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Where is the knock sensor and the EGR...are they a hard to find or difficult to access?
I have an 04 MDX Navi/RES
Thanks
The EGR valve is pretty easy to get to! Take off the intake manifold and ignition coil covers, and it's right there on top(right side) of the engine. Looks like a round little house, lol!
Now, getting to the knock sensor is a whole different ballgame! In addition to taking off the parts(which is the easy part) I mentioned above, you gotta take off the intake manifold itself(the sensor screws into the engine below the manifold).
That involves alot of work. 'Cause, to get the manifold off, the intake air duct(which has about 3 connectors attached to it) has to be separated from it. Plus, all the vacuun hoses and emmision connectors(there's alot of 'em!) that's attached to the manifold and throttle body! Add to that, a new gasket for the manifold!
It's time consuming. But the main reason I didn't do it myself, is because I'd need a spot(garage) where I'd feel comfy taking my time to do the job.
Last edited by vybzkartel; 10-21-2010 at 08:53 PM.
The EGR valve is pretty easy to get to! Take off the intake manifold and ignition coil covers, and it's right there on top(right side) of the engine. Looks like a round little house, lol!
Now, getting to the knock sensor is a whole different ballgame! In addition to taking off the parts(which is the easy part) I mentioned above, you gotta take off the intake manifold itself(the sensor screws into the engine below the manifold).
That involves alot of work. 'Cause, to get the manifold off, the intake air duct(which has about 3 connectors attached to it) has to be separated from it. Plus, all the vacuun hoses and emmision connectors(there's alot of 'em!) that's attached to the manifold and throttle body! Add to that, a new gasket for the manifold!
It's time consuming. But the main reason I didn't do it myself, is because I'd need a spot(garage) where I'd feel comfy taking my time to do the job.
Thanks...so the knock sensor is right under the plenum?
If the knock sensor is bad....the the check engine light would come on and kick out a code first...right?
I have had a similar issue with my 2003 MDX - the lights no longer come on but right if its cold and when i reverse it will die. I tried to duplicate the issue with my mechanic but have had no luck. I will bring him the information you have but is there anything I should suggest first, it looks like EGR or valve adjustment is in order but not sure in what order. Looks like process of elimination - plus want to fix it so I can put my baby up for sale.
I have an '04 MDX I bought a year ago with 120k miles. Shortly after I got it, the CEL and the VTM-4 lights came on sporadically and the engine started running rough. I took it to the local Acura dealer, who replaced the spark plugs. Didn't help. I'm now up to 155k miles, CEL & VTM-4 light still on sporadically, still runs rough and lousy milage (19 highway). A mechanic suggested two possible fixes - either a valve job or changing the spark plug coils (@ $55/plug). He wants to check the compression. If that's OK, change the spark plug coils. Reading thru this thread, I wonder if the EGR/PCV can be part of the problem. Anyone know of a really good MDX shop in the northern NJ area?
Thats strange. Maybe a fuel issue? No idea how the VTM could be connected to that though.
I had similar problem on my 2004 MDX, the engine light and VTM 4 light came on after 105K service. I normally use Costco fuel which contains 10% ethonol. Changed to Cheveron gas and both lights went off for about a week. Now the lights are back again. The engine light stays on but VTM 4 lifht comes on and off.
Replaced the egr valve and the plugs. The car did run better but did not resolve the problem. This engine has solid lifters so the valves need to be adjusted from time to time. the owners manual doesn't give you a time frame but does say "as needed" or when they get noisy. But heres the deal, The valves wont get noisy. what happends is over time the exhaust valves hammer the valve seats in to the head. closing the gap and changing the valve duration and in some cases holding the valve open a bit. I did the job myself and when i got to the valve train sure enough ALL the exhaust valves were tight, zero clerance, After i adjusted the valves, intake valves as well, i now have a smoother running engine, 4 mpg increase, better throttle responce and acceleration. and the dash lights never came back on. The valve clearence specs. are on a decal under the hood near the latch..... above your head, look up and Good luck!
