[CapBels]

I have almost a year with my 97' S320 now. I really love that car, but it had (and still have) so many problems, and im really thinking it is better for me to sell it even if i don't want to. The major problem is the gas consumption (8-10 Mpg, maybe 12 if i got lucky). Replaced the engine because the old one lifted the head and blew up, and sitll bad mpg. Replaced coils and wires, evap purge valve, spark plugs, and still really bad mpg. SDS only shows a code for the Fuel Level Sensor and the camshaft sensor, wich was recently replaced. The car had its conductor plate replaced and it is going into limp mode sometimes (Maybe because i installed a used one?). i am wondering, is there any "mods" for turning this car into a better daily driver? I love my car, even if its slow or problematic sometimes, so i want to make it a better dayli so i won't need to sell it. Maybe LPG? some people have told me these engines doesn't like lpg. Any ideas on what can i do?

 

[MAVA]

These cars suck in the city. I'm a 95%-98% open highway W140 driver. I'm going from one end of the state to the other kind of thing.6hrs here 2hrs here, or 4 hours here one way These cars really are bad in the city.I have 50PSI tires inflated to 40 to 45psi that is how I do it. I get 25/26 mpg with 1000lbs of load on my 5liter S500 on the highway...

Get your self a W210 E320 with at M112 50PSI tires. Inflate them to 40 or so PSI for around town driving...

Martin

 

[speedn_j]

Is it just the gas mileage that makes them suck in the city or are there other things. I’m looking at a s320 this weekend to replace my w124. More or less to be used as a work commuter. I been wanting something bigger people drive insane nowadays

 

[Elefant]

I have almost a year with my 97' S320 now. I really love that car, but it had (and still have) so many problems, and im really thinking it is better for me to sell it even if i don't want to. The major problem is the gas consumption (8-10 Mpg, maybe 12 if i got lucky). Replaced the engine because the old one lifted the head and blew up, and sitll bad mpg. Replaced coils and wires, evap purge valve, spark plugs, and still really bad mpg. SDS only shows a code for the Fuel Level Sensor and the camshaft sensor, wich was recently replaced. The car had its conductor plate replaced and it is going into limp mode sometimes (Maybe because i installed a used one?). i am wondering, is there any "mods" for turning this car into a better daily driver? I love my car, even if its slow or problematic sometimes, so i want to make it a better dayli so i won't need to sell it. Maybe LPG? some people have told me these engines doesn't like lpg. Any ideas on what can i do?

Hi There!!

Cannot really tell you if you should sell or keep your S320. This is really a matter of how deep in love you are . I can tell you my experience with my 99 S320:

First, 8 to 10 MPG sounds way out of spec even for city driving. I get around 17 city 22 highway. Something is off with yours.

I bought the car two years ago with 136K miles, used it as my daily driver on my 80 mile commute, no problem. I also took it on a bunch of road trips, desert and snow. Now it has 195k and still running strong.

I did do a lot of work on the car, good part is I did it myself so saved a bunch of money on labor. The first thing I had to do on it was rear shocks / swaybar links (broken). Front suspension is almost completely new too minus the lower control arms (I am afraid of the coil springs). In total over the past two years, I paid around 4K in parts, and 0 in labor. Now that the car is somewhat sorted, I follow FSS and keep my tires inflated at 32 front and 35 rear. Love the ride and won't sell in the short term, that's for sure.

My list of things that I had to do included:

Front suspension: sway-bar links, sway-bar bushings, lower balljoints, upper control arms, shocks, drag link, tie rods, steering shock absorber.
Brakes: new brakes and rotors all round + fluid flush.
Transmission: Fluid + filter + conductor plate + pilot bushing.
Differential fluid flush.
Valve cover gasket.
Water pump / thermostat (@180K).
Drivebelt system: Fan bearing bracket / idler pully / tensioner + pully.
Alternator voltage regulator(changed for peace of mind, it will get you stranded and it only costs 20 dollars, really easy to do).
PS pump reseal (cost me 20 dollars in parts and took me a couple of hours to complete. Also flushed and refilled with genuine Mercedes fluid).

I also changed the driver side window regulator, passenger side lock actuator rod, both broke around the same time at 170 K.

