Sorry. I also tested t-stat last night. It opens at 175-180F and second action rises.

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

I am sorry I am not completely up to date on this thread, but for all this testing and modifying etc..

wouldn't it be much simpler to run the engine without the t-stat installed? the engine will run cooler than desired... but its better than over heating.

using regular water during all this dismantling / reassembling is fine. Install the correct fluid once you have a functioning system.

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does your engine have a catalyst on the exhaust, or some other device that might restrict exhaust?

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Was told I cant remove t-stat because she will still over heat when under load. I tried that already. Did not fix the problem. And as for exhaust it does have a cat but she spools up easy and does not seam restricted at all. I had a rig with bad cat, you could hear and feel the restriction.

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

I believe the thermostat housing is part of the car and the part you removed the notch from is part of the thermostat housing. Seems to me the notch was not the problem. Like someone else noted, take the thermostat out and see what happens.

If you have manuals, the flow path should be checked to verify where you feel heat is where you should be feeling heat on the hoses and the radiator.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Could the head or block having a crack cause all this? I dont have fuel or oil in Coolant and dont have coolant smell in exhaust. But there's something going on and I have replaced just about everything. The only thing that's not new is the water pump. Mine looks fine but i got to do it. I found a used one 2 hours from here. Going to go get it and give it a try....

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

the last thing on my mind is that the headgasket (or something worse) has failed and gases are entering the cooling system and accumulating.

this will prevent proper flow

###we posted at the same time (see above) ###

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I guess that answers the question of no thermostat operation. If there is truly no difference there is a blockage of flow elsewhere, or another problem altogether. Trace the flow path from the radiator to the engine and back, check the hoses, run some water through the various connection points for the hoses and see what you find. Then, take the car back to the guy you bought it from, buy something cheap and get home.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I thought I needed the T-Stat to redirect the coolant. I will pull her out and try in again. As for the notch I removed from the housing. I had to so the T-Stat could go into the block like pic 4.

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

what brand was the t-stat?

the engine will need the the t-stat in higher ambient temps under high load only when there is low air flow over the radiator (assuming a healthy system)

__________________

So gases in the coolant system would make seance. What is " Too Hot " for her anyway?

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

Sorry to be the bearer of bad news, but yes having the temperature go up to 115 on the highway after a few minutes is the same behavior my #14 head exhibited. It was cracked and warped.

After the car sits overnight, is the upper radiator hose soft or firm? Firm would not be good.

Did you try a new expansion cap as someone else mentioned? It's a long shot, but far cheaper than a new head.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

Not sure of the brand. But it works.

__________________
83 300TD Sable 402K " Work Truck "
81 300SD Gray 240K " Loner Car "
04 E320 Blue 90K " My Winter rig "
07 BMW X5 4.4 118K " My Summer rig"
04 Jetta TDI Wagon 168K " Wifes "
08 Toyota FJ 109K " Wifes winter rig "
04 Jetta TDI 120K " Daughters Car "

115 is certainly close to too hot. I think 110 is safe, but 115 would scare me.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I think you have established that it is not the thermostat. Does the gauge go to 115 at idle? If so how long does it take to happen?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss