Hello all - first about the car - it is an 84 300D turbodiesel, been running biodiesel for most of the 5 months I've had her. I really don't know much about her past - there are definately plenty of things to keep me busy, but she has been running, well, fine(not to say great by any means!).

First -I left a friends after picking up some commercial biodiesel(!!!) - the car had run fine on the trip to her house. Upon leaving, I noticed the heat was actually hotter than usual. A few minutes later I noticed the temp gauge was very high - close to 120C. It had usually run around 90. I limped to a friends, with the temp gauge occasionally in the red. The heater was now intermittent - I tried to dissipate as much as I could - occasionally it would be HOT, occasionally much cooler. When I came to a stop, I heard a gurgling sound coming out of the heater vents. When finally at my friends, I noticed no fluid in the resevoir tank. After letting it cool, I coulnt get the radiator cap off(it was dark and I didnt want to crank on it - for fear of breaking the res. tank). So i poored in some water through a hose. Started her up and she was hot right away! Limped home with the gauge between 100 and 120c most of the way.

The next day I searched (in the daylight ) for problems. I found a heater hose clamp undone, but the hose was still connected. It came off with little effort. Was this why the heater was being erratic? I tightened the hose back on, filled the resevoir with fluid(the cap was a little difficult to remove, but looks fine). Started her up, and soon the temp gauge was around 100! Is my thermostat stuck? I drove a few blocks and it seemed to be ok one minute, then the next it was up around 110. It fluctuauted like this several times. And the heat wasnt hot.

So sorry for the lengthy post - I just wanted to relay as ,much as possible. Yes I have read other related posts - but I havent figured this one out yet.

And if it was overheating - did I totally screw up the engine? Thank you so much - peace - roger

ps - could a clogged fuel filter be part of the problem?