|
Thai G
Elite Veteran
Date registered: Jul 2007
Location: Texas
Vehicle(s): 2004 G500
Posts: 940
| Re: G500 Terrible misfire, flashing CEL
MarcO - 2/11/2010 6:55 PM
Very observant. Though the prancing moose was probably a dead giveaway.
Had a little electrical problem with the Cayenne. Short story shorter.... it is gone. Volvo is a true appliance though suprisingly comfortable. Still have the SWB and it is better every day.
hmmm, all those comments about how great the cayenne is...at least, this time, you were not the one that personally killed it...congrats on that part. 
As for the Toyota comment, when did i say anything close to what you implied, Marco?? Help me out on this one. |
|
| |
|
4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| Re: G500 Terrible misfire, flashing CEL
Thai,
you have to renew the lease on "I AM FAMOUS!" - the CNET review is almost a year old.
I nice freeway chase would get you on TV.
Edited by 4x4abc 2/12/2010 9:45 AM
|
|
| |
|
Titus Pullo
Elite Veteran
Date registered: May 2007
Location: Ottawa, ON, Canada
Vehicle(s): '90 Wolf 240GD, '06 G270 CDI.
Posts: 1010
| RE: G500 Terrible misfire, flashing CEL
Harald, if you mean my "Me is famous" tread, please dont get me into it, OK. |
|
| |
|
Thai G
Elite Veteran
Date registered: Jul 2007
Location: Texas
Vehicle(s): 2004 G500
Posts: 940
| Re: G500 Terrible misfire, flashing CEL
4x4abc - 2/12/2010 8:44 AM
Thai,
you have to renew the lease on "I AM FAMOUS!" - the CNET review is almost a year old.
I nice freeway chase would get you on TV.
Maybe i will get a used white bronco.... |
|
| |
|
4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| Re: G500 Terrible misfire, flashing CEL
Bronco is a good choice - don't drag the G into it |
|
| |
|
G4Garret
Veteran
Date registered: Apr 2006
Location: Oak Ridge - Knoxville - Windrock Tennessee
Vehicle(s): 2000 G500, U1100, SLK350, LR 101, WC-63 6x6
Posts: 243
| RE: G500 Terrible misfire, flashing CEL
I think I may be on to the problem. Today I swaped coil packs between #5 and #1 cylinders. Noted the not very tight mounting screw and the corrosion underneath the pack. Anyway, cleaned both coil packs up where the corroded ground is, cleaned up the plug cables, inspected electrical connections in general, then put it back together, cleared the DTC codes and CEL (MIL), and drove for about 45 minutes with no problems.
I don't think I'm out of the woods yet, but I do think I'm narrowing things down a little bit. Becuase it seems to run with basically normal power at all speeds and typical loads, and after being warmed up, so I don't think it's the cat converter. I think it's the ignition. However, I also noted that I was low on coolant. I had just added some a few months ago.
Anyway, I'm off to install new plugs and clean the rest of the coil-pack grounds and plug wires.
Edited by G4Garret 2/12/2010 5:00 PM
|
|
| |
|
G4Garret
Veteran
Date registered: Apr 2006
Location: Oak Ridge - Knoxville - Windrock Tennessee
Vehicle(s): 2000 G500, U1100, SLK350, LR 101, WC-63 6x6
Posts: 243
| RE: G500 Terrible misfire, flashing CEL
Took off all the ignition coils and wires to change the spark plugs. Found 2 wires that are defintely bad for resistance, 10K ohms where they should be 2K.
Anybody have any thoughts on NAPA Belden ignition wires? They look like the only ones I can get first thing in the morning.
Interesting this is that I had been noticing one particular cylinder making extra loud radio interfence on my HF radio, so I probably could have figured this without opening the hood if I had really though about it.
Garret
|
|
| |
|
G4Garret
Veteran
Date registered: Apr 2006
Location: Oak Ridge - Knoxville - Windrock Tennessee
Vehicle(s): 2000 G500, U1100, SLK350, LR 101, WC-63 6x6
Posts: 243
| RE: G500 Terrible misfire, flashing CEL
Couldn't get new wires anywhere in town. Amazing. Not a single set of V8 Mercedes M113 wires to be had in this whole town (on a Saturday). So, in the meantime I took the old wires, ran them through the dishwasher, cleaned up the coil packs, and re-installed them. Along with the new plugs, it runs MUCH better. And the interesting thing is that the HF radio noise is now virtually gone. Completely gone on most bands. The difference on the radio is really telling. I'm guessing it's due to plugs more than anything.
Fortunately no more misfiring, and no more Check Engine Light. I think it is just amazing that the motor is running fine one minute, and then the bad plugs could result in the engine misfiring on half the cylinders seconds later. I understand it's probably the computer trying to protect the cat converter, but dang. |
|
| |
|
ewalberg
Expert
Date registered: Apr 2006
Location: Past: San Francisco. Present: Germany
Vehicle(s): 2000 g500
Posts: 1887
| RE: G500 Terrible misfire, flashing CEL
And those spark plug wires are EXPENSIVE! Is it a pretty straight forward job to change plugs and wires yourself? I'm due for new plugs and i'm thinking to change wires while i'm at it since i've got 145k miles on the car... if i don't have to pay someone to install all the better. |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| RE: G500 Terrible misfire, flashing CEL
Those wires are pretty easy to replace yourself. Each one has a letter on it, like 'K" or "G" to identify the three different lengths needed. On the engine next to the coil packs those corresponding letters are stamped, so you can't really go wrong. The list price for a full set is up around $800, but you should be able to get them for $500. You can get aftermarket leads for $200.
