Oil Temp in a Climb

[Ed Cesnalis]

Just modified my SW with the spring in the hose. At a humid 90+ degrees , initial climb 1000 ft/ min to 1000 then 500 ft/ min to 4000. Oil temperature stability < 230 and cyl temperature decrease ( oil system also takes heat away ). Roger got this one right.

 

Good on you for realizing an improvement.  

 

This subject is broader than 'roger got it right' on one issue 'spring in oil line'.  There have been big improvements from other changes like separating the coolers and relocating the oil cooler.  Addressing air flow through the cowling is another.  The amount of debris that came from my oil cooler overhaul had a negative effect on cooling capacity even if we don't know yet how much.

[Roger Lee]

Hi Ed,

 

It isn't a big problem or 1800+ CT's in the world (360 in the US)  would be having issues. It is a very small select few. Most can be traced back to things like your oil cooler clog and the #1 offender is the reduced radius hose. Both of these are easy enough to fix. I live and so do others here in AZ in a hotter climate than most and we don't have over temp issues with the factory design. Being in the yellow at 230F-240F in climb on oil temp is not over heating. Just because a few have not found their issues doesn't translate into fleet wide problems.

 

Most of these temp issues can be fixed by a cooler flush, a hose re-route, a spring in the hose of flattening prop pitch.

 

The separation of the coolers is drastic and a very involved mod which you would have to be ELSA to do. (I have already seen pictures of this)

Is it best to have them separated, I would agree, but the fact that the other 1800 CT's don't need that mod should show the other way also works.

 

You never had the problem in the beginning and yours seems to be debris caused and not a design issue. Yours still would have happened even with separated coolers. Yours may have been owner caused (Not design caused, need to know what the yellow debris was) and or hose radius reduction caused or a combo of both. 

You can flush your own cooler just as easy as sending it off. I have done a few. It's quite easy. Some lacquer thinner or toluene and high pressure air works wonders.

You can buy a high pressure air / liquid siphon at Ace Aviation or Home Dopey.

 

Even with your cooler now flushed you should put a spring in the oil line like I showed in the video and re-route the oil hose off the bottom of the tank.

Your re-route choices are;

Turn the banjo bolt on the bottom straight out under cyl. 2&4 and change the straight fitting to a 90 degree to go back into the tank. You will need to change the hose length and make the outlet to the cooler slightly longer, but this makes both hoses absolutely straight without a chance to reduce radius.

 

The second is to turn the bottom banjo bolt more towards the battery(instead of the oil tank) and then lengthen that hose and make a nice gentle loop back behind the engine to the oil tank inlet. No more short "S" turning hose. Springs here in the short "S" turn hose would work too.

 

Both of these work well. (I like the first way better)

 

Jumping into the deep end is probably over kill for a problem with a simpler solution and cutting and modifying your cowl, muffler and hoses is a drastic and most likely not needed mod. when the other couple of mods above does just fine.

 

If someone were to start experiencing higher and higher oil temps over time or even an acute sustainable high oil temps I would flush the cooler and fix the hose.

 

Always start simple and inexpensive and work your way up with the most common causes. 

[Ed Cesnalis]

Roger,

 

I'm not advocating that anyone separate their coolers and I'm not saying there is a big fleetwide problem.  Until we hear the same report from CTLS owner's I am going to assume that the problem begins with air-flow (lack of) through the CTSW cowling.  I'm also going to assume that it is possible that there is a common thread there in Phoenix coming from your maintenance that has kept you guys on the cool side of the line.  You messaged that your plane finally got hot and that you were going to try a spring and report back, how did that go?

 

To a few of us with older CTs it is a big problem.  One in my group would be Wayne and you worked on his plane for a day and did not solve it.  Did you put springs in his oil lines?

 

Both Hot flush and http://www.oilcoolers.com/images/articles/Pacific%20Oil%20Cooler%20Article%20Pip%2001-2012.pdf Pacific oil cooler services say that simple flushings with solvent don't work.  Pacific says a cooler after 2-3 years or 300 hours needs an overhaul.  Mine first got hot on the 2nd McMinville fly-in which was 2-3 years and over 300 hours.

 

Air-flow through cowling/cooler - oil flow through cooler - contaminants in cooler are the 3 areas that I see that can cause or contribute to diminished cooling capacity.  I used to be able to climb to 10,000' from sea level at 500'/min without getting hotter than 230.  It has got progressively worse in spite of 3 hose replacements and backflushing with solvent until I can hit 265 climbing 1,000'.

 

It would be great if simply adding springs would fix most CTSWs.  I guess time will tell on that one.  It has only become the fix of the day in recent weeks.

 

It is my understanding that the oil tank and cooler cannot be by-passed and if you take this thinking farther a reduced radius should backup oil in the tank and starve the oil pump.  Do you think this is happening as well?

 

Hot Flush did have more of my yellow contaminant and sent it to me so we can look at it and have it analyzed, it gets here on Monday.  Jeremy says that in 05 and 06 Rotax was using a yellow sealant on the crank, he thinks the color matches that and we will compare it.

