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Oil overheating

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I finally finished my annual and flew my CT for the first time in many months. I did not have anyone local with any CT or Rotax experience, so it took me forever and a day, ha ha. 

I flew it 3 times and decided I had to tear into it again!!! I have had problems with overheating on climb out, but this time it was oil temp more than CHT. I had cleaned the radiator last year but never got out all the "goop" (oil soaked dust). Now that it is removed I can see the clogged cooling coils and they are more in the center part of the radiator (where the oil cooler is).

I researched for a local radiator shop and we have one, but he didn't seem like he really wanted to do an aluminum radiator (you cannot "boil them out" like a normal radiator because of the caustic solution used). I decided (since my clogging is mostly exterior) I will put my radiator in a milk crate and take it to the local coin operated car wash! For the interior flushing I will make sure and "back flush" by having the inlet side down, and blast thru the outlet side.

So, tonight I went to make sure of the flow direction and by chance I turned on the battery and noticed that my oil temp gage went up to 140 degrees! And, after staring at that for about a minute, it popped up to about 180 degrees! So, I was pretty relieved that the overheating is probably not as bad as it was showing. But, I know I needed to clean the exterior of the radiator. Next year I'll come up with a better way to clean it without removing it. I have a degreaser sprayer, but I need to make a right angle nozzle so I can spray from behind the radiator. And, I'll heat the 505 degreaser liquid while I'm spraying. 

Question: Anyone have a source for a new oil pressure sensor?

Regards all . . .

ET

Pic of radiator.jpg

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There was a recent thread that has the part number for both oil pressure and temp sending units. The only that might not be there is pressure if it is remote mounted.

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Looks like you did a nice clean job.

You can check to see if you have a bad oil pressure probe by swapping out the left side CHT wire to the oil temp probe. These two senders are identical. Swapping wires will help rule in or out a probe and see if it is a wire issue. The VDO temp probe is a very rare failure and usually last forever. You could if you want swap the CHT probe and oil temp probe. Like I said they are identical.

The oil hose on the right side (the one just out of the picture) that makes a 180 turn from the radiator back to the oil pump housing most times is the culprit. I ALWAYS put a spring or two where that hose makes the 180 degree bend. I have found that this many times will drop the temp by 20F. As that hose gets hot it gets soft and is more likely to pinch down and reduce its ID radius which slows oil flow which increases temps. Making that hose a 180 was never a good idea, but is easy to fix. All you have to do is pull the hose off the radiator fitting and shove a spring down its throat. I use a 12" long 1/4" ratchet extension turned backwards to push the spring down the hose. The back end of the 1/4" extension is a perfect fit.

Don't forget to silicone your exhaust springs. Don't forget to put the drain hose on the fuel pump.

Double check to see if any other oil hose has a flattened spot under the fire sleeve after it is hot. You can feel them.

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1 hour ago, Roger Lee said:

. . . Don't forget to silicone your exhaust springs.

Roger,

What is the brand name of that red compound found on most of those springs?

A web link to that stuff would really be appreciated. I need some of it.

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It's just high temp red silicone RTV. You could use the black if you wanted, but it must be high temp. Any auto parts store or Ace Aviation. The spring coils should be stretched enough to have a 1mm (fingernail width) between coils. When you apply the silicone you work it in between the coils. It needs to have enough body to do some good so make the silicone bead about 3/16" thick and about 3/8" - 1/2" wide. This is in the manuals and an SB. This is for vibration dampening.

 

DO NOT fill the coils like Vans does. This practice was abandoned many years ago due to the spring retaining too much heat and causing early spring failures. The spring needs air flow to help dissipate heat.

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Thanks you guys!

Roger, you always amaze me with your effort to help others here. If I didn't love Kingman, Bullhead City, and Laughlin so much, I would consider relocating to the Tucson area!

I'm pretty sure I have a bad probe or wire connection by the fact that my gage goes up to 140 degrees when I turn on the battery with a cold engine. Then, if I wait an extra minute or 2 it pops up to about 180 degrees. The fact that it jumps up makes me suspect that I also have a sticky  gage. I'll have to keep an eye on that.

I will definitely try swapping the leads and cleaning the clips/terminals with acetone.

As far as the hoses, extra heat shielding, etc, that was done by Rex Johnson at the Riverside Airport in Tulsa, OK when I bought the airplane (5 year rubber change).  

Thanks again . . .

