obZidian

iTrader: (2)

I was talking this over with a family member who works at the collection here in miami. They sell Audi's, Porsche's, Ferrari's,etc.

Anyways... we started discussing some of the issues he sees there with the high end cars and we ended up talking about the necessary maintenance the audi's (or any there with DI) need just about every 25k-30k.

Basically, the carbon buildup is so bad that the top end of the engines are replaced FREQUENTLY under warranty.

So, I got to wondering if the new LT1 will also suffer from this and what could be done to avoid it. Some of the Audi guys run 100% meth and they still see carbon build up. You can read threads after threads about this and basically, they take the mani's off every 5k miles and clean them.

Your thoughts? Maybe Big Gunz's can chime in? Or not.

VodeAn

iTrader: (2)

Seafoam through the intake every few months?

Billy the Great

iTrader: (2)

https://ls1tech.com/forums/16980597-post459.html

Whistler

iTrader: (46)

Ask the turbo 335i BMW or the Ecotec guys how often they replace their top ends. They've been DI since 07/06

99peweterls1

iTrader: (1)

^^ thank you

obZidian

iTrader: (2)

Did he go into how that might work? I believe this humps on the valve covers is part of the new pcv system. I wonder how that might work with a vacuum pump?

I guess time will tell then.

MyFirstLS1

iTrader: (8)

oh boy oh boy

I have some pictures for you guys

I'm a tech at BMW and I myself am worried about the DI in the vettes. Obviously the issue is going to be on the intake valves only. You have no fuel running over the valves due to direct injection. But.....the saving grace may be the non forcefed application and you may not have the blowby that we do on the twin turbo (n54) engine

Pictures are from a 07-08 335xi
You mean like this ? ? ?









For reference this is what it should look like prior to lapping

ramairetransam

iTrader: (18)

post them then

obZidian

iTrader: (2)

Go take a look on the BMW forums and ecotec forums. Carbon build up is a real issue my friend. Just because a manufacture continues to build something doesn't necessarily mean that the all the issues have been dealt with. I.E. the LS7 or the Audi's DI engines.

Hopefully the vacuum pump (in the LT1) will help pull the oil coming through the pcv out of the intake tract enough to reduce any significant carbon buildup.

MyFirstLS1

iTrader: (8)

Pictures are posted now ^^^^^

It almost needs another set of inectors just for cleaning purposes like the style thats currently in use. I'm sure they can figure out a way to cut out the DI and run off them but I don't see that happening.

obZidian

iTrader: (2)

http://mbworld.org/forums/c-class-w2...n-buildup.html

Interesting read.

MYFirstLS1: Tell me about it. I have seen these engines in person before and its crazy the gunk that comes off the intake tract. What I find comical is the idea the car manufactures are still producing these engines as to assume that the problem is resolved. Some are introducing a secondary injector back into manifolds to wash the valves off.

Again, hopefully GM has considered the issue and the pump will help instead simply adding another service item to keep their service departments busy.

MyFirstLS1

iTrader: (8)

This motor is only being produced in one car the 335is

All the new turbo direct injection motor use a new style injector but I have yet to come across this issue with the new style single twin scroll turbo cars n63tu ttv8 or n55 single twin scroll straight 6

Haven't seen anything like that at least from BMW (as far as a secondary injector)

obZidian

iTrader: (2)

Could it be for a lack of time and miles or was there another change made? Maybe a new pcv/egr system?

The ones I've seen have been the Audi/VW engines and I was just amazed considering the miles the engines had.

I read in one of those mbboard threads about Porsche adding an injector however I haven't seen found anything related to it. That may just be a rumor for all we know.

obZidian

iTrader: (2)

This is from the details released about the new lt1:

PCV-integrated rocker covers: One of the most distinctive features of the new engine is its domed rocker covers, which house the, patent-pending, integrated positive crankcase ventilation (PCV) system that enhances oil economy and oil life, while reducing oil consumption and contributing to low emissions. The rocker covers also hold the direct-mount ignition coils for the coil-near-plug ignition system. Between the individual coil packs, the domed sections of the covers contain baffles that separate oil and air from the crankcase gases – about three times the oil/air separation capability of previous engines.

-Perhaps those baffles and new pcv system will help keep the intake ports/valves clean.

MyFirstLS1

iTrader: (8)

I can't see it being any different then what's already out there on DI cars. Just more expensive to service lol

The head that is pictured has 90k but I have seen one with 25k just as bad

But like I said it may be OK since it won't be turboed

wssix99

iTrader: (5)

Why does this still worry you if a GM engineer has stated that they are aware of the phenomena and have addressed it? Is a problem with BMW's engines really an indictment of all DI engines made by every manufacturer?


This is really the true measure of progress isn't it? As the engines get more complex, the servicing also becomes more involved. BTW - I'm not worried about the expense, I'm worried about more stuff in tight spaces and the resultant cuts and bruises from the work. Its getting more and more to the point where you have to pull an engine to do anything on it.

obZidian

iTrader: (2)

Well... how many engineers and people in the know stated that the ls7 engine failures were caused aftermarket parts and tunes, that there was NO REAL problem however to only release a recent statement indicating that the machining of the heads are the real problem?

The MB engineer stated in that thread that they were not aware of such a problem. Do you have that much faith?

I ALSO hope that the engineers working on the new lt1 found a way around this but one thing is the engineers time and costs associated dealing with the problem and another are those that pay the bills which dictate what.gets fixed and what gets left for us to deal with. The percentage of failures versus overall production numbers play more into all of this then we would like, including the engineers.

obZidian

iTrader: (2)

Do you guys just clean the ports and valves with a solvent or do you replace parts as well?

wssix99

iTrader: (5)

I think BG addressed that pretty well and said the machining problem was on a single batch of parts from an outsourced company. That kind of issue doesn't show up in testing and every manufacturer has to deal with it. A widespread problem like BMW's DI carbon build up is a different kind of animal...


Not when engineers are breaking new ground or aggressively pioneering. In this case, others led the way, exposed the issue, and the engineers following have the opportunity to specifically address it.

If anything, I'd be more worried about problems no one has seen before.

Gordon0652

iTrader: (4)

Why would you have carbon build up on top of the intake valve when no fuel it up there? Nothing but air and maybe come contaminants that pass through the filter.