Engine oil leak

[preinke]

My '77J in in for annual and oil is leaking from through bolt 2->3 and internal o ring is thought to be culprit. Sounds like case split is the best practice fix but was wondering what others' experience was for this. Engine has about 950 hours and mostly a top end in last 200 hours ( 3 of 4 cylinders). Once you part the case it seems to become a can of worms. Are there any shops that specialize in this ? What does a shop have to do for oil leak only ? What should a shop do ? What would you do ?

 

Thanks,

 

Paul Reinke

77J KIKV

 

[N601RX]

Are you sure your case has orings around the bolts? If not lycoming has a service bulletin that allows installing .001 and I believe a .003 oversized throughbolt in the field to stop leaks.

If I remember correctly the .001 is just a press fit into the existing hole and the .003 requires reaming 1st.

[preinke]

No I'm not sure . Would oversize help if it has o rings? I saw on another post that sudden oil usage can come from the mag mount. The mag was taken off last annual .

[N601RX]

Read Service Instruction 1290. It's been a while and I don't remember the exact wording. If they have any questions call Lycoming for clarification. It would depend if the engine had orings only or orings and dowls.

If its not one that the publish on their website pm me with your e-mail address and I'll e-mail it to you.

[Mooney1401]

I just got my engine back after my engineer found a hair line like crack in the case. Tomorrow is install day hope there are no more issues.

[Lood]

Same here. We tried every trick in the book to fix the minor leak at the through bolt, but in the end two hairline cracks were discovered in the case. Sure hope this is not the same with your engine.

[bd32322]

Why do cases crack?

Is there something we pilots can do to prevent it or is it a metallurgical issue?

[N201MKTurbo]

Don't operate your engine in the yellow arc of your tach. This is the RPM range which causes high levels of torsional vibration in the prop/crankshaft, and I believe the crankcase.

[preinke]

Follow up, The bolt was corroded in the center where the case halves meet. There didn't appear to be any fretting of the cases. The bolt was 8 thousandths under due to corrosion. A 1 thousandths over bolt was tried but it still leaks. A 2 thousandths bolt is being tried currently.

[Cody Stallings]

1 over fixed my oil leak, the through bolts seem to have a thick coating of cad on them. If you want your std. Bolts platted with cad, send them to me.

[kmyfm20s]

Any updates on the 2 thousandths over bolt? I have the same exact leak but my mechanic just said leave it be. It just bothers me to see oil on the ground and have to keep cleaning it off the belly of the plane. If it did correct the problem was it worth the expense?

[Heloman]

My '77J in in for annual and oil is leaking from through bolt 2->3 and internal o ring is thought to be culprit. Sounds like case split is the best practice fix but was wondering what others' experience was for this. Engine has about 950 hours and mostly a top end in last 200 hours ( 3 of 4 cylinders). Once you part the case it seems to become a can of worms. Are there any shops that specialize in this ? What does a shop have to do for oil leak only ? What should a shop do ? What would you do ?

 

Thanks,

 

Paul Reinke

77J KIKV

 

What you're talking about is a shop that looks the other way when opening a motor. Another way you could find the answer to this question is to ask around for the worst/cheapest shop people have ever heard of. I know of these shops, as I used to work for a company with a 145 engine shop. It sucks for everyone involved when a motor has to be opened for a "repair." The customer is on the "lookout" from the start thinking he's going to be ripped off and the shop knows it, we rarely would except a repair job like this, and would often ask the customer to come look at the motor after it was apart, but they rarely did. What repairmen wants to sign off a motor when they know they saw "something" or they're not supposed to be looking "there???" 

[preinke]

The .oo2 oversize bolt seems to have fixed the oil leak. I'll report longer term results after a few hours. Haven't received the bill yet but it will be an expensive annual with engine,gear,and aileron pushrod repairs

[Cody Stallings]

The .001 bolt fixed my leak. I can run 7qts now.

[preinke]

It ended up costing about 1AMU . 700 labor , 300 for two bolts. Anbody have a 180 they want to trade. Also have a 8A Luscombe