How to clean the cylinders/combustion chamber w/o opening the engine?

[ahmadbila]

to clean the combustion chambers, a product called kreen is the best, GM, Ford and Chrysler also have their own proprietary cleaners which are very heavy duty and require a professional mechanic to perform the job.

Such products are used by feeding the engine in a flooding technique till the engine balks and stalls out. Then the ignition system is disabled and the same liquid form of the same product is then injected into the cylinders after removal of plugs and the engine rotated by hand then left alone overnight in normal ambient temperature of no less than 10C and no more than 30C.

the next day the engine is cranked manually and then with the starter - after the black goo has stopped coming from the cylinders the plugs are installed back, the engine oil is changed along with filter and the engine is started in an open atmosphere environment and held at 2000 rpm - it will smoke like a Pakistan Railway loco for a few minutes. Engine is now clean.

One mistake on this procedure can cause the engine to completely sieze of even sometimes hydrolock.

Liqui moly also have such a product - its called intake valve cleaner you can feed it to the engine mixed with some petrol but if your engine has a cat converter make sure you only feed it less than 200cc otherwise you might destroy/melt the cat.

whoa... that is some serious c.c cleaning job! would love to get something similar on my car but im sure i dont need THAT much cleaning. i ll check for the liqui moly product. btw, can a simple carb cleaner product do that? carb cleaner is easily available in my city so i can do this tomorrow morning, though i can get LM shipped from isb in 1 day too... thanks for ur time Zulfiqar bro...

[Xulfiqar]

carb cleaner wont cut it - too volatile - CC cleaner is like oil, to clean it out on a budget do an italian tune up - which is gunning the engine to redline on every gear change.

before doing anything - I would suggest you replace all 8 spark plugs with new genuine parts, also verify that your timing advancer is not mucking up the ECU while running on petrol or the wiring is not fudged up or any sensor is not hanging. It is also wise to check the injectors for flow - dribbling or leaking can cause knock too.

[a_n_memon88]

carb cleaner wont cut it - too volatile - CC cleaner is like oil, to clean it out on a budget do an italian tune up - which is gunning the engine to redline on every gear change.

before doing anything - I would suggest you replace all 8 spark plugs with new genuine parts, also verify that your timing advancer is not mucking up the ECU while running on petrol or the wiring is not fudged up or any sensor is not hanging. It is also wise to check the injectors for flow - dribbling or leaking can cause knock too.

How often the italian tune up should be done to protect carbon deposit built up. Does italian tune up involve redline and than reducing rpms or redlining for say half a km.

[Xulfiqar]

I do it everyday - nothing like hearing that MB DOHC diesel six at 5600 rpm. keeps the engine and particulate filter clean and the oil clean too.

italian tune up means to run the engine aggressively once in a while - to ensure that your ring lands etc are always free for the rings to move in.

[SER_GTR]

So Much Cleaning Is Bad

[a_n_memon88]

I do it everyday - nothing like hearing that MB DOHC diesel six at 5600 rpm. keeps the engine and particulate filter clean and the oil clean too.

italian tune up means to run the engine aggressively once in a while - to ensure that your ring lands etc are always free for the rings to move in.

I do it once in a 50 kms drive. Stretch the car in 1st gear and keep stretching it in the 3rd gear. Not more than that because at 4500 rpm in 3rd gear my car is close to 100km/hr. Well I really fell the difference in drive after that

[a_n_memon88]

So Much Cleaning Is Bad

Not much bad if you do it properly. I mean drive normally at 2.5 rpm for 50kms and at 4.5 rpm for 1 km wont affect your engine that badly

[ahmadbila]

Time for another marathon. Tamam hazrat say guzarish hay kay hazmay ki goli kha kay yeh post parhein.

First of all Ahmed bhai you need to post the sound clip of that tick tick sound so that we can comment exactly what is it. For that tick tick sound there are 2 things.
1 Knocking
2 Engine

