regardless of those advertisements, they’ve changed their bottles since Likely somewhere when they decided to release their “Extended Performance”.....that’s what I don’t quite understand about M1.....their EP advertises 15k OCIs possible (though I’d recommend a filter change or 2 sometime in between those miles! hehe) - where does that stand for the “regular” Mobil 1...?  10k?  8k?

But yea, either way, I can’t see “dark oil” causing a CEL.....but as mentioned, most CEL trips are usually due to a sensor gone bad, reading wrong, etc.....

So simply put, I won’t “recommend” changing the ignition coils, etc. components, until you get that CEL scanned; AutoZone, and Advance Auto Parts will do it for FREE...but the kicker, they can only check 96 and newer vehicles.  Buddy of mine has a 94 Honda Accord, and they couldn’t scan his.....NM, re-read, you got an 04....so you’re “in the clear” there

BTW, also recommend an oil analysis, it can turn up other valuable information regarding the “life” of your oil and the crankcase.

I know my 88 Dodge Aries needed an EGR replacement, apparantly it was way gunked up; the old lady who owned it before me, didn’t drive it much, and when she did she barely drove it, maybe max 10 miles to church, or getting groceries from the corner store....but yea, we took a look at the EGR valve and it was all dirty, so while we changed that, also changed the fuel filter, PCV valve, and MAP sensor.

Apparantly what happens is when the oil gets hot, the gasses from the oil get to the EGR valve and crudded it all up....likely due to the short trips, car rarely ever “completely” warmed up to burn away the condensation etc....

All in all, the CEL light is probably something stupid, but unless you want to go just pulling apart the vehicle and changing EVERY sensor, just go get that code read at advance or auto zone and then google the “codes” it printed out and you’ll likely find forums filled with info on what to check/change in relation to that code....

bugs~ - 27 December 2010 03:10 PM

regardless of those advertisements, they’ve changed their bottles since Likely somewhere when they decided to release their “Extended Performance”.....that’s what I don’t quite understand about M1.....their EP advertises 15k OCIs possible (though I’d recommend a filter change or 2 sometime in between those miles! hehe) - where does that stand for the “regular” Mobil 1...?  10k?  8k?

Mobil-1 dropped advertising a mileage limit long before they came out with the extended performance line. They just stopped saying how long you could run OCI’s. They started listing mileage numbers again (15K) when the extended performance line was introduced.

Tom and Ray Magliozzi of the radio show “Car Talk” (Ray is a graduate of MIT) have long said that 3000 mile oil changes are too short, even for conventional oils. They recommend 5000 mile OCI’s with dino oil unless you drive in very dirty conditions. Almost any full synthetic oil should be good for at least 7500 miles in a vehicle in good condition. I do all highway driving in my “drive to work” car. It gets about 12,000 miles a year put on it. I change once a year with either Amsoil, Royal Purple, Mobil-1 extended, or Castrol Edge. You can run that long on a single oil filter if you buy a good synthetic media filter. Stick with these filters, Amsoil, Bosch, Puralator Pure-One and Mobil-1.

Oh, by the way. Mobil-1 extended performance does NOT meet GM4718M (GM Corvette high performance) certification.

chuckbarry - 23 December 2010 01:13 AM

Situation: I have a 2004 Cadillac at 79,000 miles when I changed the oil. Instead of 5/30 semi-synthetic, I used regular oil, and added MMO as it was needed. Also added it to the gas tank.  I went 17,000 miles before I decided to change the oil in preparation for a smog test. ( I noticed the tach was more efficient with RPM about 3-7% lower, and 3 times I got 40-41MPG at 54 MPH on cruise control from Palm Springs to Los Angeles on the 10 FWY). I used MMO and STP gas additives when the check engine light came on, and after 2 tankfuls, the light went out. Again, I did it twice with good results turning the light out.

After the oil change and replaced oil and air filters, I noticed the new oil was darker than I expected after 1,000 miles of driving. Kinda black, but I wrote that off as MMO really cleaning out the engine from the previous oil change.

As I was traveling to get my smog test, the check engine light came on and that stopped me from getting it smogged that day.

Next day, the car wouldn’t start and I had to jump start it. Cleared everything, but check engine lite is still on, even after the 3rd tankful. Most driving was easy freeway driving at high speed.

My question is: 1.) Could the blackened oil be part of the problem, and should I change oil again with semi-synthetic oil and 1 quart of MMO and MMO to the gas,

2.) could the ignition coil or solenoid be the problem with the light because of the jump,

or 3.) mass flow air sensor and connector have been the cause for the light to come and should be replaced.I thought maybe the MFAS and connector may have been damaged by the mechanic.

Marvel Mystery Oil is really great. I can’t get over the effect it has had on my Caddy, the power acceleration, smooth ride, MPG. It pays for itself.  I hope it pays for my smog test by avoiding the costly repairs I live in fear of. It relly works!

Thanks for your answer on my behalf.

The problem is obvious.
Code 904: Loose nut behind the wheel.

Though I can agree that 3k OCIs are too short.....some “nuts” need those “short” OCIs

I got a buddy of mine who works as a “tech” at a local Walmart T≤....and he says they have “regulars” that come in with “dry” dipsticks even....

Basicallyy, they drive their cars right up to their next posted oil change intervals as noted on their sticker, never minding to bother checking the fluids under the hood until their next scheduled service day lol.

They had one guy come through, claiming his washer fluid wasn’t topped off last oil service....LOL....so, they took a look under his hood, the washer fluid container cap was busted up...lol.well duh, it spilled out while driving

bugs~ - 31 December 2010 12:13 AM

Though I can agree that 3k OCIs are too short.....some “nuts” need those “short” OCIs

I got a buddy of mine who works as a “tech” at a local Walmart T≤....and he says they have “regulars” that come in with “dry” dipsticks even....

Basicallyy, they drive their cars right up to their next posted oil change intervals as noted on their sticker, never minding to bother checking the fluids under the hood until their next scheduled service day lol.

If you noticed, I said a vehicle “in good condition” can go longer OCI’s. Obviously, a car that is using oil to the extent of not showing on the dipstick by the 3000 mile mark is NOT in good condition.

No these aren’t people running sythetics, just cheap “dino” or what they now call “eco box” oils now.. Though I’m not a fan of 3mo/3k OCIs, they are good for those who don’t want to pop their hood to top off their fluids

People who don’t take the time to do at least the basic checks on their equipment deserve what they get.

In March I changed my oil, oil filter, and air filter again at 109874 miles with Penzoil and added MMO to crankcase, gas, and tranny. That’s just under 31,000 since the last oil change in December, 2010. I noticed my MPG was dropping to 32-34 form the really high MPG I was getting on very long trips.

MMO is great. The original reason for using MMO was the ‘check engine light’ was on which turned out to be the gas cap. I mentioned to the Smog personnel that ‘Why not just change to a new gas cap’ and run the test, and he said he would still have to charge me. Rip off. It’s a free test if you pass, so they don’t want you to do anything they know will work the first time.

Next oil change: 150K