Needing Advice: 94 C280

[Sulaco]

Over the years the sunroof has slowly but surely fallen completely apart. The only piece that's not broken is the glass itself. EVERYTHING but the glass and motor need to be completely replaced. I've had to drive around for the last, get this, THREE YEARS with the roof permanently in the "moon roof" position (because it howls like a sick dog in the fully-closed position). I'm told it's going to run $500 to have it rebuilt. Any idaes how to get the parts and rebuild it myself? I'm fairly mechanically inclined. I've done lots of minor jobs on the car myself (fixing the "loose" transmission linkage, replaced water pump, etc) and I am going to force myself to learn to do everything on the car anyways.

Secondly. Thanks to a leak in the trunk's lining (from the rear-end collision before I owned it) and a piece of paper clogging the drain hole in the trunk, the trunk FLOODED. I was in college and it sat parked in monsoon-rains and underneath a daily sprinkler for 3 weeks. I get in it, it won't start. The SRS, CEL, and battery lights are all on, but it won't start. I assume dead battery, open trunk, and I find the battery is half-submerged in water: along with all the other electrical junk back there. I assumed the car was dead. A total electrical failure. But I drained it and dried it for a week before messing with it again. And, God as my witness, it cranked right up and ran just fine. But the SRS light never, ever went off, and that auto-roll-down feature on the windows never worked again. Plus, that auto-roll-up when locking the doors feature for the windows/sunroof feature never worked again either. I found this rather expensive looking brain box beside the battery mounted on the frame rail. It was deffinitely under water in the flood, so I took it off and disconnected the 50 little wires from it. I cleaned the part completely (using electrical parts cleaner) and hooked it back up. Then, my windows stopped working. Some would roll down but not back up (until I banged on the brain-box in the trunk). I think the box itself is fine, but perhaps the tips of those 50 cables are ruined. Some of the tips BROKE OFF when trying to connect them again and I had to get creative on how I was going to hook that wire back up to it's intended lead. Plus, ALL of the remaining tips are so corroded and crusty that I can't clean them, or even tell what metal they are made of. My question is this: The dealership can't even begin to get me an estimate on what it's going to cost to replace those batches of wires that obviously run to the switches in the console. I have gone 2 years now without having windows that roll down now. I can take it no longer. If ANYONE can get me in touch with a junkyard or perhaps a parts dealer who can even identify (or maybe even sell) these harnesses, I would be VERY appreciative. I live in TN, and I'll drive to anywhere in the U.S. to remove the wires myself if I have to.

Aside from that, I'm having the same old MAF, O2 sensor, ignition, worn control arms, and the other usuals of an 11-year old W202 with 158k miles.

I had a new MAF installed 3 years ago. Few months later, the local Benz "specialist" tuned it up for me with a K&N filter (which some believe fouls out MAF's). And now, for the last year, I've had random misfirings which boot it into limp mode. I put new Bosh Platinum +2 plugs in today which worked like MAGIC on alleviating that problem, smoothed out the acceleration, vastly improved performance, and greatly increased responsiveness. I would have gotten those $12 iridium plugs if these redneck, backwoods parts stores carried them. Anyways, I drove around trying to force it to misfire (which always only happened when accelerating, gently or full throttle). Throughout an entire day of testing, it only misfired once/went into limp mode. However, with the new plugs, limp mode isn't NEARLY as weak. And one cause of concern is (with the new plugs installed) strange idling characteristics. It idles at around 600rpm, but randomly, quickly, and quietly shutters down to about 200rpm and instantly back up to 600. It never did that before the new plugs. I'm going to slowly but surely replace the entire ignition system. Next: the wires and coil connectors. Then, coil packs. Then, O2 sensors. Then, MAF (cheapest to most expensive). Or whatever it takes until the problem is completely solved.

[Sulaco]

Bump.

After installing the spark plugs, the engine's performance has increased greatly, and it goes into limp-mode far less often, but something is wrong with the idle. I mentioned it in the previous post, but it's really starting to worry me. When stopped and idling in gear, the RPM's seem to dance around, causing the car to want to jump forward every couple seconds if I'm not holding the brake hard enough. With the old, worn-black spark plugs, it did not have this problem. Could it be a poor choice in replacment plugs, or is there something seriously wrong?

I reset the CEL (disconnected the battery) and it's been 3 days. But the CEL has not come back on. Yet it's kicked itself into limp mode twice and idles very strangely (in gear only).

