Author Topic: 70 280SL engine overheating (Read 30893 times)

Michel MB280SL · « **on:** June 28, 2006, 22:55:42 »

This is my first experience with the 280 SL and I'm looking for sound information. I have experienced overheating of the engine since the valves and camshaft were replaced. The temp will remain constant at 180F when the car is moving but will creep up to the red indicator in traffic and 80F weather. My mechanic says this is normal and that these engines are well known for overheating. Reading from the owner's manual, M-B indicates at page 31 that: " During hot weather the temperature may rise to 239F (red spot on gauge) without causing concern". I can hardly accept this comment from M-B and believe that the engine temp should not rise beyond 195-200F in any case.

Can 70-71 280 SL owners provide me with their experience. What is the temp in their cars in stop and go traffic.

Thanks for any help!

n/a · « **Reply #1 on:** June 28, 2006, 23:33:14 »

Hi Michel,
I'm having the same problem with my 70 280SL. Take a look at the responses I've received from my posting. It appears to be an elusive fix at best. May we both find the answers.

Don't give up!

TR · « **Reply #2 on:** June 29, 2006, 09:02:48 »

Strange how many people report this same problem. There is no end of observations & comments about all the basics and how to address them. Yet even after doing all of those typical things the vexing problem of engine overheating seems to persist. Or at least so it seems for late model 280SLs, especially with A/C. Maybe this is the ultimate mystery of the M-B world(?). Perhpas I've missed it, but has anyone ever identified and then clearly articulated/communicated the overlaying & fundamental cause(s) behind this Pagoda shortcoming?

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

peterm · « **Reply #3 on:** June 29, 2006, 09:17:39 »

I have tried all possible solutions- recored radiator, new fan clutch, water wetter, new water pump. I have explored the additional electric fan solution with no satisfactory resolution. My main fix is AC off, one quick burst in traffic sends the needle soaring, and venting the heat into the cabin lovely on a nice hot day

n/a · « **Reply #4 on:** June 29, 2006, 09:47:35 »

I have a 70 280sl but does not have the overheating problem. I have a/c but it is not hooked up. My heater is not connected also. I do not have a thermostat because my mechanic said I do not need it in my region (East Bay). The car has the auxillary fan installed (it is from Hawaii) but I never have to use it. the car can sit idle for a long time and the temperature remained at the middle of the gauge around 180 I believe. I hope this information could be of some use.

Louis 70 280sl Red Auto

harleydan · « **Reply #5 on:** June 29, 2006, 09:56:43 »

Hello,

I have owned my 1970 280SL for over 24 years

and never had an overheating problem until recently

. My mechanic changed the suspect thermostat and bad points, and had the suspect radiation acid cleaned. He said that it is much better; however, the temperature will climb if it idles for about ten minutes but it does not get much over 100 degree Celsius. I will pick the car up today and will see if this is satisfactory with the driving that I do :?: ; especially in light that a lot of effort and money could be spent with little to no significant change.

In addition, it seemed that my car backfired more as of late. Hopefully, some of the recent changes to help fix the overheating problem will take care of this symptom also. Has anyone experienced this?

Yes, indeed overheating seems to be a problem that haunts some of us :twisted: , and hopefully my overheating ghost has been somewhat exorcized

.

Cheers,
Danny
1970 280SL silver Euro manual

TR · « **Reply #6 on:** June 29, 2006, 10:08:06 »

Danny -- Does your '70 280SL also have A/C?

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

harleydan · « **Reply #7 on:** June 29, 2006, 10:13:36 »

Tom,

My car does not have air conditioning.

Cheers,
Danny in Denver

J. Huber · « **Reply #8 on:** June 29, 2006, 10:38:49 »

This seems to be the time of year when "overheating" becomes an issue. In the winter people notice their heaters don't work -- or worse yet -- their tops leak...

In 20 years, overheating has rarely been an issue for me. I say rarely, because 95 percent of the time, my needle will not budge. Of course, our version of traffic here is a family of deer crossing the road.... However, one time my car did overheat -- and it was an eye-opener. I've related the story before but here is a synopsis: One warm sunday evening in 1991, while heading home to Santa Barbara from San Diego, needle started to rise. I noticed it, and pulled off the freeway and let it cool down, also added water. This was a Sunday mind you -- no shops, etc open. Also pre-cell phone. Anyway, back on the road -- still running hot. Kept stopping at gas stations, then about Ventura decided I had to go for it. Well, needle rose and rose and then even disappeared! 10 miles from home, the car just quit. A complete rebuild of the upper engine was next. Now I watch that needle like a hawk. In fact, it started to move a few years back -- I replaced radiator with a H/E. Has been steady ever since...

Moral of a very long story -- these cars can run normally much of the time -- but if needle moves, Passen Sie Auf! (pay attention!)

