About to buy a 1992 300sl, any tips?? - Mercedes-Benz Forum

LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old 08-22-2010, 02:47 AM Thread Starter
BenzWorld Elite
Date registered: Feb 2008
Vehicle: Too many to list
Location: USA
Posts: 5,965
Mentioned: 6 Post(s)
Quoted: 901 Post(s)
(Thread Starter)
About to buy a 1992 300sl, any tips??

Hi Im thinking of buying a clean 100k mile 1992 300sl, what are the problem areas I should look out for?

Are there any problems common to all these cars such as wire harness, ??? Or do these not apply to 1992?

Ive read the 129 buyers guides etc online but most have little coverage of the 300sl and focus on the 500sl

Its being sold at an independent non mercedes used car dealer with no service history.

Beyond having it scanned on Star and getting a PPI, Any tips appreciated.
tusabes is offline  
Sponsored Links
post #2 of 21 (permalink) Old 08-22-2010, 03:04 AM
RedLiner's Avatar
Date registered: Sep 2006
Vehicle: 1998 Pano SL500; 1993 SL500; 2005 ML270cdi
Location: Spain / Gibraltar
Posts: 7,456
Mentioned: 4 Post(s)
Quoted: 415 Post(s)
Lifetime Premium Member
How about completing your user profile, we'll then know if you're in Siberia or in the Sahara desert region, both climates would affect the car in different ways.

Is the car an auto or manual?
How much is the dealer asking?

No trees were harmed creating this message, however some electrons were very inconvenienced.
RedLiner is offline  
post #3 of 21 (permalink) Old 08-22-2010, 04:55 AM Thread Starter
BenzWorld Elite
Date registered: Feb 2008
Vehicle: Too many to list
Location: USA
Posts: 5,965
Mentioned: 6 Post(s)
Quoted: 901 Post(s)
(Thread Starter)
Im in California, automatic, asking price is $7000
tusabes is offline  
post #4 of 21 (permalink) Old 08-22-2010, 05:17 AM
Sith Lord
elbeik's Avatar
Date registered: Sep 2009
Vehicle: 72 280SE 88 560SEC 92 E500 6.0 95 SL320 14 GLK350
Location: Beirut / Jeddah
Posts: 11,779
Mentioned: 3 Post(s)
Quoted: 217 Post(s)
Lifetime Premium Member
The 3.0 straight six engine is rock-solid. It is widespread namely on w124 e-class.
With 100,000 miles, it still has a lot to go.
Watch for the overhead gasket and oil vapors.
elbeik is online now  
post #5 of 21 (permalink) Old 08-22-2010, 06:08 AM
BenzWorld Member
Date registered: Oct 2007
Vehicle: 1992 300sl
Location: Atlanta, Georgia
Posts: 159
Mentioned: 0 Post(s)
Quoted: 2 Post(s)
I have a 92 300sl that now has 107,000 miles. I have had the car just shy of three years. I use it in conjunction with another car and try to drive it less than 1,000 miles per month. Overall the car has been great. I bought it in 2007 with about 75,000 and paid less than $11k. The repairs I have done include:

New hydraulic cylinders in the windshield top at 85,000 miles. The job cost $100 and I did it in about three hours.

Head gasket replacement at 104,000 miles. I knew it was coming for some time as there was a oil leak at the back of the block. Finally I got some oil in the coolant and had it done at a great Indy. Cost about $1,300 and the inside of the engine looked great. Of course the coolant was flushed and replaced. Be sure to determine if this has been done. If not, reduce the price as I understand that it is just a matter of when, not if, the gasket will go. Check with your dealers and Indies as to cost. I found the range here was from $1,200 to $3,000.

I have replaced a few rubber items under the hood as they get very hard and crack. Nothing major just $25 here and $25 there and 20 minutes of time. I have also replaced all the fuses with the copper style.

The hardtop headliner separated from the foam and it took an afternoon to fix that.

I am currently replacing the strut mounts.....an easy job at home.

I am due for brakes and have assembled all my rotors and pads, just waiting on another Saturday to complete the job. It last had pads and rotors at 55,000 miles before I bought the car.

I will also be servicing the trans, replacing the motor mounts, and flex discs. Not major items, but anything rubber based fails after nearly 20 years.

My biggest problem is that it won't go into fifth gear and the cruise control doesn't work. I understand they are related so I am chasing down those gremlins.

I have been meticulous on maintenance and the car asks for very little. Cosmetically the car is very good. Only interrior wear is on the drivers side seat bolster. Other than that the leather looks new. I will have to do a soft top but I will wait on that at least another year. I understand the wiring problems were with 93-95 so shouldn't be a problem.

The 300sl has great and seems to be less expensive to maintain and easier to work on than the other models. Gets very good mileage. I get 27-30 on the road without fifth gear!
jnf300sl is offline  
post #6 of 21 (permalink) Old 08-22-2010, 10:03 PM
BenzWorld Member
1992300SL's Avatar
Date registered: Jan 2008
Vehicle: 1992 300 SL,1999 SL 500
Posts: 294
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Send a message via MSN to 1992300SL
check the hydraulic cylinders and check the head gasket those are major problems with this car. As far as the engine goes I had mine for 3 years and no engine problems and its not bad on gas either. But my softop needs to be redone and i need to fix my hydraulic leaks because they are leaking all over the car and on the floor by the rear wheel.

