Thermostat change turned out wrong! - PeachParts Mercedes-Benz Forum

190dee · #1 10-30-2002, 02:21 PM

I did change my thermostat earlier today. The success of it was limited

First after removing the old thermostat and putting the new one in there I did notice that the rubber seal is not similar to the former one. Since the old one was rather used it broke and crack when I removed it. So it wasn't an option to use that. The rubber o-ring Whaler did supply with the thermostat was another type of ring. This was designed to be put around the thermostat itself(old one was installed with rubber ring between thermostat and plastic cap. I did try to install it with the seal around the thermostat but the thermostat housing was to small for that.So I ended up cutting it in two halves to get a rubber o'ring that could be placed in the same way as the former one was.

Have anyone experience same problem with whaler thermostats? I will try to contact the part shop tomorrow so I can get the right o-ring.

Then when I was putting things together I notice the threads in one of the thermostat housing is in very bad condition. I'm now considering changing the whole housing in the same run. I did already take it for a test drive and it doesn't leak but it bothers me when I know about it.

Maintainance like this sucks.

Cap'n Carageous · #2 10-30-2002, 03:02 PM

It sounds as if you may have the wrong part. Was the new stat exactly the same size as the old stat? If not you may have problems down the road.

190dee · #3 10-30-2002, 04:01 PM

Yes, it's the same stat. The only thing that didn't match was the o-ring. The only thing that's different is that the old one was 87 degrees and new one 85 degrees. Anyway, still got higher temp after stat change. And that's what I've been after because my car didn't go over 80 degrees running temp. Now I'm at 83-84 degrees...

190dee · #4 10-31-2002, 02:19 PM

I contacted the shop earlier today. They did find out that it was a termo for a 190 DIESEL they sent to me!!! They told me a change will be fine so tomorrow I'm gonna mail it to them...

Ain't it funny...

Stephen: Sorry, I should've payed more attention to you advice. But since the termostats were identical except for the degrees I really thought I had the right part.

Cap'n Carageous · #5 10-31-2002, 07:37 PM

Don't be sorry.. That's why we're here!!, to ask the questions that hopefully will lead us to a solution. I have learned so much here that I feel I should have a degree hanging on the wall!!!

400E · #6 10-31-2002, 08:07 PM

I've had exactly the same problem even WITH the correct thermostat! Don't know why they send those "figure 8" seals.

Also, I believe there is a replacement metal thermostat housing you may want to replace the plastic one with, if memory serves.

Piotr · #7 11-01-2002, 12:50 AM

I had a reverse problem. I've got the right thermostat for my 190D, but I bought the seal from a stealer. You've guessed it- he sold me o-ring seals (whole bag of'em), instead the one that fits around the stat. he he, ain't the life fun??

haasman · #8 11-01-2002, 01:00 AM

190dee

I had a similiar problem with our '91 300E. Was running too cool. I was afraid of using up the engine. Eventually it would get above 80 degrees, but even on a warm day it took a loooooong time.

I replace the T-stat and it seemed better, but now with the cooler weather I was getting 80 or less even after hard driving.

From another post it hit me: May the sending unit and/or the conection has a problem. I took the wire off the Temp sending unit and grounded it. Tested fine. I then cleaned the inside of the connector and the post on the sending unit. I gave 'em both a quick shot of WD40 (allows conductance) and guess what!

Normal operating temps.

My 2 cents

190dee · #9 11-01-2002, 05:09 AM

Here's the first one.

190dee · #10 11-01-2002, 05:10 AM

As you see there are some differences but if the old one is 15 years old it wouldn't surprice me if the design was changes somewhere down the line.

Got a mail from my part supplier and they will change it for me but I have to pay the shipment. I comfortable with that.

And thanks for all the replies.

engatwork · #11 11-01-2002, 07:46 AM

Not sure if you are aware but the thermostat should be inserted with the little "button" at the highest point.

190dee · #12 11-01-2002, 09:13 AM

I know...but thanks for the consern. I mailed the diesel termostat today so I hope I get the right one sometime next week.

Piotr · #13 11-01-2002, 05:24 PM

Guess what??? I have a 190 E t-stat in my 190 D.... CRAP!!!!!!!!!Thanks for the pics...

400E · #14 11-01-2002, 08:52 PM

Don't want to harp on it, but did you see my comment about the plastic thermostat housing? If you indeed have this, you want to change over to the metal one to avoid a potentially catastrophic failure.

190dee · #15 11-02-2002, 06:26 AM

Thanks for the suggestion, Steve. I will ask for a metal cap. I did get this advise from another user as well so I guess it's really a risk counting on the plastic cap.