Owning several of these older cars I have become aware of issues that are seemingly a non-issue. The non-issue ( in this case an exhaust leak) does however seem to be the problem causing culprit in the end. I searched and have not seen a thread specifically and uniquely for the symptoms and problems that arise from this needed repair. Many of you more experienced will help in this thread I trust.
To start I own two M119 powered cars. A 1991 500SL and a 1995 S420. I am not privileged to own the W124 M119 500E (yet). My problems have been the usual; others may say "many". With ANY old thing that is mechanical the problems are many. I began searching all the causes of misfire, spotty performance under certain conditions which I will enumerate later and just plain bad driving experiences. I first expected the usual suspects- we all know them to well: throttle body; cam sensor. rotor cap et al, plugs and wires; bad ecu; faulty degraded wire harness. Once you've thrown money at all of that and still have a problem either all or one of the replacement parts are bad or you don't have the correct answer. After many conversations with pros and pseudo pros we would inevitably and eventually get down to asking the question each of us assumed was a non-issue: the exhaust system. Moreover, are there any leaks, are the cats good, do you have the correct O2 sensor. Let's be clear that an exhaust leak, well I should say the farther back an exhaust leak is the less likely it is to be a problem other than YUCK. But a leak toward the front, and I would think especially on any car with two o2 sensors, can be the exact thing that is causing a temperamental system to have an error in it's A/F ratio and cause all of the problems that the above parts replaced would cause as well.
I bought this car in Spring of 2017. The following year it developed a leak at the front of the o2 sensor. As I began addressing that issue and sourcing the needed parts I ran in to a problem that no-one had prepared me for: the gauge of steel used on these cars exhaust WILL NOT be matched by ANY after market supplier. It is very thick, very heavy and meant to last. That brings into question how the leak occurred anyway?!! Well.....
As it turns out when i bought the car I looked for the cat and o2 sensor. The o2 sensor was in place as were all of the heat shields. After this problem developed I took the car to a very good muffler repair shop. He called me and told me he couldn't work on the car because it did not have a cat! YES I felt stupid. Easy to miss in February in Minnesota I guess. At least I am telling myself that. So I installed a lift in my barn and got to work on the system. Because I am me I installed a X pipe with the new low resistant cat. Still problems persisted. My car is like many- it has the the (hated) left to right cross-over at the trans pan! I would love to have the 98 ish downpipes but no luck in finding them. I knew I would be doing some transmission work later and hoped to find a way to allow me to still access the transmission- no luck really other than cutting and using V-Band (which may not always perform well) So I got it all back together and still would have this problem we are speaking off. Finally I got the car back to the muffler shop and guess what?! Well most of the problems were solved- accept the transmission slipping ones...
Well lots of love and I am sure all can relate and hopefully contribute to my plight and success.
To start I own two M119 powered cars. A 1991 500SL and a 1995 S420. I am not privileged to own the W124 M119 500E (yet). My problems have been the usual; others may say "many". With ANY old thing that is mechanical the problems are many. I began searching all the causes of misfire, spotty performance under certain conditions which I will enumerate later and just plain bad driving experiences. I first expected the usual suspects- we all know them to well: throttle body; cam sensor. rotor cap et al, plugs and wires; bad ecu; faulty degraded wire harness. Once you've thrown money at all of that and still have a problem either all or one of the replacement parts are bad or you don't have the correct answer. After many conversations with pros and pseudo pros we would inevitably and eventually get down to asking the question each of us assumed was a non-issue: the exhaust system. Moreover, are there any leaks, are the cats good, do you have the correct O2 sensor. Let's be clear that an exhaust leak, well I should say the farther back an exhaust leak is the less likely it is to be a problem other than YUCK. But a leak toward the front, and I would think especially on any car with two o2 sensors, can be the exact thing that is causing a temperamental system to have an error in it's A/F ratio and cause all of the problems that the above parts replaced would cause as well.
I bought this car in Spring of 2017. The following year it developed a leak at the front of the o2 sensor. As I began addressing that issue and sourcing the needed parts I ran in to a problem that no-one had prepared me for: the gauge of steel used on these cars exhaust WILL NOT be matched by ANY after market supplier. It is very thick, very heavy and meant to last. That brings into question how the leak occurred anyway?!! Well.....
As it turns out when i bought the car I looked for the cat and o2 sensor. The o2 sensor was in place as were all of the heat shields. After this problem developed I took the car to a very good muffler repair shop. He called me and told me he couldn't work on the car because it did not have a cat! YES I felt stupid. Easy to miss in February in Minnesota I guess. At least I am telling myself that. So I installed a lift in my barn and got to work on the system. Because I am me I installed a X pipe with the new low resistant cat. Still problems persisted. My car is like many- it has the the (hated) left to right cross-over at the trans pan! I would love to have the 98 ish downpipes but no luck in finding them. I knew I would be doing some transmission work later and hoped to find a way to allow me to still access the transmission- no luck really other than cutting and using V-Band (which may not always perform well) So I got it all back together and still would have this problem we are speaking off. Finally I got the car back to the muffler shop and guess what?! Well most of the problems were solved- accept the transmission slipping ones...
Well lots of love and I am sure all can relate and hopefully contribute to my plight and success.
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