Hello from Atlanta! How long are coil packs supposed to last? Had mine replaced 34k mi. ago. Yesterday, as I stopped at a red light,the engine quietly stopped. Started back up and it had a distinct miss. The miss is slight, but constant. Assume it is a coil pack problem. Any advise would be appreciated.

 

It depends on your enviornment but they should not go in 30-40k no matter where you are. Were they new or refurb? you can always check them with an ohm meter to be sure.

 

Thanks GEDaggett. They were new. Any info on what the ohms should be?

 

To be honest I would have to look up the testing process in my books. Typically you want to have the meter read near 0 on you r meter. That means the connections, points and internals are in good shape. there are some other guys that might be able to help out.
Not to put him on the Spot but I think SHDOUG might be able to get the info for you. I will check it out when I get home.

 

Thanks. I'll pull all three and compare and should be able to see which one is bad.

 

My coil packs are original and still work fine.

If your wiring harness has not been replaced or effectively repaired yet, I would strongly suggest taking a careful look at the harness before assuming a coil pack.

Why do I say this....well, I suspected the same last week and as it turns out the 1/6 coil pack was not getting signal...due, it turns out, to the original harness and it's deteriorated condition.

I narrowed it down to that coil pack by removing plug wires until I found that removing the plug wire from cyl 1 did not change the sputtering idle. Went and wiggled the harness wire which connects to the coil that serves cyl 1&6 and she ran smooth and sweet. Ahh, she ran so good...but not for long. =(

Now my harness is in my kitchen awaiting major surgery. After a brief inspection of it's condition.....I can't believe the ole girl ran at all!

STEVE
94 320 Wagon
139k mi

 

Thanks Steve211. The harness was replaced by the dealer at 61k mi, which was 171k mi ago. Don't know how long the replacement is supposed to last. I did notice one of the coils wouldn't give a reading on the ohmmeter, so I'm assuming it's ng. The plugs' gaps were worn to about .40 and the insulators were burnt down a bit.

 

that's most likely it. I would take that coil over to a good Euro shop and sweet talk them into confrirming that by saying you may have to bring the car in but didn't want to waste thier time if it was something as simple as this. Dealers won't accept return on electrical sometimes so I weezle a test out of folks. You would be surprised how often it works.

 

Thanks GEDagett. I replaced the one coil that was giving a different reading than the other 2. Replaced the plugs ( and the insulators on the bottom of all 3 coils- at the encouragement of my parts guy). Just drove it around the block and everything is working fine. Thanks again. Since the plugs look like the engine is running very lean, that's my next problem. With the car running good again, I'm really not to motivated to mess with it.

 

That's cool...I was too late anyway.

 

Glad it worked for you. Give it a little time with the lean mixture. The cars voltage was probably maxed out compensating for the bad coil and it will most likely correct itself. When the voltage is screwed with sometimes the car fires early and then the leans out the mixture.

 

Will do and thanks again.

 

...Now my harness is in my kitchen awaiting major surgery. After a brief inspection of it's condition.....I can't believe the ole girl ran at all!

STEVE
94 320 Wagon
139k mi[/QUOTE]

Steve

I feel for you. I just rebuilt the harness in my 1993 300E (3.2L M104). If you decide to tackle it, get a new housing for the computer connector (PN 000 545 53 81, cost $18.93. They come form Germany and the shipping is 5-7 days). and replace all of the wire from the computer connector to each sensor and or switch / valve.

Take your time and do one wire at a time. I found it helpful to lay the old harness out on pegboard and tie down each connector and branch point with wire ties. Lay the new wire out over the old wire, unsolder the old wire from each connector and then re-solder the connector to the new wire. As the wires come together to form bundles, tie them together at the branch points so that all of your connectors will land in the right spot when you reinstall.To make trouble shooting easier in the future, buy a pack of wire markers and label each with a unique number and cross reference this number with the original wire color code. Keep copies this reference with your owners manual and taped into your shop manual.

The pins on the computer connector are held in by two small metal tabs. You can push the tabs in with a dental pick or similar tool and pull each pin out for re-soldering.

The engine monitoring leg of the harness is comprised of shielded coax. The insulation on the center conductor on this section appears to be silicone so you might not have to replace it.

The wiring in the area under the spark plug cover and around the coil packs is kind of tricky. I had to perform surgery on the funky rubber shape to get at the wiring scheme . Once i figured it out, I laid out the scheme with new wire and wrapped it with self amalgamating loom tape to approximate the funky rubber part.

When you are all finished wrap the new wire harness with self amalgamating tape ( you can get it at Walmart in the plumbing section for less than $5.00 a roll or at the auto parts store for closer to $10.00 a roll.

You will need 18ga, 16ga, 14ga, and 12ga wire with decent insulation. The wire I used was rated for continuous service at 120 deg C. The bulk of the wire required is 16 and 18 ga. There are a number of online wire sources, I've had good luck with Del City.

Good luck
Greg

 

GDC,

I'm impressed that someone did a DIY instead of just buying a new one.

I may soon be doing that as well for my 95 E300.

I'll guess that it cost you about $100 for the connector and wires and wrapping. Is that close?

Thanks, Dave