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93 300E 2.8, 79 450 SLC
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539 Posts
Discussion Starter · #1 · (Edited)
OK. After 2 months reading this forum and craigslist, I finally bought a beautiful 79 450 SLC. :D Silver. black interior. 199k miles. (photos coming soon) I drove 600 miles in southern California and took it back home yesterday. The car passed 600 miles test under 100F outside temperature. No over heat all all. In fact, it runs cooler than my 93 300e. Temperature gauge is constantly at slight over 80 mark.

I do have some newbie questions on the SLC and hope you 107 experts can help me out.

Engine: the 4.5L v8 engine is not as smooth nor as powerful as the V6 engine in my 300e. At cruising speed on highway, the rpm is at 3000 and is significantly louder than the V6 engine. It sounds like the engine is working very hard. Is this normal? May be that's the difference between 70s technology and 90s engine technology?

Transmission: the 3 speed tranny does not shift smoothly. It seems to shift at 3000 rpm or higher. May be I can adjust the vacuum line?

Thanks.
 

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Premium Member
2010 Mercury Milan Hybrid, 1993 BMW 325i convertible
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6,077 Posts
Engine: the 4.5L v8 engine is not as smooth nor as powerful as the V6 engine in my 300e.
Vacuum leaks would be my guess.

At cruising speed on highway, the rpm is at 3000 and is significantly louder than the V6 engine. It sounds like the engine is working very hard. Is this normal?
Normal.

Transmission: the 3 speed tranny does not shift smoothly. It seems to shift at 3000 rpm or higher. May be I can adjust the vacuum line?
This is why I think vacuum leaks. Serious, big time vacuum leaks.
 

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93 300E 2.8, 79 450 SLC
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539 Posts
Discussion Starter · #3 ·
Thanks Scott. I thought the engine is fine because it idles steadily. But I will check the vacuum leak.
 

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93 300E 2.8, 79 450 SLC
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539 Posts
Discussion Starter · #4 · (Edited)
Here's a pic of my car. Newer paint job. original 14" wheel chrome wheel.


IMG_9854.JPG
 

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Administratoris Emeritus
2024 SL770
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Those do not appear to be original rims...
 

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500SLC #2624. Black on Black.
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Engine: the 4.5L v8 engine is not as smooth nor as powerful as the V6 engine in my 300e. At cruising speed on highway, the rpm is at 3000 and is significantly louder than the V6 engine. It sounds like the engine is working very hard. Is this normal? May be that's the difference between 70s technology and 90s engine technology?
Your 300E has a V6?? that is quite a collectors item.
 

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93 300E 2.8, 79 450 SLC
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539 Posts
Discussion Starter · #7 ·
Very helpful. Find anything else wrong?
 

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2001 SLK320, 2001 C320
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2,267 Posts
The transmission is 1960's technology. 3-speed with no overdrive. One of the reasons these cars get lousy fuel economy.

There is an adjustable vacuum modulator. Sometimes, making the adjustment will help smooth out those shifts. (I forget how it works -- someone else will chime in, I'm sure.)

Oh...and get used to the barbs. We tend to fling them wildly around here in the R107 forum...
 

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Outstanding Contributor , Bob's Your Uncle!
83 280 SL- 5 speed-The PIG
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31,364 Posts
Oh...and get used to the barbs. We tend to fling them wildly around here in the R107 forum...
Never any offense intended...you just have to be on your toes with your posting info.
 
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