Throttle Body Has Black Sticky Buildup!

[niko11]

I had my air intake tube off today and looked into the tb and noticed that there is a black sticky buildup on the inside walls of the tb.I have run a k+n in it since it was new. I just cleaned the mass air flow because i heard that the oil will raise heck with them. That made some difference.I have been trying everything latley to get my 02 5.3 to get back to 15 mpg again like it used to. I am getting 11.5 now and have checked and done everything but a fuel injection service on it to get my milage back. my truck has 41,000 miles on it, and in 05 i let it sit alot, only put 2,000 miles on it that year. Since then it has been terrible on fuel. Do you guys think a tb cleaning and fuel injector cleaning at the dealership my solve this problem. I also might add that the truck runs great and has never thrown an ses light for any thing. Any input would be greatly appreciated.

Thanks

[03sierraSWB]

yeah i just say spray the TB with b-12 and put an injector cleaner in the tank. I have had to clean the TB more than once on mine as well, and it has 48K miles on it.

 

but maybe some more people will chime in later on.

[Nytemare]

K&N is where the black gunk came from man. Just get some good spray TB cleaner and use as directed.

 

I would say that you have build up on your valves too. I use Lucas fuel system treatment in my truck (and used it in both of my old cars) use it as directed in every tank until the bottle is gone than get another bottle and use it every 2nd or 3rd tank

 

Another thing you may want to look into is changing the plugs. I have 75Km's on my truck...about the same mileage as you... and my plugs were toast when I took them out today.

 

If you can get your hands on it....there is a product called seafoam. its used to clean the TB, valves and combustion chamber. you basicly pour it into the TB with the butterfly open about 1/4. Pour it in slowly at first keeping the engine from stalling until you have about half a bottle left. Than you just pour in whats left at a steady stream and let the engine stall out. Let it sit for about 10-15 min than start up the engine again, there will be an unholy amount of black, gray and white smoke bellowing out of your exhaust. Once the smoke clears your good to go.

Only problem with this is that its quite hard to pour into a horizontal TB.

[terry2004]

I had my air intake tube off today and looked into the tb and noticed that there is a black sticky buildup on the inside walls of the tb.I have run a k+n in it since it was new. I just cleaned the mass air flow because i heard that the oil will raise heck with them. That made some difference.I have been trying everything latley to get my 02 5.3 to get back to 15 mpg again like it used to. I am getting 11.5 now and have checked and done everything but a fuel injection service on it to get my milage back. my truck has 41,000 miles on it, and in 05 i let it sit alot, only put 2,000 miles on it that year. Since then it has been terrible on fuel. Do you guys think a tb cleaning and fuel injector cleaning at the dealership my solve this problem. I also might add that the truck runs great and has never thrown an ses light for any thing. Any input would be greatly appreciated.

Thanks

now is the time of year that they will be changing the fuel to the summer blend .your gas milage shoud go up .mine will go up because with the warmer temps the truck wont have to idle as long to warm up

[niko11]

have any of you guys found that your truck ran better and or got better fuel milage after cleaning your tb??

nytemare- how did your plugs look. I pulled three random plugs yesterday to look at them and they looked alright, no noticeable fouling or any thing. They all were about 09-.10 thousandths over gap. Just curious how yours were compared to mine. My dealership had suggested plugs as well yedterday, I just have not got to them yet. Thanks guys

[pwall]

My truck was suffering from poor gas mileage as well. Cleaned out the TB, changed the plugs and wires (I was running non-GM wires before), and it's back to normal....600kms on a tank of gas. It had gone done to 500.

Plus the buildup on the throttle plate was causing the gas peddle to stick a little...that droves me nuts when sitting in traffic.

[frdfandc]

K&N is where the black gunk came from man. Just get some good spray TB cleaner and use as directed.

 

I would say that you have build up on your valves too. I use Lucas fuel system treatment in my truck (and used it in both of my old cars) use it as directed in every tank until the bottle is gone than get another bottle and use it every 2nd or 3rd tank

 

Another thing you may want to look into is changing the plugs. I have 75Km's on my truck...about the same mileage as you... and my plugs were toast when I took them out today.

 

If you can get your hands on it....there is a product called seafoam. its used to clean the TB, valves and combustion chamber. you basicly pour it into the TB with the butterfly open about 1/4. Pour it in slowly at first keeping the engine from stalling until you have about half a bottle left. Than you just pour in whats left at a steady stream and let the engine stall out. Let it sit for about 10-15 min than start up the engine again, there will be an unholy amount of black, gray and white smoke bellowing out of your exhaust. Once the smoke clears your good to go.

Only problem with this is that its quite hard to pour into a horizontal TB.

 

 

This is incorrect. The black gunk on the inside of the throttle body is CARBON buildup. It does not come from the K&N. It comes from the engine directly via the tube that runs from the valve cover to the throttle body/intake tube. Its a normal characteristic of a GASOLINE engine.

 

All you need to do to clean the TB is to get some T-body cleaner, remove the intake tube, hold open the throttle blade and spray it in there. If it seems thick, you can use a rag or an old toothbrush to clean it better.

 

The Seafoam is for cleaning the combusion chambers, and the best way is to suck it into the intake thru a vacuum line, because the vehicle will not run correctly with the intake tube disconnected from the T-body. The engine needs the Mass air meter connected to the throttle body to run properly.

 

With the Seafoam, the easiest way to explain it is when you are using a vacuum line to suck it into the enigne, imagine that you are slurping soup. If you use this method, you will prevent engine damage.

[niko11]

thanks pwall- that gives me a little hope. i am going to schedule a total injection service for it tommorow, and if we were'nt in the middle of a nasty nor-easter tonihgt and tommorow i would change my plugs and wires as well. Thanks again.

If any one else has input, i'll take it!! thanks

[niko11]

thank youfrdfandc- that clears up the seafoam thing for me. I have never done it. do you know if the fuel injection service from the dealership involves a cleaning equivelent to the seafoam trick??also, have you had problems with your truck due to a dirty tb, or have you just cleaned it to be on the safe side?? thanks again.

[frdfandc]

Dealers use products similar to Seafoam. Each dealer is different. Some use products that are GM products, others use items from the aftermarket. They pretty much do the same thing.

 

As far as the dirty TB goes, I was getting an intermittent stall, bad idle surge when coming to a stop. Cleaned the TB and problem went away.

 

I normally do this during regular maintenance, since being I am a auto tech, but I let it go the past year.

 

Time to step up the maint. program again.

[HyperBuzzin]

Another thing that can drop fuel mileage are bad O2 sensors.

My truck went from about 17mpg down to 10mpg.

Changed plugs, wires, air filter.... no help.

Changed the O2 sensors and all is normal again.

[pwall]

I wanted to change out the O2 sensors at the same time (getting the truck ready for towing a travel trailer again) and my dealership said not to bother. They said to only change them when they throw a code.

Makes me wonder though....

[niko11]

thanks for all the help guys! i have an injection service scheduled for wed. Well see how that works. As for the o2 sensors, i have heard that they will get lazy over time and not throw a check engine light. My dealer says no way but an awful lot of peaople have had that problem on this forum. I thought about replacing the pre cat sensors to see if it would make a difference, but then i saw the price. I think 160.00 is a bit much just for a trial and error thing.

Hyperbuzzin- how many miles on your rig when the 02's got weak???

Thanks again everyone.