[Roger Lee]

In my video post I stated that the spring fix on my plane reduced temps by 20F. Mine never gets over 230F now on a nice hot day no matter how hard I climb.  I have flushed my cooler about 200 hrs. ago and just installed the hose spring. Wayne was here one day and we did not get a chance to do everything. That said he had done several things I would have done up front, but a few items we did not get to try. I would have liked his plane here a couple of days. Most of the CT's that had an increasing oil temp issue has come from the SW's of which is a huge majority of the fleet and it's the oldest segment so an oil cooler cleaning would be more appropriate. Hose change can also be a factor if it happens after that. The hose we tend to use now is a little more pliable than the European factory hose especially when hot. Using a lot of 100LL will also eventually add to unwanted debris in more than just the cooler.

That older accepted gearbox sealer was orange (Loctite 567) not yellow, ( http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802627223553 ),   a red (Loctite 518),  and then the black 5910 (European) or Loctite 598 (US). We don't use the first two any more and it wasn't used from the factory. It was an alternative.

 

If air flow was an issue with the SW or LS with 1800+ worldwide we would certainly be hearing about it. That said I have seen some radiators need better alignment in the air intake opening. You can also trim the air intake bottom lip down some to allow more air to cooler surface area. Takes maybe 3-4 minutes to do with a Dremel.

 

I'm sure the hot flush system may work a tad better than other ways, but saying other ways don't work I think is propaganda. It does work or the hot flush would be all that anyone with a car, motorcycle or anything with a cooler would be willing or setup to do. Any chemical that will dissolve i oil and cause a hurricane air flow through the cooler should break any debris loose since it isn't hammered in place.

 

The oil tank can not be by-passed, but slowing the oil flow will cause the oil to absorb more heat and reduce the cooling process. You may have had just the cooler flow deduction or a reduced flow from a hose on top of it. Both items should be addressed. My bet is your temp issues will disappear. Don't let the hose go now that you have invested all the time and money on the cooler and this job.

[Ed Cesnalis]

I'm sure the hot flush system may work a tad better than other ways, but saying other ways don't work I think is propaganda. It does work or the hot flush would be all that anyone with a car, motorcycle or anything with a cooler would be willing or setup to do. Any chemical that will dissolve i oil and cause a hurricane air flow through the cooler should break any debris loose since it isn't hammered in place.

 

Hot flush flushes at 190 degrees.  Their reasoning is that passageways  (hundreds of small corrugations stamped into what's known as the "turbulator plate") have to be enlarged to the size they are at running temperature.  Upon cooling down they contract and trap the metal contaminants until the high temps return and the passageways regain their size.  Only then do they have success in backflushing under pressure with reversing pules.

 

Pacific has an early step where they use ultra-sound and save 13 hours of flushing time, after that their flushing process takes up to 40 hours.

 

In both cases the process is complete when 12 micron filters come clean after a series of contaminated filters.  When Flight Design Nevada backflushed my cooler there was no debris.

[Roger Lee]

So put the cooler in boiling water at 212F then flush. What was the cost of their flush?

 

Regular oil starts to breakdown around 260F-270F and synthetic around 350F.

We should all be using a full or semi synthetic oil and never a straight petroleum oil. Our temps that we see in our engines should never be a problem with our oil (full or semi synthetic) at 250F and under.

 

 

Ed,

What oil have you been using?

[Ed Cesnalis]

Mobil 1 4T full syn for most of the oil changes.  I do have 1 change with Shell Sport 4+.

[Ed Cesnalis]

I only burn mogas.

[Roger Lee]

Flew yesterday. Did a  hard climb to 6500' and a  medium climb up to 8500' (two people on board)  and never saw over 220F. The OATs were a little lower than our usual yesterday. Opening up those hoses with springs works quite well.

 

I wish I had used springs in the oil lines years ago.

 

Who knew, live and learn. Something always new out there.

The day I quit learning is the day I probably be dead. 

[Ed Cesnalis]

If the springs provided and instant fix for some of us old-timers like me, Wayne and Sandpiper I would be quite impressed and relieved.  Woodstock goes back together on Wednesday, at this point I may not need springs but they will be handy if I'm not back so 230 max.

[WmInce]

If the springs provided and instant fix for some of us old-timers like me, Wayne and Sandpiper I would be quite impressed and relieved.  Woodstock goes back together on Wednesday, at this point I may not need springs but they will be handy if I'm not back so 230 max.

 

Instead of goofing around with this CT, upon a great recommendation from a competent mechanic and just like Michael Jordan says, "Just do it."

 

When mine goes in for its next conditional, I'm going to have the springs installed.

 

Thank you Roger.

[Ed Cesnalis]

Instead of goofing around with this CT, upon a great recommendation from a competent mechanic and just like Michael Jordan says, "Just do it."

 

When mine goes in for its next conditional, I'm going to have the springs installed.

 

Thank you Roger.

