Copyright (c) Marc Dacey/Dark Star Media unless otherwise indicated. Above photo (c) Marc Dacey. Powered by Blogger.

2014-09-20

Feeling hot, hot, hot

Just because there has been a dearth of postings of late doesn't mean I haven't been beavering away en bateaux, but as I prepare a couple of fairly large and technical entries, here's a short, sharp one.

Valiente, the 33 foot sloop, is a year older than Mrs. Alchemy, and boat years are briefer than human. Consequently, things break, fail or require pre-emptive care. Such was the case just prior to our August mini-vacation down the lake. The Atomic 4 engine panel has not much in the way of instrumentation, but the little there is I consider essential. So when the temperature gauge failed to budge one day, I got out the digital multimeter in order to see if it was getting power. Indeed, it was. So this suggested that the engine block's temperature sensor, or thermistor, was on the fritz. It was.

The Frankensteinian nature of my rebuilt Atomic 4 is revealed in the variety of engine paint on the various bits.
Some measurements and twenty bucks later, a replacement was installed with PTFE tape on the threads and enough torque on the wrench to forbid leaking. A new crimped on ring terminal completed the clean-up. 
It looks worse than it is. It starts readily enough and very little smells funny.
 Proof equalled pudding as a static test in neutral at the dock yielded a gradually rising temperature gauge needle that actually showed a slightly higher reading that more closely agreed with a fully opened thermostat (180F). So a quick fix actually worked out as it should have.
Not seen: the little piece of tape on the ammeter that lines up with the black shifter knob to indicate "you are in neutral".

4 comments:

Silverheels III said...

...and many with the sage advise and assistance from our good friend and talented mechanic Sajeeve. we've both managed to keep the diesel game going.

Stan said...

With only one wire going to your temperature sensor you are relying on an electrical connection between the body of your sensor to the block of the engine. PTFE tape can at times behave like an electrical insulator in these applications. In future I would use pipe thread compound rather than PTFE. It worked this time for you but it might not next time.

Rhys said...

Thanks, Stan. That tape only goes part of the way down the thread as a "leak-deterrant", so the body is in fact in full contact with the head into which it's threaded. I also tested the previous sensor with a meter and it was well shot. Your suggestion of pipe thread compound instead of PTFE tape, however, is an excellent one that I hadn't fully considered, and I'll keep it in mind. Things like my oil sensor and a few other bits of plumbing around the Atomic 4 are sealed with pipe thread compound; I tend to only use the tape on things that tend to need replacement, but I'll rethink that in terms of electrical contact in the future.

Rhys said...

Yes, I should give him a call and offer him a beer to eyeball my own diesel installation when I have it finished (fingers crossed) before I haul in October.