The car had random vacuum leaks which I was able to fix through trial and error. Make sure you have no vacuum leaks around the intake and attached sensors.

For what it is, I really don't think the car needs to be modded to be a daily driver, I enjoy it for what it is but I am an old hag . The car keeps up with traffic very well and is very easy to drive and maneuver around town.

To sum up: if the car is sorted and you like it, it really is a very good daily.

Please feel free to PM for questions...

Take care!!

Hamzah

 

[Elefant]

I been wanting something bigger people drive insane nowadays

Lol, got my 140 for the exact same reason, only to find out that the sheer mass attracts cars around you, and in some cases (e.g. Smart and Honda Fit), some cars will enter your orbit for a few miles on the freeway until you're able to shed them on a rig. 🤩

Stay safe!

Hamzah

 

[Mercedesist]

I have almost a year with my 97' S320 now. I really love that car, but it had (and still have) so many problems, and im really thinking it is better for me to sell it even if i don't want to. The major problem is the gas consumption (8-10 Mpg, maybe 12 if i got lucky). Replaced the engine because the old one lifted the head and blew up, and sitll bad mpg. Replaced coils and wires, evap purge valve, spark plugs, and still really bad mpg. SDS only shows a code for the Fuel Level Sensor and the camshaft sensor, wich was recently replaced. The car had its conductor plate replaced and it is going into limp mode sometimes (Maybe because i installed a used one?). i am wondering, is there any "mods" for turning this car into a better daily driver? I love my car, even if its slow or problematic sometimes, so i want to make it a better dayli so i won't need to sell it. Maybe LPG? some people have told me these engines doesn't like lpg. Any ideas on what can i do?

I have a 1991 W140 300SE. It's the "pre S320". It has distributor ignition, but otherwise the same head and block etc. I think the distributor ignition could cause worse mileage and the fact, that I have low compression. Anyways - I get bad mileage too... For example I filled up till 1/4 tank, drove 65 kilometers and the gauge is just above the "yellow light" indicator. So... knowing that it has 100 litre tank, 1/4 is 25 litres. I assume I "lost" about 10 litres in 65 km trip. So it is 15 Liters per 100 km or 15.68 U.S. MPG... But I should mention, that I have 722.3 trans (4 speed) and pretty "short" differential (3.45)...

 

[CapBels]

These cars suck in the city. I'm a 95%-98% open highway W140 driver. I'm going from one end of the state to the other kind of thing.6hrs here 2hrs here, or 4 hours here one way These cars really are bad in the city.I have 50PSI tires inflated to 40 to 45psi that is how I do it. I get 25/26 mpg with 1000lbs of load on my 5liter S500 on the highway...

Get your self a W210 E320 with at M112 50PSI tires. Inflate them to 40 or so PSI for around town driving...

Martin

The thing is, i want to see if it is factible for me to sort the thingas that are still bad (Installed new, oem conductor plate today btw), or if i should sell it and buy another thing. I like the m112, but i dont like the w210, or the w220. I "Have" a w220 (It's my dad's car, but i work on it too) but i really don't like the driving experience, it feels cheap compared to my w140

 

[CapBels]

Hi There!!

Cannot really tell you if you should sell or keep your S320. This is really a matter of how deep in love you are . I can tell you my experience with my 99 S320:

First, 8 to 10 MPG sounds way out of spec even for city driving. I get around 17 city 22 highway. Something is off with yours.

I bought the car two years ago with 136K miles, used it as my daily driver on my 80 mile commute, no problem. I also took it on a bunch of road trips, desert and snow. Now it has 195k and still running strong.

I did do a lot of work on the car, good part is I did it myself so saved a bunch of money on labor. The first thing I had to do on it was rear shocks / swaybar links (broken). Front suspension is almost completely new too minus the lower control arms (I am afraid of the coil springs). In total over the past two years, I paid around 4K in parts, and 0 in labor. Now that the car is somewhat sorted, I follow FSS and keep my tires inflated at 32 front and 35 rear. Love the ride and won't sell in the short term, that's for sure.

