Cylinder Wear/Oil Leak during Bravo Prebuy

[Starlifter27]

Hello everyone,

I'm under contract to buy a 2005 Bravo.  It's in prebuy currently.  It has under 800 hours since new and has been flown regularly (if not a lot) during its life and by all accounts has been well-maintained at a very reputable shop. 

The cylinders were all removed at ~350TTSN for high oil consumption, the #2 cylinder was repaired at ~400TTSN and all cylinders were removed at ~440TTSN for warranty repair.  During the prebuy, some high temps/asymmetrical heating was found on the exhaust valves of #1 and #3 (pics attached) and a small oil leak that appears to originate from the front bottom of the case halves was noted.

My question to the wealth of knowledge out there is whether these findings are abnormal or to be expected with a TIO-540 with that amount of time on it?  Everything else appears good with the engine and the compressions are all between 74 and 77.  So far opinions from a couple of people I know have ranged from "eh, not sure about this" to "no worries, that's a turbo for you."  So I'm looking for some thoughts on these findings.

Thanks in advance!

 

Tom

 

[alextstone]

2 minutes ago, Starlifter27 said:

Hello everyone,

I'm under contract to buy a 2005 Bravo.  It's in prebuy currently.  It has under 800 hours since new and has been flown regularly (if not a lot) during its life and by all accounts has been well-maintained at a very reputable shop. 

The cylinders were all removed at ~350TTSN for high oil consumption, the #2 cylinder was repaired at ~400TTSN and all cylinders were removed at ~440TTSN for warranty repair.  During the prebuy, some high temps/asymmetrical heating was found on the exhaust valves of #1 and #3 (pics attached) and a small oil leak that appears to originate from the front bottom of the case halves was noted.

My question to the wealth of knowledge out there is whether these findings are abnormal or to be expected with a TIO-540 with that amount of time on it?  Everything else appears good with the engine and the compressions are all between 74 and 77.  So far opinions from a couple of people I know have ranged from "eh, not sure about this" to "no worries, that's a turbo for you."  So I'm looking for some thoughts on these findings.

Thanks in advance!

 

Tom

 

Hi, 95 Bravo owner here,... Good luck with your purchase!

 

Both cylinders need either IRAN or overhaul.  Budget $2500 per cylinder plus 10-15 hrs labor.  

Don't accept the plane without factoring this into the price.  Those valves are going to fail ...soon perhaps

 

Alex

 

[Fly Boomer]

14 minutes ago, Starlifter27 said:

My question to the wealth of knowledge out there is whether these findings are abnormal

Not sure about abnormal, but not good.

[Rick Junkin]

The repair history and current condition do not sound/look normal to me, but I'm not familiar with the specifics of what was happening with the aircraft produced in 2005 (mine is an '89). I'm curious what caused the cylinder issues early on, and how the current owner was running the engine. If he was running it in "full fire breathing dragon mode" as @carusoam would say, meaning consistently at 34/2400 for max performance in cruise, that could possibly explain the cylinder and valve life issues. #1 and #3 are definitely in trouble. It may not be too late to save them by lapping in place, but I wouldn't bet on it.

800 hours over 17 years is enough to make me go "hmmm...." but if as you say the airplane was flown regularly over that period, 4 or 5 hours a month, I'd be less concerned. Still, with all of that cylinder work I would want to know more about operation technique and specific issues that may have plagued that vintage of the TIO-540-AF1B. That said my cylinders were overhauled and flow balanced by the previous owner about 370 hours ago and all still have nice symmetrical exhaust valves and the engine only burns about a quart every 25 hours. My oil consumption is NOT normal, most Bravos appear to be more in the 10 hour/quart neighborhood. But I also run an extremely conservative 30/2200 in cruise, LOP at 13.8gph.

Let's see what other Bravo folks have to say about their experience with exhaust valves and cylinders in general. I'm thinking you'll want to ask the current owner some questions about how he ran the engine. I'm assuming this is a one-owner airplane.

Cheers,
Rick

[Boilermonkey]

Absolutely have it fixed.  Not normal.   I mean it happens, but when it does, it needs to be fixed.    Be ready for delays in getting cylinders.

[Shadrach]

Those valves do not look healthy.  I can not say why, but the green area is telltale sign of seat issue and overheating. maybe warped as well. Did they seal during the Comp Check?  Would not change my opinion, I'm just curious. 

[LANCECASPER]

6 hours ago, Starlifter27 said:

Hello everyone,

I'm under contract to buy a 2005 Bravo.  It's in prebuy currently.  It has under 800 hours since new and has been flown regularly (if not a lot) during its life and by all accounts has been well-maintained at a very reputable shop. 

