SL/R129 R 129 Coolant Temp Question

Aug 23, 2022 | 06:04 PM

kwelch02

Thread Starter

Junior Member

Joined: Sep 2021

Posts: 59

Likes: 2

From: Ann Arbor Michigan

1996 sl 500

R 129 Coolant Temp Question

I have a 97 SL 500. 106k

My Coolant gauge shows a reading of between 80 and just under 100c at the top end. This is on expressway or surface streets with AC on and outside temps in the 80s.
Is this a normal range?

I have had new hoses, belt and pulleys and new coolant in the last few months. I believe the clutch may be original, but not sure.

If this is too high, where should I be looking?

Thanks.

Aug 23, 2022 | 10:46 PM

mahunt

Super Member

Joined: Aug 2019

Posts: 701

Likes: 207

From: Lutz, FL

1997 MB SL600

That's perfect.

Figure 100C as 212F and you are probably right at 195F. Perfect for an aluminum engine.

Aug 24, 2022 | 07:01 AM

kwelch02

Thread Starter

Junior Member

Joined: Sep 2021

Posts: 59

Likes: 2

From: Ann Arbor Michigan

1996 sl 500

Thank You!

Aug 25, 2022 | 03:28 AM

Ahmed

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Joined: Apr 2002

Posts: 2,665

Likes: 208

From: Bahrain

R129 SL55 AMG & W208 CLK55 AMG

Quote:

Originally Posted by kwelch02

My Coolant gauge shows a reading of between 80 and just under 100c at the top end.

What exactly do you mean by that? Is the needle actually oscillating from 80 to "just under 100" repetitively?

Last edited by Ahmed; Aug 25, 2022 at 03:32 AM.

Aug 25, 2022 | 05:33 AM

kwelch02

Thread Starter

Junior Member

Joined: Sep 2021

Posts: 59

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From: Ann Arbor Michigan

1996 sl 500

No, it does not bounce around at all. Just climbs to just under 100c

Aug 25, 2022 | 08:02 AM

AndreasHannover

Senior Member

Joined: Oct 2017

Posts: 368

Likes: 73

SL600

That's too much for normal conditions. Can you stop the cooler blower with a rolled newspaper when the engine is hot? If so, the clutch is dry.

Aug 27, 2022 | 03:20 AM

Ahmed

MBWorld Fanatic!

Joined: Apr 2002

Posts: 2,665

Likes: 208

From: Bahrain

R129 SL55 AMG & W208 CLK55 AMG

Quote:

Originally Posted by kwelch02

No, it does not bounce around at all. Just climbs to just under 100c

It should not climb. The thermo's job is to stop it from doing that.

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Aug 27, 2022 | 06:40 PM

Sparrow141

Junior Member

Joined: Aug 2022

Posts: 19

Likes: 2

A45

I drive a lot of new model MB, typically less than 5,000km, and noticed that 90 degree when cruising is quite common.

Aug 28, 2022 | 01:51 AM

#10

AndreasHannover

Senior Member

Joined: Oct 2017

Posts: 368

Likes: 73

SL600

All newer cars dont show the real temperatur. As long as the real temperatur is within a range, it shows always the same. At the R129 which showas the realy temperatur, a M119 should be behave like you can see at the picture above.