Decarbonizing GDI Engines....

[5030]

That's a good approach. Up here in salt-country, enough electronic modules rot out - even if the body holds up, plenty of vehicles get scrapped because it's too expensive to replace the modules.

I haven't had a recent look at extended warranties..... factory coverage on wiring harnesses can be poor.

If I was inclined to buy new (pigs might fly too), I'd find out what the dealer charges to decarbonize that GDI engine, and drop my offer accordingly.

Rgds, D.

I'm in salt ' calcium chloride / brine country too. Probably the worst is post brine application. That stuff eats wiring. Salt and calcium chloride is a major reason for foliage die off on roadsides. Molex connectors are a gift from technology that work as advertised, keeping contacts clean and dry (with a little di-electric grease added....

I'm pretty religious about washing vehicles off, especially the undersides and engine compartments.. I added a angled end to my pressure washer wand just to get under the chassis (with a wide fan tip) and wash them off to keep the corrosive road treatments under control. I wash all my vehicles with rain water. I catch off roof water in IBC totes for vehicle washing.

 

[5030]

Couple comments on turbochargers and catalytic converters....

Turbo chargers use a ceramic seal on the hot side and a synthetic 'o' ring on the cold side to keep lube oil from seeping along the shaft and getting into the exhaust stream. It would be a rare occurence for any hard carbon to impact the turbine (hot side) blades and the compressor side is completely isolated. I've seen turbo's get destroyed but from collateral damage from piston parts or injector parts or valve train parts, never from carbon.

Far as a convertor is concerned, I have no idea what the palladium coated ceramic substrate can withstand concerning hard carbom impact but I believe it would be minimal because the gas velocity is minimal when you are dosing the engine anyway. The turbo isn't spooled up either. Turbo's only spool up when an engine's gas flow is high, IOW, it's working. Thats not going to occur when dosing an engine to remove intake carbon. The engine is in an idle or just above an idle state and not loaded so no high velocity gas flow is occuring.

Cats are pretty cheap to replace anyway. I tend to replace everything from the manifold back when doing an exhaust system, Lambda sensors included.

Not saying it cannot happen, but I don't think (from my experience with turbocharged engines) it would be a major concern.

You could always totally eliminate the culprit in the equation.... Eliminate the crankcase vapor into the intake tract entirely, that removes the carbon producing element. in lieu of that, keep your oil changed regularly and don't extend the change intervals, dirty oil produces more vapor and the more vapor induced into the intake tract produces more carbon at the intakes. Same goes with a worn engine that is allowing more blowby from worn rings. The rings are allowing combustion fases into the crankcase which has to be expelled to maintain pressure equalization and that blowby goes right into the intake tract and right to the valves...

While it's not exactly legal to remove a crankcase breather system, it's doable. legal, not really.

Some observations.

 

[3930dave]

Couple comments on turbochargers and catalytic converters....

Turbo chargers use a ceramic seal on the hot side and a synthetic 'o' ring on the cold side to keep lube oil from seeping along the shaft and getting into the exhaust stream. It would be a rare occurence for any hard carbon to impact the turbine (hot side) blades and the compressor side is completely isolated. I've seen turbo's get destroyed but from collateral damage from piston parts or injector parts or valve train parts, never from carbon.

Far as a convertor is concerned, I have no idea what the palladium coated ceramic substrate can withstand concerning hard carbom impact but I believe it would be minimal because the gas velocity is minimal when you are dosing the engine anyway. The turbo isn't spooled up either. Turbo's only spool up when an engine's gas flow is high, IOW, it's working. Thats not going to occur when dosing an engine to remove intake carbon. The engine is in an idle or just above an idle state and not loaded so no high velocity gas flow is occuring.

Cats are pretty cheap to replace anyway. I tend to replace everything from the manifold back when doing an exhaust system, Lambda sensors included.

Not saying it cannot happen, but I don't think (from my experience with turbocharged engines) it would be a major concern.

You could always totally eliminate the culprit in the equation.... Eliminate the crankcase vapor into the intake tract entirely, that removes the carbon producing element. in lieu of that, keep your oil changed regularly and don't extend the change intervals, dirty oil produces more vapor and the more vapor induced into the intake tract produces more carbon at the intakes. Same goes with a worn engine that is allowing more blowby from worn rings. The rings are allowing combustion fases into the crankcase which has to be expelled to maintain pressure equalization and that blowby goes right into the intake tract and right to the valves...

While it's not exactly legal to remove a crankcase breather system, it's doable. legal, not really.

Some observations.

