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Discussion Starter #1
A couple of weeks ago, I picked up a 2014 Elite model. I had planned to get rid of my 2006 NAV/RES with 380 000 KM, but it's running so well, I just couldn't do it..lol. My plan was to keep it garaged and drive my 2005 TSX and the 2014 MDX until closer to spring when my teenage son finishes his last year of high school and 'may' need a car for full time work until university in the fall and then, depending on insurance cost, put it back on the road.

Anyway, we had a big dumping of snow this week and apparently the rest of the winter may be similar, so I've garaged the TSX instead (after getting hung up on the mound of snow left by the snow plow) and brought the 2006 MDX back for the ground clearance and AWD (and I just like it better than the TSX..lol).

However, I started it today after about a week of no driving (in bitter cold and it turned over very slowly, but started and idled fine) and as I drove I got the check engine light and the VTM - 4 light. The driveability was fine...no stumbling or hesitation etc. I pulled the codes and got 4 cylinder misfires (all different cylinders) and 4 pending for the exact same misfire codes. After I cleared the codes and drove for a bit, they didn't return.

Any ideas? Never had these codes in 380k KM of driving. The only code I get, and only when it's cold is the P0420 (catalyst efficiency - because the cat is old and less efficient when cold).

PS - I love the 2014, but man, the ground clearance sucks in snow compared to Gen 1. It's basically like a station wagon...lol. Also, the SH-AWD is great, but I miss the VTM - 4 Lock for those times where the snow is just too deep.
 

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Discussion Starter #2
Yup...she's higher than the 2014. It's only 0.7 inches in height, but look at the approach and departure angles. No wonder the front lower grill on my 2014 is currently packed full of snow...lol.

2006

<table cellspacing="0" cellpadding="2" border="1"><tbody><tr><td>Minimum Ground Clearance </td> <td> 8.0 in </td> <td colspan="2"> (203 mm) </td> </tr> <tr> <td> Approach/Departure Angle </td> <td> Approach-28 degrees </td> <td colspan="2">Departure- 21 degrees
Breakover- 19.4 degrees
</td></tr></tbody></table>

2014

Approach Angle: 14.9º
Departure Angle: 15.2º
Breakover Angle: 19.4º
Ground Clearance: 7.3"
 

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Not sure I follow. Did you get a P0420 and you want to know why? In addition to the catalytic, book says it could be low quality gas (old, cheap, a little water). For my 06 X with P0420, I cleared the code and then tried Shell premium and some fuel additives. When that didn't work, I replaced the rear catalytic.

You didn't mention any other codes - did you get P030X misfire codes? 380KM is 263K miles. Not accounting for for the freezing cold, could be a number of things. Have you checked/changed plugs, checked coils, adjusted valves, pcv, etc? If you got these codes after the car was sitting and then right after start, your fuel pressure might have dropped during the week it was not used. If it persists, an easy/cheap thing you could try is turning the key to position II and wait 2 secs, then repeat before starting. That will pressurize the fuel line.
 

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Heavy oil in the engine and transmission in very cold weather can cause enough drag to false-trigger misfire codes. Unless they show up regularly, don't worry.

If the check light starts flashing while you drive, that is a sign of a serious misfire that can melt the converter cores if you continue driving for a long period.


Good overview of misfire detection in this video. Index 34:50 through 39:30

https://youtu.be/zQXeMqlBagI
 

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Discussion Starter #5
Crap.. Lol. Forgot the codes.. All cylinder misfire codes (4 of them all different cylinders) and 4 pending for the exact same codes.

The P0420 I get semi regularly as soon as it gets cold. Not worried about that one.

Thanks for mentioning the heavier oil thing. I am running heavier oil and Lucas oil additive (which is thick when it's hot out, never mind in the cold) to help with a rear main seal leak. Could be the cause...
 

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Lucas... The worlds foremost snake oil company.
 

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Discussion Starter #7
Lol. Seems to have slowed my RMS leak a decent amount. Just using Valvoline Maxlife stopped it dead for about 2 years but it's slowly returned. Lucas seems to help, snake oil or not.
 

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Lol. Seems to have slowed my RMS leak a decent amount. Just using Valvoline Maxlife stopped it dead for about 2 years but it's slowly returned. Lucas seems to help, snake oil or not.
But what other problems could it be causing? Why not actually fix the problem and replace the rear main seal?
 

