Red liquid on turbos

[dkkim73]

Hive mind, 

Puzzled and wondering if anyone here can shed some light. 

There has, for a bit, been a slight oil film on my left (pilot) side turbo. It was felt to be from a flange gasket (where the oil lines connect). That gasket was replaced a month or two ago, but it's still there. Not high volume, so watching it. 

Today, I saw a few drops of red fluid on both the pilot and passenger-side turbos (TSIO-550G(3)). 

Where is this from? I am unaware of any red fluids in the aircraft... The oil is a golden color, slowly browning a bit but still honey-colored. No recent increase in consumption (two cylinders replaced about 35 hrs ago). 

I did run TKS a lot about 2 flights ago, but unsure how that would affect anything. They used Leak-Tec spray compound to check the exhaust at the end of October 2024 (CO leak in recent months). But I would imagine seeing something earlier if that was where it was from.

Any ideas? (please don't tell me it's the tranny or turbo encabulator, I've heard they're both back-ordered...)

D

Edited December 24, 2024 by dkkim73
Adding engine type

[ArtVandelay]

Isn’t brake fluid red? Although I have no idea how that could happen.

[MB65E]

What prop do you have on your airplane? 
-Matt

[Fritz1]

Loctite thread locking compound is red, any maintenance done around the turbo?

[Ragsf15e]

It would be strange to get this fluid there, but it is a red fluid, so here it is… as @MB65E alluded to, there are some props that have red grease in them to show you they’re leaking.  Usually noticeable on the prop, cowl or windscreen.  Unlikely on the turbo but there you are.

[exM20K]

Photo?

[dkkim73]

1 hour ago, exM20K said:

Photo?

Doh! Thought I did that. 

 

[dkkim73]

16 hours ago, MB65E said:

What prop do you have on your airplane? 
-Matt

Hartzell 3-blade scimitar with ice boots, PHC-J3YF-1RF. 

It was overhauled (not IRAN) about 120 hrs ago by Jordan Propeller in TX (working with the Mooney factory, came well-recommended). 

I had the thought about Loctite. Two cylinders were replaced about 35 hrs ago, #3 and #4, somewhere not far away there was a gasket on a Left turbo flange replaced (under theory that was causing a slow seep)... That's the one with two bolts that has a stalk attaching to the little cylinder. They said they tightened some sump bolts, a rocker cover, etc. Not sure if some loctite might have been used. 

It occured to me that the leak check compound (LeakTec) might have been colored, and either of the abovet was "liberated" by precip and heavy TKS use recently, finally washed down. 

I may go and decowl it after Christmas events and see if I can discern more of a pattern or source. 

D

[EricJ]

20 minutes ago, dkkim73 said:

Hartzell 3-blade scimitar with ice boots, PHC-J3YF-1RF. 

It was overhauled (not IRAN) about 120 hrs ago by Jordan Propeller in TX (working with the Mooney factory, came well-recommended). 

I had the thought about Loctite. Two cylinders were replaced about 35 hrs ago, #3 and #4, somewhere not far away there was a gasket on a Left turbo flange replaced (under theory that was causing a slow seep)... That's the one with two bolts that has a stalk attaching to the little cylinder. They said they tightened some sump bolts, a rocker cover, etc. Not sure if some loctite might have been used. 

It occured to me that the leak check compound (LeakTec) might have been colored, and either of the abovet was "liberated" by precip and heavy TKS use recently, finally washed down. 

I may go and decowl it after Christmas events and see if I can discern more of a pattern or source. 

D

Hartzell props don't get the red grease, and that doesn't look like loctite, plus there aren't very many places on an airplane where red loctite is used.    It looks like 5606 or other hydraulic fluid, but you may be right about it being LeakTec if somebody used that recently. 

[dkkim73]

@EricJ I did a web search and saw bottles of LeakTec looking fluorescent greenish-yellow. Are there varieties, and does it change color? 

 

[EricJ]

49 minutes ago, dkkim73 said:

@EricJ I did a web search and saw bottles of LeakTec looking fluorescent greenish-yellow. Are there varieties, and does it change color? 

 

There's all different kinds and colors.   If they were checking for an upper-deck leak they may have used something like this:

https://www.amazon.com/Gasoila-LT28-Leak-Tech-Temperature-Detector/dp/B0025Q784I

 

[MB65E]

Interesting. Could be loctite. Definitely not the propeller then. 
-Matt

[MikeOH]

Does it 'come back'?  I.e., have you cleaned it up, gone flying and found more upon return?

[dkkim73]

So... mystery solved. I spoke to the mechanics who've worked on the plane most recently. It turns out that the oil used to recharge the Challenger air filter for the 100 hr ICA (done only a few hours ago) is red in color. The LeakTec they use is, on the other hand, the blue or green variety. 

I decowled the engine top & bottom today and looked carefully. The red oil is clearly distinct from the circulating engine oil, and I see the drops at the lowest point on the compressor side of both turbos. A trace along the underside of the air filter, and some lesser traces elsewhere. 

Nothing on the upper portions of the engine at all. 

My theory is that either: 

1. The oil misted into the induction system and collected on the manifolds, or the compressor scroll, and dripped back down, a bit worked out along joints or the turbo housing. A trace along one of the compressor discharge hoses (routed upward) might support this. 

2. It simply leaked out the air filter housing and was blown about the lower compartment, eventually collecting on the lowest points. 

Either way, it's very reassuring that there's no source of other red stuff (like degenerating Loctite, gasket compound, etc.). And the small amount of oil is a previously-known thing, attributed to that flange gasket or collection of dipstick drip from above. 

Thank you all for the inputs! I'm going to separately figure out a good cleaning solution (mineral spirits) for future use, but the current worry is addressed. 

D

[EricJ]

Is there a paper filter option for your airplane?    This sort of thing is why I changed to a paper filter on my M20J.   The oiled filters never contain the oil very well.

[A64Pilot]

If it’s that, then it’s K&N oil

It’s easy to over oil a filter and it does run out, but it doesn’t hurt anything. Attached pic is of a new K&N filter used on a Thrush turbine, maybe 3 ft square, it came from the factory a little over oiled.

The issue with a cotton gauge oiled filter isn’t that they drain oil, it’s that the do flow air very well, they do that by not being a very good filter, the paper filter, filters much finer particles, and I think a Brackett does to, but the bracket is very sticky oil, like glue.

I’ve always wondered how well a paper filter does in soaking rain though.

Edited December 28, 2024 by A64Pilot

[Pinecone]

I am familiar with the oiled filters from cars and motorcycles.

There was some tested a number of years ago that a fresh paper filter flowed almost as much as a oiled filter.  But over time, the flow went down.   

But the oiled filter did not filter well when freshly cleaned and oiled.  It took sometime to build up dirt, which made it filter better.  But it lost less flow as it got dirty versus a paper filter.

Some competition people I know, just used a fresh paper filter every weekend.