Lycoming IO360 oil leak = case crack?

[Igor_U]

Good evening,

I hope everyone had a great Thanksgiving. We certainly did but I think I found  source of recent oil leak on my engine (not so good ). 

 

Engine in question is IO360-A1A in my 67 M20F.

My IA and I just recently completed the annual and concentrated on finding persistent but slow oil leak as oil would drip on bottom cowl from somewhere what it looked bottom of Cylinder 2. One shop working on a plane thought it could be from the Cylinder 2 attached to the case, not case itself...

We didn't find anything, replaced rocker cover gaskets and such but at the same time found for the first time small leak on top of Cylinder 2 bolt dripping on a front baffle. my IA thought it's coming  from a pushrod tube so we replaced the shroud tube seals.

Well the other day while refueling, with sun at the right angle, I spotted a leak on top, through the cowl intake and what looks like a crack by the bolt. After cleaning I couldn't see anything but after returning to my hangar, it was more obvious. My IA seems to agree but we haven't done penetrant inspection yet.

Attached are pictures for you to see.

I'd like to see your opinion and what should I do with the engine. It was overhauled by Victor in 2002, just before I bought the plane and has 1300h on it. Apart from recent leak it was running well but now I'm also not sure if the crack could be somewhere else. I've read about cracks showing in general area of cylinder 2 but also Divco or others can repair that. Also, it just might be time for OH, considering hours and age.

Some shops recommended are Premier in Troutdale, OR, Wester Skyway, Jewell in MO and also Progressive Air in BC where I could benefit from exchange rate and maybe no sales tax for export (might be still tax for import, so no sure about that).  What would you suggest, and should i go with repaired case or new?

Factory OH? My understanding from Lycoming website is that for engine of my age (original to Mooney) and not Factory OH'd I would have to pay core surcharge... I don't think I can justify that expense for the old airframe like mine.

 

I'll probably do some other upgrades/OH like Bendix fuel controller, prop governor and new Lord mounts, Alternator to replace Generator... paint the baffles and engine mount (is powder coating recommended for engine mount?), perhaps few other things. some new hardware as well.

Good thing is winter is here so now is the good time to do it... Engine removal and install would be done by myself and IA so there will be opportunity to learn new things as well.

 

Regards,

 

 

Edited November 29, 2020 by Igor_U

[N201MKTurbo]

Could be a crack.

Ive found if you spray a case crack with brake parts cleaner, it will stand out.
 

The trichlor will soak into the crack and after it evaporates, it will still be wet at the crack.

[carusoam]

Around here somewhere... somebody pointed out the most common location for a case crack to appear...

Expect that you may have found the bolt hole that has become famous...

I tend to invite the guy who has seen the most engines in a year to have a look... @M20Doc (case crack IO360)

Best regards,

-a-

[Shadrach]

We can only guess looking at pictures. Hoping for the best.

[Igor_U]

1 minute ago, N201MKTurbo said:

Could be a crack.

Ive found if you spray a case crack with brake parts cleaner, it will stand out.
 

The trichlor will soak into the crack and after it evaporates, it will still be wet at the crack.

Trichlor? For pools? Not many pools around in Seattle but I could try with brake cleaner. but it seems obvious when I have oil coming out there... 

[MB65E]

It’s a crack.  Mine cracked the same place.

New cases have come down in price. I’ve had two cracks. Divco is a joke. Next crack I’ll just buy a new case and change it. 

:-(

-Matt

[Guest]

It does look like a crack.  Dye penetrant, or spray the suspect area with Arid Extra Dry and run it again.  The Arid will show a nice oily line if it’s a crack.

Clarence

[N201MKTurbo]

50 minutes ago, Igor_U said:

Trichlor? For pools? Not many pools around in Seattle but I could try with brake cleaner. but it seems obvious when I have oil coming out there... 

TCE. that’s what’s in the red stuff that will cause cancer and make the ozone hole bigger. It works great.

[corn_flake]

Honestly, I don't see the crack at all.  Can someone add an arrow to where you think the crack may be?  

[carusoam]

Flake,

expect that this ugly crack in the paint is following the crack emanating out of the machined hole with a bolt in it...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Tim Jodice]

I dont think your engine is original to the airplane. I say that because it looks like you have a wide deck engine and if it there will be no surcharge from lycoming even if you want a different engine say an IO-390. If it is a narrow deck you would need to get a rebuilt or new. You might want to go that way anyway to get the roller cam.