Lets take the first case i.e knocking. First of all very important thing is what is knocking. Knocking is the ignition of air fuel mixture at a time when the piston is moving upwards i.e still in the compression stroke. As the piston is moving upwards and is connected to crankshaft so it cannot move downwards immediately with the ignition hence it hits the piston hard and produces a sound that sounds like knocking. To my limited knowledge 80-90% of the time knocking is related to ignition timing.
Another question arises here is that why the car from factory does not knock and when they are old they knock. The reasonse for knocking are
1 Petrol which has very low RON.
2 Antiknock sensor not working or some other sensors not working optimally
3 Timing too advanced for the operation of vehicle under use.
First of all coming to petrol and RON. Higher the RON of petrol the slower it burns i.e the time it takes from a spark to a big flame. This means that the fuel that has low RON will burn quicker than the one with high RON. So the petrol we have in Pakistan is of low RON and will burn quickly and produce knocking. To eplain this we have to consider something about ignition timing, what is it. Ignition timing is the timing when the air fuel mixture is ignited. It is measure in degrees BTDC i.e before top dead centre. As the mixture is ignited it formes into a big flame certain degrees ATDC i.e after to dead centre. Now comes the point that higher the RON of fuel the greater we have advance its timing so that the ignition turns into a large flame certain degrees ATDC. Every engine has its specific ATDC for optimum performance. Now take a rough example. Suppose an engine is made for 91 RON fuel and its timing is 10 BTDC such that flame is produced 5 ATDC now the burning time of mixture is 15 degrees i.e 10-(-5). Now suppose we feed the car with 93 RON whos burning time is 17 degrees. Now if we dont change the timing what will happen that the flame will be produced at 7 ATDC far beyond engines most effective performance point. To take care of this what we can do is advance the timing so that flame occurs at the most optimum point. Advancing the timing by 2 degrees is the right action but if we advance the timing but 7 degrees now what will happen. With even 93 RON fuel the flame will occur at 0 ATDC too away from most effective point and with 91 RON it will occur at 2 BTDC and will produce knocking. That is the reason our cars that are run on CNG knock on petrol and keep in mind that RON of CNG is well beyond 100 RON so optimum performance is not possible for both fuel.
In efi cars we use advancer for the advance of timing on CNG and it advances according to its calibration. Another thing in most efi cars and the one under condition particularly is that the timing changes with rpms and demands of engine. Why an engine requires to changed its timing with the changing rpms. The answer is that as the rpms increase the timing between each movement of a piston in the cylinder decrease so if the timing is not advanced it wont be possible for the flame to be produced at optimum ATDC, because we cannot increase the burning rate of fuel with our changing demands. So the ecu works like this it tends to retard the timing at lower rpms and advances it at higher rpms.
As the signals to the ecu are fed by sensors so the sensors have to be working correctly for proper operation by ecu. The sensors that come to my mind are knock sensor, TPS, MAF sensor, O2 sensor they all have to be spot on even one of them is not performing the required performance cannot be achieved.

If we take this tick tick as anything other than the knocking than it can only be said after hearing the sound. And yes talha bhai said its coils. Coils can also be the culprit because because they might be sending the current to the spark plugs too late and that is why knocking

Now coming to the conlusion and remedial actions to take.
I dont think its the carbon buit up thats causing the problem because each time the piston moves up the oil cleans the cylinder walls so there is less of chance of carbon built up there. The knocking is usually not permanent I mean to say its not on all engine speeds. i,e a engine can not knock at all engine speeds ideally most engines dont knock at higher rpms because there as less time to burn is require so the fuel that was causing knocking in low rpms would not knock at higher ones. Now the remedial actions are I would like to advise is that find yourself an idsi that is on low miles and runs perfectly. Connect to OBD II scanner to that car and note down the readings like, timing, and there are other things as well that I dont remember. Take all readings at 500 rpm interval i.e at 1000,1500,2000 so on till 5500 rpm. Because the owner of that second car is not going to allow you redline his car:P infront of his eyes. Now take a drive and again note down the readings at different speeds i. 30,50,60,70 etc. But here you have to keep the rpms and gear noted because you are going to take similar test on your car as well so you can be in a better position to decide. After all the readings have been noted take the same readings on your car. Now compare both I hope that you will find the culprit. As your car is a high miles car and its run on fuel >100 RON so it seems a pssibility that some or any one of your sensors has malfunctioned or about to die so it is not sending proper signals to ecu to retard the timing and hence producing knocking. Check engine light only lights up when a sensor if fully dead so if its working on its 10% the CEL wont light up.
Still I will be waiting for the sound clip to know what actually the sound is. Do update us about the results
Regards

well first of all, Ali noman bro, im sorry for taking sooo long to replying to such a beautiful n informative post! im getting too lazy lately... anyways, coming to the issue...