My list of things that I had to do included:

Front suspension: sway-bar links, sway-bar bushings, lower balljoints, upper control arms, shocks, drag link, tie rods, steering shock absorber.
Brakes: new brakes and rotors all round + fluid flush.
Transmission: Fluid + filter + conductor plate + pilot bushing.
Differential fluid flush.
Valve cover gasket.
Water pump / thermostat (@180K).
Drivebelt system: Fan bearing bracket / idler pully / tensioner + pully.
Alternator voltage regulator(changed for peace of mind, it will get you stranded and it only costs 20 dollars, really easy to do).
PS pump reseal (cost me 20 dollars in parts and took me a couple of hours to complete. Also flushed and refilled with genuine Mercedes fluid).

I also changed the driver side window regulator, passenger side lock actuator rod, both broke around the same time at 170 K.

The car had random vacuum leaks which I was able to fix through trial and error. Make sure you have no vacuum leaks around the intake and attached sensors.

For what it is, I really don't think the car needs to be modded to be a daily driver, I enjoy it for what it is but I am an old hag . The car keeps up with traffic very well and is very easy to drive and maneuver around town.

To sum up: if the car is sorted and you like it, it really is a very good daily.

Please feel free to PM for questions...

Take care!!

Hamzah

Yo gave me an idea. i will check for vacuum leaks on the engine. Thanks

 

[Mlthoma]

I have had 2 w140s, a s420 (current) and a s500 (RIP). I have put about 140k miles on w140s between the two of them and I've kept track of every gallon of gas through them. Average has been just a shade under 20MPG. Engine size made only a tiny difference in economy, easily offset by needing new plugs or a small vacuum leak. I live at 5000 ft. elevation as well. Your S320 should be doing better. Hamzuh, your replacement parts all look familiar, but I will tell you that I lost the fuel pumps in both of my cars right at 185k miles. If you haven't done yours you might want to have one ready to go.

Mike in ABQ

 

[Seppo]

I recall that our ´95 S320 went on average 10 l / 100 km on highway on road trips. The car actually stood for a year (engine wire harness issue) and now after repairs, it became my daily driver just last week. I will be interested to monitor the consumption during the winter and towards summer (used to be my wife's daily driver, she did not keep track...).

First tank filling indicated 12 l / 100 km (winter conditions -18°C - -25°C, both city/highway driving).

 

[CapBels]

The car is running better with the new conductor plate, but mpg is still too Bad. Checked vacuum leaks and found none. Spark plugs looks a little dark but not too dark. New error code on sds, it says camshaft sensor and actuator, replaced both (second camshaft sensor on this engine) and still getting camshaft sensor error code. Does that sensor affect the mpg so much?

 

[MAVA]

@CapBels

What I would. Watch all your temperature sensors before you start making sure they are close to the cluster reading. Nothing should be a high or low? Watch the sensors rise as the engine is rising to temperature. None of the ones in the engine/heater core should stay flat at ambient. After driving around, the engine/heater those readings should be high. Use your climate control to see the running numbers. Use the following to see how it is done:

Need help Decoding Climate Control Data

Gentlemen, I need help interpreting the data from my climate control module on my 1998 S500, and the reason I need help. I have no heat coming out of the vents. I just get cold air. The fan works fine, and the AC works fine too, but no heat of any kind. I acquired the car with no heat working...

www.benzworld.org

This engine sensor. You should be able to see the timing reading on "live data" OBDII when the engine is warming up, warmed up, in traffic, and one open road.

JimF talks about this on W140 site and it applies to all engines about timing percents on how it affects power and economy

K6JRF Auto Page

My Mercedes S500 Coupe

www.k6jrf.com

Lastly, that CAM solenoid should activated(on) when you punch it or over 3k or so, but I would disconnect it for a while, and see what kind of economy you get...

Martin

 

[hamada128]

8-10 mpg is too low. The attached screenshot is the typical MPG on my 99 S320 with mainly local drives.

