Cold engine tonight -- thermostat?
 

This evening, on the way home, I noticed that the engine temp never rose above 60 degrees C, well below its usual 90 degrees. It was, therefore, a rather chilly trip. I presume that the thermostat has stuck open, but I'm surprised that the engine never warmed up at all, rather than warming rather slowly. Could there be any other explanation, or is this normal behavior for a stuck thermostat on a 617?

Phil

'84 300D
'85 300D

Stuck therostat. This is normal behavior, since it's not closing, then engine will warm up but never reach operating temp. If it was really cold outside, the temp would drop while you were idling, too!

Replacement is fairly easy so long as none of the housing bolts is siezed. Use some anti-seize on them when you put them back in.

Peter

Phil

Be sure to put the little arrow UP too. Good party, Huh:)

Steve

i had the same problem and it was definitely the thermostat. it was cracked and a piece was broken off on one side so it could not close. i went out and bought a new one for like 12 bucks or so and installed it in about 10 minutes. nothing to it, definitely anybody can achieve this minor repair.

once you put it in you will get HOT air blowing into the car again

Good Luck

Arrow, what arrow?
 

Stevo says to put the arrow up. I been lookin' and I been lookin', but I sure can't see no arrow nowhere. Hints, anyone?

He's right about the party, though.

Phil

'84 Euro 300D, looking for an arrow
'85 300D

Phil

I have heard roomers of T stats w/o the arrow. What brand did you get. I dont have a new one over here ether. I did installed one without regard to arrow position and she ran hot tho.

No arrow , no matter.
 

I put the new thermostat in place oriented exactly like the one I removed, and all is well once again. I saw no arrow on either thermostat, nor did I see that the orientation would matter anyway.

Now, the engine runs a little cooler than it did before the thermostat broke, but lots warmer than it did with the (obviously) broken thermostat in place.

I'm still curious about the reputed arrow. Might this consideration pertain only to older model year diesels? 240D's only?


Phil

'84 Euro 300D, warm again inside
'85 300D