Muffler tail pipe Carbon: CHR vs Eclipse Cross

[vitz]

Hi All,

A close look at our Eclipse Cross and and CHR Muffler tail pipes revealed that the inside the EC tail is very cleaned and but CHR tail contains some carbon (see figure below, lt looks bit more dirty than on the figure). Deposit is thick enough to come on to the finger. Recently I cleaned up the tail pipe but it looks that C building happens. Does it mean the CHR needing an engine tune up or any engine issue is popping up. 

Some details of two vehicles"

EC (2018): clocked 12000 km, mostly short distances, but runs in kandy traffic too often. OCT 92 used. 

CHR(2018): clocked 30000 km. This runs a long trip daily, around 90 km one way in less traffic. We got it when it has done nearly 18,000 km (6-7 months ago). OCT 92 used after we purchase. No sign of oil burning. 

 

Edited April 3, 2020 by vitz

[AVANTE]

Shouldn't the CHR be running on 95 as it's a turbo? 

[vitz]

14 minutes ago, AVANTE said:

Shouldn't the CHR be running on 95 as it's a turbo? 

Nop, both are turbos' run on 92 without any knocks. I am a believer of OCT 92 on Japanese DMs (As per the user manual)

Edited April 3, 2020 by vitz

[vag2]

Maybe the EC has better combustion control or better/more frequent after treatment? Mitsubishi performance Vs Toyota reliability.

[ghostwriter]

maybe another CHR owner can show how it looks on theirs, so OP can clarify if its distinct to his CHR or common to all CHRs

[AVANTE]

@sathyajithj99

[Devinda_Z]

@vitz are you 100% sure about the 92 Octane ? @iRage I have a vague recollection of us all discussing this on some other thread?

[sathyajithj99]

On 4/3/2020 at 7:56 PM, AVANTE said:

@sathyajithj99

Nope. Doesn't look like any carbon deposition there. And  I'm close to 30k

[vitz]

17 hours ago, Devinda_Z said:

@vitz are you 100% sure about the 92 Octane ? @iRage I have a vague recollection of us all discussing this on some other thread?

@Devinda_Z. According to the user manual of 1.2 L turbo (8NR-FTS), Unleaded Regular Gasoline is recommended for CHR. Under Japanese Industrial Standard, octane rating of gasoline must be 89.0 or above for Regular. Thus, it looks that OCT 92 is more than enough for the CHR....

[vitz]

4 hours ago, sathyajithj99 said:

Nope. Doesn't look like any carbon deposition there. And  I'm close to 30k

Thanks. It looks than our one needs an attention. I cleaned it well and expecting to monitor the C building up....

Edited April 5, 2020 by vitz

[iRage]

23 hours ago, Devinda_Z said:

@vitz are you 100% sure about the 92 Octane ? @iRage I have a vague recollection of us all discussing this on some other thread?

Yes....we did...in Japan Regular can be anything from 90OCT to 95OCT.  Which octane it actually is depends on the fuel company; which ispartly the reason why some regulars in Japan are cheaper than others. (eg. small budget fuel companies might carry 90, a large one like Idemitsu might carry 95) . HighOku/Premium will range from 95 upwards. Nowadays, more and more regular gasolines are starting to be more towards 95 and 98OCT for HighOku is becoming more common.

[CNX]

21 hours ago, sathyajithj99 said:

Nope. Doesn't look like any carbon deposition there. And  I'm close to 30k

Are you on 92 or 95 RON?

[sathyajithj99]

7 hours ago, CNX said:

Are you on 92 or 95 RON?

92

[MaxFirst]

I have seen quite a few posts on local groups about injector failures in CHR , anybody know what's going  on? Apparently there are few people offering injectors on those forums as well.  

[iRage]

15 hours ago, MaxFirst said:

I have seen quite a few posts on local groups about injector failures in CHR , anybody know what's going  on? Apparently there are few people offering injectors on those forums as well.  

So did some digging around the TSBs. It seems like there is a TSB out for most 1.2T equipped vehicles for premature carbon build-up on the inlet valves...which subsequently can lead to buildup in other areas. 

Toyota claims the cause is due to engine being constatnly operated under ircumstances which does not let the engine fully run under operating tempreture (so short drive..low speed movement)...so that could be the cause of the injectors going bad (combined with impure gasoline...note the octane of the fuel would not have anything to o with it but what is actually in it) ? The TSB is not issued for Japan. 

I hope this is not a symptom of this (atleast I do not recall seeing it as such)...other symptoms seem to be abnormal injector noise, retarded performance, engine misses.

The solution seems to be clean-up of the injectors (replace if needed) and regular maintenance (EDIT: this seems to include the general clean up of valves, chambers, through chemical flushes). 

