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Discussion Starter #1
There is a DIY on the horizon............

 

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Discussion Starter #3
Yep...
 

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Discussion Starter #4
Some notes:
The EGR System is pretty aggressive on the MDX there was a thin coat of Carbon Build up in the entire Intake Manifold nothing was spared.. The EGR passages were un-obstructed either but considering how I take care of my MDX and only use Premium on it? It seems the EGR was tuned for complete overkill, My PCV valve was also healthy.

The valve covers and valve train itself is very stained on the front one.. The front valve train is heat stained to hell but the rear is pristine.. My TL-S had the heat stain on the rear and the front one was very clean but the TL-S was bought brand new so we had the maintenance done right.

The joys and glory of buying a used vehicle I guess? These are the kind of things you cant spot when looking at the vehicle before buying.
 

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Some notes:

The EGR System is pretty aggressive on the MDX there was a thin coat of Carbon Build up in the entire Intake Manifold nothing was spared.. The EGR passages were un-obstructed either but considering how I take care of my MDX and only use Premium on it? It seems the EGR was tuned for complete overkill, My PCV valve was also healthy.



The valve covers and valve train itself is very stained on the front one.. The front valve train is heat stained to hell but the rear is pristine.. My TL-S had the heat stain on the rear and the front one was very clean but the TL-S was bought brand new so we had the maintenance done right.



The joys and glory of buying a used vehicle I guess? These are the kind of things you cant spot when looking at the vehicle before buying.


So your front valve train is with heavy heat stain just like mine and the rear valve train is cleaned as mine as well. I bet all MDX are like this because the PCV valve is connected to the front cylinder head. Make sure to check for worn lobes on the front camshaft!! I can't wait to find out!


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Discussion Starter #7
So your front valve train is with heavy heat stain just like mine and the rear valve train is cleaned as mine as well. I bet all MDX are like this because the PCV valve is connected to the front cylinder head. Make sure to check for worn lobes on the front camshaft!! I can't wait to find out!


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Yeah its probably the same but your intake manifold was almost hospital levels of clean in comparison... Mine was heavily coated in a thin layer of carbon, Granted it wasn't thick carbon build up as it got clean easily with carb clean but it was nothing like yours... I feel ashamed of the conditions it was in, But there isn't much I can do but to clean it.
 

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Discussion Starter #8
Dude, what's that dust all over everything? If my dog were half that dirty, I'd give him a bath ASAP. :grin:
I do off road with my MDX and México streets are all time covered in loose dirt.
Those areas are beneath the intake manifold as well so I cant clean it with a rag easily, They will get cleaned for sure because of this but at the first off road trip they will get all dirty again anyway.
 

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I do off road with my MDX and México streets are all time covered in loose dirt.
Those areas are beneath the intake manifold as well so I cant clean it with a rag easily, They will get cleaned for sure because of this but at the first off road trip they will get all dirty again anyway.
I lived off a gravel road years ago, so I know all about dust shaming.

This is what a bike looks like after 160 miles of gravel roads in the rain ( at 35°F with 15-20 mph wind, but I'd rather not talk about that part, cuz people would think I'm crazy ).

Almanzo aftermath - 1.jpg

At least dust washes off, unlike the rust all over my car's undercarriage. :frown2:
 

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Discussion Starter #10
Yeah rust is no issue here in the south... Sadly I had a power steering leak on the Pump inlet so there are parts that became oily mud and that is a PITA to remove even with Carb Cleaner..

I wasted 2 cans of carb cleaner on the intake manifold and I could not clean it completely to my liking.... So first thing in the morning is going for at least 3 more cans before tackling the adjustment because I also have to do the manifold cover and valve covers, Carb Cleaner get spent quite quickly.. UBER here we go!
 

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Please help me make this super clear. By adjust valve clearance, we are adjusting the distance between the bottom of the adjusting bolt and the top of the valve stems, correct? Is there anything else below the adjusting bolt? Also on the top of the valve stem, there is spring, spring retainer and two half circle rings. Is there any shim on top? (I guess not.) So the bottom of the bolt is directly hitting the top of the stem?

Also can anyone tell me at the end of the rocker arm, how do the bolt, nut and the arm fit together? I imagine that both the nut and the arm have grooves inside, so the bolt can be screwed in. But what is preventing the bolt from backing out?

Finally, when doing the adjustment, it is said that all the valves should have play. Here all the valves means all the valves for a single cylinder, right? Is there a position such that all the valves on all the cylinders on a single bank all have play at the same time? If anyone can find the relative position of all the cylinders when cylinder 1 is at TDC, that will be very helpful. Thanks!
 

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Discussion Starter #12
1.- Yes the adjustment is basically setting the correct gap between the tip of the valve itself and the adjusting bolt on the rocker arm. There is no shim, The Adjusting bolt hits directly into the valve tip itself, there is nothing in between but engine oil.

2.- The rocker arm "adjusting bolt" (The part that hits the valve tip) is threaded all around and it threads in into the rocker arm end that is also threaded. There is a secondary nut to lock it in place by tightening the adjusting bolt to the rocker arm end threads this way the Adjusting Bolt cannot undo itself even with extreme vibration.

3.- The cylinder you are adjusting must be at TDC (Top dead center) when it does the camshaft is in such position that the rockers are "idling" so the valves are fully shut and the rockers have no load on that specific cylinder, This way you can tell there is gap or not because you can literally push the rocker to hit the valve tips.. Since the correct gap is either 0.22mm or 0.30 mm on intake and exhaust should have some play. Because of the firing order its impossible to be able to adjust all 3 cylinders in a bank at the same time. I think you can do more than 1 at a time if you can spot the rockers that are idling but its not the correct procedure... Better do it right the first time.
 
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Suppose the correct clearance is 0.22mm and the torque is 12 ft lbs. Is there a rule that if I put a thicker feeler gauge, like 0.25mm and tighten to 12 ft lbs. After I remove the feeler gauge, the gap will shrink to 0.22mm? That will make life much easier by taking the guess work out.
 

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Discussion Starter #14
Most feeler gauges are actually not finished in exactly 0.22mm they are 0.229mm which technically makes them 0.23mm I think this is exactly for that reason so when you torque the adjusting bolt it will "hopefully" end up something closer to true 0.22mm.. In any case Honda gives a hefty tolerance of +/- 0.02mm so it has some room for error.

In any case I don´t plan on torque specific the adjusting bolt, I do them by hand and it hasn´t failed me once.
 

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Discussion Starter #17
Is that Teflon tape on the manifold bolts?
Just noticed that.. I will check it out I think they had some form of threadlocking.
 

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Discussion Starter #18
Skirmich, did you inspected the camshaft lobes for any wear?


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Thats the first thing I did when I removed the covers :) luckily there is no damage on mine.
 

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