If you've ever seen photos of inside the intake manifold of a modern engine with port injection and EGR you know what a carbon and goop nightmare looks like. With a carburetor this wasn't an issue because the fuel/air mixture continually washed out the intake runners and kept them clean from the EGR deposits. So, here's my question: If a FlexFuel vehicle runs E85 all the time, shouldn't these EGR deposits be all but eliminated? I've seen photos of engines that had been torn down after running E85 for tens of thousands of miles and the pistons and piston crowns were extraordinarily clean. Wouldn't that mean that the intake manifold would be too because the exhaust from burning E85 is far cleaner (less carbon)?
Intake deposits from EGR and E85 use
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Alot of those are from the pcv system and with port and direct injection they have nothing to flush them away
Originally Posted By: Roadkingnc
Alot of those are from the pcv system and with port and direct injection they have nothing to flush them away
Yes, it's a combination of blowby from the PCV and EGR. Regardless, I would think the deposits in the manifold would be greatly reduced (if not eliminated) from 100% use of E85.
Alot of those are from the pcv system and with port and direct injection they have nothing to flush them away
Yes, it's a combination of blowby from the PCV and EGR. Regardless, I would think the deposits in the manifold would be greatly reduced (if not eliminated) from 100% use of E85.
CNG is the way to go if you can. The engine oil doesnt even get dirty.
E85 would keep the intake valves cleaner on port injection but I dont think it would impact the upper intake area much
Originally Posted By: Roadkingnc
E85 would keep the intake valves cleaner on port injection but I dont think it would impact the upper intake area much
I think it would by the mere fact that E85 blowby and exhaust gases are cleaner than those produced from burning gasoline.
E85 would keep the intake valves cleaner on port injection but I dont think it would impact the upper intake area much
I think it would by the mere fact that E85 blowby and exhaust gases are cleaner than those produced from burning gasoline.
A well-running engine shouldn't coke up an intake manifold very badly. The insides of the intake manifolds I've seen have been relatively clean. If the EGR is that dirty, I think there might be another cause than simply "burning gasoline". Rich mixture, poor combustion, something else.
Originally Posted By: Roadkingnc
CNG is the way to go if you can. The engine oil doesnt even get dirty.
Absolutely!
I once bought a 1970 E250 at auction and it was run on Propane its whole life. It's engine was super clean inside.
CNG is the way to go if you can. The engine oil doesnt even get dirty.
Absolutely!
I once bought a 1970 E250 at auction and it was run on Propane its whole life. It's engine was super clean inside.
I use a catch can. $20 for an almost spotless intake, IAC valve, intake valves, and TB is far better than considering the drawbacks of almost pure alcohol as a fuel.
But yes, E85 should be cleaner.
But yes, E85 should be cleaner.
It's reported that deposits in Direct Injection engines come mainly from the PCV system and not the EGR system. On Port Injection engines the intake valves are washed by the fuel but not on a DI engine.
If I have to replace the IACV on my vehicle, I may go the route of the catch can.
More alcohol in the fuel is harsher on the oil, right?
More alcohol in the fuel is harsher on the oil, right?
What car do you have? I've seen before and after pictures on a VW forum showing that catch cans on the 2.0T DI engine did nothing. Lot of owners there trying catch cans. I'm glad it works for you. All engines react differently. Thanks.
Originally Posted By: ffhdriver
What car do you have? I've seen before and after pictures on a VW forum showing that catch cans on the 2.0T DI engine did nothing. Lot of owners there trying catch cans. I'm glad it works for you. All engines react differently. Thanks.
The car you mention is very specific. There are umpteen jillion others.
If there is residue being collected in the catch can, it HAS to be doing some good.
It HAS to.
What car do you have? I've seen before and after pictures on a VW forum showing that catch cans on the 2.0T DI engine did nothing. Lot of owners there trying catch cans. I'm glad it works for you. All engines react differently. Thanks.
The car you mention is very specific. There are umpteen jillion others.
If there is residue being collected in the catch can, it HAS to be doing some good.
It HAS to.
The interesting thing is EVERY 4 stroke pressure lubed engine creates a bit of oil in the intake.
But almost no engines have catch cans. Hmmmm, makes me wonder why they are not OEM.
Not usually needed
But almost no engines have catch cans. Hmmmm, makes me wonder why they are not OEM.
Not usually needed
Pretty much agreed on that one.
With some of the oil manufacturers (it's on the board here somewhere), citing research into OIL formulations to reduce intake deposits,I'm stating to think that some wetting of the intake, and maybe with esters etc. from the oil may be a good thing for deposit reduction.
With some of the oil manufacturers (it's on the board here somewhere), citing research into OIL formulations to reduce intake deposits,I'm stating to think that some wetting of the intake, and maybe with esters etc. from the oil may be a good thing for deposit reduction.
^As long as you clean your TB (on FI vehicles, not apps with DWB) and prevent actual caking...on some apps that 'need' it seem like a catch can would have to be drained fairly often(once a month?).
I mean, that can't be good for the air/fuel mixture if enough is getting through the PCV system to thereby influence the vicious cycle of EGR deposits from such excessive oil via intake/ironically from blow-by?
...or is that stretching it too far?
I mean, that can't be good for the air/fuel mixture if enough is getting through the PCV system to thereby influence the vicious cycle of EGR deposits from such excessive oil via intake/ironically from blow-by?
...or is that stretching it too far?
Just so you know I have removed intakes from late model cars and found HUGE amounts of oil in them!
A catch can will 'catch' some on any car. But this isn't something that the mfgr's don't know about.
A catch can will 'catch' some on any car. But this isn't something that the mfgr's don't know about.
Originally Posted By: SteveSRT8
Just so you know I have removed intakes from late model cars and found HUGE amounts of oil in them!
A catch can will 'catch' some on any car. But this isn't something that the mfgr's don't know about.
That oil, plus condensate, plus blowby, plus EGR = gunk in unwashed intake runners from port-injected or DI engines. I still say the EGR and blowby from E85 is inherently cleaner than gasoline and will result in less buildup in the EGR plumbing and intake manifold.
Just so you know I have removed intakes from late model cars and found HUGE amounts of oil in them!
A catch can will 'catch' some on any car. But this isn't something that the mfgr's don't know about.
That oil, plus condensate, plus blowby, plus EGR = gunk in unwashed intake runners from port-injected or DI engines. I still say the EGR and blowby from E85 is inherently cleaner than gasoline and will result in less buildup in the EGR plumbing and intake manifold.
The Mfrs will not put a device on a car that has to be emptied every month or two by the average civilian.
THAT is why there is no catch can system on most cars!
Needed? What does that mean?
A cleaner intake, TB, idle air motor, valves, and combustion chambers are enough for me to warrant it's use.
Needed? Why not use a crankcase vent tube like in the old days? Is a PCV system needed?
What is best is the real question.
And things are absolutely better with a catch can.
THAT is why there is no catch can system on most cars!
Needed? What does that mean?
A cleaner intake, TB, idle air motor, valves, and combustion chambers are enough for me to warrant it's use.
Needed? Why not use a crankcase vent tube like in the old days? Is a PCV system needed?
What is best is the real question.
And things are absolutely better with a catch can.
Road draft tube, pollution and bad odors.
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