1997 Sentra Trottle Body Gummed Up?

You can buy a can of throttle body cleaner (not carburetor cleaner) at any auto parts store and do it yourself. A small brush like an old tooth brush will help.

I would try wiping the most dirt with a lint free rag, avoiding shoving the dirt in the lil holes in the throttle body. Then I would use some carburetor cleaner spray to dissolve the remains and finally I would try to figure out why this is happening so frequently. Too much blow-by in the engine? Oil level too high all the time? Incorrect oil type?

Good luck.

Joe wrote:

VLIP

First time. 160,000 miles. Just bult up over time would be my guess or a symptom of a problem I'm going to have in the future I suppose...

Carbon deposit build up is normal for any car. Also, do not use carburetor cleaner. The intake system has a smooth vinyl-like coating which helps to prevent carbon buildup. Carburetor cleaner destroys that coating and carbon build up will happen much faster. Use throttle body cleaner that's safe for fuel injected engines. Pep boys, autozone, they all have it.

CD

codifus wrote in news: snipped-for-privacy@57g2000hsv.googlegroups.com:

why would you get carbon deposits building up in the throttle body? It's strictly an AIR intake,no fuel passing thru at all,unlike a carburetor that mixes fuel and air.

Even the PCV valve dumps into the intake manifold,AFTER the TB.

Maybe it's dirt,a cruddy air filter.

innews: snipped-for-privacy@57g2000hsv.googlegroups.com:

You likely need to clean the Idle Air Control Valve also. Only use induction system cleaner and not carburator cleaner for fuel injection systems. Good luck. Al

al wrote in news: snipped-for-privacy@o80g2000hse.googlegroups.com:

that still doesn't explain CARBON deposits or grease in the TB.

All that stuff would also screw up your MAF sensor.

As an avid motorcycle rider, I can tell you that the exhaust and "road grime" that builds up on stuff comes from he air around our roadways. Simply riding a few hundred miles with my skin exposed to the air brings on a huge amount of sooty black stuff. I'm guessing that regardless of my air cleaner, enough of this stuff has made its way into the system in 160,000 miles to cause this.

I can't explain why it happens, just know that it does. One reason might be that when you let your foot off of the accelerator, for a brief instant the pressure in the throttle body will be in reverse. The blowby gases which the PCV is recirculating as well the exhaust gases that are being rerouted back to the intake by the EGR may then push back a bit. This would cause all that dirty air to flow back into the throttle body for a very brief moment. Some of the carbon in the dirty air would then settle on the throttle body which isn't totally closed. After thousands of miles of this repetition, it will blacken up the throttle body.

That's one possibility, but who knows, really.

The MAF sensor is pretty robust and usually far enough away from the throttle body to not have too much carbon dirty it up. Despite its name, the MAF doesn't actually "read" the air. All it does is heat up. The ECU reads how fast the MAF is cooling down to get a reading of how much air is coming through. The quicker it cools down, the more air that is coming through. If needed, you can clean your MAF using electrical parts cleaner from Radio shack.

CD

on 11/11/2007 12:27 AM AS said the following:

I read it as starting at 160,000 miles and then every 3 or 4 months thereafter.

That's how often the problem occurs, but revving the engine or driving of to my daily 35 mile commute clears it up for 3-4 months then it happens again. I'm just not thinking about fixing it since I'm betting it affects gas mileage too.

"Joe" wrote in news:wpuZi.3619$WN2.1572@trnddc08:

Then what does your air filter look like? it would have to look worse.

I'm in the wrong job.

on 11/10/2007 10:11 PM Joe said the following:

Don't ride around oil fields. :-)

on 11/11/2007 2:25 PM Peter Hill said the following:

That's pretty cheap. Around here. the hourly rate for auto service is $88.

Sometimes it does... But generally, the air filter is changed often enough that the micro-particles that get through and probably gunk up the TB don't get "changed" so they build up over the years.