James
63 230SL

Kenneth Gear · « **Reply #9 on:** June 29, 2006, 10:45:50 »

Same problem here! 71 280 sl , auto, air conditioning. Tried a new raditor, water wetter etc.. all to no avail. On a 90 degree day, the needle instantly moves up when stopped at a light.. I drive all summer with the heat on and top down.

I finally had enough and shipped the car to SL TECH ... I'll let you know how it turns out when I get it back.

Ken G
1971 280 SL
Silver/red

TR · « **Reply #10 on:** June 29, 2006, 11:46:09 »

Ken -- Great move, IMO, sending your car to Gernold. If I had it all to do over that's exactly what I'd do.

Yours is yet another late model 280SL with A/C, and an overheating issue... Might there be a pattern here?

As some on this board are aware, I've been battling this one for a long time. But I think I'm almost there. For example, on a very hot day last summer (108 degrees) I let the car idle (setting on asphalt, and with the top off) for 1/2 hr. with the A/C running at max. The engine held temp. and the A/C continued to blow cold air. The only remaining issue now is long & steep mountain inclines (going up several thousand feet) on the hottest of days (100+ degrees), climbing under throttle, with the top off, and with the A/C running full blast. We have some final tweaks (at least I hope that's all it'll be) to do to get this to my full satisfaction.

Regarding this particular issue my expectations are high. When it comes to this sort of thing, well, to each his own I suppose. But neither my wife nor I are disposed to giving up on this particular creature comfort.

Best of luck on your project. I suspect you'll be very pleased with the result from SL Tech.

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

rwmastel · « **Reply #11 on:** June 29, 2006, 21:05:14 »

quote:
Originally posted by Michel MB280SL

Reading from the owner's manual, M-B indicates at page 31 that: " During hot weather the temperature may rise to 239F (red spot on gauge) without causing concern".

From this owner's manual quote, and all that you guys are writing, it sounds like a manufacturing issue that M-B knew about and told us about in the owner's manual. If they could not get around an over heating problem then I'm sure it will be tough for us to get around it.

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

J. Huber · « **Reply #12 on:** June 29, 2006, 21:17:35 »

I see your logic Rodd, but I just can't quite buy the "red spot is ok" mentality. I have seen the needle NOT move long enough to feel that when things are working correctly, the car stays at a very consistent temperature. If it moves a bit, I'll concede it's within a "normal range" -- but going up to the red has to be some cause for concern. Thats way up there.

James
63 230SL

TR · « **Reply #13 on:** June 30, 2006, 07:15:45 »

quote:
Originally posted by rwmastel

quote:
Originally posted by Michel MB280SL

Reading from the owner's manual, M-B indicates at page 31 that: " During hot weather the temperature may rise to 239F (red spot on gauge) without causing concern".
From this owner's manual quote, and all that you guys are writing, it sounds like a manufacturing issue that M-B knew about and told us about in the owner's manual. If they could not get around an over heating problem then I'm sure it will be tough for us to get around it.

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

Yup. I've read that in my manual too. It's interesting though that the head recirc. kit was developed to help address this problem. Even after doing all the many things typically recommended, including the addition of the recirc. kit, my '71 Pagoda still moved to the red while sitting through a long stop light. Under such conditions I found driving the car was anything but a pleasure. To get my 280SL to hold temp under the hottest conditions (with A/C running) has indeed proven difficult...but not impossible. (still gotta little bit of work left to do on the steep mountain climbing thing though).

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

J. Huber · « **Reply #14 on:** June 30, 2006, 09:58:12 »

For the sake of discussion, I checked my 230SL manual and it reads slightly different.

"This vehicle has an overpressure cooling system. Therefore, the cooling water will only boil at 239F (115C) (red mark on cooling water thermometer). When driving in the mountains or in areas with high oustide temperatures, the cooling water may rise up to 239F (115C) [red mark]"

I take this to mean that the red mark is the absolute point where the boiling starts. Anything after that, of course is bad. Now, I interpret the "may rise up to 239F" as: if it doesn't reach a boil, nothing gets damaged. (from a mechanical standpoint) This is different than "all is well" i.e at say 235F there is "no cause for concern." Instead, I think that gauge is signaling the rise -- and if it gets anywhere close to that red mark, I'd be concerned. Imagine making pasta, that moment where the water comes to a boil is pretty sudden. Make any sense?

James
63 230SL

Dick M · « **Reply #15 on:** June 30, 2006, 10:39:40 »

Is the temperature control more of a problem with the 280 than with the 250 and 230? Is the placement of the temperature guage senor in same location for all three?
My 280 never goes to last white mark on the gauge (temp. ?) even when pulling hills but it gets close. If I open the heater valve it will drop down immediately. Is the heater just adding cooling capacity or is it the proximity of the heater hose connection on the head to the temperature sensor?

Dick M
1970 280SL

Benz Dr. · « **Reply #16 on:** June 30, 2006, 15:21:05 »

Here we go again......