 

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1 hour ago, WmInce said:

Roger,

What is the brand name of that red compound found on most of those springs?

A web link to that stuff would really be appreciated. I need some of it.

I think I use Permatex Red, as do the two RV-12s on the field.

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4 hours ago, Roger Lee said:

Permatex owns Loctite

 

I thought that before, but looked it up. Loctite is owned by Henkel AG & Company, KGaA, while Permatex is owned by Illinois Tool Works.

I do believe at one point in the past they were owned by the same company. I know permatex has been bought, sold, bought again.

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6 hours ago, FlyingMonkey said:

I think I use Permatex Red, as do the two RV-12s on the field.

Thanks Andy!

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7 hours ago, Roger Lee said:

It's just high temp red silicone RTV. You could use the black if you wanted, but it must be high temp. Any auto parts store or Ace Aviation. The spring coils should be stretched enough to have a 1mm (fingernail width) between coils. When you apply the silicone you work it in between the coils. It needs to have enough body to do some good so make the silicone bead about 3/16" thick and about 3/8" - 1/2" wide. This is in the manuals and an SB. This is for vibration dampening.

DO NOT fill the coils like Vans does. This practice was abandoned many years ago due to the spring retaining too much heat and causing early spring failures. The spring needs air flow to help dissipate heat.

Thanks Roger!

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1 hour ago, Anticept said:

I thought that before, but looked it up. Loctite is owned by Henkel AG & Company, KGaA, while Permatex is owned by Illinois Tool Works.

I do believe at one point in the past they were owned by the same company. I know permatex has been bought, sold, bought again.

Hi Corey,

Not sure where I got that, but you're absolutely right. Here is a little history.

https://en.wikipedia.org/wiki/Loctite

http://connection.ebscohost.com/c/articles/4109905/permatex-buys-own-brand-related-business-from-loctite

2005
ITW Acquires Permatex

Permatex was acquired by ITW (Illinois Tool Works Inc.), a NYSE listed U.S. based corporation. ITW was founded in 1912 and is a Fortune 200 diversified manufacturing company with more than a 90 year history. ITW’s decentralized business units in 49 countries employ 50,000+ people focused on creating value-added products and innovative customer solutions.
Permatex Partners with Jay Blake and Follow A Dream NHRA Racing Team

 

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I flew my CT with the clean radiator and it is better but the oil temperature still got near red line. Tonight I tested my sensor by placing it in boiling water. The gage went to a hair over 230 degrees (Yaaaaaa). This means my gage is not reading correctly up in the operating range. I'm at 3,400 elevation, so the gage should have gone to about 205 degrees. That means my oil temperature is within acceptable limits. 

Now, tomorrow I'll hook the same sensor to my CHT gage and see what reading I get (I need to determine if the error is in the sensor or in the gage. I suspect the gage.

My sensor says VDO 4.06 801/10/1. I found a site selling an 801/10/3 and the picture looks identical to mine (oops, I guess the threads are different). I did search prior posts here, and apparently the correct P/N is VDO 801/10/1. 

I guess if it's the gage, I'll have to contact FD (nope, see later post in this string, I found the gauge at AC Spruce). I'll also have to check the back of the gages and see if there is not a way to calibrate them (no there isn't). 

Happy flying all. I"m thinking I will take a trip to Columbia, CA and stay at the camp ground beside the airport for a few days. ????

 

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I redid that test tonight and the CHT gage read 201 degrees (with the sensor in boiling water). So, I took the Oil Temp gage out and I'll see if I can find a source. Its a UME gage (USA made) so it should not be too hard to find (hope, I hope, I hope). 

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I ordered the oil pressure gauge last night from AC Spruce. After ordering I realized that it says it is a non-stocked item! 

Anyway, for anyone in need, I have not found a better source:

AC Spruce P/N  10-02779 UMA 1-1/4" OIL TEMP 100F - 300F FOR ROTAX 912 NON TSO

They charge $190 and I used USPS priority for $9.00 and they did not charge tax (they are CA and I am AZ). 

I will have to make the color arches (I have sticky back clear vinyl printing paper, gonna use that for all my markings). 

I can see happy skies ahead . . .

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UMA guages are not high accuracy guages but are adequate for lsa and experimental. They are not built to TSO standards and the very small size makes them even less accurate. If you want accurate guages buy the ones used on a Gulfstream. It is smart to check them in boiling water (adjusted for altitude) and then note the difference especially for temps closer to limits. I look for sudden changes in temp or press. I would be interested to see what indication is on a new guage in boiling water. Some of the ones on older certified aircraft are not much better. UMA will repair a guage with a quick turn and very reasonable, I have found them to have outstanding customer service and am very impressed.