first of all, it surely is knocking. i can distinguish between knocking n engine tapping noise easily. the tapping is also there as its an old engine but knocking exists too (in specific rev bands)

u explained everything quite well. i had some idea of timing etc but u made it crystal clear, specially by referring to the examples. i still however, do not understand how knocking can be caused by weak coils. from my minimal knowledge, i have deduced the following. knocking is... burning of the mixture due to some source other then the plug itself. i.e. if the timing is correct. as u said, weak coils may slow down the spark, would'nt that just cause loss of some fuel n power, may be a misfire sometime but how can it cause knocking? experts please dont take me wrong, im not disagreeing with ur statements, its just that i like getting to the core of things and would like to learn more about it and convince myself before i go on to changing the coils.

as for carbon, well it may not be the reason in my case but it CAN be a reason. piston operation cleans only the cylinder walls, n even that not completely. a little portion at the top is usually left. other then that, as i stated in my earlier post, it can stick to valves, piston tops etc etc.

so, the conclusion i ve drawn from ur wonderful post is that i ll have to have all hands on deck. will have to hunt down the readings on every sensor. will have to check for any faulty sensor itself. the procedure that u ve suggested, the one with another idsi, that might be of a lot of help. i have a car in mind that i think i can use for the test. will just need the OBDII scanner. will get that from my mechanic on friday, perhaps...

once again, thanks for taking out time. please let me know what u think about the contents of this post of mine...

[ahmadbila]

carb cleaner wont cut it - too volatile - CC cleaner is like oil, to clean it out on a budget do an italian tune up - which is gunning the engine to redline on every gear change.

before doing anything - I would suggest you replace all 8 spark plugs with new genuine parts, also verify that your timing advancer is not mucking up the ECU while running on petrol or the wiring is not fudged up or any sensor is not hanging. It is also wise to check the injectors for flow - dribbling or leaking can cause knock too.

lol... thats one tuning we'd all love to do everyday
well i do that atleast once in a week or 10 days. i think thats more the enough. will get the rest of the stuff u mentioned checked. hopefully the situation will improve!

[a_n_memon88]

well first of all, Ali noman bro, im sorry for taking sooo long to replying to such a beautiful n informative post! im getting too lazy lately... anyways, coming to the issue...

first of all, it surely is knocking. i can distinguish between knocking n engine tapping noise easily. the tapping is also there as its an old engine but knocking exists too (in specific rev bands)

u explained everything quite well. i had some idea of timing etc but u made it crystal clear, specially by referring to the examples. i still however, do not understand how knocking can be caused by weak coils. from my minimal knowledge, i have deduced the following. knocking is... burning of the mixture due to some source other then the plug itself. i.e. if the timing is correct. as u said, weak coils may slow down the spark, would'nt that just cause loss of some fuel n power, may be a misfire sometime but how can it cause knocking? experts please dont take me wrong, im not disagreeing with ur statements, its just that i like getting to the core of things and would like to learn more about it and convince myself before i go on to changing the coils.

as for carbon, well it may not be the reason in my case but it CAN be a reason. piston operation cleans only the cylinder walls, n even that not completely. a little portion at the top is usually left. other then that, as i stated in my earlier post, it can stick to valves, piston tops etc etc.

so, the conclusion i ve drawn from ur wonderful post is that i ll have to have all hands on deck. will have to hunt down the readings on every sensor. will have to check for any faulty sensor itself. the procedure that u ve suggested, the one with another idsi, that might be of a lot of help. i have a car in mind that i think i can use for the test. will just need the OBDII scanner. will get that from my mechanic on friday, perhaps...

once again, thanks for taking out time. please let me know what u think about the contents of this post of mine...

The coils job is to increase the potential difference of current so that they provide high voltage current to spark plugs. If coils are weak 2 things will happen.
If they are very weak they would not supply the proper potential difference i.e voltage to the spark plugs so improper sparks but that is not in your case.
Other thing that can happen is that coils taking a small fraction of second more than the standard time to step up the voltage and hence the spark occurs a fraction of fraction of second later than it should occur, producing the same effect as that of a advanced timing. Let me explain you that your ecu sets the timing to fire at 10 degrees BTDC but due to weak coils the spark actually occurs at 12 degrees BTDC, and you know what will happen next. So yes weak coils can cause knocking.
Well knocking is not only spark produced by anything other than spark plugs. Actually anything that causes air fuel mixture to ignite while the piston is in upward motion i.e compression stroke or exhaust stroke is knocking.
To tell you an interesting thing. These days I am fideling with my mehrans timing on petrol as I dont have timing gun I adjust it by andaazas. My timing was right just a little bit advanced knocking at very low rpms. I tried to retard it and now its a bit retarded now guess what is happening. The car is knocking at very high rpms. Why is that its because at higher rpms spark is occuring so late that the flame is interfering the motion of piston in exhaust stroke. Before car used to knock at 20km/hrs in 3rd gear now it starts knocking after 60km/hr in 3rd gear and does that till 80km/hr. So knocking is anything that ignites the mixture while the piston is in upward motion be it carbon deposits, advanced or too retarded timing etc.

