New member needs tips on Thermostat replacement

[n/a]

I recently purchased a 67 250 SL with add-on A/C.  I have reason to believe I need to install a new thermostat and have been told by a local Dallas shop that this is quite an ordeal on the air conditioned cars. They want $250 labor Minimum to do the job, so I am thinking that I need to consider doing this myself.

Can anyone direct me to posted instructions for this procedure.

Please respond to my direct email address: bc1@joimail.com

Thanks in advance,
Brian

Brian

[n/a]

Wow, not a single reply to this?  Has no one ever replaced a thermostat on an air conditioned 113?

Thanks,
Brian     bc1@joimail.com

Brian

[Tom]

Brian,

I am confused on the labor charge.  The thermostat is in an alloy housing that is fairly easy to access on an air-conditioned w113.  The alternator is elevated on an air-conditioned model, with the A/C compressor below and it is true that this configuration causes extra labor in a number of jobs on the car-but not the thermostat.  Water pump replacement is an example.  I have not personally replaced my thermostat, but I have replaced the housing and do not recall it to be difficult. Perhaps I am mistaken and others have thoughts.

Also, everyone may benefit from the postings that appear publicly on the site so if you have received an answer you may want to post what others have shared.  One reason some of our mechanically oriented members have not posted may be that they are assuming someone privately emailed a response.

Best,
 
Tom

[n/a]

Tom, I appreciate your reply,  yours is the only one thus far.  Guess I need to go pop the hood and do a visual, The $250 labor quote was supposedly the "good buddy" quote from a friend of mine who owns a shop and said,........"OH, you don't want to try that yourself,  you would think it would be easy, but you wouldn't believe how complicated it is on the A/C equipped car"

When I posted the query 2 days ago,  I had just comitted to buying the car, and it was not yet here for me to look at.

It overheats without the radiator ever getting at all warm,  obviously a circulation issue,  figured the Thermo is bad.

I just got the car dropped here by a wrecker last night, so I will have a look at it at some point today.

Brian

Brian

[J. Huber]

Hey Brian.

I hesitated to respond because I don't have A/C on mine. However, I do not think replacing the thermostat is too difficult (at least on a non AC). Sorry, no particulars as my mechanic did mine years back along with other stuff -- so it was blended in. But labor was not 250, I can tell you that.

PS My workshop manual makes it sound very straightforward.

James
63 230SL

[Tom]

Brian, et al,

I must be missing something.  Took a quick peek under the hood to verify the brackets that hold the alternator on to see if it would interfere with the thermostat replacement.  I also looked on the parts diagram to make sure I had the thermostat placement correct.  The thermostat housing is easily accessible even with an A/C equipped car with the alternator up top.  I can't imagine an easier job other than replacing a spark plug.

Mercedes does a pretty good job on their vintage cars of making simple maintenance simple.  $250 to replace a thermostat seems  not just high but outrageous.

Best,

Tom

[n/a]

Brian,
I have relaced the thermostat on my 1970 280Sl w/ A/C and it was easy.
I don't know if the 230 is the same.
The thermostat housing is held on with a couple of bolts. Once the housing is off the thermostat lifts out and the new one put in it's place. It was one of the easiest things that I have ever done on the car. If I recall correctly, the thermostat comes with a rubber seal ring the seals the housing cover that you remove.
It was very simple.

Regards,
Stan

[n/a]

quote:Originally posted by houstonbuckeye

Brian,
I have relaced the thermostat on my 1970 280Sl w/ A/C and it was easy.
I don't know if the 250 is the same.
The thermostat housing is held on with a couple of bolts. Once the housing is off the thermostat lifts out and the new one put in it's place. It was one of the easiest things that I have ever done on the car. If I recall correctly, the thermostat comes with a rubber seal ring the seals the housing cover that you remove.
It was very simple.

Regards,
Stan

Regards,
Stan

[dldubois]

Brian:

If you ever do need a mechanic, I'd recommend Arthur's Mercedes in Carrollton.  He knows these cars.

Dana

1970 280sl Ivory/4 speed

[n/a]

Heres an update.  

2 of the 4 bolts are coverered with a metal coolant line, which I removed and got 2 off,....the two on the valve cover side are blocked/covered by all the metal fuel injection lines,  I suspect I will need to remove all the fuel line at the injectors and the pump in order to get the thermo off.

Brian

Brian

[rwmastel]

Brian,

Hi.  I don't have A/C, but I have replaced my thermostat and all the hoses around it.  The bolts under the fuel lines are tough, but you can get to them.  One of mine was slotted to accept a flat head screw driver which made it easier.  Check for that.

If necessary, I guess you could remove the fuel line at the injector to give it more play, but I've never done that and don't know the procedure or risks involved.

For a first timer novice, getting the whole housing off and changing the hoses is difficult.  The thermostat itself should not be much work except for those obstructed access bolt heads.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[J. Huber]

Hi. I just went out to see my access to the bolts. The fuel lines sure do make access to the inside two a challenge. But it look like the whole housing unit bolts onto the engine. I wonder if it would be easier to pull whole housing unit off then get two those bolts? Just wondering?

James
63 230SL

[rwmastel]

I don't recommend removing the housing from the head.  It is very difficult to remove the housing.  It helps to cut the small bypass hose at the bottom of the housing to remove it.  To reinstall the housing the new bypass hose needs to be just the exact length and it's still very difficult.  I didn't try heating the hose to make it more flexible.  Would that work?

Perhaps you could loosen the housing and just move it enough to help with bolt access.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420