GSLEX0586

iTrader: (1)

Interested to know if any1 here has seafoamed their 3GS? If so, was it worth it?

mmade22

I just have put it in the gas every 15k.....every three months for me. With a low milage car, I wouldn't run it in the vacume lines on mine. I heard that Direct Injection needs to be cleaned more often than FI. Can anyone else chime in on this?

BinaryJay

Seafoam or anything else for that matter in the gas won't clean the intake valves in the slightest on a direct injection engine without the secondary port injectors on the GS350/460.

I'm not sure how well the various vacuum lines would work either, unless they feeds air equally into all of the cylinders.

There is a TSB for this (IS250 and GS300), top engine cleaning, and Lexus' fix involves pulling all of the plugs and marinating the valves in some super solvent for quite a long time.

GSLEX0586

iTrader: (1)

do TSB's apply even if im out of warranty?

BinaryJay

No they don't.

dunnojack

does Techron work for DI ?
I just poured a bottle in the gas tank.
never did any of this additive crap before...

rominl

iTrader: (4)

i hope/guess it's ok, otherwise it's like saying you can't get gas from chevron

rigs

I've run it in the gas tank and added to oil a few days prior to scheduled oil change. Doesn't seem to make any difference in my opionion. I have a 08 460 with over 30K on the odometer.

pkp207

Do you have the form the TSB? I'd like to get this done.

dunnojack

i know it doesn't harm the engine.

but if it doesn't work, no point spending money on it


i'm just asking because BinaryJay mentioned something about seafoam and direct injection not doing squat

rominl

iTrader: (4)

to be honest, i don't think these will hurt, maybe keep things a little clean (big maybe), but i wouldn't go get a specific bottle to put in the tank. if i go to chevron already, then i consider it "might as well", but that's about it. my 2 cents though

BinaryJay

And here's why. On a traditional engine the fuel injectors are located above the intake valves (hence, they are not directly injecting fuel into the cylinders). On a direct injection engine, the injectors are located directly in the combustion chamber. Because of this, the fuel never touches the intake valves (they aren't "bathed" in fuel). On DI engines, it's the intake valves that get dirty with buildup mostly from the PCV system with crankcase vapor being fed back into the engine past the valves because of this.

Think about it, you can put the most magical cleaning stuff into your fuel, but since the fuel is injected past the intake valves and doesn't get anywhere near them how is it going to clean anything? It may help, somewhat, to clean the exhaust valves but those aren't usually the problem.

daman7676

iTrader: (1)

Thanks BinaryJay for that explanation. With that said, is our only option to get those intake valves cleaned to take it to the dealer? And how do we know when we need to have those valves cleaned?

BinaryJay

You can do it yourself if you can remove the spark plugs. The chemical they use actually comes from GM, I'm not sure what the part number #. Yes, Lexus dealer has to go to GM and buy it... weird right?

I think it goes mostly like this:

- Spark plugs out.
- Dump cleaner in
- Turn the engine over manually a few times
- Let marinate
- Drive for a while
- Change the oil
- Drive for a while
- Change the oil again (oil gets changed twice as part of the Lexus procedure).

They have it listed as taking a few good hours to complete but the majority of that time is just waiting so I'm not sure how much they should bill for it if you went in and asked for it to be done not under warranty. Make sure they aren't billing you for the marination time which is a large percentage of it.

There are some induction cleaning methods that claim now to clean intake valves, there is one from Terraclean... it involves not only running cleaner through the fuel system but also spraying it directly into the throttle body while the car is running... though I'm not exactly sure how they do that, probably with a long rod that they insert past the MAF which sprays the chemical. I have no idea how well this works but if you're going to get a service like this performed make sure that they aren't just adding stuff to the fuel line and are doing something through the air intake as well.

Hopefully this completes clearing up the idle gremlins from the car, it's not terrible but it's noticeable sometimes... if the procedure is good on this engine for another 100,000 km I don't have any problem payiing somebody a couple hundred bucks to do it again every 100K.

daman7676

iTrader: (1)

Awesome, thanks!

Doesn't seem like rocket science but it does seem like a decent effort. I have an '08 with 35K miles so I think I have some time. Nonetheless, great information to know for the future.