 

[CapBels]

@CapBels

What I would. Watch all your temperature sensors before you start making sure they are close to the cluster reading. Nothing should be a high or low? Watch the sensors rise as the engine is rising to temperature. None of the ones in the engine/heater core should stay flat at ambient. After driving around, the engine/heater those readings should be high. Use your climate control to see the running numbers. Use the following to see how it is done:

Need help Decoding Climate Control Data

Gentlemen, I need help interpreting the data from my climate control module on my 1998 S500, and the reason I need help. I have no heat coming out of the vents. I just get cold air. The fan works fine, and the AC works fine too, but no heat of any kind. I acquired the car with no heat working...

www.benzworld.org

This engine sensor. You should be able to see the timing reading on "live data" OBDII when the engine is warming up, warmed up, in traffic, and one open road.

JimF talks about this on W140 site and it applies to all engines about timing percents on how it affects power and economy

K6JRF Auto Page

My Mercedes S500 Coupe

www.k6jrf.com

Lastly, that CAM solenoid should activated(on) when you punch it or over 3k or so, but I would disconnect it for a while, and see what kind of economy you get...

Martin

I will test that and see what happens. Thanks

 

[CapBels]

8-10 mpg is too low. The attached screenshot is the typical MPG on my 99 S320 with mainly local drives. View attachment 2677304

I would be happy with that mpg readings. What app is that?

 

[CapBels]

@CapBels

What I would. Watch all your temperature sensors before you start making sure they are close to the cluster reading. Nothing should be a high or low? Watch the sensors rise as the engine is rising to temperature. None of the ones in the engine/heater core should stay flat at ambient. After driving around, the engine/heater those readings should be high. Use your climate control to see the running numbers. Use the following to see how it is done:

Need help Decoding Climate Control Data

Gentlemen, I need help interpreting the data from my climate control module on my 1998 S500, and the reason I need help. I have no heat coming out of the vents. I just get cold air. The fan works fine, and the AC works fine too, but no heat of any kind. I acquired the car with no heat working...

www.benzworld.org

This engine sensor. You should be able to see the timing reading on "live data" OBDII when the engine is warming up, warmed up, in traffic, and one open road.

JimF talks about this on W140 site and it applies to all engines about timing percents on how it affects power and economy

K6JRF Auto Page

My Mercedes S500 Coupe

www.k6jrf.com

Lastly, that CAM solenoid should activated(on) when you punch it or over 3k or so, but I would disconnect it for a while, and see what kind of economy you get...

Martin

Checked the temperature sensor trough the ac controls, gauge cluster and obd2 scanner and they seem the same

 

[hamada128]

I would be happy with that mpg readings. What app is that?

It is called Fuel Log, but I think it is no longer available on Google or App store.

 

[act1292]

Just curious how you checked for vacuum leaks. I had a '96 S320 until last year and when I got it I found many of the small hard plastic vacuum lines in the engine compartment very brittle and would break if moved even slightly. The worst ones were the ones that run under the plastic cover on the head. I ordered a roll of replacement line from some internet site (I had to research size and materials as this stuff needs to hold up to both heat and gas/oil) and replaced it all. Some of the rubber fittings also need to be replaced. If yours are original I'm sure they need replacing.

You just need to go through all of this if you have both the time an patience. You can get it sorted out. The numbers quoted by Elefant seem along the same line I would get. I had mixed city/highway driving on my car and I would get around 18 in the winter and around 21 in the summer.

 

[CapBels]

Just curious how you checked for vacuum leaks. I had a '96 S320 until last year and when I got it I found many of the small hard plastic vacuum lines in the engine compartment very brittle and would break if moved even slightly. The worst ones were the ones that run under the plastic cover on the head. I ordered a roll of replacement line from some internet site (I had to research size and materials as this stuff needs to hold up to both heat and gas/oil) and replaced it all. Some of the rubber fittings also need to be replaced. If yours are original I'm sure they need replacing.

You just need to go through all of this if you have both the time an patience. You can get it sorted out. The numbers quoted by Elefant seem along the same line I would get. I had mixed city/highway driving on my car and I would get around 18 in the winter and around 21 in the summer.

I only have 4 vacuum lines on my engine. One for the fuel regulator, one for the map sensor, the grey one in the back for the ac controls i think, and a big one for the brakes and fuel gas recirculation. All 4 are sealed and not leaking air (Tested with soapy water first, then sprayed a little bit of carb cleanner to see if the engine shakes, and then disconnected one by one to check if someting changes), maybe i could have left someting not checked correctly, will se tomorrow again.