[W126 Coupe] Running Hot update

[Shayegan, Richard]

I'm curious to know what engine the car has and what are the ambient
temps. The 380 (and IIRC the 500) have a pin on the side of their
thermostats. When I replaced the one in my 380, I noticed something
similar to what the OP is experiencing (but it was the summer). I asked
the shop that I use for stuff I can't do if they could tell what I did
wrong. He said to me, "the one you replaced didn't have a pin on the
side but the one you put in did, right?" which was correct, then he told
me that if you leave the pin in they will do that, and back in the day
when people would complain the dealers would just cut the pins off and
it would fix the "problem," but he said that the early ones were made
with that pin in mind so it's best to leave it in place. However, when
the ambient temps get cooler, this issue shouldn't surface.

-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Mike R.
Sent: Tuesday, October 17, 2006 10:28 AM
To: 'Mercedes Coupes Mailing Lists'
Subject: RE: [W126 Coupe] Running Hot update

That does not sound normal at all. That big lump of metal will not
change temperatures instantly, so you likely have a gauge or sensor
problem.

FYI, I went to Harbor Freight Tools (on-line or brick/mortar) and bought
an infrared temperature "gun" for about $40. Doug called it a "held
digital temperature sensor gun". Same thing.

At the moment, they have a HANDHELD INFRARED THERMOMETER WITH LASER
SIGHT for $27. This won't be anywhere near as good as the $65 Fluke
instrument, but we're not normally interested in that much accuracy.
 
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93984

Get one of these then your problem can be properly troubleshot - is the
problem with the instrumentation or with the actual temperature of the
coolant.

If you are in Las Vegas, we'll use mine.

Later,
Mike R.
(702) 494-8056
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com]
On Behalf Of Doug Gavin
Sent: Tuesday, October 17, 2006 7:12 AM
To: Mercedes Coupes Mailing Lists
Subject: Re: [W126 Coupe] Running Hot update

Mister McGoo wrote:

> Pavel;
>  
> Not sure what the problem is.  You say your temp stays at 88 - 90 C 
> while driving around but drops to 85 when you "hammer" it.  What is 
> your thermostat temperature rating?

---snip---

Just an additional 2 cents if I may. This will only confirm or deny some
of your issues. Most good radiator shops have a hand held digital
temperature sensor gun that they can point a various places on your
engine and tell you exactly what the temp. is let's say at the intake
manifold the thermostat housing etc. I found that my guage was 5 degrees
hotter than the  actual temp.. at the thermostat. Most won't charge you
and it takes about two minutes. Good luck


The MB Coupes Website!
W126 SEC Mailing List
Postings remain property of MB Coupes, L.L.C.