DIY Intake Manifold/EGR port cleaning

[IBJim]

Like many others here I developed a clogged EGR valve and intake manifold ports on my 03 Honda Pilot. After reading the posts here I decided that I'd try to tackle the job myself rather than giving $300 to the Stealership. This was a complete success!! If you need to replace the EGR valve on an 03 or 04 Pilot, I strongly suggest that you clean the intake manifold (aka plenum) ports as well. Read on and you'll see why. It's an easy, if not enitrely enjoyable job. Pics follow.

I decided to pull the upper intake manifold cover and couldn't believe the amount of gunk. The EGR port was literally plugged solid! It's amazing the truck ran at all.



After seeing this, I thought I'd remove the upper intake manifold gasket and look at the ports in the cover (the cover is an essential component of the system and I suspect that it's often overlooked). The channels/ports in the cover were also plugged solid. Doh!



I removed the EGR valve (not shown), dug out the ports in the upper intake and cover with a small screwdriver and then soaked everything w/ carb cleaner. Here's what functioning ports look like. No, they're not perfectly clean but they work.





I replaced the gasket (seems like $20 well spent) and slapped everything back together. NOTE: Local Honda dealer says to torque the manifold cover bolts to 8.7 ft-lbs. No more hesitation and runs like new.

Here's the amount of carbon and crap that I dug out of the intake ports (not counting the amount that I flushed out of the EGR valve port). Think this could be a problem?



Hope this helps a brother out!

[rocky]

Two questions

How many miles?

Would seafoam do anything to clean this up?

Once open, what did you use to make the inlet all nice and shiny again?

[samc]

How did you know you egr ports were clogged?
And how many miles?

Just looking for info.

[dzus]

excellent post!

[IBJim]

Page 2. The rest of the story....

I had the Check Engine and VTM-4 lights come on at 129k miles and had the code read at AutoZone. This really sucks in the winter here in the buckle of the snow belt since Honda, in their infinte wisdom, has the AWD disengage when the VTM-4 light is on...even though it had nothing to do with the AWD!!

Anyway...the code was for "EGR Valve or Clogged EGR port." I replaced the valve first but the lights came back on shortly afterwards. I read one of the posts here on the forum about cleaning out the EGR port and thought that I'd give this a try before throwing money at sensors, etc. As soon as I pulled the intake cover I realized that the problem was MUCH bigger than just the EGR port. This is probably why some guys clean only the EGR port and still have the problem. The key, IMHO, is getting at that maze in the manifold cover. Screwdriver first, then solvent (I used B-12 Chemtool).

I did give the EGR port a little extra love and attention, first filling the port w/ B-12 and letting it soak, then pulling the EGR valve and flushing the crap out of it. The result is an impressive pile of goo on the garage floor. I did the trimmer string in drill thing too, but I wasn't too good at this and didn't get much (black gooey) juice for the squeeze.

This problem is bigger than a Sea full of Seafoam, though I admit that I tried this first. There is already a noticable improvement in mpg and I only had half a tank left when I did the procedure. Well worth the time IMHO. In fact, I don't think that I needed to replace the valve and would absolutely try this first before shelling out $130+ for a new EGR valve.

I kinda think this is worth a free Piloteer sticker, don't you?

[kevinssf]

Originally posted by IBJim
Page 2. The rest of the story....

I had the Check Engine and VTM-4 lights come on at 129k miles and had the code read at AutoZone. This really sucks in the winter here in the buckle of the snow belt since Honda, in their infinte wisdom, has the AWD disengage when the VTM-4 light is on...even though it had nothing to do with the AWD!!

Anyway...the code was for "EGR Valve or Clogged EGR port." I replaced the valve first but the lights came back on shortly afterwards. I read one of the posts here on the forum about cleaning out the EGR port and thought that I'd give this a try before throwing money at sensors, etc. As soon as I pulled the intake cover I realized that the problem was MUCH bigger than just the EGR port. This is probably why some guys clean only the EGR port and still have the problem. The key, IMHO, is getting at that maze in the manifold cover. Screwdriver first, then solvent (I used B-12 Chemtool).

I did give the EGR port a little extra love and attention, first filling the port w/ B-12 and letting it soak, then pulling the EGR valve and flushing the crap out of it. The result is an impressive pile of goo on the garage floor. I did the trimmer string in drill thing too, but I wasn't too good at this and didn't get much (black gooey) juice for the squeeze.

This problem is bigger than a Sea full of Seafoam, though I admit that I tried this first. There is already a noticable improvement in mpg and I only had half a tank left when I did the procedure. Well worth the time IMHO. In fact, I don't think that I needed to replace the valve and would absolutely try this first before shelling out $130+ for a new EGR valve.

