Put a refreshed 3.0L M103 in my mom's 190E 2.6

[w123fanman]

This engine was originally meant for my 5-speed EFI build but I ended up having to reuse my original 2.6 in my 90K mile Sportline because once we got the 3.0L all resealed and into my car, it ran horribly. Even though it had near perfect results from a leak down and compression test, the original camshaft had a severely flattened lobe (early cams were known to fail) and the headgasket that was put in the engine shortly before I bought it for $100 wasn't the updated style and had already failed.




My mom's car was going to get my 2.6 as hers had 235K miles on it and had been neglected by one of the previous owners and therefore was severely down on power. Haven't done a leakdown test on it yet but we'll see how off it was.


The 3.0L had over 200K miles as well but had been religiously maintained so the bottom end and cylinder walls were still within factory spec. I ordered a remanufactured cylinder head off of eBay when there was a 15% coupon so it came out to be around $380. I used the updated style head gasket and we installed it in my mom's car with the stock 2.6 ECU and EZL, plus didn't touch any of the adjustments on the CIS as the CIS wasn't the issue on the old motor and I had spent a considerable amount of time getting it to work properly. It runs great, doesn't seem to be too rich or too lean and makes great power, I'm surprised I didn't have to adjust anything to get it to that point since this engine would require more fuel since it is bigger displacement.



This was a reassembly shot. As you can see, we've done a few modifications. That's a Toyota Sienna trans cooler, and oil thermostat for it is mounted on the engine cross member. This is probably overkill but allows the transmission to warm up faster and keeps the heat of the transmission out of the radiator because the cooling system for the engine is overstressed as it is in a 190E 2.6. We replaced the original AC condenser with a parallel flow unit from a W202. It actually makes it so the AC running R134 refrigerant gets nice and freezing cold in the summer here in Georgia. Soon, I'll probably add an aux radiator or oil cooler or both to help increase heat dissipation for Atlanta traffic.

Since we also used the 90K mile auto transmission out of my car and ran new vacuum lines to it, it shifts much better than before. These auto transmissions, when getting proper vacuum, are really very good, especially compared the transmissions Ford used in the Crown Vics.

The power increase is very nice. They should have offered the 3.0L in the 190E from the factory. To give an idea of the performance gain from the worn out 2.6 to the fresh 3.0L, before this swap in similar weather conditions, the 0-60 with one 200lb passenger and probably 100lbs of my mom's junk was 11.03 seconds. After, with two 200lb passengers and the same amount of junk, the 0-60 time was 8.65 seconds. Not fast, but fast for a W201.