I have an oil leak that is driving me nuts. Oil appears on the carburetor, the front left stud is wet. It does not leak unless the prop is spinning. My question is does the carburetor mounting studs go in to the oil side of the sump? It looks like a real mess taking all of that baffling off. My oil consumption is 3 hr to quart and most of that is o the belly of the aircraft. Any help would be appreciated
Thanks
Dave
oil leak
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Dave
I would Strongly recomend you check this out immediately as you may have an early warning of the infamous C-145/O-300
oil pan failure! The area in front of the induction tube which goes thru the oil pan is the area which traps moisture and sets up the corrosion. The studs are blind (they don't go thru the pan) Removing the baffling or pulling the engine is a pain but nowhere near as painful as spreading your engines oil over the countryside.
I would Strongly recomend you check this out immediately as you may have an early warning of the infamous C-145/O-300
oil pan failure! The area in front of the induction tube which goes thru the oil pan is the area which traps moisture and sets up the corrosion. The studs are blind (they don't go thru the pan) Removing the baffling or pulling the engine is a pain but nowhere near as painful as spreading your engines oil over the countryside.
Not sure about the studs going through the sump. We did have an Ercoupe in the shop last summer that leaked oil out of the carburetor. Turned out the intake guides were worn allowing oil to leak back into the induction pipes and out through the carburetor.
Hope this helps!
Hope this helps!
Happy Flying,
Mark
1958 Cessna 172 N9153B
Mark
1958 Cessna 172 N9153B
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Bruce Fenstermacher
- Posts: 10325
- Joined: Tue Apr 23, 2002 11:24 am
Dave the sump is a concern but more that likely you have a leak from a push rod tube. Clean the engine really well then carefully run it and check.
Look around the rubbers at the base. Also the leak more commonly at the head end. I actually had several tubes with hole rotted in them when I rebuilt my engine.
Oil can get every where and can really be a pain to track down.
Look around the rubbers at the base. Also the leak more commonly at the head end. I actually had several tubes with hole rotted in them when I rebuilt my engine.
Oil can get every where and can really be a pain to track down.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
There is a good thread on finding leaks here....
http://cessna170.org/phpBB2/viewtopic.p ... 54&start=0
I find that the Magnaflux developer works well.
http://cessna170.org/phpBB2/viewtopic.p ... 54&start=0
I find that the Magnaflux developer works well.
John
N2865C
"The only stupid question is one that wasn't asked"
N2865C
"The only stupid question is one that wasn't asked"
IF it truly only leaks when the engine is running, ...wash the engine down and blow it dry. With the cowl off, run the engine 5 minutes and shut it down and watch it.
It could be from any of the sources mentioned already, or it could be a leaking prop-shaft seal, and running/blowing back.
It's also possible that a cylinder is leaking at it's base.
If it leaks only 5-10 minutes after shut down, then remove the induction from the suspect cylinders to see if it's wet inside and coming from worn valve guides. (This can be seen by loosening the induction hose clamps and sliding the hoses down the pipes to see if oil drips out. This method may save you a lot of unnecessary work locating which valve guide is leaking.) What sometimes happens is,...while the engine is running the valve guide has a vacuum on it due to the intake stroke....so the oil is burnt in the combustion chamber. But when the engine is resting the excess clearance between the valvestem and guide allows the oil in the rocker-box to drain down the valve stem/guide and run down into the intakes....and may eventually make it all the way to the carb. (But usually this becomes evident inside the air box and carb throat....not external to the carb.)
If you end up removing the baffling surrounding the sump.....use a 1/2" wooden dowel, rounded on the end, and by hand, attempt to "punch" a hole thru the floor of the sump about 2"-4" forward of the carb, in a pattern covering every half-inch of that entire area. Don't be gentle. If you can punch a hole thru the sump with a 1/2" wooden dowel by hand...then consider yourself lucky to have discovered it on the ground.
It could be from any of the sources mentioned already, or it could be a leaking prop-shaft seal, and running/blowing back.
It's also possible that a cylinder is leaking at it's base.