You definitely need a pair of ignition cable pliers to remove the old leads. And a spark plug socket obviously. Don't use an ordinary socket - the spark plug types have a rubber cushion to avoid damaging the white part of the plug. When installing the new leads, you will know they are seated when you feel a definite "click", both on the the spark plug end and the coil end.
Replacing the spark plugs is mostly straightforward. Six and seven are awkward to get at with a torque wrench, but you'll figure it out. The torque spec should be on the box for the spark plug if it's a Bosch. 21ft-lb is normal. Expect to shred your knuckles on the heat shields.
I don't know the expected life of these leads. I just replaced mine at 130k miles, and the old ones all tested OK, so I could have gone longer. I think I would not replace them all if I was making the decision again. Better to just wait until individual leads start playing up, and replace them one at a time, which might be never. The old spark plugs had 60k on them, and they all looked perfect under the microscope. Gaps were still good. Could have gone much further on those, but didn't relish putting them back, and they are cheap anyway.
Good luck! |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| RE: G500 Terrible misfire, flashing CEL
G4Garret - 2/12/2010 1:12 PM
I think I may be on to the problem. Today I swaped coil packs between #5 and #1 cylinders. Noted the not very tight mounting screw and the corrosion underneath the pack. Anyway, cleaned both coil packs up where the corroded ground is,
Garret,
That metal plate on the bottom of the coil pack is not electrically connected to anything. Neither is the bolt that goes through. They are just for mechanical mounting. The ground connection is via the three-pin electrical connector on the low voltage side. Surprising to me too.
Removing and replacing your coils probably improved the electrical connection by wiping the connector blades.
Any news on your fix? You have all the symptoms I have, so I'm hoping you'll get it figured out before me. |
|
| |
|
G4Garret
Veteran
Date registered: Apr 2006
Location: Oak Ridge - Knoxville - Windrock Tennessee
Vehicle(s): 2000 G500, U1100, SLK350, LR 101, WC-63 6x6
Posts: 243
| RE: G500 Terrible misfire, flashing CEL
Just thought I would update this thread after 4 months of smooth running V8 nirvana. After I replaced the plugs and wires, all is still good.
Although the plugs were pretty worn, it was apparently really the wires causing the problem. Each and everyone of the original wires tested bad at some level. Some had pretty high resistance as I'd mentioned already (10k instead of 2k ohms). The difference in running is remarkable. Also, the difference in fuel consumption is even more remarkable! My mileage immediately jumped from the displayed 10-12 mpg right up to 14 mpg, with long term following right along. Just like that, and it's been consistent. The actual calculated MPG is now about 14.5, with better than 15 on long trips. This is better than it's ever been. Could be that the synthetic oil I put in the drive train is now showing also. I had figured that was a waste of money after I put it in, as it didn't seem to change things in any noticeable way.
Now, the second unexpected side benifit is that my brakes work better than ever. I had thought I had some serious brake problems, coincidentally it was when the misfire problem started, and it apparently was just the lack of proper engine vacuum cuased by the misfire. The brakes were feeling pretty bad and I'd already started researching rebuild of the ABS pump/valve box. Thank god it was just the ignition wires!
With all the vehicles I've ever owned, I don't quite recall ever having as dramatic a problem with ignition wires before. I'm guessing that what is going on is the modern coils and computer controlled systems can make up for significant problems in the engine running, such as what is cuased by poor wires. I imagine that had this been a traditional carburetter fuel delivery system, it would have not run much at all with the bad wires.
Garret
My truck now has over 90k miles and it's 10 years old. I surely wished I had changed these wires 3 years ago, as that's when I first started to notice the decline in mileage and slight roughness in the idle. The differenc in mileage over the past 50K miles would have easily paid for the wires. Probably 10 sets of wires!
|
|
| |
|
DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| RE: G500 Terrible misfire, flashing CEL
G4Garret - 6/6/2010 11:38 AM
With all the vehicles I've ever owned, I don't quite recall ever having as dramatic a problem with ignition wires before. I'm guessing that what is going on is the modern coils and computer controlled systems can make up for significant problems in the engine running, such as what is cuased by poor wires.
Both Porsche and Audi have recalls going right now for Ignition Coils. When they start to go bad, they definitely run like crap. I'm very pleased to have a new car without spark plugs, wires or coils. |
|
| |
|
wolfgang36
Member
Date registered: May 2009
Location: Memphis, TN, USA
Vehicle(s): 1999 G500, 2009 e350
Posts: 44
| RE: G500 Terrible misfire, flashing CEL
I am hoping to revive this thread as I am experiencing some similar issues.
