I ordered a new ECT sensor for my 1990 740GL regina non-turbo

(the on board diagnostics had told me it was bad plus the temperature takes awhile to get up to operating temperature of late - I also order the thermostat, but figured I'd fix the sensor first),

but before I take out the old one I need to know if I am suppose to put some type of silicon or resin on the new one before you put it back in the block? Also, do you have to drain some of the coolant?

Hopefully you can give me a break on some of the things that most mechanics know because it's my first car I've worked on, but I've had success with the help of the brickboard members and the FAQs.

Thanks in advance,
Paul
--
1990 740 GL 293.2k miles

I believe that the new sensor will come with a gasket, a copper one. It should work just fine but a bit of RTV (sold by permatex "Ultra Grey" is the best stuff). There is a drain plug on the on the block near the back. Drain a bit from there and you should be fine.

The only other bit of advice I have is that I had a similar problem. It ended up with a total car rebuild. I also found that it was easier to pull the intake manifold, but if you have small fingers and tons of patience you should be fine.

Andrew

Change the thermostat now,while the coolant is lowered.The ECT sensor will adjust the fuel mix properly only when the engine is at the correct operating temp.

The sensor has a copper washer on it.Don't drop it,it will hide behind the starter and refuse to come out.

Bill

You should drain some of the coolant because if you don't, it will come out of the coolant sensor hole.

As of putting the new sensor in, you don't need to put anything on it.
--
FCP Groton