The cylinders were all removed at ~350TTSN for high oil consumption, the #2 cylinder was repaired at ~400TTSN and all cylinders were removed at ~440TTSN for warranty repair.  During the prebuy, some high temps/asymmetrical heating was found on the exhaust valves of #1 and #3 (pics attached) and a small oil leak that appears to originate from the front bottom of the case halves was noted.

My question to the wealth of knowledge out there is whether these findings are abnormal or to be expected with a TIO-540 with that amount of time on it?  Everything else appears good with the engine and the compressions are all between 74 and 77.  So far opinions from a couple of people I know have ranged from "eh, not sure about this" to "no worries, that's a turbo for you."  So I'm looking for some thoughts on these findings.

Thanks in advance!

 

Tom

 

Thankfully you’re catching this during a pre-buy and not your first annual after ownership. Do you mind sharing which shop is doing the pre-buy?

[carusoam]

Welcome aboard starlifter!

First: What caused the oil consumption, what was the solution?

Then: Check the details of your first post…

800 hrs over 17 years… < 50 hours each year…?

That is not flying a lot….

If not spread evenly…. It may have been dormant for a while…. Somewhere in between…

 

Some owners try to see how many hours they can get out of a set of cylinders…. For a TC’d Mooney getting to 1khrs is a nominal goal…

Running into oil consumption at 350hrs… eesh…

For TC’d engines… temp control is everything…. Starting with the TIT…

Good temp control can get more hours out of the cylinders….

 

Some Mooney owners prefer speed over efficiency….. and don’t mind the extra costs involved in going fast….

 

If you decide to fly around in flaming dragon mode… the extra cost of a TOH is already in your plan….

 

Have you discussed how the plane has been operated?

Sounds like the seller may not actually be the pilot of the plane….

Cylinders have been off twice already… and looks like whatever the issue is… hasn’t gone away….

As far as asymmetric heating goes… is that new? 

a giant ball of flame occurs within the cylinder… the exhaust valves don’t get the same cooling that the rest of the cylinder sees….

Might be asymmetric cooling….

 

Either way…

Know what makes a Bravo different than a TLS…. I’d be wondering how well the wet heads are behaving….

 

Tough first post…

What does your Purchase agreement say about this issue?

How does the rest of the plane look so far? 
 

What do you know about Bravos, TC’d plane engines, GA flying?

Looks like it could be a nice plane looking for a simple valve job…

But, why would such a well developed plane be going through such cylinder difficulties…?

Do you get to download the engine data as part of the PPI?

The engine data is almost as good as talking with the pilot….

Some engine monitors store tremendous amounts of data…

 

Tradition for posting valve pics… post them all, numbered by cylinder….  Best pics are looking directly at the surface…

Essentially we are looking for six identical pizzas…  nobody really likes to eat an asymmetrical pizza… 

 

I bet it’s been a busy week…. 

 

PP thoughts only, not a mechanic or plane seller…

Best regards,

-a-

 

[Starlifter27]

All,

Thanks for all the opinions so far and for welcoming me here.  The prebuy is complete and I've shared the info with a couple more A&Ps to get some additional thoughts as well.

Some shotgun answers to the various questions and points raised here:

-The prevailing opinion from the A&Ps is that the engine wasn't properly broken in when it was new, which is what led to the excessive oil consumption and the first pull of the cylinders off the engine.  The second pull came from a lycoming warranty repair or recall, so there's less concern about that.

-The asymmetrical heating of the two valves is believed to most likely be a result of over-aggressive leaning.  Quite possibly it's been operated in "flaming dragon" mode as was eloquently stated here.  The airplane has been kept in excellent condition inside and out, so it does seem to point to how it was operated rather than indifference or neglect.

-It is a low-time aircraft for its age, but the logs show it was flown steadily over its life and it's been a one owner, one pilot plane that has been otherwise well-maintained.  Other than the cylinder issues, all the other squawks found on the prebuy were the typical minor issues they normally see. 

-Those two cylinders will need replaced in the short term, so the issue now becomes what agreement, if any, we can negotiate to account for that.  My purchase agreement allows me to walk no questions asked, so I'm not too worried about that.  The seller is motivated to sell, so we'll see where it ends up.  If I walk, the next buyer is going to discover the same issues, so one way or another it's going to have to be addressed.  My preference at this point is to negotiate a price reduction to account for the cylinder replacement and have a shop with extensive Mooney experience near me do the work after I take possession.

Again, I appreciate all the opinions and insight.  Keep them coming, as I'm getting back to my GA roots flying after 20+ years of military and airline flying and this is my first aircraft purchase adventure.

Thanks,

Tom

 

[Boilermonkey]

Have you flown a Bravo?   I'm in Indiana, once my reman is done I'd be happy to come over and take you up.

[philiplane]

The half round heat signatures on the valves indicates they aren't seating evenly, probably due to misalignment during the previous repair. The seat was not ground perpendicular to the valve. So the heat transfer area is wide on one half, and narrow on the other half.

