[jonatangan]

First off I'd like to sat that I'm newbie... so be gentle.
Well, I was forced to sell my old car due to a number of mechanical problems and my parents passed down to me their 1988 300 SEL. Its a great car and only has about 92K on it. Looks new and even smells like new.
The car was not driven very often and would sometimes sit garaged for months at a time.
The only problem I have now is that it seems not to have any kind of power and it sucks gas like a friggin camel. Is this normal? My previous car was a 300zx and it was also a 6 cyl but WOW does this car have a thirst for gas!!!
When the engine is cold and I drive it around I get this weird problem: When I give it some gas it seems to just sit there then about a couple of seconds it would KICK in. It's kind of scary when getting on the freeway and I forget and I try to over take the guy next to me then i just sit there. The car is fine when I warm it up for a while but I dont believe this is normal.
Is the 300 SEL just slow and gas hungry because its such a TANK, or do i have some problems. I was going to get a tune-up, but my parents said they had just got it done a few months ago. I tried to search for possible answers in this forum but I had difficulty searching for the right terminology.

THANKS ahead of time

 

[mansito]

Check the DIYs at the top of this group. I would start by doing a complete tune-up, that is, replace spark plugs, cap, rotor, air filter, & spark plugs wires. Maybe your fuel mixture is rich. Take it to a good local indie shop to adjust the fuel mixture. You should get about 20 miles/gallon.

Keep asking questions. This is a great forum

 

[mansito]

Forgot, you should also change the O2 sensor.

 

[p100]

What kind of fuel are you using in this car? Try BP 93 octane. Also, get some Chevron Techron, and put several bottles through the tank mixed with 12 gallons of fuel and run the tank almost empty each time.

 

[jonatangan]

"Several Bottles"??? Meaning 2-3 bottles for every 12 gallons? I used that stuff for my other car but only used 1 bottle for every full tank like it said on the directions.

 

[S_Class_Don]

i dont know about several bottles i would be hesitant to in put 2..I remember jono talking about it does damage in the long run...but i second everything mansito said above.

 

[jhodg5ck]

It would also be helpful if you filled out your profile, told us where you are etc..

How about bringing it back to whom ever did the work the last go around..that is if they specialize in Mercedes...otherwise I would look for someone new.

How long has it been driving like this? What is your actual mileage?

While you are out next time I would take a look under the car @ your cats, see if they are glowing red.

Jonathan

 

[Michael Pillay]

On my 1990 300SEL, if you floor it the car takes of like a rocket. I have never had a problem entering the expressway or anything like that. It can cruise easily at 100mph. I get between 16 to 18 mpg in mixed driving. I keep a log of my gas mileage. I cant remember a time I got less than 16mpg.

 

[BARW126420SEL]

First off I'd like to sat that I'm newbie... so be gentle.
Well, I was forced to sell my old car due to a number of mechanical problems and my parents passed down to me their 1988 300 SEL. Its a great car and only has about 92K on it. Looks new and even smells like new.
The car was not driven very often and would sometimes sit garaged for months at a time.
The only problem I have now is that it seems not to have any kind of power and it sucks gas like a friggin camel. Is this normal? My previous car was a 300zx and it was also a 6 cyl but WOW does this car have a thirst for gas!!!
When the engine is cold and I drive it around I get this weird problem: When I give it some gas it seems to just sit there then about a couple of seconds it would KICK in. It's kind of scary when getting on the freeway and I forget and I try to over take the guy next to me then i just sit there. The car is fine when I warm it up for a while but I dont believe this is normal.
Is the 300 SEL just slow and gas hungry because its such a TANK, or do i have some problems. I was going to get a tune-up, but my parents said they had just got it done a few months ago. I tried to search for possible answers in this forum but I had difficulty searching for the right terminology.

THANKS ahead of time

Welcome. Are you ready for this? The 300SEL does not actually accelerate. It just gains momentum.

Actually it should accelerate very well. This car starts in 2nd gear, though. This means that unless you kickdown the transmission, little button just past full throttle, or shift manually into 2nd, it will not use 1st gear. This car should rev very quickly because of its very aggressive gear ratios. 1st 32, 2nd 60, 3rd 90, and 130MPH top if my mind serves me right. It should be eager to rev at full throttle and have no problem with reaching the 6200RPM redline.

Your fuel economy should be between 17 and 23 with a highquality gasoline of 91 or higher octane. I would bet this car may need some minor routine maintenance to get it zipping around again. Don't forget about fuel filter, fuel injectors, etc.

Best of luck.

 

[p100]

"Several Bottles"??? Meaning 2-3 bottles for every 12 gallons? I used that stuff for my other car but only used 1 bottle for every full tank like it said on the directions.

No. One bottle per 12 gallons, just like the directions say. What I meant was running two bottles consecutively with 12 gallons each of gasoline. This is the smaller bottle that Auto Zone sells for about $ 6.50. For better effect, you can mix it with 8 gallons of gas. So for 16 gallons, use two bottles.

