Why do gas powered direct injected engines get deposits on the back of the valves but diesels dont? A diesel is basically the same,has the injector in the cylinder,not the intake.
direct injection deposit question
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It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
Originally Posted By: Chris142
Why do gas powered direct injected engines get deposits on the back of the valves but diesels dont? A diesel is basically the same,has the injector in the cylinder,not the intake.
usually its a product of EGR, and some diesels can now suffer from intake deposits..
http://en.wikipedia.org/wiki/Exhaust_gas_recirculation
not exactly proof being a wiki but its an explanation
Why do gas powered direct injected engines get deposits on the back of the valves but diesels dont? A diesel is basically the same,has the injector in the cylinder,not the intake.
usually its a product of EGR, and some diesels can now suffer from intake deposits..
http://en.wikipedia.org/wiki/Exhaust_gas_recirculation
not exactly proof being a wiki but its an explanation
Originally Posted By: Eddie
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
many do as does the f250 in my sig.I was not aware of the vw's.
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
many do as does the f250 in my sig.I was not aware of the vw's.
Originally Posted By: Chris142
many do as does the f250 in my sig.I was not aware of the vw's.
your F250 does not have an "EGR valve", it has a CDR valve.. its not the same thing and sometimes they do get clogged.
you arent rerouting exhaust, its more like a PCV valve in a gas engine
Edit: I forgot to add, the cdr valve also functions as an oil separator.
many do as does the f250 in my sig.I was not aware of the vw's.
your F250 does not have an "EGR valve", it has a CDR valve.. its not the same thing and sometimes they do get clogged.
you arent rerouting exhaust, its more like a PCV valve in a gas engine
Edit: I forgot to add, the cdr valve also functions as an oil separator.
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Originally Posted By: supton
How much does it matter on a turbocharged diesel versus a NA gasser? I'm not sure how many NA diesels get sold, but many gassers are NA.
Take the Nissan ZD30 which is pretty common in Oz, there seems to be a perfect storm which occurs when deposits either stop the swirl valve from functioning, or restric airflow enough that the fuel/air mix approached stoichiometric from the (far) lean side that diesels run and increase piston temperatures...until "poof" cloud of smoke, and no go.
Appears to take out # 3 preferentially.
How much does it matter on a turbocharged diesel versus a NA gasser? I'm not sure how many NA diesels get sold, but many gassers are NA.
Take the Nissan ZD30 which is pretty common in Oz, there seems to be a perfect storm which occurs when deposits either stop the swirl valve from functioning, or restric airflow enough that the fuel/air mix approached stoichiometric from the (far) lean side that diesels run and increase piston temperatures...until "poof" cloud of smoke, and no go.
Appears to take out # 3 preferentially.
Originally Posted By: Eddie
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
Whoops, wrong conclusion. Must not have been around any diesels made in the last 7 years. They have both EGR and routed to intake CCV. Imagine that one.... even with the filtration that is on many diesel PCV systems, especially the heavy diesels, you combine that oily flow with EGR from sooty exhaust being fed back in there, and boy, you have a nice recipe for a nasty mess.
Ask the folks over at commercial truck forums what they think about all of this. If you talked with them live, outside of the forums where they could be more verbal, you would experience a stream of newly invented swear words.
This is why I bought a 2013 Freightliner Columbia kit truck and dropped in a pre-emission, factory rebuilt Detroit Series 60 in it. Just to avoid all of this mess.
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
Whoops, wrong conclusion. Must not have been around any diesels made in the last 7 years. They have both EGR and routed to intake CCV. Imagine that one.... even with the filtration that is on many diesel PCV systems, especially the heavy diesels, you combine that oily flow with EGR from sooty exhaust being fed back in there, and boy, you have a nice recipe for a nasty mess.
Ask the folks over at commercial truck forums what they think about all of this. If you talked with them live, outside of the forums where they could be more verbal, you would experience a stream of newly invented swear words.
This is why I bought a 2013 Freightliner Columbia kit truck and dropped in a pre-emission, factory rebuilt Detroit Series 60 in it. Just to avoid all of this mess.
