Low Oil Temperature

[rfeydo]

We have just had our 0-360 A4A complete a major overhaul,its in our 1968 PA-28 180. Break in procedures call out that we need to get our oil temp. up to 180-225F. We have also replaced our oil cooler with a new one, including all new hoses. My issue is that during the intial flights, (OAT was around 50F) the oil temp. is only reaching 100F. We have a mounting location on the baffling for what im told is a restrictor plate, that will do just that and restrict the airflow to the oil cooler. I cant find any information on this plate or what size hole or holes should be used if one is fabricated. When OAT change, how is this addressed? are multiple plates needed?

 

[Let'sgoflying!]

You can heat the sensor in water to validate it first. Get a cooking thermometer with a similar range and a small electric hotplate. Sometimes these things get banged about at engine swap.

 

[Dan Thomas]

You can heat the sensor in water to validate it first. Get a cooking thermometer with a similar range and a small electric hotplate. Sometimes these things get banged about at engine swap.

I would second that. You can do it just with boiling water, which we know to be at 212F and no more. Thermometer isn't necessary.

And if it's an electric gauge, make sure the engine is really well grounded. Some installations have a separate ground wire for the gauge itself. Alternator current flow can upset electric gauge readings if the engine's ground is even a little sketchy. The current finds other ways into the airframe, including through gauges, although that usually causes a high reading, not a low one.

A mechanical gauge, with the sealed oil bulb, can get its line cracked and leak a bit of the internal oil. That will make it read lower and lower until it's dead altogether. 100°F is low indeed, far lower than an overhauled engine should display unless you're OAT is really low.

Dan

 

[murphey]

The oil cooler plate is nothing more than a piece of thin aluminum with 4 holes in each corner to match the holes around the oil cooler. I've got the same engine and can provide a bit of insight (anything else requires an A&P). BTW officially this part is 67769-04 on Fig 58-15, page 3B11 of the Piper Parts Manual and is named the Winterization Kit Assembly, which is nothing more than a placard and the piece of Al. I remember seeing a photo somewhere online but can't find it now.

Find someone on your field with the same engine and ask them to show you around the interior where the oil cooler is located (if you don't already know the insides)

If they have one of the plates, take the measurements otherwise....

Take off the top cowl.
Stand on the pax side of the engine and look on the top left, just below the baffling, inside the engine area. You should see a hole about 3 in across - that's the intake for the oil cooler. Around that big hole are 4 tiny holes, in each corner.
Get a piece of paper, tape it to the hole, then mark the little holes. That's where the screws will go.

Note: Some people use duct tape or Al tape across but there's a chance that the tape may some off and get ingested and block the oil cooler.

Find the local EAA members around your airport and ask them (bring something either liquid or really good munchies) to cut a square piece of scrap Al and punch the holes for you.
Find the appropriate washers, bolts and locknuts to fit (I've seen U clips used very successfully).

And there you go. I only attach the top 2 screws on the plate.

Now you also need a placard (which should still be in the cockpit on the panel) that states the Winterization Kit should be installed when the outside temp is below 50F.
As owner/operatory you can install/remove the Al anytime you want. Officially, you should also make note in the log book.

Lastly, find an A&P and have them bless the new part that you have just fabricated to AC-43.13B Acceptable Methods, Techniques and Practices, and away you go.

As you watch the oil temp you may find that covering the entire oil cooler hole is raising the temp too much. Take a pair of tin snips and cut a bit off the bottom of the plate.

 

[TMetzinger]

The oil cooler plate is nothing more than a piece of thin aluminum with 4 holes in each corner to match the holes around the oil cooler. I've got the same engine and can provide a bit of insight (anything else requires an A&P). BTW officially this part is 67769-04 on Fig 58-15, page 3B11 of the Piper Parts Manual and is named the Winterization Kit Assembly, which is nothing more than a placard and the piece of Al. I remember seeing a photo somewhere online but can't find it now.

Find someone on your field with the same engine and ask them to show you around the interior where the oil cooler is located (if you don't already know the insides)

If they have one of the plates, take the measurements otherwise....

Take off the top cowl.
Stand on the pax side of the engine and look on the top left, just below the baffling, inside the engine area. You should see a hole about 3 in across - that's the intake for the oil cooler. Around that big hole are 4 tiny holes, in each corner.
Get a piece of paper, tape it to the hole, then mark the little holes. That's where the screws will go.

Note: Some people use duct tape or Al tape across but there's a chance that the tape may some off and get ingested and block the oil cooler.

Find the local EAA members around your airport and ask them (bring something either liquid or really good munchies) to cut a square piece of scrap Al and punch the holes for you.
Find the appropriate washers, bolts and locknuts to fit (I've seen U clips used very successfully).

And there you go. I only attach the top 2 screws on the plate.

Now you also need a placard (which should still be in the cockpit on the panel) that states the Winterization Kit should be removed when the outside temp is above 50F.
As owner/operator you can install/remove the Al anytime you want. Officially, you should also make note in the log book.

Lastly, find an A&P and have them bless the new part that you have just fabricated to AC-43.13B Acceptable Methods, Techniques and Practices, and away you go.

As you watch the oil temp you may find that covering the entire oil cooler hole is raising the temp too much. Take a pair of tin snips and cut a bit off the bottom of the plate.

FTFY. At least that's the way the placard reads in the Arrow - "Oil Cooler winterization plate to be removed when ambient temperature exceeds 50F"

 

[weirdjim]

Lastly, find an A&P and have them bless the new part that you have just fabricated to AC-43.13B Acceptable Methods, Techniques and Practices, and away you go.