This is not a typical defect.  You usually find localized hot spots which occur due to a worn guide where the valve wobbles, and doesn't contact the same place twice. 

Either way, the cylinders will need to come off and be repaired properly, with new exhaust valves and guides.

[Cruiser]

can you download or get the historical engine monitor data to look at? I would be particularly interested in Cylinder temperatures during climb. 

 

[LANCECASPER]

11 hours ago, Starlifter27 said:

All,

Thanks for all the opinions so far and for welcoming me here.  The prebuy is complete and I've shared the info with a couple more A&Ps to get some additional thoughts as well.

Some shotgun answers to the various questions and points raised here:

-The prevailing opinion from the A&Ps is that the engine wasn't properly broken in when it was new, which is what led to the excessive oil consumption and the first pull of the cylinders off the engine.  The second pull came from a lycoming warranty repair or recall, so there's less concern about that.

-The asymmetrical heating of the two valves is believed to most likely be a result of over-aggressive leaning.  Quite possibly it's been operated in "flaming dragon" mode as was eloquently stated here.  The airplane has been kept in excellent condition inside and out, so it does seem to point to how it was operated rather than indifference or neglect.

-It is a low-time aircraft for its age, but the logs show it was flown steadily over its life and it's been a one owner, one pilot plane that has been otherwise well-maintained.  Other than the cylinder issues, all the other squawks found on the prebuy were the typical minor issues they normally see. 

-Those two cylinders will need replaced in the short term, so the issue now becomes what agreement, if any, we can negotiate to account for that.  My purchase agreement allows me to walk no questions asked, so I'm not too worried about that.  The seller is motivated to sell, so we'll see where it ends up.  If I walk, the next buyer is going to discover the same issues, so one way or another it's going to have to be addressed.  My preference at this point is to negotiate a price reduction to account for the cylinder replacement and have a shop with extensive Mooney experience near me do the work after I take possession.

Again, I appreciate all the opinions and insight.  Keep them coming, as I'm getting back to my GA roots flying after 20+ years of military and airline flying and this is my first aircraft purchase adventure.

Thanks,

Tom

 

Engines will come and go and get overhauled during the life of the airplane, but a tired Mooney airframe can’t be “zero-timed”. All that just to say that a well-maintained low time airframe is worth a premium. Getting those two cylinders taken care of should make this a good airplane for you. 

(Although one thing I would be very concerned about on a 2005 or 2006 Bravo is has it had the WAAS upgrade yet? An often-used argument is that “I don’t need WAAS - everywhere I fly has an ILS”. The next person you try to sell it to may not feel that way. Anything resembling an airplane is selling right now. When, not if,  the market slows down, a non-WAAS G1000 airplane will be much harder to sell. If it doesn’t have WAAS what is your plan to add it? Garmin doesn’t make GIA-63W units anymore, although they service and exchange them. If Don Maxwell or Brian Kendrick has a pair of used GIA-63Ws it will cost somewhere between $30,000 and $35,000 to do the upgrade.)

[201Steve]

On 5/10/2022 at 10:13 AM, Starlifter27 said:

The asymmetrical heating of the two valves is believed to most likely be a result of over-aggressive leaning. 

Stick around here and you’ll learn this is a highly controversial assumption. 
 

whatever the case, the valves are toasted and they need to be replaced. I would be hesitant to even fly it at all, until resolved. That’s just me. But I have found great intrigue digging into this stuff and learning the various theories. That would be my recommendation- read, learn, pick a side, consider the ramifications of each operation style and then cross your fingers because sometimes it seems to be idiopathic.  Also agree that if you can capture some engine monitor data, upload it, have it analyzed, you might learn a thing or two about the potential conditions that could lead to a burning valve and then, not do that anymore for this engine. That would be a great starting point to figuring out which type of engine operator you want to be. ROP, LOP, Red boxes, red fins, chts, TEL, egts, combustion pressures, guys named Mike, guys named George….

 

-Not an anything, just some stranger on the internet. =)

[Starlifter27]

Thanks again for the advice and knowledge from everyone here.

We negotiated a lower price to account for the cylinder repair and the rest of the prebuy didn't bring up any showstoppers in the opinion of either the A&P overseeing the prebuy (I used Savvy since I'll be using them for engine monitoring going forward) or the A&P I'll be using who has a lot of mooney maintenance experience.

Now the hard part is finding a CFI with 50 hours in make and model to give me the 4 hours of dual I need for my insurance...

[LANCECASPER]

3 hours ago, Starlifter27 said:

Thanks again for the advice and knowledge from everyone here.

We negotiated a lower price to account for the cylinder repair and the rest of the prebuy didn't bring up any showstoppers in the opinion of either the A&P overseeing the prebuy (I used Savvy since I'll be using them for engine monitoring going forward) or the A&P I'll be using who has a lot of mooney maintenance experience.

