300CE weird behavior
 

My 300CE seems to be having some weird issue lately. Heres a quick run down of the story:

It seems after a trip driving from the SF Bay Area down to LA and back, the car would smoke at the rear of the engine. It still continues to do so. It smells like oil but my oil level has not dropped in over 2 weeks of it smoking. I've checked pretty much every day.

But something else has arrived now. As of yesterday, I was driving down a normal route I go and stop at a stop sign. Suddenly I get vibrations and the engine starts to idle rough. I accelerate and it feels like ABS brakes are on as I get the kinda quick continous thumping feel but ABS is not on nor the brakes. So I was careful with accelerating and barely touched pedal. I noticed if gave it a little more gas, I would get this popping sound. After 2000rpm seems to be somewhat smooth. This whole issue (except for the smoking) seems to be erratic as I'll be driving with this problem and then it disappears and will re-appear at some other time. When its not having this problem, the engine runs perfectly fine and no popping sound, even when I floor it.

Anyone have an idea? Tranny issue?

Thanks

A good place to start is to check for codes and see what the computer has to say about your running problems.

M103s leak at the back of the head onto the bellhousing then down to the exhaust pipes. A little liquid oil produces a lot of smoke. If you measure very carefully to the drop, you'll note that you're losing oil.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

He has a 1993 300CE.

All 1993 300E's / 300CE's / 300TE's are misbadged.

They all have 3.2 liter M104 engines, not M103's.

I think you are suffering from the two major problems this engine has from the model years 1993-1995:

1. You are likely leaking oil at the right rear corner (passenger side) of the head gasket, and the smoke you are seeing is a result of the oil dripping on the exaust manifold. The leak is very small, which is why you are not seeing your oil level go down.

2. The rough idling and popping are likely due to a failing engine wiring harness. Engine wiring harnesses from 1993-1995 are bad. The insulation flakes off the wires, causing your car to idle rough, misfire, hesitation on acceleration, backfiring through the intake manifold (the popping noise), etc.

Both of these problems are very, very common, and any dealer or Mercedes independent has problems done hundreds of the above repairs.

Try the search function on this site for "wiring harness", and you'll have enough reading to keep you up all night.

Typo. My bad.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

It's o.k.

It seems my function on this board is to remind the world that 1993 300E's are misbadged, have 3.2 liter M104 engines, and should've been called E320's like '94 and '95.

Maybe I'm trying to compensate for having small feet.:eek:

Hmm.. . you do seem to do that a lot.. :p

Don't see how the feet come into it though

Speaking of 1993 300CE's, did MB make a '93 300CE convertible? I saw one today. Definately a '93-'95 because of the interior, but the exterior was 1993 style, and badged as a 300CE. Thought they only make the convertible in 94 and 95.

Matt

It just drives me crazy that in the U.S. Mercedes didn't change the badge on 300E's in 1993 with the 3.2 liter engine. In 1993, they sold the 300E with the 2.8 liter engine, and called it a 300E 2.8. The 300E, when badged as a 300E, always had the M103 3.0 liter engine. When they dropped the 2.6 liter in it, they badged it as a 260E, then later as a 300E 2.6.

In 1994, Mercedes went with the letter first badging system, and called it an E320.

In the rest of the world, this model was a 320E, so there was no confusion.

I was actually joking about the feet. Usually, it is said that some men try to over-compensate for having a small penis. Since I'm hung like a horse;) , I hypothesized that it must be because of the feet.:eek:

Yes, Mercedes sold a 300E convertible in 1993. Again, it has the same chassis code, 124.032, as 1994 and 1995 E320's. It has the same engine and interior.

The differences are all exterior. 1994-1995 E320's have the updated hood / grill with European style headlights. The bumper impact strips are painted. They also got clear / yellow front corners, and clear / red tail lights.

1994-1995 W124 sedans got a chrome strip on the trunk below the star emblem, but W124 coupes and covertibles kept the black plastic strip that 1986-1993 cars have.

The '93 300ce convertible must have been more limited in production, this being the first one I have ever seen. Am I correct?

matt

Rascel,
Have you resoled your problem? I had a 300ce that had a mechanical vacuum pump located in the front of the engine. The pump was driven by the intake cam, this pump had a diaphram that failed and caused exactly the symptons you described. The power booster to the brakes used the boosted vacuum for power and the busted diaphram caused the engine to smoke because the pump had one like to the booster and one line to the manifold. The line between the pump and the intake manifold was clear plastic, when the pump failed it allowed oil to flow into the manifold and the clear line turned black. I purchased a diaphram for like 20 bucks and fixed the problem. If your car has a mechanical vacuum pump give it a check. Take care and good luck!
Regards,
Brian

Yes. Following are the model years and the number of convertibles sold:

1993 - 766
1994 - 1,698
1995 - 3,676

Hey guys,

I know its been awhile but I'd just like to reply for future reference for people.

This was definitely a wiring harness problem. The harness was SO unbelievably bad that on one connector (not sure which) there was at least a good inch to inch and a half of wire exposed. The others at least had about half an inch exposed so it definitely was causing issues.

Thanks for the replies!

Edit: Oh and the oil leak was actually in FRONT of the engine. This was from the magnet connection for the varieble intake camshaft puking out oil and getting blown to the back of the engine hitting the exhaust.

Rascel- did you keep your twin-turbo setup?

If you're willing to part with it, and I'd like to try it on my C36 powered wagon.

BTW: you could do a C36 transplant very easy on your 300CE.

:-) neil
1988 360TE AMG
1993 500E