If it leaks only 5-10 minutes after shut down, then remove the induction from the suspect cylinders to see if it's wet inside and coming from worn valve guides. (This can be seen by loosening the induction hose clamps and sliding the hoses down the pipes to see if oil drips out. This method may save you a lot of unnecessary work locating which valve guide is leaking.) What sometimes happens is,...while the engine is running the valve guide has a vacuum on it due to the intake stroke....so the oil is burnt in the combustion chamber. But when the engine is resting the excess clearance between the valvestem and guide allows the oil in the rocker-box to drain down the valve stem/guide and run down into the intakes....and may eventually make it all the way to the carb. (But usually this becomes evident inside the air box and carb throat....not external to the carb.)
If you end up removing the baffling surrounding the sump.....use a 1/2" wooden dowel, rounded on the end, and by hand, attempt to "punch" a hole thru the floor of the sump about 2"-4" forward of the carb, in a pattern covering every half-inch of that entire area. Don't be gentle. If you can punch a hole thru the sump with a 1/2" wooden dowel by hand...then consider yourself lucky to have discovered it on the ground.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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Tom Downey
- Posts: 285
- Joined: Thu Apr 25, 2002 4:50 am
found the leak
After removing the paint in the area of the leak I now have a 2 to 3 oz leak a day.
Engine does not need to be running now to leak.
I am in need of a sump for a 145-2 and my sump has 5 bolts.
If any one knows of a good sump please let me know.
I hope you guys, that have responded to my questions, know how much and I value your comments.
This could have turned out a lot different.
Many thanks
Dave
Engine does not need to be running now to leak.
I am in need of a sump for a 145-2 and my sump has 5 bolts.
If any one knows of a good sump please let me know.
I hope you guys, that have responded to my questions, know how much and I value your comments.
This could have turned out a lot different.
Many thanks
Dave
When mine went I found a sump from an engine shop that recycles usable parts. I must have called 20 or 30 places and had 3 or 4 shipped to my mechanic before we found an acceptable one. I don't kow if you can still get these new or not. My used price 7 years ago was about $400 + shipping.
Try calling TCM and see if you can even get a new one any more. That will at least let you kow what you are up against availability-wise. In the mean time start calling places like Preferred Airparts, Dodson, Global Aircraft, Dawson, etc., etc. (these and many others can be found in Trade-a-Plane and other publiations or you can Google them on the web). When I was searching for the sump, if the place I called didn't have it I asked them for names/phones numbers of other places to try. Most everyone was willing to refer me to other shops, so don't be afraid to ask. It wasn't long before I had a large list of companies and phone numbers.
Have a good look at the inside of your sump when you get it off the engine. You'll be amazed at how much damage water can do just sitting there.
Try calling TCM and see if you can even get a new one any more. That will at least let you kow what you are up against availability-wise. In the mean time start calling places like Preferred Airparts, Dodson, Global Aircraft, Dawson, etc., etc. (these and many others can be found in Trade-a-Plane and other publiations or you can Google them on the web). When I was searching for the sump, if the place I called didn't have it I asked them for names/phones numbers of other places to try. Most everyone was willing to refer me to other shops, so don't be afraid to ask. It wasn't long before I had a large list of companies and phone numbers.
Have a good look at the inside of your sump when you get it off the engine. You'll be amazed at how much damage water can do just sitting there.
Last edited by doug8082a on Thu May 10, 2007 7:53 pm, edited 1 time in total.
Doug
oil sump
When the oil pan starts to go watch out! It develops a large leak fast. I found one that had been overhauled by Drake. I believe that they may be one of the only companies that can fix and certify your old sump. I couldn't find a new one anywhere. Here is their web link
http://www.drakeair.com/
PS once your pan is off, Have a good look at your cam lobes... I had a slight flat spot on the lobe closest to the prop shaft and had to change the cam too.
Best wishes Eric
http://www.drakeair.com/
PS once your pan is off, Have a good look at your cam lobes... I had a slight flat spot on the lobe closest to the prop shaft and had to change the cam too.
Best wishes Eric
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cessna170bdriver
- Posts: 4068
- Joined: Mon Apr 22, 2002 5:13 pm
Okanagen Aero Engines Discussion found here;cessna170bdriver wrote:What is the name of the outfit up in Kelowna that does a certified repair to the sumps with epoxy?
Miles
http://www.cessna170.org/phpBB2/viewtopic.php?t=3746