Now the hard part is finding a CFI with 50 hours in make and model to give me the 4 hours of dual I need for my insurance...

@mike_elliott is at least on the eastern half of the country and well exceeds those requirements

[Boilermonkey]

My partner in our M20M is a CFII with hundreds of hours in it. 1000s in others.  We are based at KBAK (Columbus, IN), let me know if you want his contact details.

[Starlifter27]

22 hours ago, Boilermonkey said:

My partner in our M20M is a CFII with hundreds of hours in it. 1000s in others.  We are based at KBAK (Columbus, IN), let me know if you want his contact details.

That'd be great, please message me his info if you don't mind.

Finding a CFI meeting insurance requirements has turned into the biggest hurdle in this whole process.

Thanks a bunch!

[Pinecone]

Bummer.  I was hoping you would pass on this one.  

 

So I could buy it.

 

 

[Starlifter27]

On 5/23/2022 at 1:22 PM, Pinecone said:

Bummer.  I was hoping you would pass on this one.  

 

So I could buy it.

 

 

Sorry! 

The test flight went well and the single owner really kept it in good shape, prebuy squawks notwithstanding.  Interestingly, from how he said he operated it and from this article AOPA_2022-05_failure-to-rotate.pdf (savvyaviation.com) (also thanks to @Junkman for sending it my way) perhaps the exhaust valve issues may stem (pun intended) more from hardware issues rather than user technique.  Either way, we negotiated a price reduction to account for needing the valves repaired or replaced in the near term.

[Pinecone]

Enjoy it.

And contact me if you ever decide to sell it.

 

[LANCECASPER]

13 hours ago, Starlifter27 said:

Sorry! 

The test flight went well and the single owner really kept it in good shape, prebuy squawks notwithstanding.  Interestingly, from how he said he operated it and from this article AOPA_2022-05_failure-to-rotate.pdf (savvyaviation.com) (also thanks to @Junkman for sending it my way) perhaps the exhaust valve issues may stem (pun intended) more from hardware issues rather than user technique.  Either way, we negotiated a price reduction to account for needing the valves repaired or replaced in the near term.

Having owned three Bravos over the years, the first thing I would check before flying this airplane home is the TIT probe. The best Bravo owners will still cook cylinders if the TIT probe is not reading correctly. These probes only last a few hundred hours on the Bravo. The previous owner may have been conscientiously flying at temperatures that he thought were fine. But once the probes start going they read low, which causes people to lean further causing further problems, which certainly could have led to the cylinder/exhaust valve problems you describe.

[tls pilot]

17 hours ago, LANCECASPER said:

Having owned three Bravos over the years, the first thing I would check before flying this airplane home is the TIT probe. The best Bravo owners will still cook cylinders if the TIT probe is not reading correctly. These probes only last a few hundred hours on the Bravo. The previous owner may have been conscientiously flying at temperatures that he thought were fine. But once the probes start going they read low, which causes people to lean further causing further problems, which certainly could have led to the cylinder/exhaust valve problems you describe.

I have dual TIT Probes

Over the years, I have sent probes back to manufacturer to check the calibration of the used probe

Years ago, Lycoming issued a SB on the TIT Probes for the Piper Malibu but not on the TLS then Bravo

Also, your fuel flow for a power setting will verify (not exactly, but close enough) 

 

[carusoam]

TIT probes live in the most hazardous environment possible…

6X more hazardous than what a single EGT sensor sees….

It is very hot, for a higher percentage of time….

Six waves of heat go by compared to a single wave for the EGT sensor…

PP thoughts only,

-a-

[affricate]

On 5/10/2022 at 3:19 PM, LANCECASPER said:

Engines will come and go and get overhauled during the life of the airplane, but a tired Mooney airframe can’t be “zero-timed”. All that just to say that a well-maintained low time airframe is worth a premium. Getting those two cylinders taken care of should make this a good airplane for you. 

(Although one thing I would be very concerned about on a 2005 or 2006 Bravo is has it had the WAAS upgrade yet? An often-used argument is that “I don’t need WAAS - everywhere I fly has an ILS”. The next person you try to sell it to may not feel that way. Anything resembling an airplane is selling right now. When, not if,  the market slows down, a non-WAAS G1000 airplane will be much harder to sell. If it doesn’t have WAAS what is your plan to add it? Garmin doesn’t make GIA-63W units anymore, although they service and exchange them. If Don Maxwell or Brian Kendrick has a pair of used GIA-63Ws it will cost somewhere between $30,000 and $35,000 to do the upgrade.)

Agreed, my 1989 TLS Bravo had less than 2000 hrs on the frame Since new.

 

After MOH, running like a champ and I have a great plane that gets me back and forth from Tucson to Baton Rouge fast and efficiently.