I kinda think this is worth a free Piloteer sticker, don't you?

Think you could post up a more detailed DIY instructional?

Although I don't think I have a problem with the EGR valve, I think what you have pictured above on the intake manifold cover will likely be my case as well.

[belundy]

I posted the trimmer string thing....using B12 or similar solvent with the trimmer string was the important. The solvent loosened the gunk and the trimmer string knocked it loose. I used a air hose with blow gun to blow it out the other end.

Also, I used the heaviest trimmer string they make, which I also happen to use in my trimmer.

[Caf2461]

Great Post.

Just wondering - is there an intake cleaning proceedure that will help avoid this problem? IE - metering Seafoam into the intake via a vacuum line?

[belundy]

I can't think of how you easily treat this from a maintenance routine. The deposits come from exhaust gases. Any B12 you put into the fuel system or intake would be combusted on the exhaust side.

You'd have to install a heat resistant "port" on the manifold side of the EGR valve, where you'd inject B12. Let the engine suck on that for a few minutes, then shut it off overnight for the fluid/vapors to do their thing.

[belundy]

It seems from postings that cold climate vehicles suffer from this deposit build up more than warm climate ones.

My '03 had about 40% occlusion on the small circle ports and 0% occluded on the big oblong port.

The EGR crossover passage was quite dirty but still open.

[Willard]

My curiosity got the best of me last night and I pulled the top cover off. There was some gunk (not as bad as above) but still enough to deserve a cleaning. I did notice that the rear cylinders were worse with the major offender being the passenger side rear cylinder.

I did not have a fresh gasket so I cleaned and reused the old one. Went for a test drive and the CEL started flashing (first time in 105,000 miles).

My wife went by Autozone this morning and the fella pulled the codes:
P0300 – Random/Multiple Cylinder Misfire Detected
P0304 - Cylinder 4 Misfire Detected
P0301 - Cylinder 1 Misfire Detected
P1399 - Multiple / Random Misfire Detected (?)

Would the codes be from reusing the old gasket or have I messed the EGR system up? The car did stumble a little bit when it first fired up after my cleaning (maybe some gunk fell into a bad place?).

Here is the part number for the upper intake manifold gasket:
17146-P8E-A21

http://www.obd-codes.com/trouble_codes/
http://www.obd-codes.com/faq/obd2-codes-explained.php
http://www.obd-codes.com/trouble_codes/honda/

[belundy]

More likely you didn't get a good seal on the cover. You can usually reuse the gasket, but the cover, gasket and manifold surfaces have to be clean and the cover bolts torqued evenly and proper tension (no, I don't remember).

[DrDon]

One more thing to add about the seal - when you place the cover back on you have to torque (8.7 lbs for cover bolts) them evenly as mentioned above, but also have to do it in a certain sequence (can't remember sequence exactly, but remember seeing the sequence pattern under the autozone website when I was looking up the manifold system). I would say go buy a new seal, properly torque it back on at recommended settings and sequence.


I have a question for OP - I understand how you cleaned the cover, but how did you clean the ports without having debris fall back down and make things worse?

[IBJim]

Originally posted by DrDon
One more thing to add about the seal - when you place the cover back on you have to torque (8.7 lbs for cover bolts) them evenly as mentioned above, but also have to do it in a certain sequence (can't remember sequence exactly, but remember seeing the sequence pattern under the autozone website when I was looking up the manifold system). I would say go buy a new seal, properly torque it back on at recommended settings and sequence.


I have a question for OP - I understand how you cleaned the cover, but how did you clean the ports without having debris fall back down and make things worse?

Yeah...I thought about sending gunk back into the intakes. My thought was I can't make it worse than it is now! Time will tell.

BTW- The torque sequence for the cover bolts is basically starting with the inside bolts and working towards the outside.

[IBJim]

Originally posted by Willard
My curiosity got the best of me last night and I pulled the top cover off. There was some gunk (not as bad as above) but still enough to deserve a cleaning. I did notice that the rear cylinders were worse with the major offender being the passenger side rear cylinder.
...

Would the codes be from reusing the old gasket or have I messed the EGR system up? The car did stumble a little bit when it first fired up after my cleaning (maybe some gunk fell into a bad place?).

My guess is that the system just needs to flush itself out after dislodging the crap. Have you tried resetting the CEL and seeing if it goes back on?

DISCLAIMER: I'm NOT a mechanic but I did sleep at a Holiday Inn Express last night. As with all of my stupid advice (mainly related to motorcycles) you follow it at your own risk. That being said, my Pilot is running like new and the the fuel needle seems to move a lot slower than before