Yes i did scan with the OBD2 and the codes were misfire on all cyl. but 9 times out of 10 when a coil pack goes bad it just stops working altogether. Get the valves adjusted you'll be happy with the results
Hi I'm new to the site... I had the same issue about a year ago on my 04 MDX at 90k with the same symptoms of cel light, vtm, and rough idle. I pulled the cel code and it gave me misfire on all cylinders! After a few months of testing and changing egr, spark plugs, pcv valve, and air filter I was ready to give up and trade it in. I was going to change the coil packs next but decided to bite the bullet and do a valve adjustment (i did not think my valves were noisy) instead. It was a time consuming job (took me about 7 hours to do) but cheap (no parts needed) and it fixed the problem. Also while I had the intake manifold off, I went ahead and cleaned the egr port in the manifold. What a major difference, rough idle gone, more responsive engine, and better gas mileage. Bottom line... if you have the same symptoms as I did, do the valve adjustment!
I've been monitoring this post for the past month while trying to fix this exact CEL and VTM-4 light on my 2005 MDX. I have had sporadic troubles with these lights coming on sporadically along with instances of poor starting. I had also noticed the engine sputtering more than normal and running a bit rough when stopped at stoplights, etc. I have had 4 batteries installed over the years thinking the starting issues were related to the battery.
After reading all these posts, I asked my mechanic to check the EGR and PCV valves. These both checked out fine. Then, since the valve adjustment seemed to be the magic bullet in this case, I asked them to check valve clearances. My result was similar to many here. All the exhaust valve were so shut that they couldn't fit the tool in to measure the gap. In take valves were close to spec.
After adjusting the exhaust valves, my car idles like new! It is more responsive and I am noticing an increase of >3mpg. It's feels like my car did back when I bought it (bought it new)!
Thanks to Acurazine and its posters for helping me identify the issue. How did we survive before the internet?
JUST HAD MY TIMING BELT AND WATER PUMP REPLACED AS A MAINTENANCE ITEM. I experienced a similar misfire as others after the TB and WP replacement with engine sputtering and w/ Engine light, VTM-4, ! , and VSA light coming on. Based on what I have read above, it sounds like the valves need adjusting. Comments?
2004 MDX(205K miles) with CEL and VTM-4 here too. Codes were multiple cylinder misfire. I changed out spark plugs and had the EGR port cleaned out and CEL and VTM-4 came back like 2 weeks later.
Seems like I may need a valve adjustment. Are there any other fixes for this?
Great thread and helped me so I wanted to follow up.
Similar symptoms on a 2003 Acura MDX that came on suddenly. left the airport running fine, got half way home check engine and VTM-4 came on. Exited the highway and rough idle.
Didn't think it was valve clearance in my case because of the sudden onset. I had just filled up a fresh tank on the way to the airport, maybe bad gas. Filled with good brand premium and no change at all.
Thought maybe a coil bad or a plug bad (255,000km on the odometer... no coils ever changed and plugs have at least 100,000km on them)
Initially I got out the code reader and just cleared to codes to see what came back and along with misfires all cylinder codes I got a P0404 EGR code.
The 2003 MDX EGR is dead simple to remove. Four 10mm bolts hold the plastic cover on. Two half turn plastic screws hold the plastic cover around the oil fill area. The a 12mm takes the two nuts off the EGR studs and the electrical connector and its out.
Mine was a dead giveaway. Seized open.
The valve has a torx socket in it, I used a torx screwdriver to twist the valve back and forth (I didn't rotate in case there is an adjustment thread) and it freed up. I cleaned with carb cleaner and a brush as well. If it was a hard part to replace I would have ordered it and waited but its easy so I reinstalled the old one I freed up and ran fine. If an EGR was expensive I would have used the working old one but they are under $100 so I ordered one on Amazon and will pop it in tomorrow when it arrives.
10-21-2010, 08:51 PM