P0300 - Random Misfire Detected - CEL only upon startup and once while driving in the rain.
Replaced and checked so far... With no improvement.
Spark Plugs - 15,000 miles ago with Bosch plugs from EuroTruck (visually inspected and electrode looks new)
8 Bosch Coil Packs
Bosch Spark Plug Wires - 16
Fuel Pump - Getting 55psi at fuel rail at idle
Coolant Temperature Sensor - old one badly degrading when removed
Visually inspected - k40 relay plug
ECU - wires and pins look new no corrosion
Issue will occur when cold starting - idles rough with definite miss. CEL activated and then I shut down. Restart and engine starts with no issues, slightly rough idle, but then pickups missing cylinder. Runs well and strong, yet gas mileage not as good as before. 10-11 mpg.
150,500 miles - 1999 G500
Any thoughts on next steps?
Thank you for your ideas.
John
 (IMG_8913.JPG)
 (IMG_8914.JPG)
 (IMG_8985.JPG)
 (IMG_9047.JPG)
 (IMG_9058.JPG)
 (IMG_9193.JPG)
 (IMG_9194.JPG)
Attachments
----------------
 IMG_8913.JPG (128KB - 0 downloads)
IMG_8914.JPG (94KB - 0 downloads)
IMG_8985.JPG (136KB - 0 downloads)
IMG_9047.JPG (103KB - 0 downloads)
IMG_9058.JPG (98KB - 0 downloads)
IMG_9193.JPG (143KB - 0 downloads)
IMG_9194.JPG (133KB - 0 downloads)
|
|
| |
|
J.R.
Elite Veteran
Date registered: Apr 2006
Location: Southern Maryland
Vehicle(s): 00 G500, 09 911 4S, 11 Cayenne S, 86 280GE (sold)
Posts: 828
| RE: G500 Terrible misfire, flashing CEL
How old and how many miles on the:
- K40 relay
- MAF |
|
| |
|
wolfgang36
Member
Date registered: May 2009
Location: Memphis, TN, USA
Vehicle(s): 1999 G500, 2009 e350
Posts: 44
| Re: G500 Terrible misfire, flashing CEL
Thanks J.R.,
The K40 has about 50,000 miles on it and the MAF is probably original to the truck. I've owned since 72,000 miles and I have 150,500 on it now.
John |
|
| |
|
J.R.
Elite Veteran
Date registered: Apr 2006
Location: Southern Maryland
Vehicle(s): 00 G500, 09 911 4S, 11 Cayenne S, 86 280GE (sold)
Posts: 828
| Re: G500 Terrible misfire, flashing CEL
John,
Based on my experiences, I carry a spare MAF, K40 relay (both retired in functioning condition) and a new CPS.
I change the K40 and CPS out every 7 years (both failed at 8 years). When the K40 fails, there is not limp mode as there is with a MAF, or CPS when it finally cools off.
From my notes:
A new K40 is about $110, last part number I had from a while back is A.210.540.00.72
A new MAF in 2009 was $135 A.113.094.00.48 . I would advise to only buy Bosch. I think the Bosch number is 0280217810
I am not a fan of solving a problem without a cause and my guess is you are not either. So back to my earlier point, if you buy into my spares idea, buy a K40 relay and a MAF, try each one, one at a time. In the end, if one of those is the issue, then you have a known good used spare in the other and two new installed for the next x years.
My guess...the MAF and the K40 is not too far behind
Edited by J.R. 1/24/2018 4:53 PM
|
|
| |
|
oskar
Elite Veteran
Date registered: Sep 2006
Location: Lyons, CO
Vehicle(s): 1981 280GE, 2002 G500, 280SE 4.5, Audi A4 1.8T
Posts: 708
| Re: G500 Terrible misfire, flashing CEL
carry : ... and a brake pedal sensor. |
|
| |
|
4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: G500 Terrible misfire, flashing CEL
I experienced something similar about a week ago
80F, sunshine, wanted to pass another vehicle at around 50mph
halfway past, the car stopped accelerating
CEL came on
car seemed to run rough
at lower speeds it seemed to run on less than 8 cylinders
I shifted down to keep the rpm up
exhaust on the left sounded like it sprung a leak
gently finished my drive home for about 140 miles
speed around 60 mph
mpg reading increased from 14.7 to 16.2
at the end of the trip the car still seemed to run on less than 8 cylinders, but felt smoother
following day the car drive as nice as always
exhaust quiet again
CEL still on after several restarts
mpg back to 14.7
will have Karl to check the readout
no rush though - Margaritas are more important
 (costa.jpg)
Attachments
----------------
costa.jpg (169KB - 0 downloads)
|
|
| |
|
DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| RE: G500 Terrible misfire, flashing CEL
4x4abc - 2/3/2018 12:40 AM
I experienced something similar about a week ago
I had a similar experience a few years ago when passing, when it went into the Limp Home Mode. Stopped the truck, turned off the engine and restarted with no problems.
I replaced the Throttle Position Sensor (drive by wire), and it hasn't happened again. |
|
| |
