BinaryJay

Guys. Techron or anything else, no matter how often you use it or for how long you use it is not going to make any difference whatsoever if your engine has buildup on the intake valves. The fuel just simply never touches the top of the intake valves on the IS250.

Some sort of regular schedule of induction service where the cleaning chemical is slowly introduced as a mist at the throttle body would probably keep things clean if they are already clean otherwise the only solution to getting it cleaned out is the TSB procedure to physically dump the cleaner onto the valves from the top and let it marinate.

At this point I'm not sure what would be more effective and economic, to just let it do it's thing and eventually pay a few hundred dollars for the top engine clean procedure every 60,000 miles or so or to pay for induction service at some more frequent schedule.

Gaugster

My thinking is to have at BG type induction service performed annually. Say every 10k or 20k miles??? idk? Large buildup on the back side of the valves should be prevented if cleaned annually. This also should prevent large pieces of carbon from falling off the valves and into the combustion chamber. This is what I think was starting to occur in my engine. IMO, it's these large chunks of carbon in the chamber that the TSB is designed to remove after the fact. But i want to prevent the buildup from ever getting to that level again.

The BG induction service also cleans the combustion chamber. My hope it that I won't have to do the TSB again with a regular induction service schedule.

chikoo

The carbon buildup is due to EGR. So when does EGR kick in? Any specific rpm or other condition?

XhyDra

iTrader: (8)

If you read a few pages back there's an interesting explanation on exactly what might be going on at both highway speeds and short trips. Up until now I can't say that we've pinpointed it to being the EGR.

And as far as Techron goes, I've done that experiment in the past 30k ago and it didn't yield any interesting or functional results. Same issue over and over.

chikoo

Am I foolish in thinking that carbon the backside of the valve cannot cause problems? The surfaces that come in contact with each other will never have any carbon deposits. The surfaces that remain untouched and not functional are the ones where the carbon would be deposited.

For some reason, I think this has to do with the VVTI, cam phasing when coming to a stop too quick and maybe that the engine is too lean (read less power) and therefore experience a momentary drop in RPM(That is why the idle goes down to 500). I almost have it down to a science and make it happen on demand. If I come gently to a stop, the RPM stays at a nice 750 at idle. Which makes me believe that the ECU needs time to change AF ratio or the CAM or the fuel injector operation.

OPTiK

It's becoming a pain finding a shop around my parts that does the BG fuel induction service.. though apparently its only ~$70 which isn't too bad.

Gaugster

The carbon buildup that I had suffocated the engine at higher RPMs. The 5k to redline pulls noticeable better without question after cleaning.

I noticed what seemed like different types of carbon deposits (Oily vs. Ashy) on the primary and secondary intake valves. So it believe that cam timing has something to do with it. Also the cam timing is used for EGR.

The RPM drop might be related to the engine switching from Stoich to Stratified injection mode. idk?

chikoo

Above 5k is not my usual rpm range so not qualified to say how it should behave there.

But the coming to stop idle rpm drop...how do we even verify what is happening with the af ratio?

MIA_LEX

iTrader: (4)

Went to the dealership. Tried to have the tsib done, they tell me they cannot do it because I have aftermarket intake(joez) and exhaust(borla). Weak! Bringing in the tsib next time with my stock intake...see what they say.

Kurtz

iTrader: (1)

Call em back.

Tell them you want their denial of warranty service in writing, including, as required by federal law under the Mangunson Moss Act, a copy of their proof that the aftermarket parts on your car caused the problem they are refusing to fix.

If anyone you speak to refuses to provide that, and still refuses to schedule the repair, ask to speak to their boss.

If necessary keep going up the chain to the dealership owner... but once you mention the federal law that makes what they're doing illegal you probably won't need to.

MBTC

I haven't seen the specific legal documentation carmakers are bound to on this, but in many types of products, modification to the original product completely voids your warranty and completely releases the manufacturer.

I know when I ship a software product, if the customer decides to go on a tweak hunt and starts adjusting things that were not designed to be tweaked by the end-user, if they call me after they've painted themselves in a corner I tell them to get stuffed. I can ship them an update but it's going overwrite their changes. If I were a car dealer I would require all stock parts before I even put it on the rack.

Sorry, but tweak it and you own it.

Kurtz

iTrader: (1)

Cars aren't software.

I already told you the law involved.

A new car warranty can not, by federal law, be "voided" simply by modifications.

To deny warranty coverage for a specific issue the warrantor must prove that the issue was caused by the modification. And even then the entire full warranty remains in force for any other issues not caused by modifications.



In case you're wondering why the law works this way I'll give you an example-

I sell X brand cars.

I condition my warranty that if you use any aftermarket parts the warranty is void.

I now price my X brand oil filters at $500 per filter. My brake pads are $250. Per wheel. I also sell X brand oil, $50 per quart. And X brand air filters, also $500 each.

You're kinda screwed now, aren't you?

Thus the Mangunson Moss act forbids denial of warranty coverage for use of any aftermarket part unless they can prove the part caused the problem.

Likewise, they can't condition the warranty on having your maintenance done by the dealership unless it's free.

Basically any time you'd have to pay for anything (a part, or service) while the car is under warranty, you are free to get that part or service from any person or company you wish...and your warranty remains 100% valid unless the problem is caused by that person doing the service or the aftermarket part used. And even then it remains 100% valid for anything not caused by that person/part.

This keeps the car maker/dealer from having a monopoly on parts and service.

chikoo

From what i know, lexus will ask you to file a case for arbitration if you push too much.

Kurtz

iTrader: (1)

I've never had an issue go past contacting corporate myself (with any car maker)... including one, specific to Lexus, where the amount it "cost" them to give me what I was asking for was a lot more than the cost of an engine cleaning.

For Mangunson Moss issues specifically I've never even had to go that far... usually just mentioning you're aware of the law is sufficient to get them to do what they're legally required to. Polite, but firmly aware of your legal rights, usually works pretty well.

chikoo

Without giving any more details, i will tell u that corporate told me exactly that for a $500 fix.