sealluke

Hello I have replaced these common items on my SLK 230 99 at 69000 miles.

1. Changed coolant/flush and all Hoses + thermostat
2. Changed oil/filter
3. Changed Serp Beltx2
4. Changed Plugs Bosch 4303 (same as before)

Ok here's where I am confused. After all that I went to start and drive it and the car is sluggish. The car will drive but the engine is struggling. One thing I do notice is the exhaust smiles like sulfer and the console area between the seats (lower Emergency Brake plastic area) is very warm (like heat coming off of the exhaust pipe from the underside??) If you are sitting in the drivers seat in park or N the car idles close to fine but put it in drive its very hesitating and slow to move.

My thoughts: I have had a full tank of gas and something like this happen before - I let some burn off and it was fine - not sure if its the same. The strong sulfer smell??? Could that be a burn in for a part I instaled? I am not sure if the reading from my OBD II are accurate.


Any thoughts or help would be welcome

Thx for your time...

LT

sealluke

While idling in the driveway The rear muffler got so hot that it melted the black plastic part of the rear lower bumper. - What would cause such high heat to do that? My guess is a bad Cat converter????? If so how what do your do to fix it - any options, ideas???

Thx again

sealluke

Ok I have made a little more progress. I took off the front O2 sensor and let it idle - It idles better. The high heat is gone around the Cat area. Then I took rear O2 sensor and let it idle and the Cat is so cool you can touch it with your fingers while running. I am thinking that with both O2 sensor off and all the exhaust/heat escaping from the two holes and remaining muffler that there is a blockage in the Cat to cause it all to build up heat and run hot. So I think I should replace the CAT and both O2 sensors and I will be back to normal??? Also while the SLK 230 is idling and when I take the RPM's above 4,000 the idle with skip/pause at that point - not sure if that's normal but with it being an automatic the gears usually never let the engine stay in the 4,000 RPM range.

Does this make any sense with my trail and error approach in narrowing it down.

Any other comment and tips are welcome thanks to all..

LT

bazzle

Engine will not rev over 4k in park or idle. Normal

I would just change front sensor.
Gas will come out hole , normal.
Sometimes a fast squirt up the highway may fix issue like that. Worth a try.

Bazzle

hineywineries

Going back to basics. Did this problem occur right after you performed the the maintence items mentioned? If so recheck the spark plug connections. Zundfolge
is firing order and should be on valve cover. IIRC it is 1342 for 4 bangers except VDUBS. and 153642 for sixes. I think this is your problem.

bazzle

If you are familiar with MB 230s used in these you cannot make a mistake with plug wire, actually 2 of the coils sit on the plugs.

Bazzle

hineywineries

OOPS
I guess I wasn't thinking. I do work on these Kompressors and should know better the old memory isn't what it used to be.

hineywineries

Was at the shop today and took a look at EPC. Didn't get around to ALLDATA, but it is possible to mix up wires. As I said earlier, the problem didn't occur until after the tune up. I would still recheak the work before replacing sensors and cats. Maybe one of the secondary wires isn't plugged in all the way. Maybe a plug was dropped and the tip mashed without notice. A missfiring cyl would produce extra O2 which would make he sensor ask for more fuel. These hydrocarbons put a burden on the cat. I say recheck the work and please report back. It's no shame to make a mistake. I once put a brake pad in with the backing to the caliper. It made an awful noise on the road test. I forgot to tighten one whole bank of plugs on a 4.5 once. When one plug blew out, the owner came in complaining of a terrible noise. When I was an apprentice, I put too much grease in a hub cap once. The grease expanded with the heat and blew the cap off. The owner came back to the dealership with the hub cap rolling around in the wheel cover. I never made that mistake again.

bazzle

You would need to be very unfortunate.

Bazzle

hineywineries

So what's your point?