RevGTO

iTrader: (12)

Not to mention the wonderful "distributorless" LTI with the Optispark mounted directly under the water pump, the 3.4 & 3.8 V6 intake manifold and head gasket failures, the "Hi-Tech 4100" Cadillac motor with intake manifold leaks into the oiling system ... the list goes on and on. When it comes to motors, the LS series is one of the few they've gotten relatively right since the old divisional V8's. New LT1: Caveat Emptor.

Kurt D

iTrader: (2)

OK, question(s): how are the diesels getting around this heavy carbon build up in the intake track and valve? They are DI, do they not have a PCV system? The issue of oil seeping from the valve guides not effect them? I know little about diesel engines other than emissions standards are different so PCV may not be required (vent to atmosphere) OR maybe they use a system similar to what GM is trying on the LT1 (baffles and pump setup). I do know the oil seeping theory would apply to them as well as a gas engine.

okieraptor

My Dmax Has Pcv But I Rerouted It To Atmosphere. Still I Dont Know Of Any Diesel Thats Pulled The Head After 20-40K Miles And Had A Problem. I Did My Reroute At 120K Miles And It Runs Fine.

GMtechmatt

on direct injected engine with General motors it is very important to run the Gm upper engine service through a vacuum port in the intake in order to clean the valves etc running it through the injector is ok but not to efficient. or remove the plugs and soak the cylinder for up to two hours then dry crank it with fuel and ignition disconnected to clean it out.

T.Man

Doesn't help. I've researched it across many DI platforms, from GM, BMW, VW and Audi. Coking is nasty stuff and doesn't come off easily.

The coking and buildup are on/in the intake ports and valves. Running it through the vacuum port does no good except, maybe clean the tops of the pistons.

I just recently took the intake manifold off of my LNF and cleaned mine by hand. Was nasty and validated the times before that I had used seafoam was a waste.

ecotec88fiero

In the Cadillac dealership we see this frequently with the DI 3.6L V6 that has been around since 2008.
It seems to me its a combination of PCV oil residue, VVT system increasing cam overlap for EGR which really bakes the oil into the valves, customers using low quality gasoline and not running the engines at high loads which usually will clear out the engine top end.

I have had these carbon deposits cause misfires and even create so much valve lash that roller rockers will get out of place.

Lexus down the street from us has brought back the walnut shell blaster to clean the deposits off on the car so the problem is even affected the Japanese manufacturers, not just American or German.

The easiest way I have cleaned this stuff if using GM's specified top engine cleaner, sucking a whole bottle into the HOT engine through a vacuum port without bending a rod and then shutting off the engine and letting it sit for about 2 hours. Then you take it on a test drive in 2nd gear and do 3-5 30-65MPH WOT pulls to blow out the carbon. Makes quite a great smoke show out of the exhaust but cleans the engine nicely and gets rid of any symptom. Badly carboned engines get this done twice and the engine oil changed.

I imagine a better LT1 PCV system plus making sure the engine gets quality fuel and a good hard running once and a while should keep carbon at bay.

BAD ASS TA WS6

iTrader: (5)

It absolutely does help, BIG TIME.

Been doing walnut/media blasting on the N54 for years now. Have seen them bad with 20k, have seen them go 120K and never had it done. Oil changes and quality of oil is big. BMW was using 15K intervals. '14+ models will use a 10k interval. Also fuel quality is a player. Customers using GOOD 93oct. and typically drive the cars a bit harder see far less issues. That said without having an injector in the runner area to "clean" them it will always be an issue.

I have heard Toyota?Subaru used DI/and SFI in the BRZ engine which seems smart to me.

Time will tell, but if it were mine I would install Meth ASAP and never deal with the issue again

SSellers

About the only fix is what Lexus has done since 2005, dual injection. VW group is also implementing it. It has your direct injector for primary along with another injector in the intake tract. The reason you don't see it more is because it costs more and is supposed to be a real bitch to tune. I remembered reading about it years ago and had to search around to see where it was actually used. Here's one article:
http://www.motornature.com/2012/08/d...-after-toyota/

BAD ASS TA WS6

iTrader: (5)

Yeah thats the 'Yota setup I was referring to. I haven't looked into it at all, just heard it was being used with success

disc0monkey

iTrader: (10)

pulled apart my buddies mk5 DI VW engine with 125,000 hard *** miles. he ran meth injection to use his 100 octane tune on 93 with his Ko4. The motor was clean as a whistle, ive never seen an engine so clean.

I would implement some meth injection system to keep it clean if you're really concerned.

disc0monkey

iTrader: (10)

btw the meth was installed around 80,000 miles. still the valves and piston tops were super clean, cleaner then my LS1 piston tops at 41,000 miles.

T.Man

You're not going to eliminate coking/sludge just by running the cleaner through a vaccuum port. If it were that easy, all dealerships would do it and wouldn't deal with the media blasting or manual cleaning.

You're cleaning the tops of the pistsons and that's about it. All of the liquid you're sucking into that motor is doing nothing for the backs of the valves/ports where all kinds of oil/fuel vapor has been baked on.

If what you're saying truly worked, BG wouldn't be trying to reformulate their "DI cleaning system".

Really? I'll guarantee the media blasting works 100% every single time. The Meth? Not a chance. It might help to keep a freshly cleaned head/valve cleaner than it otherwise would be without it but it will not clean anything.

There's tons of evidence out there but here's what I was able to quickly find.


