Its getting cold up here in Minnesota and guess what. My 93 400SEL has no heat. Is the usual suspect this notorious "monovalve" and are they serious that this one, which as far as I can tell is a double valve is really gonna cost me $800? Im starting to really regret buying this thing....

wish you could have some of our natural heat from where we are.

__________________
... Kerry

126 tailed by a 203, 129 leading the pack.

What year / model is it? This is the kind of "little" problems I am worried about... as I entertain the purchase of a used 300E.

"minor" little $1K problems

What is this "monovalve"? I replaced a vacum operated valve in the coolant line going to the heater core for about $40 last year. Is that it?

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

that diverts the coolant to the heater core I guess. I beieve they range in price from around $40 for the old 300's series all the way up to $800 for the s-class like I have. I guess the best advice is dont even think of buying a used 92 or 93 s-class unless you are rich. I thought I was getting a deal , $14,000 for a 93 400SEL with only 139,000 miles. Then I found out what it would cost to fix the stereo, oil tem light, abs light and or brakes.
Im starting to think Mercedes are really over priced pieces of junk.
The Bodies and chassis and engines seem ok, but everything else is expensive and hard to work on.
My 1982 300SD seems like a lot nicer car. Wish it rode like the 93.

Fastlane shows two parts, depending on whether you have rear a/c. One is $417, the other $253.

I don't know anything about your monovalve, but I looked it up on Fastlane using the button above. They list the thing for $400 or $253 depending on which you need. Still expensive compared to a 300E.
It seems to me that early 90's S-classes can be really expensive. There is a known problem with the wiring harness, too, that can set you back thousands. We are all used to climate control problems with our cars, but if the entire electrical system can fail as well, you have to be thinking production defect. The S-classes are typically out of warranty now so many owners are starting to feel as you do.
I suggest that you post a message something like "Poll: S-Class problems", track people's troubles and start organizing a class action response. Mercedes has to know that there are big problems with your car, they just won't want to admit it.

__________________
VR
1967 250SL

The W140 S class is a great car, but is possibly the most expensive Mercedes ever made in terms of repair costs.

Shopping here for parts is infinitely cheaper then getting them at the dealer.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

Ali is on target again. The early 90s S classes are documented in a number of threads for their problems, and I believe a class action suit was launched by their owners. EVERY CAR MADE BY EVERY MANUFACTURER has at least one problem area. Some models from each manufacturer had many, many problems - read up on why Hyundais offer such a long warranty now - To overcome all the lawsuits and Junk status from when they first came out! Some models of each manufacturer run forever with minimal repairs. Others have many more problems. My 88 Legend Coupe was "one of the 10 best cars in the world" according to all the car magazines, yet everyone I ever met who owned one paid for the car at least twice before dumping them in frustration ($200 power window switches, etc.). There was also a recent thread on why Infinity Q45s and BMW 740s are so inexpensive to buy - you will go broke keeping them running!

All you can really do is never buy the first 2 years of any production model of anyones car, and read everything you can find on the problems before you buy. But you can't make a blanket statement like MBs are overpriced Junk. Some models/years certainly are, but my 87 300E is more reliable and a very small fraction of the repair costs (labor and Parts) of my Legend coupe, which is gone and unlamented. And it is easily the reliability equal of my Toyota Celica which just passed 250,000 miles. (The MB needed less work in the first 80k miles than the Toyota did in that period, and the MB was neglected for the first 40k miles.

You bought a problematic model and year. You may even have gotten one of the worst examples of that genre. search the forum and find a better one, maybe one of the last of the W140s if that is your taste. (I think there was a thread on the best w140s, and Stevebfl had some recommendations). As I found with my Legend, sometimes all you can do is admit defeat and move on. Best of luck in resolving your issues on this. Don't go broke like I did in waiting too long to give up. (After the AC and CV joints went out again, I was able to sell it for the cost of the used imported japanese motor I had just put in!)

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E

the original hot water valve assy. (1408300784)was problematic
it has been superceeded to 0018301484 $437.00 dlr list
it's no big thing to change.
make sure to use mercedes coolant!
MF

What is so chemically different and superior about the MB coolant?

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

The pH is all wrong, leads to chemical erosion of plastic components in the cooling system, particularly the radiator neck.

EVERY PLASTIC,RUBBER AND METAL PART IN THE COOLING AND HEATING SYSTEM WAS DESIGNED TO OPERATE WITH M.B. COOLANT.
THEIR PRODUCT IS SPECIFICALLY DESIGNED TO OPERATE WITH ALLOY BLOCKS AND HOLD PARTICULATES IN SUSPENSION.
MF

I'll have to research this one ...

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Start here - more than you ever wanted to know! Coolant RED vs. GREEN

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E