[Igor_U]

14 hours ago, carusoam said:

Flake,

expect that this ugly crack in the paint is following the crack emanating out of the machined hole with a bolt in it...

PP thoughts only, not a mechanic...

Best regards,

-a-

 

Anthony,

Thanks for pointing out the area; I meant to do that but posted unedited pictures.

It is a quite visible after running the engine, this picture was taken after it was partially wiped out. I'll try a Clarence's advice and also see when my mechanic can perform penetrant inspection.

 

13 hours ago, Tim Jodice said:

I dont think your engine is original to the airplane. I say that because it looks like you have a wide deck engine and if it there will be no surcharge from lycoming even if you want a different engine say an IO-390. If it is a narrow deck you would need to get a rebuilt or new. You might want to go that way anyway to get the roller cam.

I do have wide deck engine as it was confirmed also by Lycoming years ago when I was looking for some parts and I can assure you it is original of the plane as it shown in logbooks. First flight was signed by one C.L. Lane...

 

[Tim Jodice]

1 hour ago, Igor_U said:

I do have wide deck engine as it was confirmed also by Lycoming years ago when I was looking for some parts and I can assure you it is original of the plane as it shown in logbooks. First flight was signed by one C.L. Lane...

 

I didn't think that wide decks were made in the 60s. I say that because a 64 M20E that is maintained by the same shop as I do has a narrow deck engine.

Do you know what year they changed?

[M20F]

4 hours ago, Tim Jodice said:

I didn't think that wide decks were made in the 60s. I say that because a 64 M20E that is maintained by the same shop as I do has a narrow deck engine.

Do you know what year they changed?

My 1967 has wide deck cylinders

[Igor_U]

Well,

Just to close this thread, engine is removed and crated, ready for pickup this week.

OH will be done by Pro Aero in BC. I have to sort out few other things, like Engine mount inspection and powder-coat and send governor for OH (West Wing in Puyallup, WA).

I'll polish the firewall and refinish baffles myself and reinstall seal kit I received from Gee-Bee  in October. Also, replace the old generator and regulator with Plane Power alternator kit... I'll have enough time to do that while waiting for my engine. It seems all the engine shop have long backlogs. 

[Guest]

3 hours ago, Igor_U said:

Well,

Just to close this thread, engine is removed and crated, ready for pickup this week.

OH will be done by Pro Aero in BC. I have to sort out few other things, like Engine mount inspection and powder-coat and send governor for OH (West Wing in Puyallup, WA).

I'll polish the firewall and refinish baffles myself and reinstall seal kit I received from Gee-Bee  in October. Also, replace the old generator and regulator with Plane Power alternator kit... I'll have enough time to do that while waiting for my engine. It seems all the engine shop have long backlogs. 

I’d remove the manifold pressure line and fitting from cylinder #3 and the vacuum pump, as well as the special Mooney fitting for the fuel pressure line on the fuel servo before you send it away.

Clarence

[carusoam]

M20F engine just became available....  here...

Worth a look, while developing your plan...

-a-

[Martin S.]

Evening everybody,

I recently stumbled over this crank case crack thread. Did some research and it indeed turns out that the IO-360s are prone to cracking in this area. Does anybody know whether this holds for all IO-360s or only for specific types e.g. the A3B6D cases? 

Trying to collect some statistics so that the day my engine goes in for overhaul I can better estimate whether it might from a crank-case point of view be worth upgrading from an A3B6D version of the IO-360.

 

Thanks,

 

Martin

[jetdriven]

I have a freshly overhauled and recertified IO360-A3B6D roller case right here now. It is about 440 hours since new.

[M20F]

Mine cracked on the case itself after almost 50yrs and @3000hrs.  New case is I want to say around 400hrs with no issues.  
 

IO360-A1A

[ArtVandelay]

Mine cracked by the alternator, PO installed a non standard 130 amp alternator. Mine was not repairable so I got a new, difference was only 1 AMU between new and a used one.

[larrynimmo]

12 hours ago, jetdriven said:

I have a freshly overhauled and recertified IO360-A3B6D roller case right here now. It is about 440 hours since new.

Are you selling this engine?

[MooneyJohn]

My IO-360-A1A cracked in the same area and also was a slow oil leak.

[jetdriven]

16 hours ago, larrynimmo said:

Are you selling this engine?

Im selling the case and the crank 

[Martin S.]

Thanks for sharing ur data gentlemen!

@Igor_U Was your case welded, or did you exchange it?