 Star Diagnosis with DELL D630 Laptop
http://www.mbstartool.com/wholesale/...ogramming.html
Next is an iCarSoft MB scanner.
http://www.icarsoft.com/web/icarsoft...48eyzy9_1.html
These go for ~$200 (US).
Next is a generic OBD-II scanner that shows real-time data.
NOTE: These will not show or display a lot of the MB specific errors, codes, or sensor values.
These go for ~$100 (US).
Next is:
If you have an Android phone, you can try the Torque app. You'll need a USB to bluetooth adapter.
NOTE: This will not show or display a lot of the MB specific errors, codes, or sensor values.
Things to try/etc for your engine.
1) Change all of the spark plugs.
See if the error changes or goes away.
2) Swap the coils between the cylinders.
See if the error changes or goes away.
3) You may have a dirty MAF. Clean the MAF.
See:
https://mbworld.org/forums/c-class-w...ml#post7136068
4) You may have the $12 hose problem. The hose costs more, and it takes time/effort (and torx & e-torx tools) to change.
https://mbworld.org/forums/c-class-w...placement.html
5) A bad seal on the intake manifold is possible, but not likely. Still, it is possible and should be checked. You can use water in a spray bottle and spray around where the intake meets the cylinder head.
So, you want to check for vacuum leaks.
How to find vacuum leaks and easily
Cody the Car Guy
Good Luck!
You can see if Google Translate makes things easier for you:
https://translate.google.com/
On to the Tech:
1) I see and feel relieved. I never restored or even opened the engine head, so I didn't know liquid gasket was used in maker factory. The deposit (is it right ?) must have been there since my car born in South Africa (Right handle w203 saloon was made there).
As long as the hole for the spark plug does not have oil leaking into it, then that gasket/sealer is fine.
2) My wife bought In 2004, recently it has been my duty to maintain the car
That's good.
That means that you did not just buy the car, and that someone sold you the car knowing that there was a very costly repair.
Many/most/all most all new members asking questions about an M271 engine seem to have bought the car, and bough the car without a full Dealer/good inspection. So, they buy a car, then an engine error shows up, they hope/think it is an easy fix, and it is really a $7,000 (US) fix. That's the cost for just replacing a cylinder head. Any other problems, or worn parts, are extra.
That repair cost is above the value of a W203 C-Class car.
3) 163HP. Code 203042 may be helpful
Again, that is good!
At 163HP and 43K miles, it is unlikely that the misfire is from oil burned on to the intake valve.
You can also help to prevent that in your engine buy using a Good full synthetic oil and oil changes every ~5,000KM or 3,000Miles. The good oil and the clean oil, help to prevent the oil from staying on the intake valve and then getting crusty/built-up.
4) Dealer man told me P0304 means "misfire of No.4 cylinder", I confirmed it in Haynes manual also.
That is correct.
5) Many information, thank you.
With a 143HP engine, if you replace the oil as I said above, that will help in the timing chain to last.
There are threads that show how to tell if the M271 timing chain has stretched too much.
*IF* the timing chain breaks, then the engine is worthless/no good. The engine is an "interference design".
So, a broken timing chain will bend the valves, ruin the valves, the cylinder head, the pistons, and the cylinder walls.
a) M271 engine have supercharger as booster, but does not have injection, is it right ?
The M271 engine has a supercharger.
A supercharger gets it's power directly from the crankshaft and the "serpentine rubber" belt.
A turbocharger gets it's power from the exhaust.
There are advantages and disadvantages to both.
The M271 has electronic fuel injection.
It does not have "Direct Injection" where the fuel is injected directly into the cylinder.
That is a newer technology. There are advantages and disadvantages.
As I mentioned, in MY view, the added power and fuel economy are NOT worth it in the engine available today. I buy a car to use for the long term, for many miles, and many years. Until they find a solution to the intake valve oil caking problems, I see the Direct Injection engines as a RISK. Some may last 100K, 150K+ miles. Many have issues before 80K miles. Many dealers have "valve cleaning procedures" to clean the intake valves for some engines. Still, that is not a solution. It is not cheap. And, it works less and less each time that it is done.
b) what is "$17 hose" ? one of breather hoses (2710160481, 2710181282, 2710181482, 2710181582)? In Japan it is famous that they tear and break, my car has been routinely experienced and replace few years ago. Very high cost wages
See #4 below:
You may have the $12 hose problem. The hose costs more, and it takes time/effort (and torx & e-torx tools) to change.
https://mbworld.org/forums/c-class-w...placement.html
"drink beers" (In U.S., every DIY needs alcohol? )
It's a friendly way of saying:
"Thanks, you deserve me buying a beer (or two) for you if we ever meet in person!"