And if you need an authority for the actual manufacture of the plate, you can quote 21.303 (b)(2).

Jim

 

[weirdjim]

I would second that. You can do it just with boiling water, which we know to be at 212F and no more.

Dan

Almost. At GOO (home airport, 3000 MSL) water boils at 206F. Sometimes I work at TRK (6000 MSL) where it boils nearly at 200F.

Jim

 

[Let'sgoflying!]

You don't need a thermometer to see if it is going to be 'working' ie the needle moves as heat is added.
But with a 5$ thermometer you can tell a lot more about its accuracy.

 

[murphey]

And if you need an authority for the actual manufacture of the plate, you can quote 21.303 (b)(2).

Jim

"(2) Parts produced by an owner or operator for maintaining or altering their own product and which are shown to conform with FAA-approved data."

And for additional explanation, refer to FAA Memorandum dated August 5, 1993 with the interpretation described on the C150 website

http://150cessna.tripod.com/parts.html

Note: You can round off the edges and do other things to keep you from cutting yourself - I just put Al tape all the way around on the edges. I also cut the 4 corners down a bit so I didn't skewer myself installing it.

 

[Skip Miller]

I would second that. You can do it just with boiling water, which we know to be at 212F and no more. Thermometer isn't necessary.

Depending on altitude.
-Skip

 

[Areeda]

I agree with the sentiment that probably the gauge is faulty. I can see oil temp not getting fully into the correct range but 100°F is tepid bath water a hand on the oil dipstick should tell you if it's correct.

Joe

 

[weirdjim]

"(2) Parts produced by an owner or operator for maintaining or altering their own product and which are shown to conform with FAA-approved data."

Here is the exact FAR quoted directly from the FAA website downloaded a few minutes ago. Your italicized and bolded words don't seem to be a part of the current regs. I am well aware of the chief counsel's opinion and am in total agreement with it. I've built a business for the last 37 years on this specific part of the regs and abide by it on a daily basis:

(a) Except as provided in paragraph (b) of this section, no person may produce a modification or replacement part for sale for installation on a type certificated product unless it is produced pursuant to a Parts Manufacturer Approval issued under this subpart.
(b) This section does not apply to the following:

(1) Parts produced under a type or production certificate.
(2) Parts produced by an owner or operator for maintaining or altering his own product.
(3) Parts produced under an FAA Technical Standard Order.
(4) Standard parts (such as bolts and nuts) conforming to established industry or United States specifications.
​

 

[GMascelli]

oil cooler plate

 

[Dan Thomas]

Depending on altitude.
-Skip

I know that, which is why I said 212°F and no more. Not many of us will be checking gauges at 10,000 ASL and even if we did the gauges in most airplanes aren't nearly accurate enough to detect the difference. I have a small electric kettle I use for the purpose; it's a cheap plastic thing whose lid comes right off to leave an open bowl. Handy. I used to use a tin can and a propane torch; a bit tricky.

The oil is typically redlined at about 245°F. If the gauge reads three-quarters of the way up when the water is boiling, that's good enough for me. To confirm the 245° I'd need to use hot oil and I'd really get nervous doing that.

Dan

 

[rfeydo]

Guys thanks for all the help, now i have some direction. GaryM thanks for the photos, looks exactly like my application.

 

[kmead]

It seems hard to believe it's really running that cool. You would have the Stewart Warner oil temp indicator in the ship. Could someone have installed a new oil temp probe? If a Rochester probe was installed your indicator won't be accurate, it's a more common problem than you would think.

Kevin

 

[Doggtyred]

I would second that. You can do it just with boiling water, which we know to be at 212F AT SEA LEVEL on a standard day. Thermometer isn't necessary.

Fixed it for ya. Lower pressures at altitude affect the boiling point. If you are in Denver or Leadville, for instance.. it will be significant.

 

[Doggtyred]

"(2) Parts produced by an owner or operator for maintaining or altering their own product and which are shown to conform with FAA-approved data."

And for additional explanation, refer to FAA Memorandum dated August 5, 1993 with the interpretation described on the C150 website

http://150cessna.tripod.com/parts.html

Note: You can round off the edges and do other things to keep you from cutting yourself - I just put Al tape all the way around on the edges. I also cut the 4 corners down a bit so I didn't skewer myself installing it.

Jim's right about this.. You can fab up your own plate. Just like you can build your own radio or nav/com. This is not replacing a PMA/factory part. This is an addition. Manufactured by the owner.

 

[Let'sgoflying!]

Guys thanks for all the help, now i have some direction.

Now don't take off in a hurry.... Your obligation, according to the user's agreement when you signed on to POA Maintenance Bay, is to report back the troubleshooting steps and findings along the way. Otherwise we are all left wide awake a month from now at 2am, wondering why that guy had such low oil temps.

 

[rfeydo]

I will post results when i can fly again, we are in the middle of getting blasted with lake effect snow. Thanks to all.

 

[rfeydo]

Guys, a quick follow up, i did manage to get an hour in before the last big lake effect event started. I installed the winterization plate and did manage to get the oil temp. up to around 140f. The oat temp at 3000' was 15f so im sure that helped keep the temp down. Thanks for all the help.

 

[N801BH]

140 is still too cold... Gauge and sending unit should be checked for accuracy.. Moisture will have a hard time evaporating out of the oil at 140f unless you fly it for a few hours at a time. IMHO.

Ben.