Engine Not Coming Up to Temperature

[M Towsley]

Hey all,

I have been meaning to ask about this situation. Apparently my engine cooling problem is opposite of the usual. I cannot get mine much over 170 degrees, even when running it harder than normal. This is during summer temperatures/humidity.

Temperature gauge, though not checked, is probably pretty close as I get a little oil/water mixture out of the crankcase vent post shut-down.

Cowling bottom has the vents along with the usual opening at the bottom. I think there are two rows of three vents on each row.

Wasn't sure if I should close off the front crankcase cooling opening like I do in winter and/or block some of the six vents punched into the bottom of the cowl.

Thanks!

[3Dreaming]

Re: Engine Not Coming Up to Temperature

Marty, I think you need to verify the gauge is correct. At least drop a temperature probe in the oil tank or digital temp the screen housng.

[Ragwing nut]

Re: Engine Not Coming Up to Temperature

why would you want it any hotter? I would be happy with that.

[M Towsley]

Re: Engine Not Coming Up to Temperature

My worry, Mike, is the water left in the engine at shutdown until the next flight. Corrosion issues, basically.

Tom, I can do that but it is the water in the oil which, to me, means it is not getting over 180. I'll digital temp the screen housing to see what it is.

[PA1195]

Re: Engine Not Coming Up to Temperature

Two things can help if condensation of water is suspected. Use ASL Camguard to fight corrosion; loosen the oil filler cap after shutdown and slide sideways or remove completely and put it on the cabin seat. In combination with the breather outlet it can allow air flow through the engine and remove some of the water. Water if present will collect on the inside of the oil filler cap and in cold wx can be seen as escaping vapor out the filler neck.

It's a continual problem in Alaska when flying below 0F. Covering the oil sump helps, but these small Continentals run cool with the exposed oil sump despite blocking off any excess crankcase or cylinder airflow and removing cooling lips from the bottom of the cowl.

Gary

[Guest]

Re: Engine Not Coming Up to Temperature

Hey all,

I have been meaning to ask about this situation. Apparently my engine cooling problem is opposite of the usual. I cannot get mine much over 170 degrees, even when running it harder than normal. This is during summer temperatures/humidity.

Temperature gauge, though not checked, is probably pretty close as I get a little oil/water mixture out of the crankcase vent post shut-down.

Cowling bottom has the vents along with the usual opening at the bottom. I think there are two rows of three vents on each row.

Wasn't sure if I should close off the front crankcase cooling opening like I do in winter and/or block some of the six vents punched into the bottom of the cowl.

Thanks!

Hi Marty,

Could the vent be blocked?

How about taking the oil temp probe out and putting it in a cup of hot water of known temperature?

Dave

[M Towsley]

Re: Engine Not Coming Up to Temperature

I'm already loosening the filler cap and letting it slide down to leave an opening after flight.

Dave, I don't think so but I will check the crankcase vent. I have a recently rebuilt correct U.S. Gauge oil temperature gauge, but just haven't had the time to install that and the three other recently restored gauges in the panel.

[3Dreaming]

Re: Engine Not Coming Up to Temperature

Marty, almost every little Continental will discharge a little milky white oil/water mixture. That is normal for these engines. I wouldn't worry to much about it.

[M Towsley]

Re: Engine Not Coming Up to Temperature

Thanks, Tom.

[Hank Jarrett]

Re: Engine Not Coming Up to Temperature

Harbor Freight sells a GREAT little remote sensing temp gauge that you can put teh laser spot on the kidney tank and see how hot it really is. Lots of fun to play around with in the house too and find areas where there is no insulation in a wall.
It works REALLY well when you have a dead spark plug. You can get nice readings of the plug tops and the exhaust right at the flange to the cylinder. Inexpensive tool that I have found LOADS of uses for. It IS a cheap China sensor and they have a reputation for NOT liking to be dropped, but for the price the only real problem is I hate buying tools from China.

Hank

[Hank Jarrett]

Re: Engine Not Coming Up to Temperature

Harbor Freight sells a GREAT little remote sensing temp gauge that you can put teh laser spot on the kidney tank and see how hot it really is. Lots of fun to play around with in the house too and find areas where there is no insulation in a wall.
It works REALLY well when you have a dead spark plug. You can get nice readings of the plug tops and the exhaust right at the flange to the cylinder. Inexpensive tool that I have found LOADS of uses for. It IS a cheap China sensor and they have a reputation for NOT liking to be dropped, but for the price the only real problem is I hate buying tools from China.

Hank

[M Towsley]

Re: Engine Not Coming Up to Temperature

Thanks, Hank. I have several IR/laser temperature gauges. They are fun to mess with.

[Guest]

Re: Engine Not Coming Up to Temperature

Marty, almost every little Continental will discharge a little milky white oil/water mixture. That is normal for these engines. I wouldn't worry to much about it.

Yeah and if it's not milky better check your oil level!

[Mark Bowden]

Re: Engine Not Coming Up to Temperature

I would offer some comments. There is no set temperature number to get the condensation and combustion water out of the crankcase. A lower operating oil temperature just means you need a longer running time to remove the water. Water will evaporate (sublimate) below freezing. Moisture will come out just fine at 125 or 150 or 170, it takes longer. I wouldn’t worry about 170 vs. 180; most of the moisture is driven out due to the piston temperature and that contact area, this makes cruise operation the most important factor in removing moisture. Don’t do weekly idle run ups, those are bad for a host of reasons.

For a reference point, since the restore in 1999 ours has always run 100 deg. over ambient temperature at altitude and made over 1500 hours to major. An engine blanket for the oil tank is used in the winter. Hot summer doesn’t mean much unless you stay low, the lapse rate temp the engine sees is much lower than the ground or in our hot “greenhouse” cabins. Engine sees cool ram air.

Please note, if you check your temperature sender at water boiling point it will be less than 212 unless you’re at sea level, standard day, about 210 deg. F at 1000 ft. elevation.

I would suggest the bigger worry about internal corrosion is if you are not flying for a while, like less than weekly or in the winter months. The combustion by products in the oil can be worse than just moisture, CO2 is an acid gas. Additionally the older the oil, the more it has oxidized and thus the more it will absorb moisture and be more acidic and react more with the combustion products making it more acidic. It’s a bad cycle.

Avoid sump-only engine heaters they just move moisture from the oil to bare engine parts. Always fly cruise more than 30 minutes, you get the most moisture shoved into the crankcase at start when the engine is cold from combustion blow-by when ring and cylinder clearances are loose. If you burn a pound of fuel you get a pound of water, most goes out the exhaust but some goes by the rings all the time. Flying more often will make your engine last longer as your oil will stay in better shape. The probably biggest cylinder killer is bad baffles and cowl seals making them too hot.

Note, Continental says you should fly 1 hour a week and if not flown for 30 days the engine should be “stored” which includes changing the oil. http://www.tcmlink.com/pdf2/sil99-1.pdf

Another good ref: http://www.legend.aero/pdf/Tips_On_Engine_Care.pdf

[M Towsley]

Re: Engine Not Coming Up to Temperature

Thanks, I am aware of everything you mentioned. I have to disagree on the extended cruise to eliminate water. It is still there after a two plus hour flight. I rarely get over 2,500 msl.

This isn't my first A-65 and my other ones never seemed to have the problem of water in the oil after flying. Just curious as to why this engine is running cooler than the others.

Thanks for the info.