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Oil Cooler burst after start-up?

blueflyer

blueflyer

Well Known Member
How many of you have ever had an oil cooler burst just after start up? I was about to go flying (not RV) the other day and the oil cooler gave up when I started the airplane. I saw the oil pressure was 3psi and waited 7-8 seconds for it to come up (it never came up) before I shut down. So, I got out and inspected. On the ground was a huge oil puddle. I bet I lost at least 50% of the oil that was in the airplane, so this was no little squirting leak. The hoses and connectors/fittings going to/from the cooler looked good from initial inspection. There is no discernable distortion of the oil cooler, but alot of oil was just dripping out of it when I looked (after shut down).

I havent removed the cooler (or cowling) for closer inspection yet, but I cant imagine why that would happen other than just a defective cooler. The cooler has about 150 hours on it, on an 0-290 engine that flies regularly. Its a 7 row Aero-Classic that is less than 2 years old.

Now, I dont know if this would make the cooler burst, but the oil screen had been inspected and reinstalled prior to this incident. Also, the oil sump has a coarse screen which had been taken out and reinstalled for inspection as well. Oil was changed and filled to normal ops level. One theory I have come up with is that somehow the oil screen gasket may have gotten pinched somehow during reinstallation and I didnt realize it??

Anyone have any ideas why this may have happened other than defective unit?
 
A similiar oiler cooler problem happen at Stead on an Lyc O-360. After an annual, on initial start up the oil cooler burst. It was attributed to the oil screen being installed backwards. Apparently, there is a solid portion of the oil screen on one end and if installed wrong can block an oil bypass port. Dan
 
Perhaps it was the gasket and not the screen.

The holes look symmetrical but they are not - however a determined person can install it incorrectly...:)

LYC_61173.jpg


Upside down installation would screw up things big time....
 
where to find the info???

I ran across a Lyc. document that had a diagram with details on the sump screen, and it showed the correct orientation of the finger screen. It's really poor engineering to make such important things so that they can easily be installed wrong, with no obvious indicators!

Gil,
I also thought the hole alignment on my dome screen gasket wasn't perfect, IIRC there were 2 holes in the block about 5/16" diameter, and one was partly covered by the gasket, one was not. It was the same as my old gasket ( also installed by me) so I didn't question it. ( dumb, yes, but nobody standing there to ask!)
 
I will certainly check into that oil screen issue. I dont recall it looking all that different on one end or the other. I guess I have gotten lucky and always put it in the correct way (if thats what it turns out to be of course). The gasket is something to check as well. I did see the info on that link, but not till after this oil cooler incident.

Perry, if you know where I can find that document that details the oil screen, I would be appreciative. I'll search the net as well.
 
The Lycoming oil screen (their cheap oil filter substitute) does not have ends...

Picture%202927-20120703-152939.jpg


If the screen in the sump at the oil pump intake was blocked I don't see how that could cause excessive oil pressure. I would think it would have the opposite effect of no oil pressure.
 
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Thats my oil screen. I have to doubt thats what cause it at this point.

It just occured to me that I was seeing 3PSI from start, so I guess the cooler gave way as soon as the engine kicked over. It never showed high oil pressure. I guess the high pressure got so high so fast and the cooler gave way before the high pressure registered on the screen. Maybe it flashed instantly high and then went down to 3 psi and I just saw the 3 psi.
 
az_gila said:
The Lycoming oil screen (their cheap oil filter substitute) does not have ends...

Picture%202927-20120703-152939.jpg


If the screen in the sump at the oil pump intake was blocked I don't see how that could cause excessive oil pressure. I would think it would have the opposite effect of no oil pressure.
Click to expand...

Gil

I'm not a Lycoming guy (yet), but isn't that a suction screen (protects the oil pump from loose stuff large enough to see the part number)? Looks awful coarse to be a pressure screen (the one that would serve as a filter). Continental pressure screens are WAAAY finer than that.
 
theres a much finer screen on the inside of that course outer screen.