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Discussion Starter #9
10 hrs of labour for a $25 part on an 11 year old vehicle with 380 000+ km is mostly the reason. Dunno what other problems it could be causing because I've been adding a 1/2 litre with my oil changes for about a year and a half and haven't had any trouble with the vehicle.

The misfire codes is new and whether Lucas is causing it is debatable. We had a cold spell a few weeks ago (not as cold as now, though) with no check engine light.

No check engine this morning at - 22 Celsius and I'm thinking it had more to do with being parked for some time with no use.
 

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Lucas sells snake oil, and that is reason enough to NEVER use their products. They refuse to provide any scientific information about their products and they make wild claims that are often demonstrably false.

Beyond that, if you still want to use their products, consider the following:

Analysis has been performed on Lucas Oil Stabilizer (BITOG Thread) and it has been determined that the product is nothing more than a low-quality petrolium oil with ZERO additives and an extremely high viscosity. When you mix Lucas with your engine oil you're actually:

  1. Reducing the overall quality of the base oil stock.
  2. Reducing the quantity of additives in your engine.
  3. Increasing the viscosity.
It is obvious why the first two are BAD. The third effect may be desired, but Lucas is not the correct way to achieve this result. After-all, you have no way of knowing what viscosity you're increasing to? If you want to use thicker oil, then just buy thicker oil! No additives required. Thicker oil would also solve #1/#2 because you can get a high-quality base stock and you'll get a proper mixture of additives. This is the same reason I don't consider aftermarket octane boosters to be a substitute for purchasing the proper grade of gasoline.

Oh, and you SAVE money by not using that Lucas crap!
 

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On the misfire codes - have the valves ever been adjusted? It seems pretty predictable that between 100-150,000 miles you'll start getting misfires if you don't adjust the valves. If I'm not mistaken, the misfires can crop up more when it's cold out (since that changes the geometry of the valve train a bit until the engine gets up to operating temperature).

An RMS leak is a pain - simple fix, horribly fiddly and time-consuming. I would be tempted to use a heavier oil to slow it down, or to maybe just stuff a shop towel into the path of the leak and change it out every six months. If it's cold out, #2 is the way I'd go for sure! ;-) This is one thing that Jeep got right - they built the RMS as a two-piece unit. You drop the pan, pull off the journal cover that houses it, peel and stick the bottom half, then push out the top half with a screwdriver, and push the new top half in with your fingers. Quick and easy (other than the suspension pieces in the way of dropping the pan, that is). Wish we could do the same with our MDX RMS.
 

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Discussion Starter #12
On the misfire codes - have the valves ever been adjusted? It seems pretty predictable that between 100-150,000 miles you'll start getting misfires if you don't adjust the valves. If I'm not mistaken, the misfires can crop up more when it's cold out (since that changes the geometry of the valve train a bit until the engine gets up to operating temperature).

An RMS leak is a pain - simple fix, horribly fiddly and time-consuming. I would be tempted to use a heavier oil to slow it down, or to maybe just stuff a shop towel into the path of the leak and change it out every six months. If it's cold out, #2 is the way I'd go for sure! ;-) This is one thing that Jeep got right - they built the RMS as a two-piece unit. You drop the pan, pull off the journal cover that houses it, peel and stick the bottom half, then push out the top half with a screwdriver, and push the new top half in with your fingers. Quick and easy (other than the suspension pieces in the way of dropping the pan, that is). Wish we could do the same with our MDX RMS.
No valve adjustments (and at 380k KM, maybe it's time). Yes, I like that Jeep RMS - even if it didn't last as long as a one piece, the ease of replacement makes up for it.

Another cold start a 5pm this afternoon (about -15 celsius) and no problems. Supposed to be -21 in the morning, so I'll get to check this again. Wonder if it was just a random, one time thing....weird..
 

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I would recommend doing the valve adjustment "just because". It's theorized (and makes sense) that over-tight valves will start to do damage to things. FWIW, my MDX went 160,000 miles (the PO who took care of the car very well managed to forget to do this). No damage, but the exhaust valves were down to zero clearance, and I certainly wouldn't have let them go any further. And FWIW, you should get a boost in performance and gas mileage when you do a valve adjustment, too. It's really not a difficult job, though it does take a certain amount of touch to get it right.
 

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Definitely do the valve adjustment, if you have not already done so. I did and was shocked at how sloppy the intakes were and tight the exhaust were. Running much better, and no misfire code for the last 1000 miles and counting.
Happy wrenching!
 
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