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Thanks for the info. I'll see if I can get an estimate from them tomorrow. I can't cancel my AC Spruce order, but Maybe I'll have this old one rebuilt anyway. 

Update: I called them today because the shipment for the new gauge was shown as 10/12/2018 (plus USPS priority shipment time). They said that delivery would probably be sooner but I said I was interested in having my existing gauge rebuilt. They said that they could probably overhaul in 2 or 3 days and the usual charge for it is $50. So, my gauge is on it's way with UPS 2 day (30 some bucks, ouch, ha ha). 

Again, thanks for the info!!!

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I got my new oil temp gauge today (way ahead of delivery promise). It had no color markings, so I took a picture of the face, and brought it into Corel Draw to create the color markings (also brought in a picture of the old gauge so I could get the markings right). Then I scaled it to true size. Then I threw away the pictures, so I can print out the color markings on clear vinyl sticky back printer stock. I'm adding a picture of the other new sticky back markings that I made up already. Tomorrow I will install the new gauge and markings and fly Lilly (weather permitting). All my engine heat problems should be gone now (knock on wood). By the way, if you need to change marking on any of your instrument panels, Acetone on a swab takes off the old markings very easily.

Markings for oil temp gauge.jpg

Markings for oil temp gauge 3.jpg

markings ready to install.jpg

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ib,

Your labels look beautiful. I want to make some too. What printer do you use (an ink jet?) and what “clear vinyl sticky back printer stock”?

Mike Koerner

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My printer is a pretty cheapy all-in-one Cannon (ink jet). I love that it has an automatic sheet feeder. I ordered my vinyl printer paper from photo paper direct. I got white vinyl paper by mistake and then I reordered and got the clear. 

I gotta update and say that the color marking for my oil temp gauge did not work out well! The clear vinyl film over the gauge glass was not totally clear and worse yet, the color arcs were translucent so they were not nearly "bold" enough (faint). I ended up making a template out of white vinyl sticky back stock, and then I cut thin strips of color vinyl tape that I had bought last year to make the color arcs. You can buy color arc decals from AC Spruce, but they are pretty expensive and their shipping rates are also pretty high. I think I will try making vinyl decals by printing on white vinyl sticky back printer paper and then cut away all that extra white material (tedious work with "senior vision" ha ha). Using the clear vinyl sticky back printer paper for instrument panel marking works fine. So great to be able to change the markings at will! 

UMA finished the rebuild of my old oil temp gauge. The rebuild charge was $49.XX, amazing (they had to replace a PCB).  

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9 minutes ago, ibjet said:

Thanks Mike! OMG, I wish I had more ambition! 

From here . . . I'd say you have plenty!?

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Oh, BTW Mike, I forgot to say that I ordered the vinyl printer paper direct online from that company, 

www.photopaperdirect.us (the packets still say .com???)

And the name of the white and clear sheets is:

1. Inkjet Vinyl, Self Adhesive, Gloss (it does not say white, but it is).

2. Inkjet, Self Adhesive, Clear Film.

For gauge markings, I think printing on the white Vinyl is the way to go. But, I'm trying to figure out how to trim them accurately. I thought about a laser cutter, but I don't think they have any cheap enough to make that practical. I saw one that is just about the size of an inkjet printer. Hmmm, there may be a laser in my future, ha ha. 

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Put the program for the outline of the arcs into your 3-D printer, fill the 3-D printer’s binder cartridge with acetone instead, carefully position the sticky-back vinyl sheet with the pre-printed arcs onto the 3-D printer's platen, then, with no media on the tray, let the 3-D printer dissolve the vinyl around the edges of the arcs.

Or, just put the acetone into one of your inkjet printer's cartridges, black for example. Then outline the part in black before you print it.  

Alternately, Use the 3-D printer with the outline of the arcs to make a plastic die, then program a plug that just barely fits inside it with a couple guide pins. Set the pre-printed sticky-back vinyl between the two and whack the assembly with a hammer.

I have no idea if these ideas will work… but you should try them anyway.

Be careful with the acetone though. It may dissolve parts of your printers too. (My wife's cat pee'd on my inkjet and despite my best efforts to clean it, it quite working a few days later.)

Mike Koerner

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