 

[jonatangan]

No. One bottle per 12 gallons, just like the directions say. What I meant was running two bottles consecutively with 12 gallons each of gasoline. This is the smaller bottle that Auto Zone sells for about $ 6.50. For better effect, you can mix it with 8 gallons of gas. So for 16 gallons, use two bottles.

OIC... Thanks.. I'll try this tomorrow and see if there will be a difference

 

[a3jeroen]

Welcome. Are you ready for this? The 300SEL does not actually accelerate. It just gains momentum.


Best of luck.

This is what we used to say about 55 hp 200 D taxicabs

gr J

 

[hoodsir]

First off I'd like to sat that I'm newbie... so be gentle.
Well, I was forced to sell my old car due to a number of mechanical problems and my parents passed down to me their 1988 300 SEL. Its a great car and only has about 92K on it. Looks new and even smells like new.
The car was not driven very often and would sometimes sit garaged for months at a time.
The only problem I have now is that it seems not to have any kind of power and it sucks gas like a friggin camel. Is this normal? My previous car was a 300zx and it was also a 6 cyl but WOW does this car have a thirst for gas!!!
When the engine is cold and I drive it around I get this weird problem: When I give it some gas it seems to just sit there then about a couple of seconds it would KICK in. It's kind of scary when getting on the freeway and I forget and I try to over take the guy next to me then i just sit there. The car is fine when I warm it up for a while but I dont believe this is normal.
Is the 300 SEL just slow and gas hungry because its such a TANK, or do i have some problems. I was going to get a tune-up, but my parents said they had just got it done a few months ago. I tried to search for possible answers in this forum but I had difficulty searching for the right terminology.

THANKS ahead of time

I was about to post a thread on this exact topic, But luckily I found a topic on it already. Too bad this guy doesn't post here anymore, I would love to know if he found a solution/diagnosis to the situation.

Loud rev and takes a little while to gather itself, I don't know if it's choking or what but it doesn't seem right. I automatically thought it was the result of the car being so huge and only containing a V6, but seems like it's something different.

Could the problem be the 2nd gear start? Like say if you started in 5th gear it would start off really slow compared to a 1st gear start (video game logic, lol).

Not a huge problem, Once it gets in the groove hitting 65-70 is nothing.

Anyone else with this problem?

 

[a3jeroen]

Well for starters you have an Inline 6 instead of a V6!
These engines like to Rev. Does your car start in first if you push the kickdownswitch? Maybe adjusting the bowdencable between your tranny and the throttlelinkage will change the shiftingpoints. It worked for me.

gr J

 

[hoodsir]

Well for starters you have an Inline 6 instead of a V6!
These engines like to Rev. Does your car start in first if you push the kickdownswitch? Maybe adjusting the bowdencable between your tranny and the throttlelinkage will change the shiftingpoints. It worked for me.

gr J

Hmm, Once I get some light out, I'm gonna take a crack at these suggestions -- may need a bit of help though.

After some searching, It's said the kickdownswitch should be right behind the gaspedal, So that shouldn't be a problem to find. Bowdencable, different story.

Where is that located, Any safety tips I need to know before hand?

I appreciate all your help a3jeroen (gr J?), I can't help but finding myself getting closer to this car the more I learn about all the bells & whistles with the inner workings .

 

[Teutone]

How about starting out with a search of 'bowden cable?'
Cheers

 

[hoodsir]

How about starting out with a search of 'bowden cable?'
Cheers

AHh, I'll honestly say I forgot the search function for this , Cheers Indeed, Teutone.

 

[a3jeroen]

(gr J?)

=greetings Jeroen (I'm too lazy)

searching on bowdencable might give a good insight.

I know there are pix on the W123forum. IIRC by member nutz4benz.

gr J

 

[cascade]

Your live in Carson.

Take your car to Enrique, at MR MB, in Tarzana.

He is probably the best Mercedes mechanic for your car, in the entire state of California.

Tell him Jim, the guy who came to there from Sacramento area in November for the work on his black 560SEC sent you.

He will take care of the problem, and charge ONLY for what needs to be done (his VERY successful business philosophy) and the hourly rate is reasonable.

 

[flavio81]

I was about to post a thread on this exact topic, But luckily I found a topic on it already. Too bad this guy doesn't post here anymore, I would love to know if he found a solution/diagnosis to the situation.

Loud rev and takes a little while to gather itself, I don't know if it's choking or what but it doesn't seem right. I automatically thought it was the result of the car being so huge and only containing a V6, but seems like it's something different.

Could the problem be the 2nd gear start? Like say if you started in 5th gear it would start off really slow compared to a 1st gear start (video game logic, lol).

Not a huge problem, Once it gets in the groove hitting 65-70 is nothing.

Anyone else with this problem?

Maybe you should first locate someone with a good working 300SEL so you can feel how fast the car should be.

The bowden cable is a good #1 suggestion. I would also just check if the air filter is dirty, as a simple check.

Then, if you got no improvement, measure compression in all 6 cylinders and compare to specs.

If compression is ok, you'll have to check the fuel injection system (mixture, etc), assuming that ignition is OK.

etc etc.