Crack in engine case...

rmorris · #1 12-22-07, 10:43 AM

I recently had have my rear turbo and exhaust pulled and overhauled.
My saga continues...
It took all Wednesday, mainly because he wasn't the one who tore it apart, but Mark got everything put back together. It was dark and cold, so we decided to hold off on a test flight until the next morning, but did run the engines for a while including a run-up to see the rear turbo kick-in. The next morning (Thur) I grabbed the plane and took off from Monroe (EQY) to meet Mark up at Concord (JQF) so he could give me the logs and make a final check. Everything seemed fine until I got into the downwind at Concord, then I heard a loud pop and the plane shuddered a second (similar to when the landing gear locks into place on both the sound and shudder). I looked out and my landing gear was still up, but the oil pressure on the rear engine was starting to drop. I put down my landing gear and pulled power back to idle on the rear engine (it was still running but the oil pressure continued to be lower than I was comfortable with seeing). I shut down the rear engine over the numbers and taxied to the ramp. After removing the rear cowling on the pilot side (same side as Turbo) I saw the source of all the oil dripping down -- there is a crack in the actual engine case. The engine through bolts where the turbo mounts were torqued according to the manual at 500 inches. Mark had been debating backing that off, but never did.

In any case, the actual case now has a crack in it and I am trying to figure out if I have any options besides getting a whole engine replacement (this one only has about 300 hours on it). If you have any ideas and/or sources to use for research, I would appreciate it. After spending close to $6K in parts and labor over the past month, for this 15 minute flight, my wife is getting less understanding with each new issue - so I need to see if there is a cost-effective solution available.

As I said, my saga continues...

Robert Morris

rmorris@agsi.us
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Jeep cherokee

Mark Hislop · #2 12-22-07, 08:14 PM

Check with TCM. Some cracks are repairable, depending on where they are located and how long they are.

Roger · #3 12-23-07, 08:51 AM

Apparently pretty common on certain Tio360 cases. Not to say the IA didn't aggrevate the problem, as it was apparently ok before you had the work done.

http://www.lightplane-maintenance.com/LPM_LPM_0605.html

skymstr02 · #4 12-23-07, 08:55 AM

Do you have a heavy or light case? A heavy case is denoted if you have a DB or CB engine model number, ie, TSIO-360-D vs TSIO-360-DB.

rmorris · #5 12-23-07, 09:00 AM

good article, thanks.

The mechanic is still looking through options for me, and I will put more up here as things develop.

Still welcoming all comments and suggestions for courses of action.
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MERCEDES-BENZ R230

rmorris · #6 12-23-07, 09:01 AM

Not sure on the case. Will have to get the logs and double-check the engine model number.
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Bmw 3 Series History

Mark Hislop · #7 12-23-07, 01:41 PM

While you're checking the logs, also see if you have a VAR crankshaft or not. If you don't, and have to split the case, you have to replace the crankshaft. The extra cost could affect your decisions on repair, overhaul, or replacement.

rmorris · #8 12-23-07, 03:20 PM

The original of the engine log is with the mechanic, since he is doing research for me towards a solution.

I did find where I made a photocopy of the pages and see that in July of 2005 the previous owner (who was an a&p and is now deceased) tore down the engine because he thought there might be metal in the oil filter. He then honed the cylinders, replaced the bearings, rings and crankshaft. He specifically states that it doesn not count as on overhaul.

The logs say it is a TSIO-360A.

Since it says he replaced the crankshaft, but does not say VAR or not-VAR, how do I figure out if there is a VAR crankshaft (short of tearing it down to take a look? I have heard that if it has a non-VAR crankshaft that it is not cost-effective to overhaul.

Again, any suggestions or thoughts are welcome (either on this blog, or via email).

-Robert
rmorris@agsi.us
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Ipad games

skymstr02 · #9 12-23-07, 05:59 PM

Sounds like you have a light case, unfortunately that is a common problem on the light cases.

In many cases, the cracks are acceptable if they are monitored for progression.

In your case, this may not be possible with the loss of oil pressure. This indicates oil pressure from an oil gallery is leaking internally into the case (think bleeding internally). This is not usually repairable. The oil gallery may become obstructed if the crack is weld repaired.

rmorris · #10 12-23-07, 06:51 PM

The crack is very obvious from the outside of the engine, and the low oil pressure (I believe) is caused by the fact that a huge amount of oil came out the crack into the engine compartment.

I found some engines on a site where they were selling them inexpensive as a result of a prop strike. Since I am only looking (I thino) for a case, is it possible to grab a case from another salvage engine and then use all the other components from mine - as opposed to welding my case? If so, can I get the heavier case (assuming one is avail) and still use my components?
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Mark Hislop · #11 12-23-07, 07:20 PM

Robert:

If your crank was replaced in 2005, and it was done legally, then you should have a VAR crank. The AD to replace them has been in place since the mid 90's at least. The paper work should verify that. I also think, but I'm not sure, that there is a serial number on the prop hub that you can use to identify the crank.

You can definitely replace the light case with a heavy case and use your original components. Whether or not that is cost effective, I don't know. I guess it all depends on what you want to replace (bearings, etc) while the engine is all apart.

Skymaster337B · #12 12-24-07, 07:54 PM

So, can a VAR crank be used with a light case? And, how does one know what case is light and what case is heavey?

rmorris · #13 12-26-07, 03:31 PM

Attached is a pic of the crack in the case.

The flange on the crankshaft (that was replaced according to the logs in 2005) shows a serial number stamped on it - that makes it a VAR crankshaft, right?
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Chevrolet captiva

skymstr02 · #14 12-26-07, 10:40 PM

That case is not repairable, sorry. That is considered in a critical area.

Skymaster337B · #15 12-27-07, 12:01 AM

How about this crack? Would it be repairable?
Just above where the cylinder mates the case. It is the longer black line, running diagonally.