As for the default values with a donor idsi do you have the different sensor readings that car factory default? If not I can give you the images of them.

[ahsanonline]

After having gone through the whole three pages...here is a little from my side:

Knocking: Its the detonation of the fuel-air mix against the motion of the piston rather than the normal timed burn of the mixture producing a flame-front well synchronized with the motion of the piston. In short - its the fuel-air mix igniting earlier than it was supposed to.

Possible Reasons:

1) Lean fuel-air mix.
2) Ignition timing too advanced.
3) Spark-plug gaps too short (less than factory recommended) - or carbon fouled plugs (which have their own varying reasons).
4) Carbon deposits on piston head.
5) Worn-out engine sucking engine oil into combustion chamber (significantly increasing the compression ratio on each stroke).
6) Bad knock sensor or circuit.
7) Badly adjusted TPS.

...so on and so forth. In short- it could be any one or any combination of these issues.

Since car has been running on CNG, carbon on piston heads is an unlikely issue.
And since its been running on CNG, my guess would be

1. plug gaps still too short (CNG spec) - our mechanics love to do that. Most of the time they don't even know the factory specs for petrol any more!
2. TPS/ throttle body messed up by CNG guy.
3. O2 sensor issues - may be fouled/dirty or the wiring may be messed up (the code came up there as well didn't it?)

You might want to look at each of these one by one. I am assuming that the advancer is taken off and wiring is back to the way it came out from the factory.

Btw, a video showing us you revving the engine from the engine bay would be really nice.

[Xulfiqar]

The coils job is to increase the potential difference of current so that they provide high voltage current to spark plugs. If coils are weak 2 things will happen.
If they are very weak they would not supply the proper potential difference i.e voltage to the spark plugs so improper sparks but that is not in your case.
Other thing that can happen is that coils taking a small fraction of second more than the standard time to step up the voltage and hence the spark occurs a fraction of fraction of second later than it should occur, producing the same effect as that of a advanced timing. Let me explain you that your ecu sets the timing to fire at 10 degrees BTDC but due to weak coils the spark actually occurs at 12 degrees BTDC, and you know what will happen next. So yes weak coils can cause knocking.
Well knocking is not only spark produced by anything other than spark plugs. Actually anything that causes air fuel mixture to ignite while the piston is in upward motion i.e compression stroke or exhaust stroke is knocking.
To tell you an interesting thing. These days I am fideling with my mehrans timing on petrol as I dont have timing gun I adjust it by andaazas. My timing was right just a little bit advanced knocking at very low rpms. I tried to retard it and now its a bit retarded now guess what is happening. The car is knocking at very high rpms. Why is that its because at higher rpms spark is occuring so late that the flame is interfering the motion of piston in exhaust stroke. Before car used to knock at 20km/hrs in 3rd gear now it starts knocking after 60km/hr in 3rd gear and does that till 80km/hr. So knocking is anything that ignites the mixture while the piston is in upward motion be it carbon deposits, advanced or too retarded timing etc.

As for the default values with a donor idsi do you have the different sensor readings that car factory default? If not I can give you the images of them.

firing later = retarded timing

firing earlier = advanced timing, coil lazy to step up will usually result in misfire - coil causing knocking means that the coil is switching off earlier than necessary - which usually does not happen.

[a_n_memon88]

firing later = retarded timing

firing earlier = advanced timing, coil lazy to step up will usually result in misfire - coil causing knocking means that the coil is switching off earlier than necessary - which usually does not happen.