1992 300 sl (sold)

2005 C240 4MATIC (SILVER moms

1999 SL 500 77K (SILVER) bros
1992300SL is offline  
post #7 of 21 (permalink) Old 08-22-2010, 10:13 PM Thread Starter
BenzWorld Elite
Date registered: Feb 2008
Vehicle: Too many to list
Location: USA
Posts: 5,965
Mentioned: 6 Post(s)
Quoted: 901 Post(s)
(Thread Starter)
Yeah the headgasket and top cylinders seem to be the common issues on this car

where should I look for top cylinder leaks specifically?

inside the trunk, or inside passenger compartment by the wheelwell?

I read i should also look somewhere on the windshield header panel, but where exactly?

Any way to check for a bad headgasket besides the "exhaust in coolant" test?
tusabes is offline  
post #8 of 21 (permalink) Old 08-23-2010, 07:10 AM
BenzWorld Member
Date registered: Oct 2007
Vehicle: 1992 300sl
Location: Atlanta, Georgia
Posts: 159
Mentioned: 0 Post(s)
Quoted: 2 Post(s)
For the cylinders, you really won't know until they show the leak. The windshield header is easy, you will get a drip of oil from the little trim piece where the sunvisor meets the header. When the cylinder seal finally goes it may be a gush.....I have been there and seen it as I was putting up the top one day and got a few ounces of oil on me! For the others look underneath the car just ahead of the rear wheels. Also check the condition of the oil in the storage cylinder just under and in front of the spare tire (has to be removed, but is easy to get to). If it is dark in color you should suction as much as possible out and replace with fresh MB fluid. If the storage cylinder is low it is a good bet that you have a leak somewhere. I found that these can leak and still operate the top just fine. Others have also pointed out that if the top is not properly operating it could be due to low oil level from leaks.

For the headgasket look along the passenger side of the engine from front to back just under the exhaust manifold for oil seepage. Also check the oil to see if it is milky and check the coolant to see if any oil is making its way into the coolant. If the gasket is going you will more likely see the oil seepage/leak first. It might be easiest to see this from underneath the car. I had enough of a seepage that it was dripping onto the belly pan. That kept it from dripping on the driveway or I might have seen it sooner.

Also check the strut mounts, motor mounts, and flexdiscs on the drive shaft. These will all go at some point as they are rubber based. If they are looking bad now, it would be good to use that to lower the price. If the previous owner has replaced them, you will dodge some maintenance. None of them are major expenses especially if you can do some of the work yourself.

Check the brakes. How much pad is left and is there a ridge that you can feel with your finger on outer edge of the rotor. Also check the brake fluid. If it is dark, it means it hasn't been changed for awhile and may be indicative of some missed maintenance.
jnf300sl is offline  
post #9 of 21 (permalink) Old 08-23-2010, 07:06 PM
BenzWorld Member
phendriks's Avatar
Date registered: Oct 2008
Vehicle: 1991 300sl, 1993 928 GTS, 1996 SL500
Location: dorchester, ontario
Posts: 122
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
To add to the previous post. The leaks in my top cylinders didn't appear until after the paper towels wedged under the cylinders inside the headliner became sodden, and couldn't conceal the leak. This didn't happen for the first half dozen cycles, but we had problems latching the hardtop for the drive home - then the dripping started. The small coolant leak was caught by the paper towel wedged along the engine block. Miscellaneous oil leaks are trapped by the factory installed sponge in the skid plate. One flex disc failed on the drive home, my strut mounts need replacing, haven't checked the motor mounts yet.

I think it's almost safe to assume that if you've no proof of the cylinders being refurbished/replaced, assume they'll need to be done and negotiate the price accordingly.

Oh well, it's still a fun car.
phendriks is offline  
post #10 of 21 (permalink) Old 11-01-2010, 04:43 PM
BenzWorld Veteran
iresfrank's Avatar
Date registered: Mar 2010
Vehicle: "NEW OWNER" of a 1991 SL 500 weekend toy. Hope I don't go broke maintaining it!
Location: South Charlotte, NC
Posts: 600
Mentioned: 2 Post(s)
Quoted: 0 Post(s)
Too much fun to pass up. If you are using it for your primary car - you may have expenses as others have stated. As a secondary "Fun Car" - its the best one to have for such in my opinion. As long as you know expenses can be $700-$1,000 here and there (at mechanic) if you are not handy.

Confident enough to be dangerous
iresfrank is offline  
Sponsored Links

  Mercedes-Benz Forum > Mercedes-Benz Roadster Forums > R129 SL-Class

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Topic Author Forum Replies Last Post
Newbie 1992 300SL Owner needs help. call4curt R129 SL-Class 8 07-20-2011 08:06 PM
1992 300sl headlight question mmborder R129 SL-Class 2 03-31-2010 08:12 AM
1992 300SL - Advice ianteo R129 SL-Class 7 02-02-2009 08:47 AM
1992 300sl - overdrive problem golffool R129 SL-Class 4 06-24-2005 12:16 PM
1991 300SL or 1992 500SL carlosamg R129 SL-Class 13 06-15-2005 06:50 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Title goes here

video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome