• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Direct Injection huge drawback

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
Ronstang said:
Then they need to have exhaust scavengers take care of it like I do on the cars I build. You end up with a great running engine that has no build up and no contaminating of the air/fuel charge and you can retrofit these to any car....no passing emissions is another issue.
Click to expand...

Hypothesis:
It's not the oil, it's the EGR system.

Test:
Open head of DI motors with no EGR system.

Results:
No buildup

Theory:
It's not the oil, it's the EGR system.

Next step:
EGR delete on motor which is known to have problems.
 
Last edited:
I've got a 335i which has a twin turbo DI engine. Apparently, ethanol is the bane of this engine. DI engines need a high pressure fuel pump but apparently the high ethanol levels in gasoline corrodes components inside the HPFP in my model engine. I've had 2 HPFPs replaced already and my third one is going as well. I'm only at 10,000 miles as well.
 
Doggiedog said:
I've got a 335i which has a twin turbo DI engine. Apparently, ethanol is the bane of this engine. DI engines need a high pressure fuel pump but apparently the high ethanol levels in gasoline corrodes components inside the HPFP in my model engine. I've had 2 HPFPs replaced already and my third one is going as well. I'm only at 10,000 miles as well.
Click to expand...

So BMW didn't realize that a huge amount of gas worldwide uses ethanol? That was a bit of an oversight.
 
Bignate603 said:
So BMW didn't realize that a huge amount of gas worldwide uses ethanol? That was a bit of an oversight.
Click to expand...

I never got this either. I feel bad for the first folks who had their warranties voided for using "bad gas." It's insane that there is still a problem with the N54 fuel pumps.
 
Doggiedog said:
I've got a 335i which has a twin turbo DI engine. Apparently, ethanol is the bane of this engine. DI engines need a high pressure fuel pump but apparently the high ethanol levels in gasoline corrodes components inside the HPFP in my model engine. I've had 2 HPFPs replaced already and my third one is going as well. I'm only at 10,000 miles as well.
Click to expand...

Have they not redesigned the replacement pumps yet? Seems dumb.
 
I think they've redesigned the pump two times already and switched manufacturers.

There's a new one out but I didn't get it the last time I had the pump replaced (in December). My 2nd pump started acting bad almost immediately. I took my car in 3 weeks ago for a new pump or so I thought but all they did was install new software (which took 2 days). The pump hasn't acted up but I'm wondering how much longer it has. My car feels very sluggish now compared to before. I'll bet the new software detuned the engine or pump somehow to increase its lifespan.
 
This was an unforseen problem with Direct Injection. Apparently nobody realized just how much gasoline kept the intake tract clean.

I am sure they'll find ways around it, but it is indeed a problem right now. I hope it doesn't sway people away from Direct Injection engines. It is a good technology.
 
Doggiedog said:
I've got a 335i which has a twin turbo DI engine. Apparently, ethanol is the bane of this engine. DI engines need a high pressure fuel pump but apparently the high ethanol levels in gasoline corrodes components inside the HPFP in my model engine. I've had 2 HPFPs replaced already and my third one is going as well. I'm only at 10,000 miles as well.
Click to expand...
FVCK ME. I remember when you had to get the second replaced I think but you're about to have burned through a third? So, basically, your car goes through fuel pumps TWICE as fast as it does oil changes? Is this common with your car, surely most others with it aren't having this problem?
 
Doggiedog said:
I've got a 335i which has a twin turbo DI engine. Apparently, ethanol is the bane of this engine. DI engines need a high pressure fuel pump but apparently the high ethanol levels in gasoline corrodes components inside the HPFP in my model engine. I've had 2 HPFPs replaced already and my third one is going as well. I'm only at 10,000 miles as well.
Click to expand...

Damn, thought they had that figured out. This is the single biggest reason I don't have a 335i in my garage.
 
It isn't a direct injection problem, hell Diesel engines have be direct injection for a LONG time. Its an control problem as Either the valve seals really suck or the PCV system is allowing too much oil to get into the intake system.
 
halik said:
The B6/B7 S4s do not, but audi makes a 2.0 TFSI also that has the same issue.
Click to expand...

Gotcha. I thought you were saying that you had carbon build up on your S4 for this exact reason. I'm aware that the 2.0L DI engines at Audi/VW have this problem.
 
ayabe said:
Damn, thought they had that figured out. This is the single biggest reason I don't have a 335i in my garage.
Click to expand...

Most BMW owners never have this problem, which makes me think there are other issues that is causing the failure on certain cars. It sucks that BMW's fix is to gimp your ride in the meantime.
 
AsianriceX said:
Here's a reference for VAG folks:
http://www.audizine.com/forum/showthread.php?336352-Audi-FSI-Engine-Carbon-Build-up-Megathread

Looks like Porsche isn't immune either:
http://forums.rennlist.com/rennforu...the-new-gt3-doesnt-have-direct-injection.html

I've heard that Mazdaspeed3/6 guys are having the same issues, but I'm too lazy to look that up right now.
Click to expand...

Yeah, I read that thread on audizine and got sad...something to look forward too I guess, LOL.

..granted, I am on 50k in my B7 2.0T and I haven't noticed any problems.
 
ViviTheMage said:
Yeah, I read that thread on audizine and got sad...something to look forward too I guess, LOL.

..granted, I am on 50k in my B7 2.0T and I haven't noticed any problems.
Click to expand...

Once we get closer to the end of the warranty on our 2.0T, I'm going to take a look at these puppies. If it looks really bad, it may influence our decision on keeping it longer if they have not come up with a decent solution for this.
 
You must log in or register to reply here.

TRENDING THREADS

Back
Top