ANY ideas, please?

[benzdude280]

I would have to say that is an MAS problem. Probably in conjunction with the O2 sensor also. The best thing for right now is to have the codes pulled. Autozone will do it for you. Just to let you know, I had the same exact symptoms in my car. Replaced the MAS and O2. Runs like a champ now.

Cheers

[benzdude280]

Oh, and I believe the best plugs for our cars are the Bosch +4's. Just my two cents.

[jnenad16]

DO NOT USE platinum plugs in your car. 104 engines(inline 6 C280, E320, C36) are not designed to use platinum plugs. I ran bosch +4 in my 95 C280 for about 3months, and my compression went from 190+ psi on all cylinders to 150psi the highest. the plugs were dark red, indicating extreme cylinder temps, and my engine ran a few degrees hotter than before installing them. so my advice to you is to put either stock replacement plugs, of beru silverstone or beru ultra-x if you are into performance plugs. as for the ruff running of your car, get it scanned, see which codes pop up. according to your mileage, if you never replaced O2 sensors, do so no matter what, even if the code does not show up. also replace the wires and the coil ends, cooland temp sensor and add a fuel system cleaner to your gas next time you fill up. that module that you tried to fix next to your battery is called the convenience feature module. It controls your windows, seats and the onboard phone(maybe a few more things, but I just cant remember). the harness connecting to it can be cut from another car and spliced on to yours. good places to start looking for it would be:
www.unap.com
www.pgauto.com
www.peachstreetauto.com
these are just few auto recyclers I deal with, they might be able to help you out.

nenad

[Sulaco]

Looks like my next step is to replace the O2 sensor(s). Should I shell out the $300 and replace them both, or just the pre-cat sensor?

I'll be changing out the plug wires asap also, as well as the connectors on the coil-packs running down to the plugs. The plug wires did look a little crusty when installing new plugs the other day.

Plus, Autozone refuses to even plug into my car. It's a 94 and they won't even TRY to plug in their scanners and see if it has ODBII. I've read in several places that my car, although a 94, has ODBII and will work on the 96-current scanning systems. I called the dealership and they were saying it's $90 to diagnose my problem on their systems.

[jnenad16]

Originally posted by Sulaco
Looks like my next step is to replace the O2 sensor(s). Should I shell out the $300 and replace them both, or just the pre-cat sensor?

I'll be changing out the plug wires asap also, as well as the connectors on the coil-packs running down to the plugs. The plug wires did look a little crusty when installing new plugs the other day.

Plus, Autozone refuses to even plug into my car. It's a 94 and they won't even TRY to plug in their scanners and see if it has ODBII. I've read in several places that my car, although a 94, has ODBII and will work on the 96-current scanning systems. I called the dealership and they were saying it's $90 to diagnose my problem on their systems.

replace both O2 sensors, you can get them cheap at www.germanstar.net or www.thebenzbin.com
yes, your car is fully compatible with OBD2, if autozone wont scan it for you, just rent the scanner from them and do it yourself, the OBD2 connector on your car is located underneath the steering wheel closer to the center console, you will see a black rectrangular cover, flip it open and plug in the scanner.

nenad

[benzdude280]

Nenad is right. Your local autozone must be a bunch of pricks. The OBDII is super easy to use so just rent it and save fifty bucks from having to take it to the stealership.

Cheers.

[Sulaco]

I've done alot of looking around on every Benz repair forum I could find. I have found a large consenus that believes the platinum plugs are universally bad for pre-98 Benz cars. I've found alot of people complaining about the exact same characteristics as me after installing platinum plugs (especially Bosch). Acceleration is improved (for a few thousand miles) but idle is random and bouncy. Most people also saw a slight drop in fuel economy. I've been kind of suspicious that my car has burned more gas than usual, but just shrugged it off as being nervous. Well, it turns out that alot of other older Benz owners have seen a slight loss of mpg as well.

Since spending $12 on the recommended copper plugs is the cheapest place to start, I'll swap plugs tomorrow and see if my idle gets any better.

Still replacing those O2 sensors asap!

Thanks!

[Sulaco]

Well, I got the OEM plugs in. Bosch F8DSC Super Coppers. Most of the clunking around at idle has been eliminated. However, it does still idle somewhat strangely. With the old, worn out plugs it idled just fine, but had frequent misfires and backfires under acceleration. With the new ones, it accelerates like a new car, but idles weird. Confusing...

