How do you know you need your valves cleaned?

[Spitfire007]

What are symptoms that warrant valves being cleaned ?

How does one present that to the dealer?

I have neither tools nor time to go borescoping...!!
Thanks!

[KingOfJericho]

on the highway going about 55mph, put the car in 6th and put the pedal to the floor. If the car sputters and hesitates before accelerating, you've got carbon!

[shah269]

So how do they clean that shit off?
I mean really?
And how often do you have to do it?

[ken1137]

Originally Posted by KingOfJericho

on the highway going about 55mph, put the car in 6th and put the pedal to the floor. If the car sputters and hesitates before accelerating, you've got carbon!

Would you recommend using Liqui Moly Jectron ? Additive for gas to supposedly clean out your injectors and vales and so forth, or other as I have seen a few different ways to spray or use an additive. I dont really want to remove the manifold and scrape...I guess I could but would like to avoid such work. Time is limited ...LMK your thoughts

[Spitfire007]

The additives won't do anything. They only work on conventional engines where the fuel is sprayed BEFORE the intake valves. So the fuel mist with the additive will hit the hot valve and help clean it off.

Our engines are DIRECT INJECTION. The injectors spray fuel directly into the combustion chamber (cylinder). Fuel never passes by any of the valves to help clean them.

Hence the carbon build up.

I just don't know the particular symptoms.

The "Italian tune-up" where you go beat the car a bit, rev it high an hard won't work either. That relies on your injectors spraying fuel directly on the back of your valves that are super hot from you lead-footing it.

[doublevanosrc]

I would imagine there would have to be a simple remedy for this besides removing the manifold and scraping. I mean almost all cars now have DI, are you telling me that BMW engineers did not encounter this issue during their prototype testing??? I've read on some Audi boards of this being a huge deal on the RS4 engine as well which is like an $80k car.

[KingOfJericho]

As spitfire said, there is nothing we can add to fuel or do to the car to get rid of the buildup. Those with short commutes, like me, who are not driving the car long enough for it to get fully up to temp each day are going to have it the worst, and mine started acting up at roughly 20k.

As for the cleaning process... they remove the valves and sandblast them. Someone in another thread said that it costs $300, but my dealer had the car for almost 10 days. 7 to figure out what the problem was, then 3 to fix it. I doubt that a place charging $200 for an oil change will charge a penny less than a grand to clean the valves out of warranty.

It's considered standard maintenance on the RS4. Audi is doing nothing for the owners and they need the cleaning done once a year at around $1,000 per.

[RnmEvo9]

Set aside some money each year to have them cleaned.

http://www.e90post.com/forums/showpo...7&postcount=47

[RPM90]

I've got nearly 28K miles on my 135i and no symptoms of carbon buildup.
I don't do under 10 miles drives so my engine always gets nice an heated to temp during every drive.

[Red Bread]

There's a reason nearly all engines are moving to have DI with a secondary set of port injectors to wash the valves and intake tract. The Subi-yota has this now, and the next VW/Audi engines apparently will too.

[1911A145]

So is there anywhere in the manual or through BMW service recommendations to have this done and at what cost?

[KingOfJericho]

I don't think you'll find "carbon buildup maintenance" in the manual for any car... for obvious reasons.

[Spitfire007]

What a pain.....major disappointment.

[brusk]

I'd like to see the difference on the guys that are running meth. See if this cleans the valves up decently or at least keeps them from getting any worse.

[icabod7]

Meth makes little to no difference. See RmnEvo9's link again.

[Spitfire007]

So looking at the link above, did a catch can make a difference?

[brusk]

Originally Posted by icabod7

Meth makes little to no difference. See RmnEvo9's link again.

Missed the link. Would be nice to see somebodies before and after pics of running a cleaner through to see how much difference that makes.

[Spitfire007]

Cleaners don't make a difference.
Only scraping it out does.

I just want to know if there is conclusive proof that an oil catch can helps.

[1speedbike]

I'll be doing my third seafoam through the vacuum line since 30K miles at 55K miles tomorrow morning before an oil change. I don't have any of the carbon buildup symptoms, but I like to do it for the longevity of the engine. I usually see a good amount of smoke come out my exhaust when I do this, so it's gotta be doing something at least. I don't think it's placebo, either, because many owners have seafoamed with good performance results and lots of smoke. I wish I would have done this since the beginning, but a few years back when these cars were new, people didn't realize there would even be an issue. I don't think many Audi owners were even aware of this stuff back then.

This summer around 60K miles (probably a little more) I think I'm going to have to take the manifold off and clean it. Even with the seafoaming, I feel like the car has gotten slower over time. It could be that I need new spark plugs or something, but part of it has to be the clogging of my engine with carbon. No OCC, either. I haven't seen any proof that OCCs work except for them needing to be emptied out (the more, the "better"). Is it actually saving you from some buildup? I don't know, but it can't hurt. I should probably get on that.

[ken1137]

Originally Posted by Spitfire007

The additives won't do anything. They only work on conventional engines where the fuel is sprayed BEFORE the intake valves. So the fuel mist with the additive will hit the hot valve and help clean it off.

Our engines are DIRECT INJECTION. The injectors spray fuel directly into the combustion chamber (cylinder). Fuel never passes by any of the valves to help clean them.

Hence the carbon build up.

Yep, I was afraid that would be the case. just need to find the time to remove the manifold and scrape and clean. Damn...wish there was an easier way.

[bmw1racer]

Originally Posted by Spitfire007

Our engines are DIRECT INJECTION. The injectors spray fuel directly into the combustion chamber (cylinder). Fuel never passes by any of the valves to help clean them.

I think the 135i has direct injection, but not the 128i...

[RimasRS]

But taking of manifold how to clean valves which is opened if some of that shit will get into a cylinder is it ok?