Replacing an oil pressure sensor (Mercruiser 454)

[pschauss]

I bought a new oil pressure sensor for my port engine because the oil pressure gauges for that engine (both upper and lower stations) are reading about 40# with the engine off. With the engine running, the gauges are pegged. It looks like it should be a simple matter of unscrewing the old one and installing the new one. Do I need any special sealant when I install the new one? Anything else that I have missed?

Thanks,

[Kevin]

I just swapped mine. Cleaned threads and appeared to be old tape or sealant on them. Put a wrap of tape on them and reinstalled. No leaks.
Make sure wire connections and or harness connection point are not corroded.

[pschauss]

What kind of tape did you use? I would be concerned that Teflon tape might melt.

[Kevin]

I believe it was Teflon tape. Hopefully someone can advise if that is the wrong way to do it. I will keep eye on it as I just did it two days ago.

[mike ohlstein]

Teflon tape begins to melt at 327° F and will ignite at 500° F. If your engine gets that hot, you have bigger problems to address.......

[Kevin]

Thanks Mike! I should be good.

[pschauss]

Since the purpose of the Teflon tape is to make certain that you can remove the sensor at a later date, is there any reason I can't use an anti-seize compound instead?

Thanks,

[mike ohlstein]

There are plenty of good Marine anti-seize products. It's hard to find them in small amounts. But here's one...

https://www.amazon.com/MARINE-GRADE-Met ... B00VM2PZYG

[pschauss]

Thanks for all of the suggestions. Getting at the sensor on the port engine was much easier than had expected. All I had to do was remove the cowling between the engine cover and the port side of the boat.

There was no sign of tape on the old sensor so I just put a thin coat of anti-seize on it.

[Rawleigh]

I have always been told that sensors don't use tape because they need the ground to the block (at least single wire sensors do).