I love aftermarket parts!

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Dec 19, 2013
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Location
Fort Worth, Texas
Had an interesting one come into the shop today.......On my second day of being open for business in my own shop, This vehicle is owned by a used car lot I've never done business with before but was referred to me by another car lot that's my biggest account. I definitely wanted to score another account if possible!

*2007 Honda Pilot with the VCM J35Z1 with @ 90,000 miles.
*P0522 (Engine Oil Pressure Sensor Voltage Low) set....Permanent & History. Resets right after clearing the codes.

According to the owner of the lot, It has been to three different shops so far & have replaced.....
*Oil & Filter.
*VCM manifold which includes the VCM Spool Valve, VCM Solenoid, & EOP Sensor.
*Oil Pressure Switch (For the idiot light)....No idea why it was changed.
*PCM.

I guess someone was convinced it was a wiring issue after the parts cannon approach didn't work, The harness is completely naked & has cut/pulled back insulation on several circuits. I can't believe a seasoned mechanic would be so intrusive while testing circuits.....I'll snap some pics of that tomorrow!

Started out buy probing the 3 circuits at the VCM EOP Sensor, With the insulation pulled back on all 3....Might as well probe them there instead of back-probing!
KOEO, Sensor plugged in.......
*Good ground.
*Good 5-volt reference.
*Signal circuit was in fact low, .006vdc.....Which is a short to ground in my opinion.

KOEO, Sensor unplugged......
*Good ground.
*Good 5-volt reference.
*Signal circuit is now at 5vdc.....This is a Bias Voltage fed out from the PCM through a resistor, Taken with my Vantage Pro. Most cheaper/low impedance DVOM's will affect this voltage reading & knock the voltage down by half or more!

The aftermarket (Dorman) EOP sensor is internally shorted to ground, Priced a Genuine Honda/Denso part @ $240.....The customer was reluctant but Ok'd it after my little rant about aftermarket parts.
Torqued the sensor down & made sure no circuits were crossed/shorted by the hack job on the wiring.






This is where it gets interesting.......
*Cleared the code, Started it up....After @ 30 seconds, Check engine light pops on & the engine starts running on 3 cylinders.
*P2647 VTEC System Stuck On (Which is actually the VCM system) is now set.

If I've learned anything from all the years diagnosing problems like this....The last thing you want to do is get angry or lose your cool, Because it ALWAYS comes down to simple things!
I pretty familiar with VCM J35's & really can't believe Honda would do this to such a good base engine design but thats another discussion. It works on the same principle as a true VTEC but has circular secondary lobes to keep the valves closed during VCM operation.......

*The first clue was the engine was hitting on all 6 before I changed the EOP sensor, That tells me the VCM Solenoid IS NOT stuck on!!! In fact (As a waste of time).....I put the old EOP sensor back on & it hit on all 6 & reset P0522.

*The EOP sensor is suppose to have oil pressure present in 6 cylinder mode & doesn't have oil pressure when in 3 cylinder mode.......Spool valve shifted by the VCM Solenoid.

*Adapted my mechanical oil pressure gauge to the sensor port, Plugged in the defective EOP.......NO oil pressure present with the engine purring away on all 6 cylinders.

I thought to myself.....That's Effing impossible!! Unless something is physically blocking the oil feed to the EOP?
Went a step further, Again it hindsight it was a waste of time......I put 30 psi of regulated air pressure to the Denso EOP (Connector plugged in), With the oil pressure gauge still hooked up.
Started the engine up......NO codes, And the engine ran on all 6 cylinders with zero pressure at the EOP port. The EOP is NOT getting a oil pressure & EVERYTHING else has checked out!

Pulled the VCM manifold assembly & disassembled it........
The EOP port was not drilled through to the spool valve! Thanks Dorman for your JUNK Chinese crap.....I love having to explain to a customer that not only was the sensor faulty but the manifold was never fully machined!

Took a .093" drill bit & drilled through to the Spool Valve.....Fixed it!!!



[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]
 
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Kudos to you!!! You ARE a mechanic who understands what he is NOT seeing no matter what the ECU is telling you!!! I would have no problem letting you work on my cars!!!
 
Whenever I did these I always swapped the whole spool valve out with an OE part, never any trouble, the cost with discount at the local dealer isnt much more. Now I think about it I have run into a couple that used an additional screen in the filter pad gasket like the one on the spool.
This one was sticking and throwing an occasional code even after a new solenoid and sensor and cleaning, that what got me swapping the assy.

Second pic is the screen I found in the pad of the same engine, it was clogged also. +1 on those wonderful aftermarket parts.

[Linked Image]

[Linked Image]

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at lest on the GMs if the oil pressure light is on the Oil pressure screen needs to be replaced as it's clogged with sludge Very good indication of poor service history...
 
I would say you are a mechanic,,way to many parts replacers out there ,,,If the part they replace doesn't work then out comes the book of excuses...
 
Originally Posted by FT92
I would say you are a mechanic,,way to many parts replacers out there ,,,If the part they replace doesn't work then out comes the book of excuses...

dude i hate that stuff I had a great mechanic but he passed away due to lung issues from his line of work Just a word the OP should have good ventilation in the shop
 
It's rare you get anything good from dorman anymore. In a pinch I had to use one of their oil standpipes for a 6.0 powerstroke. It failed in less than a week, exploding and sending debris throughout the oil rail!
 
Originally Posted by mattd
It's rare you get anything good from dorman anymore. In a pinch I had to use one of their oil standpipes for a 6.0 powerstroke. It failed in less than a week, exploding and sending debris throughout the oil rail!

i have consistantly had better luck with random parts from the local u pull yard than with dorman stuff.
ebay china parts are better too.
only thing dorman is ok for is the penny parts in the help section.
 
That is some very impressive root cause analysis and corrective action.
 
Originally Posted by clinebarger
Had an interesting one come into the shop today.......On my second day of being open for business in my own shop, This vehicle is owned by a used car lot I've never done business with before but was referred to me by another car lot that's my biggest account. I definitely wanted to score another account if possible!

*2007 Honda Pilot with the VCM J35Z1 with @ 90,000 miles.
*P0522 (Engine Oil Pressure Sensor Voltage Low) set....Permanent & History. Resets right after clearing the codes.

According to the owner of the lot, It has been to three different shops so far & have replaced.....
*Oil & Filter.
*VCM manifold which includes the VCM Spool Valve, VCM Solenoid, & EOP Sensor.
*Oil Pressure Switch (For the idiot light)....No idea why it was changed.
*PCM.

I guess someone was convinced it was a wiring issue after the parts cannon approach didn't work, The harness is completely naked & has cut/pulled back insulation on several circuits. I can't believe a seasoned mechanic would be so intrusive while testing circuits.....I'll snap some pics of that tomorrow!




This is exactly the type of work you knew you'd be competitive at if you ventured out on your own! Who knew it'd come so quickly!

Great work, also shame on Dorman and the 3x previous ships to work on the vehicle.
 
Originally Posted by demarpaint
Nice work! Good mechanics like you and Trav are far and few.


Seriously. If I could find someone like these guys within 50 miles of me I would probably retire from fixing my own stuff.
 
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