That carbon issue would still scare me with a turbo... thinking of the heavy-deposit BMW pic in this thread. If every last spec of debris is vacuumed out (head not removed), OK then, maybe.

Typical backyard approach like Seafoam - all that displaced carbon from the head ends up somewhere. Will some of that carbon incinerate in the combustion chamber ? As theories go, I could run that.

Even at 1/5 of max rpm, a turbo spins PDQ. Would I be willing to bet that all displaced carbon gets incinerated before the exhaust valve opens ? I hope that I don't have to make that call anytime soon....

Not sure that you even need to take chunks out of a vane to get into trouble..... how much fine debris do you need to add to a variable-vane turbo before it stops being able to sweep ? <<< Honest question, that I don't know the answer to....

Things that make you go Hmmmmm............

Rgds, D.

 

[5030]

I've seen the inside of a lot of turbochargers with serious mileage 100's of thousands in big trucks, which produce a lot of carbon (as a result of combusting diesel fuel) and the only failures I've seen were from shrapnel passing through in an engine failure. Ocassionally, a hot side ceramic seal failure but thats about it. The design of the blade wheel sitting in the housing (scroll) is such that the exhaust gas only impacts the outer edges of the turbine wheel.

Not saying it can't happen, I've not seen it. DD engines, especially with the pre-def emissions, create hard carbon in the intake runner, to the point where it fills in the sensor ports and impacts intake valve stems but I've never seen a turbo failure because of hard carbon pass through, never.

Anything is possible, but IMO, the probability of it happening is in my opinion, pretty slim.

 

[3930dave]

I've seen the inside of a lot of turbochargers with serious mileage 100's of thousands in big trucks, which produce a lot of carbon (as a result of combusting diesel fuel) and the only failures I've seen were from shrapnel passing through in an engine failure. Ocassionally, a hot side ceramic seal failure but thats about it. The design of the blade wheel sitting in the housing (scroll) is such that the exhaust gas only impacts the outer edges of the turbine wheel.

Not saying it can't happen, I've not seen it. DD engines, especially with the pre-def emissions, create hard carbon in the intake runner, to the point where it fills in the sensor ports and impacts intake valve stems but I've never seen a turbo failure because of hard carbon pass through, never.

Anything is possible, but IMO, the probability of it happening is in my opinion, pretty slim.

That is good field data, thanks.

I hope the turbos on the recent generations of small gas DI motors stand up as well as those heavy-truck ones you describe. Would that generation of truck turbo have been variable vane ?

I know one guy who had a turbo replaced on an early/mid 2000 TDI Jetta, from what was described as carbon issues. Warranty claim, so can't say what the turbo looked like.... he did have some driveability issues, but perhaps it was just a slow $ week at the dealer and they wanted to push through a turbo claim....

With the Connectivity of Things migrating onto car platforms, it won't be long before the vehicle is "phoning home" the second you start to monkey with the EGR or anything else critical. That speed of reporting is already fairly common on heavy equipment.....

Rgds, D.

 

[5030]

Most compliant Class 8 engines are now adjustable pitch impellers. (it's not the hot side that is adjustable, it's the cold side btw). Some are even compound turbocharged, that is, the turbo is driven through a geartrain at low RPM to achieve the high pressurization required at low rpm's for a cleaner burn but thats rare..

My new Ford Focus with Ford Sync does the phone home thing. It gives me a 'health report' via my I-phone, including soft codes. A little over the top IMO. I've never accessed it but it's there.

Soon as it moderates here a bit, I have to dose the Transit. It's running extremely rough and sooting the tailpipe. No codes though. I'll be pulling and cleaning the MAF sensor too, might get a new one not the expensive. The air control motor is going to get cleaned too. I suspect thats where the big issue is. I suspect it's crapped up and the pintle isn't actuating properly. The Focus and the Transit have the same engine but the Transit has a conventional automatic with a tiorque convertor instead of the troublesome twin clutch, twin 3 speed siamesed transmission. Ford has never been able to get the electronic clutch actuation down properly.

I'd never buy one. It's a neat idea an auto-manual but the electronically actuated clutch is the weak link.

 

[3930dave]

Most compliant Class 8 engines are now adjustable pitch impellers. (it's not the hot side that is adjustable, it's the cold side btw). Some are even compound turbocharged, that is, the turbo is driven through a geartrain at low RPM to achieve the high pressurization required at low rpm's for a cleaner burn but thats rare..

My new Ford Focus with Ford Sync does the phone home thing. It gives me a 'health report' via my I-phone, including soft codes. A little over the top IMO. I've never accessed it but it's there.