Just guessing here since I havent pulled the screen yet, but i guess its possible the gasket got moved a little bit during installation to cover one of the little holes. In all honestly, I dont know what the small holes are for, or if covering them (due to misalignment of the gasket) would cause an immediate high oil pressure condition and blow the oil cooler.
 
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i cant imagine I would put the gasket on backwards, but i guess mistakes do happen. I plan to get out to the airport tomorrow and hopefully figure out the issue. Thanks for all the suggestions so far.
 
Just for Completeness

Since I have an O-360 in parts I thought some pics to show the area and gaskets would help -

The pad on the accessory cover -

pad_zps0986a34e.jpg


The 61173 gasket that is the one that goes with the Lycoming Oil Screen - the filter substitute -

61173_zpsb5778ec9.jpg


This gasket can go on backwards, but is a poor fit since the mounting holes are not symmetrical -

gasket-2_zpsb84adcf7.jpg


If you have a real oil filter then a LW-12795 filter is called out. This Lycoming one is marked for correct orientation -

LW-12795_zps3b9fbfe5.jpg


I had both a Superior and a Lycoming 61173 gasket and neither were marked for correct orientation.
 
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How embarrassing.....

OK, heres the deal. I just want to say that I did get the gasket oriented correctly:D.....its just that I had put the oil screen housing on upside:eek:!!!

A new oil cooler, fresh oil, a properly oriented oil screen housing and a couple hours later, she cranked right up and ran like a top.

Man, oh, man.......
 
can anyone explain this silly gasket?

Blue, appreciate you explaining what happened, I'll be sure to watch for that myself next time!!!

Gill, if you're still listening.........can i ask what the last 10,000 guys have wondered when cleaning the oil screen...." why the heck is the gasket made with a big cut out, that makes it look wrong",
.......partially covering what you seem to say is a passage for the oil filter.
surely they could make a gasket that covers this hole properly.

...so there's no detriment to this installation? it just kind makes a half-baked seal further out on the perimeter of the gasket? crazy!

thx
 
flyboy1963 said:
Blue, appreciate you explaining what happened, I'll be sure to watch for that myself next time!!!

Gill, if you're still listening.........can i ask what the last 10,000 guys have wondered when cleaning the oil screen...." why the heck is the gasket made with a big cut out, that makes it look wrong",
.......partially covering what you seem to say is a passage for the oil filter.
surely they could make a gasket that covers this hole properly.

...so there's no detriment to this installation? it just kind makes a half-baked seal further out on the perimeter of the gasket? crazy!

thx
Click to expand...

It's the other way around, the hole is needed to let the oil flow through it... why half a hole, who knows...

I have no idea why they did it that way, or why the asymmetry is so small, and the holes sloppy enough, that it is possible to install the oil screen on incorrectly without too much force.

It's a Lycoming mystery....:confused:

I hope my pictures help folks get the gaskets correctly aligned.

Or you can just use Lycoming SSP-885 (even on certified engines) and convert from the oil screen to a real oil filter and the problem goes away.
 
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Hmmmmmm, I think I got it.....

So, if oil needs to go thru the hole that's partly covered, to the oil screen, wouldn't it make sense just to use the LW-12795 gasket for ALL applications?
They could stop making the 61173 non-centric gasket altogether, as it doesn't seem to fit anything correctly.
Funny how these things keep on for 50+ years even tho they don't make sense! eh?

( and yes, thank for the pics, they really help us neophytes out!)
 
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flyboy1963 said:
So, if oil needs to go thru the hole that's partly covered, to the oil screen, wouldn't it make sense just to use the LW-12795 gasket for ALL applications?
They could stop making the 61173 non-centric gasket altogether, as it doesn't seem to fit anything correctly.
Funny how these things keep on for 50+ years even tho they don't make sense! eh?

( and yes, thank for the pics, they really help us neophytes out!)
Click to expand...

The big hole in the screen gasket may have something to do with the diameter of the end of the screen....

The gaskets are quite different in composition. The oil filter adapter one is much thicker.
 
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