Turbine inlet temp gage quit working - 231 rocket

[Omega703]

hey guys,

I recently had my TIT gage stop working. it was rock solid a month ago, then the needle started jumping around, now it sits at the bottom of the gage (stock 231 analogue gage). If anyone has had the same issue, was it the probe or the gage that was faulty? The engine is run ROP IAW the POH, has not exceeded 1600F since I purchased the A/C (2 years).

 

Regards,

Derrick

1980 M20K 231/rocket

[carqwik]

How many hours on the probe?  More than 400+ and possibly it is the probe that's failed....although mine start showing TITs lower than normal at first so never gotten one yet to completely fail and read zero....I replace them prior to a total failure.

[Omega703]

The probe has at least 400 hrs on it. Would you get erratic indications or just a drop in temp as the probe reached the end of it's service life?

-D

[carqwik]

Drop in temperatures...but it may have different modes of failure.  In a 252, I had the TIT go off the chart (pegged at the limit past redline) nearing the top of a climb out of Vegas on a hot day.  Cross-check of the other instruments showed nothing had really changed....CHTs and oil temps were fine so continued the flight...turned out the TIT probe had failed IIRC.

If I was you, the first thing to do would be to remove/replace the TIT probe...it might be covered with carbon build up.  Replace the probe with new one and see what happens.  Heck, with over 400 hrs on it, it will fail soon anyways even if the probe isn't the problem for now.

[AndyFromCB]

You might get no reading at all if the probe simply "disappears" from heat and corrosion. I was just at the airport watching my engine being reinstalled.

The main probe connected to panel gauge at 200 hours is looking pretty rough by still gives good reading. The probe connected to the GEM is gone, as in gone, not there. Simply corroded and whatever was left broke away and turned to dust inside the turbo.

Andy

[Omega703]

Thanks guys. I'll replace the probe as soon as I get back to Vegas, setting known power/fuel flows in the mean time.

D

[davidsguerra]

get a jpi 830. it is more accurate for tit.