Originally Posted By: heynow
Who says diesels don't have this problem?
It's been a major issue for TDI engines since the 90's.
No it has been an issue on LSD fuel from '96 to ULSD inception in mid 2000's. It really only affected one family on engines primarily. The engines used in the Passat from '96-'97 and the Jetta/Golf/Beetle from '98-2005.
It was not widespread or even understood at the time as it is today. This is not an issue in any common-rail diesel that I an aware of.
So your statement of it being a major issues on TDI's is somewhat false & vague.
Who says diesels don't have this problem?
It's been a major issue for TDI engines since the 90's.
No it has been an issue on LSD fuel from '96 to ULSD inception in mid 2000's. It really only affected one family on engines primarily. The engines used in the Passat from '96-'97 and the Jetta/Golf/Beetle from '98-2005.
It was not widespread or even understood at the time as it is today. This is not an issue in any common-rail diesel that I an aware of.
So your statement of it being a major issues on TDI's is somewhat false & vague.
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Originally Posted By: TiredTrucker
Originally Posted By: Eddie
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
Whoops, wrong conclusion. Must not have been around any diesels made in the last 7 years. They have both EGR and routed to intake CCV. Imagine that one.... even with the filtration that is on many diesel PCV systems, especially the heavy diesels, you combine that oily flow with EGR from sooty exhaust being fed back in there, and boy, you have a nice recipe for a nasty mess.
Ask the folks over at commercial truck forums what they think about all of this. If you talked with them live, outside of the forums where they could be more verbal, you would experience a stream of newly invented swear words.
This is why I bought a 2013 Freightliner Columbia kit truck and dropped in a pre-emission, factory rebuilt Detroit Series 60 in it. Just to avoid all of this mess.
Wait a minute.....
Did you write that you've got a pre-emissions engine in a new roller,so you could circumvent all these new emissions laws and run an engine that in effect pollutes the air we breathe on a larger scale.
And you say it like it's no big deal.
I'll nutshell it for you.
Yeah I've got a brand new semi except I put an older engine in it so I could get around all these new pollution gizmos that are required by law to help improve the air for everyone.
Awesome.
I don't even know what to say about that. Your certainly something else man.
Since it's no big deal maybe pipe that exhaust right into your front door maybe,or your kids,since when your on the road it's someone's else's problem,right.
I'm so glad this generation that cares only about right now and doesn't think about future generations is expiring. How selfish.
Because it saves you a few bucks you don't care about the environmental impact of your decisions.
Didn't you say you burned old plastic oil jugs too? Iirc that was you who posted that one day.
Originally Posted By: Eddie
It may be that diesels don't have crankcase vapors re-routed back into the the intake manifold.
Whoops, wrong conclusion. Must not have been around any diesels made in the last 7 years. They have both EGR and routed to intake CCV. Imagine that one.... even with the filtration that is on many diesel PCV systems, especially the heavy diesels, you combine that oily flow with EGR from sooty exhaust being fed back in there, and boy, you have a nice recipe for a nasty mess.
Ask the folks over at commercial truck forums what they think about all of this. If you talked with them live, outside of the forums where they could be more verbal, you would experience a stream of newly invented swear words.
This is why I bought a 2013 Freightliner Columbia kit truck and dropped in a pre-emission, factory rebuilt Detroit Series 60 in it. Just to avoid all of this mess.
Wait a minute.....
Did you write that you've got a pre-emissions engine in a new roller,so you could circumvent all these new emissions laws and run an engine that in effect pollutes the air we breathe on a larger scale.
And you say it like it's no big deal.
I'll nutshell it for you.
Yeah I've got a brand new semi except I put an older engine in it so I could get around all these new pollution gizmos that are required by law to help improve the air for everyone.
Awesome.
I don't even know what to say about that. Your certainly something else man.
Since it's no big deal maybe pipe that exhaust right into your front door maybe,or your kids,since when your on the road it's someone's else's problem,right.
I'm so glad this generation that cares only about right now and doesn't think about future generations is expiring. How selfish.