It is difficult to write in bulletin board because of technical terms,
.... not only beyond wall of different language.
But your reply relaxed me at first, thank you very much.
You question showed thought and consideration.
MANY/?most? posts by new members show that they wrote it very quickly with very little thought and didn't care about obvious typing mistakes. And, they don't capitalize the start of sentences. They write run on sentences. They don't use paragraphs.
And I could go on and on and on.
If someone isn't going to spend even some simple/quick effort or time on asking a question, then *I* am not going to spend my time answering it.
I do a good amount of technical writing and technical correspondence. I'm an engineer "with a few degrees".
And, I taught for many semesters.I also decided to stay on the technical side of engineering - not managerial. So, you name it, I often do it when it comes to a product. I've done everything from initial proposal to helping pack and ship an item.
And, I've been doing it since "The dinosaurs roamed the Earth".
So, I can recognize questions that have thought put into them. And, I can recognize questions that someone wrote with very little thought, very little time, and very little care.
For Scanner/sensor data:
You will need a good scanner that shows real-time data to get basic diagnostic information.
There are a number of options.
The best is a "China Clone" of the MB STAR system that runs on a laptop or Tablet. We have ebay for an auction/buying site. Those systems go for ~$1,000 US.
These DAS systems will do a lot besides just showing errors and values.
Such as:
Note: I have not used this company. So, I can not recommend them, or say anything good about them, or say anything bad about them. I listed them as a reference.
V2012.11 MB SD Connect Compact 4 Star Diagnosis with DELL D630 Laptop
http://www.mbstartool.com/wholesale/...ogramming.html
Next is an iCarSoft MB scanner.
http://www.icarsoft.com/web/icarsoft...48eyzy9_1.html
These go for ~$200 (US).
Next is a generic OBD-II scanner that shows real-time data.
NOTE: These will not show or display a lot of the MB specific errors, codes, or sensor values.
These go for ~$100 (US).
Next is:
If you have an Android phone, you can try the Torque app. You'll need a USB to bluetooth adapter.
NOTE: This will not show or display a lot of the MB specific errors, codes, or sensor values.
Things to try/etc for your engine.
1) Change all of the spark plugs.
See if the error changes or goes away.
2) Swap the coils between the cylinders.
See if the error changes or goes away.
3) You may have a dirty MAF. Clean the MAF.
See:
https://mbworld.org/forums/c-class-w...ml#post7136068
4) You may have the $12 hose problem. The hose costs more, and it takes time/effort (and torx & e-torx tools) to change.
https://mbworld.org/forums/c-class-w...placement.html
5) A bad seal on the intake manifold is possible, but not likely. Still, it is possible and should be checked. You can use water in a spray bottle and spray around where the intake meets the cylinder head.
So, you want to check for vacuum leaks.
Cody the Car Guy
Good Luck!
The following users liked this post:
runmercedes (05-07-2017)
05-07-2017, 11:54 PM
#5
Newbie
Thread Starter
Red Grey, thank you.
I have replace plugs, so I'll follow now. Your technical explanation is very detailed, so I understand that you are engineer. I thank you have spent making answers.
Other troubles,,, for example, Clicking noise after engine-on for some minutes(maybe cause by broken parts; 203 830 000 33) are also going on. I had ever Japanese car so I am amazing that such a trouble exit "routinely" and not treated as "recall". But other charming point, and history that made our family memory, I will cure her.
If I want another help, I will ask here again. Mr. Red Gray, and this forum, thank you !
I have replace plugs, so I'll follow now. Your technical explanation is very detailed, so I understand that you are engineer. I thank you have spent making answers.
Other troubles,,, for example, Clicking noise after engine-on for some minutes(maybe cause by broken parts; 203 830 000 33) are also going on. I had ever Japanese car so I am amazing that such a trouble exit "routinely" and not treated as "recall". But other charming point, and history that made our family memory, I will cure her.
If I want another help, I will ask here again. Mr. Red Gray, and this forum, thank you !
04-12-2020, 01:04 PM
#6
Senior Member
Spark Plug replacement interval is good. Black deposit is ????? Check spark-plug/coil boot for electrical sparking. No need to replace oil gaskets if not leaking oil into spark plug wells. A 'burned' spark plug tip and insulator tip indicate a lean fuel mixture---partially plugged fuel injector or air in-leakage.