Edited July 25, 2020 by iRage

[MaxFirst]

Thanks @iRage. Local guys have been experiencing rough idle after start up and abnormal engine noise . Also been told injectors cannot be cleaned and has to be replaced. [May be they do not know how to clean them ? or been damaged beyond repair  ?]. Do you think this can be avoided if we let the vehicle warm up before driving since it's hard to avoid traffic in Colombo ?

Edited July 25, 2020 by MaxFirst

[iRage]

1 hour ago, MaxFirst said:

Thanks @iRage. Local guys have been experiencing rough idle after start up and abnormal engine noise . Also been told injectors cannot be cleaned and has to be replaced. [May be they do not know how to clean them ? or been damaged beyond repair  ?]. Do you think this can be avoided if we let the vehicle warm up before driving since it's hard to avoid traffic in Colombo ?

Sorry no idea how to physically clean the injectors. Again...I am only speculating that the carbon build-up can subsequently lead to the injectors to get clogged up as well. Over here the Toyota dealers use a lot of flushes to clean out the engine as well as the injectors and fuel lines (in fact Toyota and other manufacturers list out many products on their websites recommended for use). So I am guessing that would be the general way they expect to keep it clean. Fuel injector cleaners I suppose would help keep the injectors clean. They were also used for cleaning carbon build up in port injected engines. Interestingly Toyota still recommends a fuel additive carbon cleaner for cleaning carbon deposits in all types of engines…..no idea how that works because the fluid will never touch the valves.

Well..if you are only going to drive for a few km and you know the engine will not reach op tempt I can see how pre-heating the engine might help. But then if you are stuck in traffic the engine will still reach operating tempreture....I think the idea is that there is enough circulation within the engine as well so that whatever does not get burnt will go through several cycles of rapid burn ? This iwll nto happen if the engine just sits at idle....Its funny...because it seems like at the end of the day part of the TSB's solution is to make sure the car gets afrequent Italian tune-ups

Also...the carbon build-up is nothing new....pretty much all direct engine cars have always had the issue of valves gunking up with carbon. 

 

Edited July 25, 2020 by iRage

[MaxFirst]

@iRage Thank you for your wisdom

[Sadeepa Dilhara]

On 4/3/2020 at 3:00 PM, vitz said:

Hi All,

A close look at our Eclipse Cross and and CHR Muffler tail pipes revealed that the inside the EC tail is very cleaned and but CHR tail contains some carbon (see figure below, lt looks bit more dirty than on the figure). Deposit is thick enough to come on to the finger. Recently I cleaned up the tail pipe but it looks that C building happens. Does it mean the CHR needing an engine tune up or any engine issue is popping up. 

Some details of two vehicles"

EC (2018): clocked 12000 km, mostly short distances, but runs in kandy traffic too often. OCT 92 used. 

CHR(2018): clocked 30000 km. This runs a long trip daily, around 90 km one way in less traffic. We got it when it has done nearly 18,000 km (6-7 months ago). OCT 92 used after we purchase. No sign of oil burning. 

 

My CHR is about 27k. No any excessive carbon build up in exhaust pipe. Looks like your eclipse. I use 92 octane. Mainly used in Kurunegala traffic.

[Hyaenidae]

  

23 minutes ago, vitz said:

anyways the link for the post:

http://autolanka.com/forums/topic/22382-muffler-tail-pipe-carbon-chr-vs-eclipse-cross/?tab=comments#comment-331839

 

Looking back at the two pictures, the bit you said about older tech in the other thread is absolutely correct. The tailpipe of my EX which is 5 years old and has clocked more kms than your CHR looks as clean as your12k kms Eclipse

 

 

Edited August 2, 2020 by Hyaenidae

[hrm]

31 minutes ago, Hyaenidae said:

  

Looking back at the two pictures, the bit you said about older tech in the other thread is absolutely correct. The tailpipe of my EX which is 5 years old and has clocked more kms than your CHR looks as clean as your12k kms Eclipse

So was mine. 9 years old and I love fuss free old tech.

[vitz]

I can't imagine how this carbon deposit happens, as i can notice water droplets passing out from the trail pipe of the CHR. 

[vitz]

The 4B40 engine of the Mitsubishi Eclipse cross  has a "Electronically controlled multipoint fuel injection and direct injection" system. Can someone explain how it works? Would that also get a chance of C build up on intake/exhaust valves!!!

This is a great video to watch...

 

it looks like 4B40 is using a technology as similar to toyota D-45, where the direct injection (high pressure) is sprayed to a side of the cylinder, not to the top....

This is how it goes in 1.2 LT CHR engine....

 

 

Edited August 2, 2020 by vitz