New or old CHT sensors? + hot oil checking

Oho!  This is a different approach.

"The gauges on your average light aircraft are notoriously inaccurate & prone to progressive even sudden failure.

At the first unexpected change in a reading; cross check with allied gauges eg oil temp high, oil pressure normal - suggests a failed sensor OR gauge, low oil pressure / coolant & oil temps okay also suggests a faulty sender/gauge, low oil pressure / coolant & oil temps okay also suggests a faulty sender/gauge."

These are MGL gauges, not cheap but not ridiculously expensive; it may be that we need to check with those folks.  Oil temp & press are together on the Stratomaster TP2, and EGTs, CHTs, H2O, fuel, and RPM are all on the Stratomaster E1.  Pressure has been normal throughout, so the entire unit isn't failing. 

We've noticed in the intense scrutiny recently that we have a difference in EGT readings, but we haven't yet had a chance to replace the EGT sensor that we figure is bad after 6 years and 1000 hours.  CHTs and H2O have all been normal.  Fuel pressure shows 3psi at WOT and 4psi otherwise, which has also been the norm.  The *only* thing out has been the oil temps except for when it showed really hot and then the H2O also climbed.

Let's see if we can catch anyone still at work in South Africa to ask, or maybe folks in Michigan as they wake up.  Stay tuned :-)

Hi GIF,

Ref "Flush" - my apologise I thought you were flushing the coolant system. 

As for flushing the oil cooler/radiator; In the distant past, I have come across ground based engines, that have consistently been run below optimum temperate and/or used the wrong lubricants, causing an internal  build up of gooey sludge, that restricted oil flow. I am aware (seen the photos/no experience) of  the sludge in Rotax 9's run on high lead/Avgas fuels. In my personal  Rotax 9 experience, my engine oil reticulation system remained clean (no build up of sludge). What did you use to "flush" your oil coolers? and why 2 coolers?

Your photos of the coolant sensor fitted to your engine, suggest to me a thermocouple ring, held in place by a bolt - bit different to the Rotax sensor but could be related to the needs of your MGL.

I stand by my comment on light aircraft gauge readings - they are indicative, not precision instruments. Purchase price/brand does not change my perception of gauge accuracy. Most will experience performance degradation over time (engine hrs) many will fail outright. Should be in every owners budget to replace, when performance falls below acceptable levels.

FYI; My ATEC Zephyr uses a single small oil cooler, located low on the firewall, in the cowling warm exit air - works a treat. ATEC supply/fit an additional oil cooler if the aircraft is to be used for glider towing.

This is your oil and cht sensor: https://www.internationalmarineservice.com/VDO-Marine-Engine-Oil-Temperature-Sensor-Single-p/vdo-323-801-010-001d.htm . what you have on your cylinder head is a type J or K (maybe even T) thermocouple (depending on wire color) attached to a ring terminal.

What's the oil pressure doing? Warm, above idle, it should increase smoothly with rpm. If, OTOH, it rises then falls, that indicates an oil line is collapsing under suction. Not only does the starve the engine of sufficient flow, it restricts full flow through the coolers and increases oil temperature.