[jnenad16]

it might be the MAS. do the rpm's fluctuate up and down, or does the engine and car shake as well?

nenad

[Sulaco]

They fluctuate up and down when stopped and in gear. I PRAY it's not the MAF. I simply can't fix that for the next few months.

[benzdude280]

I would probably say it's the MAS also. Let me know, I have a brand new one that I can sell to you. Email me if you would like.

Cheers,

[estrellajon]

Originally posted by Sulaco
They fluctuate up and down when stopped and in gear. I PRAY it's not the MAF. I simply can't fix that for the next few months.

I had the very exact symptoms. Definitely the MAS. Changed mine and runs so much better. It's only $300 online. The faster you replace them, the better for your plugs. I learned that a bad MAS will make the car run richer and will foul the plugs sooner.

[LV202]

This is crazy.

First things first: get car CEL codes read, then replace as needed.

OBD connector is under the steering wheel. AZ always tells me I don't have obdII, and I tell them them I do, and to pull the codes!!

Get what the code is and replace as needed! Why throw good money away if the item is not needed?

Second and maybe just as important is the wiring harness issue....Do you have the original wiring harness? If you do (and they ALL go bad) it will cause misfiring and all kinds of symtoms, including what you are describing. Also it will cause all kinds of false CEL codes to be thrown out. People will chase these codes replacing away and nothing seems to fix the problem. The true culprit: degrading wiring harness.

I can't believe nobody on this site has not mentioned this.

Tell AZ you have pulled codes before and the port is under your steering wheel!!!

Check the condition of the harness...does it have exposed wire?

[estrellajon]

Originally posted by LV202
This is crazy.

First things first: get car CEL codes read, then replace as needed.

OBD connector is under the steering wheel. AZ always tells me I don't have obdII, and I tell them them I do, and to pull the codes!!

Get what the code is and replace as needed! Why throw good money away if the item is not needed?

Second and maybe just as important is the wiring harness issue....Do you have the original wiring harness? If you do (and they ALL go bad) it will cause misfiring and all kinds of symtoms, including what you are describing. Also it will cause all kinds of false CEL codes to be thrown out. People will chase these codes replacing away and nothing seems to fix the problem. The true culprit: degrading wiring harness.

I can't believe nobody on this site has not mentioned this.

Tell AZ you have pulled codes before and the port is under your steering wheel!!!

Check the condition of the harness...does it have exposed wire?

I agree. Definitely get the error code first. I started my first CEL issue without a code reader and its a shot in the dark. I have since bought myself one.

[Sulaco]

I am very well aware of the wiring harness issue. But I don't have the means of replacing it. I know I can replace it myself but I am in college, I'm poor, and I never have time to work on it. Not to mention the fact that I am parked in campus parking and the tools required are hard to come by right now. This summer I'll get on it and see if I can replace it, but that's a while away.

Secondly, all the sites that sell a wiring harness for my car, it lists 2 harnesses. I can't figure out which one to use...



A 165602-
F 135856-


Which is me?

[jnenad16]

Originally posted by Sulaco
I am very well aware of the wiring harness issue. But I don't have the means of replacing it. I know I can replace it myself but I am in college, I'm poor, and I never have time to work on it. Not to mention the fact that I am parked in campus parking and the tools required are hard to come by right now. This summer I'll get on it and see if I can replace it, but that's a while away.

Secondly, all the sites that sell a wiring harness for my car, it lists 2 harnesses. I can't figure out which one to use...



A 165602-
F 135856-

those numbers should be a range in your VIN.

nenad

Which is me?

[jnenad16]

my bad I quoted mysefl.
Those numbers are a range in your VIN.

nenad

[estrellajon]

How do I find out if the previous owner has changed the wiring harness or not. How hard is it to replace a warning harness?

[Sulaco]

Replacing isn't that hard. There's a guide for changing the wiring harness on a 1994 E320, which is virtually the same, or at least incredibly similar.

Linky

Takes a couple hours, he says.

[Sulaco]

Neither of those figures are in my VIN. Not even close.

[jnenad16]

I guess its best you call them. they can run a check with your VIN and get you the right part.

nenad

[LV202]

Where did my post(s) go????

[jnenad16]

Originally posted by LV202
Where did my post(s) go????

the site got hacked earlier today.

nenad