not2fast

I was going to run a can throw my GL550 before changing the oil. What vacuum hose do people use?

DennisG01

Chevron Techron - dump it in the fuel. Anytime.

SeaFoam (can) - you can put that directly into the oil and run the truck for a couple hundred miles before doing an oil change.

I've personally done this with good results - other times, didn't seem to make a difference. I've never known/heard/read about anyone having a bad experience due to those. The only nay sayer's I've even seen are those that are assuming it would cause problems or simply regurgitating info from someone else that is guessing. Will those absolutely make a positive difference? No, of course not. There's too many variables. But they won't cause any harm and they "might" help.

not2fast

I have been using the can stuff forever, but used the spray on my Q7 and BMW N55 to clean the intake valves with decent results. It is almost like fogging my boat and wave runners. Skip to about 8:40 in the video. Crazy home much of a difference it made on that POS.

eric_in_sd

There could be merit to cleaning the injectors with a PEA additive, as Dennis pointed out. I believe the best way to do this is leaving the vehicle idling for prolonged time, so the PEA spends time in the injector innards. I let mine run for about four hours. Yes, the garage door was open.

If for some reason you think the intake valves need cleaning, the fuel-delivered PEA additive will work there as well.

An intake spray is going to be a huge pain to administer. You have to get past the mass air flow sensor, and then down a 90 degree bend. I wouldn't try it unless I were really motivated.

I wouldn't do any of these things without reason to believe they need being done.

Note that Dennis drives a diesel, which places much higher demands on the injectors.

DennisG01

True. But just for clarity (since I wasn't overly clear in my first post), I've done this on gasser's, too. Actually, more often with gassers over the years.

I might be a little wary about injecting that much "stuff" directly through the intake - not sure if it's good for the sensors. On a carb'd engine - or even a very early throttle body injection system - no big deal.

For example, talking about fogging a boat engine. We can spray fogging fluid directly into an intake of a carb'd boat engine, but the manufacturer's specifically advise to NOT do that with fuel injected engines due to fouling sensors. However, they do recommend cleaners introduced through the fuel system.

not2fast

I have never had a problem do it. Did it on my BMW with N55 last week. My concern there is direct injection and independent throttles getting carbon build-up. Not as big a problem as N54 motors, but I would rather stay in front of it. It actually cleared up some rough idle after startup. I had tried changing coils and plugs, but that didn't help. I also did this with my Audi with the 4,2L V8 with DI. I had taken the intakes out and had to scrub down the valves. The seafoam spray became a maintenance item on that.

As for fogging on boats, I have not heard of not doing it. My Yamaha MR1-s and SVHO motors Ion't have MAF's. Fogging usually causes people to swap plugs, but my boat is on season 3 without changing plugs. I usually spray in seafoam to clean up fogging in the spring before changing the oil.

DennisG01

I work in the marine industry - specifically at a place that specializes in Mercruisers. Less so with the OB's. I do own a Yamaha 250HP - but it's an OX66 and I don't have any issues spraying fogging oil into the intakes with that. But with sterndrives - the EFI's, and especially the MPI's - yes, fogging oil can cause problems. Instead, we "fog" by running the engines on a special mix of gas, 2-stroke oil and stabilizer.

You're probably right that the Seafoam is fine spraying into the car engines - I only mentioned what I did as I wasn't sure and would err on the side of caution. The fogging oil example was just a side note - that stuff is a lot stickier than Seafoam.

It's funny you mention BMW. I have a '97 528 and the VANOS (single) system was throwing codes. I don't know the exact name of the part, but it was determined that the little hydraulic cylinder that moves the cam was the culprit and likely gummed up. Before replacing it, I tried the Seafoam... that was about 10 years ago... never had to replace it.

Max Blast

I have used this stuff with great success on small engines...old lawnmowers and yard machines and the like.

If your GL450 has stuck tumble flaps due to carbon buildup I’d be very very very cautious in putting anything into the intake that might dislodge it.

alx

I would not put seafoam or any other detergent in oil or intake of a higher mileage truck. You will dislodge all kinds of crud that will end up in places you don’t want it. I have torn apart several engines that had oiling and intake clogging issues just to find what I mentioned above. Sesfoam or even better - Techron in gasoline fuel system is a good thing though...

fabbrisd1

On fuel/injection - I would strongly recommend using Stabil Marine Fuel Stabilizer (Blue Bottle) - 1/2 bottle - starts the "clean-up" from the fuel tank sensor going forward - using "hard core" solvents will certainly give you a "clud" - but frankly with the extremely much higher injection pressures"old school" is not "best school" anymore. - really.

Travelness

Not sure who would advise to not use seafoam directly into an intake,.but I have been using it for many years and have recently sprayed directly into my GLK throttlebody, have done the same with every vehicle I have owned and not one time had anything but positive results and not once a "fouling" of any sensors,this includes spraying into my Ford Truck that is a Diesel.

DennisG01

I said "wary". I didn't say don't do it. I was relaying a known fact about the use of fogging oil. Also note my comment "You're probably right that the Seafoam is fine spraying into the car engines - I only mentioned what I did as I wasn't sure and would err on the side of caution. The fogging oil example was just a side note - that stuff is a lot stickier than Seafoam."

not2fast

I want to do it, but couldn't find a vacuum line to use after the mass air flow sensor.

Travelness

Please note my comments were not directed in a negative manner to you nor anyone else. As to fogging oils, never used any for cleaning purposes only for spraying into an engine during a "build" to keep everything nice from any possible rust/oxidation issues. I have one friend that has used liquid wrench being sprayed into a throttle body on a Mopar engine, it did create some havoc on 02 sensors for a few hours then wore off. As to CRC or Seafoam,,personal use of Seafoam worked better so I always go with what worked for me. And I do agree about being careful as you said,,.some times it is best to not mess with something unless it is a known good product to use. Hope I have not caused you any concerns about my post on this. Thanks!

Travelness

Just wondering do you think it would mess up your mass flow sensor if you just sprayed it into your throttle body? I've not had that happen to me, but I am not 100% sure on your vehicle...

DennisG01

Thanks for chiming back in on that. Yeah, sometimes things get lost in translation on forums. Appreciate it!

No, you're right about the fogging oil - it's for storage, not cleaning. I was simply trying to use it as an example of what that does to explain where I was coming from - but I wasn't sure about the heavy doses of SeaFoam introduced in that manner (especially with "heavily-sensored" engines). Meaning, I wasn't sure one way or the other but just wanted to voice a "just double check before you do it" kind of opinion.

Travelness

I just finished doing my GLK with Seafoam, but I also had planned to get that process done before a tune up. As the plugs and coils needed to be changed out, that way I was not having the crud from using the Seafoam get all over new spark plugs. This all helped my gas consumption for now, but soon my gas mileage will go out the window as I have a project for this GLK having some performance modifications that will create a true gas guzzler out of it.