Because it saves you a few bucks you don't care about the environmental impact of your decisions.
Didn't you say you burned old plastic oil jugs too? Iirc that was you who posted that one day.
To all those that thank that diesels do not suffer from the same issue as di gas engines need to do some resurch. The post form heynow is spot on. All diesels have egr since around 2003, and i mean all that were sold in ca. The rest of the us was around 04-05 range.
The same said engines have a pcv set up as well. The oil mist mixed with alot of soot sets up like paste in the intake, egr valve, cac etc...
Check any of the forums for powerstroke, cummins , and durmax. There are alot of people doing a "rerouteing of the pcv" so as not to put all the mist into the intake etc. Even with all the oil seperatiors there is still a mist the acts like glue.
Check out the images on yahoo and you tube.
The same said engines have a pcv set up as well. The oil mist mixed with alot of soot sets up like paste in the intake, egr valve, cac etc...
Check any of the forums for powerstroke, cummins , and durmax. There are alot of people doing a "rerouteing of the pcv" so as not to put all the mist into the intake etc. Even with all the oil seperatiors there is still a mist the acts like glue.
Check out the images on yahoo and you tube.
My 08 duramax has an EGR and a PCV system (since been deleted) and I can tell you that my EGR riser has at least 3/8" of buildup as well as my intake bridge. The PCV leaves an oily residue in the intake and the recirculated exhaust causes a pretty bad carbon deposit to be left behind and it doesn't take long to happen. I've seen intakes clogged nearly 80% in less than 60,000mi. It has gotten worse since they kept making the EGR's larger to lower NOx emissions. With the addition of the SCR and DPF injection the buildup problem seems to have gotten a little better as they were able to reduce the size and flow of the EGR and still meet emissions standards.
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Originally Posted By: Thermo1223
Originally Posted By: heynow
Who says diesels don't have this problem?
It's been a major issue for TDI engines since the 90's.
No it has been an issue on LSD fuel from '96 to ULSD inception in mid 2000's. It really only affected one family on engines primarily. The engines used in the Passat from '96-'97 and the Jetta/Golf/Beetle from '98-2005.
It was not widespread or even understood at the time as it is today. This is not an issue in any common-rail diesel that I an aware of.
So your statement of it being a major issues on TDI's is somewhat false & vague.
I disagree. I owned an 02 Jetta TDI. I had to clean it out twice in 80,000 miles. Cruise on over to TDIclub. They will tell you the same thing. I had the Jetta in at the dealer more times than I would like to remember. There was ALWAYS at least one TDI in there spending a grand to get the carbon cleaned out. Luckily I was able to do my own. Not to terribly difficult but it is a 6 to 8 hour procedured depending on how much needs to be cleaned.
When it was running it ran well but over time I could tell the carbon was building up as MPGs and driveablitiy went down. First time it happened the car would not even start when it got really bad.
Originally Posted By: heynow
Who says diesels don't have this problem?
It's been a major issue for TDI engines since the 90's.
No it has been an issue on LSD fuel from '96 to ULSD inception in mid 2000's. It really only affected one family on engines primarily. The engines used in the Passat from '96-'97 and the Jetta/Golf/Beetle from '98-2005.
It was not widespread or even understood at the time as it is today. This is not an issue in any common-rail diesel that I an aware of.
So your statement of it being a major issues on TDI's is somewhat false & vague.
I disagree. I owned an 02 Jetta TDI. I had to clean it out twice in 80,000 miles. Cruise on over to TDIclub. They will tell you the same thing. I had the Jetta in at the dealer more times than I would like to remember. There was ALWAYS at least one TDI in there spending a grand to get the carbon cleaned out. Luckily I was able to do my own. Not to terribly difficult but it is a 6 to 8 hour procedured depending on how much needs to be cleaned.
When it was running it ran well but over time I could tell the carbon was building up as MPGs and driveablitiy went down. First time it happened the car would not even start when it got really bad.
The US model of the BMW 335d has been plagued with carbon buildup with the intake and cylinder head.
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