There IS something about late model 280SL's with air that makes them run hot. It's obvious and I'm surprised that no one has picked up on it.

Dan Caron's
SL Barn
benzbarn@ebtech.net
slbarn.mbz.org
1 877 661 6061

Raymond · « **Reply #17 on:** June 30, 2006, 16:12:49 »

My '68 280 with A/C didn't run hot the first two years. (Due to other issues I haven't run it this year.) But, I am wondering if Dr. Benz is alluding to timing advance and idle differences because of the air pollution plumbing on the later model cars?

If so, it begs the question, "What's the solution?"

Ray
'68 280SL 4-spd Coupe

Michel MB280SL · « **Reply #18 on:** July 03, 2006, 19:24:59 »

Come on guys! I'm surprised that this overheating problem is so common with the car and that no solution has ever been found in 36 years... I'm sad to realize that my local M-B mechanic is right and that these otherwise wonderful cars do have an unsolvable heating problem in traffic. Did even the M-B engineering department abandoned their customers?

I'm taking the car in next week to have the timing and mixture redone for a third time and hope this will make the engine behave. I do have A/C installed in the car but I'm not using it. I have not had the system restarted with the new freon yet. I'm going at the car by priority and want the overheating solved before I spend any money on other things. If I can't solve this, I guess I'll have no other choice but to get rid of the car. I don't want to have to do the valves, cam and head again.

Thanks for all info. If you have had any success, please indicate how you didi it.

erickmarciano · « **Reply #19 on:** July 03, 2006, 20:36:30 »

where in Canada are you?

1999 ml320<sold it at last>
2004 Volvo s60 T5
1971 280sl
1962 VW bug
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

Cees Klumper · « **Reply #20 on:** July 03, 2006, 23:28:18 »

My 280 SL is from 1969 and it never runs warmer than 80 degrees C, the middle of the scale. We've been having an official heat wave (30 degrees C plus = 86 degrees F) the past couple of days, and still the cooling is fine. No modifications, no 'water wetter', original fan, the fan clutch was replaced w/ new about 4 years ago. Just had the coolant replaced, no influence on the engine temperature. So it can work, I suppose.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

bpossel · « **Reply #21 on:** July 04, 2006, 06:10:51 »

Hi All!

Maybe instead of discussing the heat issue tied to model year, we should be discussing it as engine model, M129 vs M130? We know that there must have been a heat issue with the M130's because MB cut add'l water channels in-between the cylindar walls of the M130's. Correct? I have wondered if on some of the M130 engines, the extra (thin) water channels between the cylinders are plugged with gunk? Maybe from lack of proper maintenance, and/or from just lack of being driven?
Any additional comments on this?
Bob

bpossel (Memphis, TN.)
'71 280SL / '97 E320

mdsalemi · « **Reply #22 on:** July 04, 2006, 06:19:29 »

I'd suggest there might be something to Bob Possel's comment. I can safely say that my car does NOT overheat, but the temperature does climb alarmingly in very hot operating conditions in stop and go traffic. It is the stop and go--when moving, even slowly, it is OK.

As witness to repeated "Woodward Dream Cruise" events here in Michigan where literally tens of thousands of older cars from the 1950's and 60's come out and cruise Woodward, I can tell you that the "problem" of overheating isn't specific to our cars--many old cars do it. And, they used to do it when new, too--overheating used to be be far more common then it is on modern cars today.

When the tranny blew up on my 113 a few years ago, we sat in my Ford Explorer idling for an hour with the air conditioning on full blast, on the side of the road when it was 100 degrees outside, and the temp gauge didn't budge off N for normal. That's modern cooling. And, the A/C kept the interior a refreshing 72 degrees.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

Chad · « **Reply #23 on:** July 04, 2006, 09:59:55 »

This car here has the M128 I believe, whatever the number is. Anyway, it is the first older car I've had that absolutely refused to overheat under any circumstances. Now I just wish that I didn't overheat driving around inside there during this hot weather. Sometimes I think about an A/C for it, but it's so much work, and I just can't bring myself to change things.

The cooling systems are comparably good on these cars.

1967 230SL (Manual, rustless driver)

Chad · « **Reply #24 on:** July 04, 2006, 10:07:35 »

I've had this M128 230SL through the Mohave, Arizona/Sedona and all of NM, the South, and just plain sticky Eastcoast days. It's a former desert rat. It has never overheated. It is the first older car I've had that hasn't done this. The original engine fan. No A/C, stick. Just a normal base model... By the way does anyone know where they sell the radio delete plates?

I'm going to go shower all the sweat off -- the car is a former desert rat but I am not.

1967 230SL (Manual, rustless driver)

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Author Topic: 70 280SL engine overheating (Read 30893 times)

Michel MB280SL

n/a

TR

peterm

n/a

harleydan

TR

harleydan

TR

TR

Dick M

Michel MB280SL

bpossel

Chad

Chad