N54 running meth for 10K miles:

This thread has multiple people stating that it does jack ****:
http://forums.bimmerforums.com/forum...2#post24931652

Here's another platform using an aquamist system (meth/water) as well as also using seafoam:
http://www.northamericanmotoring.com...-build-up.html

Here's another platform using the BG service I mentioned above:
http://www.bobistheoilguy.com/forums...2101483&page=1

Here's my platform, 48K miles and seafoamed every oil change since new:
http://www.cobaltss.net/forums/6660151-post143.html

Here's another N54 owner who did a write up on manually cleaning the valves, didn't use meth and obviously had a nice surprise waiting for him. He then used meth for 10K miles after cleaning the valves and guess what? Well, see for yourself:
http://www.n54tech.com/forums/showthread.php?t=12258
http://www.n54tech.com/forums/showpo...8&postcount=19

disc0monkey

iTrader: (10)

not a chance? really? I've seen it with my own two eyes on my best friends car. no one worked on that car with out me. how do you explain the cleanliness of that motor? More miles on that VW then the bmws you've shown and still cleaner then your valves are.

How do you know results might not vary according to application?

how much actual experience do you have running meth?

just curious how you're so sure about that, thats all.

T.Man

The post I provided about my platform is not my car. I cleaned mine by hand: http://www.cobaltss.net/forums/7054707-post1.html

Regarding your friends car, that's awesome but that's your anecdotal evidence. Not only that but I highly doubt the motor was as clean as you say. Want to know why? Because the Audi/VW FSI motors are some of the worst offenders when it comes to carbon build up/coking. And when you tell me the "motor" was clean, that doesn't tell me how nasty the intake ports/trays/valves were. So the pistons were cleaner than yours? I'd hope so with the meth? No one is disputing that the meth will keep piston crowns clean?

Regarding meth injection and my experience, what does that have to do with the discussion at hand here? Just because I've never used it myself doesn't discredit one single thing that I've researched/found. There are hundreds of threads/posts of peoples results with meth injection on DI cars, including on my own platform.

Check it for yourself.

Edit - Here's another N54 that had meth run through it for 5K miles, in the very same thread I posted above:
http://www.n54tech.com/forums/showpo...1&postcount=23

Another:
http://www.n54tech.com/forums/showpo...6&postcount=40

Another meth user who also used an OCC:
http://www.n54tech.com/forums/showpo...4&postcount=29

And those were in just one small thread...

BAD ASS TA WS6

iTrader: (5)

It discredits everything you have said as you have no first hand knowledge of what you're speaking of. Posting other peoples results (who are also not credible) does nothing to prove the point. Some of these clowns on the various forums are something else...

I work on a lot of cars, at my dealer, and at my house! I have one 335 I did running meth since 15k, intake runners are clean, and it makes 415/440 wheel with basic mods.

Walnut blasting is the only way you are going to recover the buildup in the runners/shroud area once the damage has been done, you are 100% correct.

Not trying to be a dick, I just calls it like I sees it. The guy in the thread you referred to put his car in first gear, and rocked it back and forth the get the valves closed. WTF IS THAT ****?!?!

disc0monkey

iTrader: (10)

dude the motor was insanely clean. It's obvious I'm talking about the intake ports and valves, that's the main topic of this discussion.
we tore down the ENTIRE engine for a rebuild, it was on an engine stand. I disassembled the heads and sent them out for a valve job, I would know if there was any build up.
I was there for every second of it. Why would I lie, I could give a ****.

T.Man

So what you're telling me is that it doesn't matter what kind of information is out there, you can NEVER base your own opinion off of others (many others) results on a particular topic and should somehow expect a radically different experience/outcome? Kind of flies in the face at the entire point of technical message boards, much like this one, no?

Obviously you would want to take a few posts/threads here and there about the topic at hand with grain of salt. However, when you have hundreds of posts/threads with hundreds of people experiencing the same exact results, one would logically arrive at the same conclusion, a round peg doesn't fit in a square hole....

No different than the hundreds of people posting about how seafoam/techron/BG system cleaners and all that other BS that's fed through vacuum ports not doing a damn thing, with both photo and video evidence. Yet you still have cheerleaders and misinformed/uninformed people who continue to spread the false notion that on a DI vehicle, they will somehow "clean" things...


Damn right it is but you have two "ASE Mechanics" in here saying otherwise, right along with many others. Meth won't do jack **** in this instance and this is entirely what my argument is about. I never said it was impossible for meth to potentially help keep a freshly cleaned/zero mile motor cleaner than it otherwise would be without it but it still will not keep it from happening. It's inevitable with the kooky assed PCV systems that are being used. Some are obviously better than others but regardless, it's going to happen. Let's hope GM's new system truly prevents it.

No one said you were?

How is it any different putting the car in gear and moving it versus getting on the crank bolt and turning it? Both accomplish the same thing?

BAD ASS TA WS6

iTrader: (5)

Sorry but if you don't see an issue there you shouldn't be working on an engine. I suppose you are accomplishing the same thing. However mechanically that is literally one of the dumbest things I've ever seen done as "normal practice". I love that he posted that up and shared it for all idiots to copy; on their $15k+ interference engine to boot.

Funny thing is all he had to do was jump the starter that is literally right there.

Seafoam and all those BG products aren't going to do ****. That stuff is old folk lore.

arghx7

Hardly anyone is going to run water/meth injection on an n/a V8.

Krom

FWIW IMHO when you are doing valves, its easier to bump the car back and forth, or use a breaker bar to turn the engine, as you can always stop the crank exactly where you want it.

Why don't you explain how it is any different to turn the engine by the flywheel with a starter, than by the flywheel with the trans???

While your at it, you can add what being an interference engine makes a difference. The starter wont save a valve from being bent, hell most starters have enough *** to bend a rod if there is too much fluid in the chamber

by that logic, pop starting a car would destroy the engine...

The engine doesn't know the difference, it only knows its being turned...