Been lurking this site for a while but I finally found somethng that isn't answered (at least as far as I can tell) on this site.

Does anyone know where I might be able to find a write up or a show thread on how to clean the EGR ports on a 97 Accord V6? (Engine C27)

The main reason I am asking is I read through a few threads that mentioned a combination of thermostat, O2 Sensor, and EGR can cause bad fuel miliage.

My RPM's in the V6 sit at about 3000 when I'm running at 100kms (70mph) which I have read is 2-300rpms too high, and my temp guage never rises much above 1/4, even in 30 degree weather (the vents do blow hot, something I read they won't do if the thermo is bad) which also could be tied into the thermostat, 02 sensor, and EGR, and thus cause bad fuel economy.

Any help/direction would be much appreciated!

 

Unless you have a P0401 I wouldn't feel a need to worry about the EGR ports, personally. I don't think any of the three things you mentioned would cause the RPM's to site 2-300 higher than what you have read.

You haven't talked much about your fuel mileage, which you seem to be concerned about. How much of a reduction in mileage are you figuring.

 

I have not noticed a reduction in fuel economy exactly, I have only been driving the honda regularly for about 3 months now so I am more concerned that the fuel economy that I am getting now, is as good as I can get. I seem to be getting about 575km (357 miles) per tank on a regular basis. I should note that I fill up the tank usually right when the low fuel light comes on, so I never end up putting more than 52L (13.7 gallons) in at a time.

I am also aware that driving style plays a rather major part in this, and I would describe my style of driving to be a bit agressive. However on take off I try and keep the rpms below 3k, and on the hwy I usually cruise at about 100 to 110kph.

That works out to 9L/100km (26mpg) mixed city/highway, but most of it is highway. Is that normal for this V6? I should also note that as of this morning it has 259,000km (161,000 miles) and a far as I know has never had the ports cleaned, which was another thing that prompted my question.

After posting this I did notice something that I hadn't before, the last tank of gas I put in the car was 89 octane, rather than 87, and my RPMs are sitting at 2,700-2,800 at 100kph (62mph).

 

If, for peace of mind, at least. You can clean out the ports and its very easy on your engine. Just remove that plate on top of the intake manifold and there they are.

 

I have the same car and 3000 rpm at 70mph is correct. It sounded high to me when I first got the car. My temp gauge never goes much above 1/4 either but my heater does blow nice and hot. I would check the cable that controls the heater valve, its located between the engine and the firewall (down low). I average about 25mpg mixed driving (mostly highway back and forth to work) which is about right for the V6 Accord. As far as the EGR system, if your engine idles smoothly the EGR system is probably ok. Things to check that effect mpg would be the air filter, tire pressure, plugs/wires, and keep the oil changed, (basic stuff).

 

Bringing this back from the dead to ask another question in regards to EGR port cleaning. I've noticed that my idle is a bit rough, but I haven't thrown a code yet. However on some future sunny day this summer I will probably pull the cover off and take a look at the ports.

The one question I have is when you are scraping out any carbon build up should I be concerned with where it's all going as I chip it off? Is this a DIY that is best done with the intake removed from the engine. It just seems to me, with my somewhat limited understanding, that having bits of the carbon falling back down into the EGR port(s) would be a bad thing. I've seen how to do it on multiple sites, on multiple different kinds of engines, but I've never seen any mention of that.

On a side note, in regards to MPG I installed a K&N drop in and I'm getting almost 50km/tank more now, so for anyone wondering if it makes a diffrence I can state from experience that it's made a difference on mine.

 

The EGR valve should never be open at idle. If your EGR ports were plugged you would never notice any issues at idle.

 

After my last posting I kept on doing research, and I found out exactly how wrong I was about the EGR causing issues with my idle, and I was going to post words to that effect but phootbag beat me to it.

My b.

However, I still am curious to know about what to do about the carbon build up.

Does one remove the intake manifold entirely or can it be left on while removing the carbon build up?

Any feedback would be appreciated.

 

Sonic28, I don't know about a V6, but on my four cylinder I just used a vacuum cleaner with a crevice nozzle next to the ports being cleaned. It sucked up most of the chunks of carbon but undoubtedly some fell into the manifold. They probably got crushed or swept away into the cat when the car was started, with no ill effects.

 

Thank you for replying Roader, I was most concerned about the carbon pieces fubaring my valves or something. Once again I plead a bit of ignorance in regards to how any deposits would/coud damage the internals of my engine if they got in there. It's good to know that you had no ill effects in your case.