 

 

I have already made too many changes at once, If I get a good result I will be guessing that the yellow contamination was a component.  If I don't get a good result then add springs and then see a good result I will know the springs are a major component.

 

I asked my dealer for springs back in 2008 and instead he installed new hoses, hoses which may have been a downgrade when it comes to holding their shape.  

 

I'm on my way to get some springs.

 

There was enough  contamination of an unknown substance in my oil-cooler where it is hard to say that I am just 'goofing around with this',   should I leave that mystery unsolved in favor of new springs?

[sandpiper]

I'll do the spring thing too as soon as I get back from AK. No, I didn't take the CT. My butt is no longer up to 5 hour legs.

[WmInce]

Good luck CT.  Hope we find out what the contamination was.  To say the least, it is a good education for all of us.

Due to the extreme interest with your experience here, this has been one of the longest forum threads I have followed since joining.  With that in mind . . . thanks for sharing all your experience with us.     

[WmInce]

. . . "My butt is no longer up to 5 hour legs." . . .

 

Yeah . . . mine is only good for about 2.5 to 3 hours.  Can you imagine sitting there for 9?     :blink:

 

But I really cherish the endurance of our little airplanes anyway.  The extra fuel buffer is comforting.

[Ed Cesnalis]

 

 

I have some samples of this yellow stuff.

 

It looks like plastic to me.  Hard but rubbery and the pieces are big enough to clog the turbulator plates for sure.

 

mysterious.

 

[Ed Cesnalis]

Here's a post from another forum that concerns me:

From the looks of it, something has bought the farm. Keep us posted as to what you find. But I think something has gone bad and these are pieces of that part. It could be an oil pressure relief valve of some sort. With it being a 912 it could be any number of things. 
Water in the oil it is not. Antifreeze in the oil it is not. Antifreeze in your oil will make the oil look like milk from the water. Water in fuel will not cause this either.
Your engine ate itself somewhere. I would lay 5 bucks on it. 

 

how many yellow plastic part s are there in a 912?

[Ed Cesnalis]

Unless it will solublize the cost is $1,200 to analyze!  And it might not work.

[FlyingMonkey]

Here's a post from another forum that concerns me:

From the looks of it, something has bought the farm. Keep us posted as to what you find. But I think something has gone bad and these are pieces of that part. It could be an oil pressure relief valve of some sort. With it being a 912 it could be any number of things. 

Water in the oil it is not. Antifreeze in the oil it is not. Antifreeze in your oil will make the oil look like milk from the water. Water in fuel will not cause this either.

Your engine ate itself somewhere. I would lay 5 bucks on it. 

 

how many yellow plastic part s are there in a 912?

 

Honestly, if something important big enough to shed that much material had destroyed itself, you'd almost *have* to see other signs.  Increased CHTs, metal in your oil & filter, RPM drops, increased/decreased oil pressure, excessive oil use, contaminated oil, contaminated coolant, leaks...*something*.

 

If your only symptoms are increased oil temps and contamination in your oil cooler, I'd replace the cooler and call it a day.  Watch for further symptoms of impending doom of course, but if none arise don't go assuming problems that probably are not there.  IMO, of course.

[Doug G.]

What comes to mind for me is one of those soft plastic temporary plugs used to keep debris out of a connector, or on the end of a new part that are supposed to be removed when the connector/device is installed.

Just a thought.

[Roger Lee]

I have had such good results with the springs in the oil lines I may put them in all CT's or LSA that have a tight turning oil hose. This has solved high temps issues in a few aircraft. I climbed out yesterday up to 8K. I never saw over 221F. What a change. I will now recommend that all CTSW's and LS CT's that I work on place a spring in the oil lines like FD already does in 2 of the coolant lines. 

 

If I was you ED I would put the springs in when you put the hoses back on. Springs cost about $2 each and take seconds to install. Why worry about the future or have to go back later and do it over.

[Roger Lee]

Doug you may be a genius, 

 

There is nothing internal in the 912 to cause this, BUT Doug keyed me back into a new engine delivery. Rotax delivers in a crate some items that have yellow plastic plug protectors. If during installation someone errored in some way that yellow protector may have been placed in a position within the system and over time has disintegrated. This makes even more since to me because it started early on and got worse.

I don't know this for sure, but it is the only thing that makes any since to me at all.

[Doug G.]

A very narrow sample for the genius label, Roger. There are others, including my wife, who have a different opinion.

[Roger Lee]

Your fault if she doesn't think you're a genius. You just need to remind her more often.  

[Jim Meade]

The plastic hose protector is a good idea. I think it raises some questions but is worth pursuing.

If it is a plastic shipping plug, it would be of a certain mass. If you gathered all the pieces, you'd have some idea of whether the amount of material fits the hypothesis. If you can get one of the plugs, you can compare it with your samples. Your samples will have been "processed" so they may be a different color and may have a different texture and even plasticity may have changed, but short of some major transformation you may get an idea if this explanation is reasonable.