Soon as it moderates here a bit, I have to dose the Transit. It's running extremely rough and sooting the tailpipe. No codes though. I'll be pulling and cleaning the MAF sensor too, might get a new one not the expensive. The air control motor is going to get cleaned too. I suspect thats where the big issue is. I suspect it's crapped up and the pintle isn't actuating properly. The Focus and the Transit have the same engine but the Transit has a conventional automatic with a tiorque convertor instead of the troublesome twin clutch, twin 3 speed siamesed transmission. Ford has never been able to get the electronic clutch actuation down properly.

I'd never buy one. It's a neat idea an auto-manual but the electronically actuated clutch is the weak link.

Thanks for the 411.... that does make more sense that the complex vanes are on the cold side. I'd heard of issues with variable vanes not being exercised enough, for some reason that had me thinking of the hot side....

I don't know those small Ford automatics well..... given any choice at all (tougher today), I pick stick when I can. Ford isn't the only one with issues in autos, though some of that IMO is from Ignored for Life ATF....

I believe you, but it is "interesting" that a modern engine can run that badly and not throw a code..... but then again that would be like the OEM admitting to a problem....

If you could do it without the data going anywhere, it would be pretty interesting to get your Transit on an Exhaust Gas Analyzer.

I'd find it pretty ironic if many of these "clean" modern GDI engines are running around spewing tons of emissions..... esp. after Vdub getting their head kicked in for "dirty" diesels.....

Good weather should be here soon, pls let us know how the Transit service goes....


Rgds, D.

 

[buickanddeere]

If you want the soot cleaned out of your vehicle . I'll volunteer Mrs B&D or any of the children. Standard operating procedure is foot to the floor on every acceleration ramp or when passing.

 

[3930dave]

If you want the soot cleaned out of your vehicle . I'll volunteer Mrs B&D or any of the children. Standard operating procedure is foot to the floor on every acceleration ramp or when passing.

Engines are digitally controlled today; I guess their feet are binary too !

Rgds, D.

 

[5030]

If you want the soot cleaned out of your vehicle . I'll volunteer Mrs B&D or any of the children. Standard operating procedure is foot to the floor on every acceleration ramp or when passing.

That might work for the combustion chamber and exhaust system but it won't work for the intake side. I suspect the hard carbon is a result of crankcase blowby mixed with incoming air building up on the hot surfaces of the valve ports and the backside of the throttle plate (and air valve). I can also see that extending the change intervals (oil) to MFG recommended 10K miles (synthetic) will have a detrimental impact on the carbon as well, the lube oil gets loaded with impurities and vaporizes even more. While it may still provide adequate film thickness for lubrication, dirty oil will cook a lot better than clean oil.

I've proved that to myself with my 1997 F 350 Ford pickup with a 7.3 diesel. I removed all the emissions related crap a long time ago, including the crankcase vapor recirc system. My blowby exits via a road draft tube now (just like it did years before all this green crap started. I can visibly see and SMELL the difference between a fresh oil change and and one with a few thousand miles on the clock. On a fresh clean change, there is little vapor and the vapor 'smells clean. After a few thousand miles, the vapor increases and it smells like dirty oil.

You cannot see or smell that with an emissions compliant vehicle because it 'vented' into your intake air stream via the PCV Valve. All that crap is going into your engine and the vapor is condensing and depositing carbon in your intake cavity. Outta sight, outta mind... until the carbon gets so bad it starts impacting performance.

Don't be sending the enviromental police to my house, I don't like strangers anyway.

Candidly, I'm half tempted to remove the crankcase blowby ingestion system from both cars and keep the pats handy if I sell either. Not hard to take off actually and eliminating the blowby gases and vapor from the induction tract should eliminate the carbon issue.

Really, just a matter of removing the PCV valve and hose to the intake, plugging the intake and running the crankcase vent to the atmosphere. There is, already an oil / vapor seperator in the valve cover. Just a matter of running the hose in a discreet fashion. The engine management system won't recognize the removal. It cannot. It has nothing to do with fuel trim or operating parameters, why, the engine don't throw a hard code when it's loaded with carbon.

Thats my wife's SOP as well and it's done nothing for her Transit. MY wife has 2 throttle positions, idle and WOT until the buggy reaches cruise speed and she pizzes about fuel mileage. When I drive my buggy, I short shift (it's a manual) and keep my foot off the loud pedal, merging into traffic using the entire on ramp, like it's supposed to be done.......I get really good mileage. She don't and it's the same powerplant in both vehicles except she has a slushbox, I don't.