Sit Thankyou for correcting my defective knowledge. Happy to learn yet another thing from you

[a_n_memon88]

well first of all, Ali noman bro, im sorry for taking sooo long to replying to such a beautiful n informative post! im getting too lazy lately... anyways, coming to the issue...

first of all, it surely is knocking. i can distinguish between knocking n engine tapping noise easily. the tapping is also there as its an old engine but knocking exists too (in specific rev bands)

u explained everything quite well. i had some idea of timing etc but u made it crystal clear, specially by referring to the examples. i still however, do not understand how knocking can be caused by weak coils. from my minimal knowledge, i have deduced the following. knocking is... burning of the mixture due to some source other then the plug itself. i.e. if the timing is correct. as u said, weak coils may slow down the spark, would'nt that just cause loss of some fuel n power, may be a misfire sometime but how can it cause knocking? experts please dont take me wrong, im not disagreeing with ur statements, its just that i like getting to the core of things and would like to learn more about it and convince myself before i go on to changing the coils.

as for carbon, well it may not be the reason in my case but it CAN be a reason. piston operation cleans only the cylinder walls, n even that not completely. a little portion at the top is usually left. other then that, as i stated in my earlier post, it can stick to valves, piston tops etc etc.

so, the conclusion i ve drawn from ur wonderful post is that i ll have to have all hands on deck. will have to hunt down the readings on every sensor. will have to check for any faulty sensor itself. the procedure that u ve suggested, the one with another idsi, that might be of a lot of help. i have a car in mind that i think i can use for the test. will just need the OBDII scanner. will get that from my mechanic on friday, perhaps...

once again, thanks for taking out time. please let me know what u think about the contents of this post of mine...

Conents of your post show the research that you have put, keep it up.

[ahmadbila]

firing later = retarded timing

firing earlier = advanced timing, coil lazy to step up will usually result in misfire - coil causing knocking means that the coil is switching off earlier than necessary - which usually does not happen.

this is it! thats why i could not understand why bad coils could cause cause knocking. coils firing off the plugs earlier would means they are GETTING the current earlier, which would mean the timing is advanced. does that means i should rule that out? the coils thing?

[ahmadbila]

After having gone through the whole three pages...here is a little from my side:

Knocking: Its the detonation of the fuel-air mix against the motion of the piston rather than the normal timed burn of the mixture producing a flame-front well synchronized with the motion of the piston. In short - its the fuel-air mix igniting earlier than it was supposed to.

Possible Reasons:

1) Lean fuel-air mix.
2) Ignition timing too advanced.
3) Spark-plug gaps too short (less than factory recommended) - or carbon fouled plugs (which have their own varying reasons).
4) Carbon deposits on piston head.
5) Worn-out engine sucking engine oil into combustion chamber (significantly increasing the compression ratio on each stroke).
6) Bad knock sensor or circuit.
7) Badly adjusted TPS.

...so on and so forth. In short- it could be any one or any combination of these issues.

Since car has been running on CNG, carbon on piston heads is an unlikely issue.
And since its been running on CNG, my guess would be

1. plug gaps still too short (CNG spec) - our mechanics love to do that. Most of the time they don't even know the factory specs for petrol any more!
2. TPS/ throttle body messed up by CNG guy.
3. O2 sensor issues - may be fouled/dirty or the wiring may be messed up (the code came up there as well didn't it?)

You might want to look at each of these one by one. I am assuming that the advancer is taken off and wiring is back to the way it came out from the factory.

Btw, a video showing us you revving the engine from the engine bay would be really nice.

thanks for posting sir. never knew worn out rings can also cause knocking. can u explain a bit more? wouldnt that be a very thin film of oil? should be immaterial, shudnt it? im afraid that also might be the cause in my car as it has 255k kms on its engine. i ll definitely put up a video for u guys tomorrow...

[Xulfiqar]

this is it! thats why i could not understand why bad coils could cause cause knocking. coils firing off the plugs earlier would means they are GETTING the current earlier, which would mean the timing is advanced. does that means i should rule that out? the coils thing?

the coils work when the negative side of the circuit is cut-off which causes the magnetic field to dump into the secondary windings which then steps up the current from a mere 14V to 25KV - point being is that the ignitor controls the switching off of the coil(s) - not on, they are on by default.

clean out the CC with some water spray, install new genuine plugs and gun the car on the road.

[Ovais007]

combustion chamber is tarah clean ho sakta hai yaani k plugs nikalo, spray karo aur phir new plugs laga k bhagao car?

[SpoonMotorSports]

i hope u are running the correct heat range of plugs!
you can have a compression test done if your compression shows higher than standard readings only then you can think of de-carbonizing of your engine a part from this here are the reasons of knocking and pre-ignition:
*Bad quality fuel
*too much timing(which in your case isn't suspected because you are running Coils)
*too hot heat range of plugs
*lean AFRs
*Hotspots in the cylinder head
*High inlet temperature (or maybe your IAT sensor is busted or not working properly check if its in place i hope it isn't hanging around)

[SpoonMotorSports]

one of the points which Ahsanonline said about the gaping of plugs is a must see! that could be the possible culprit