Recent work in this area was 6 months ago, re-plumbing the oil return lines from the cylinders. The problem had been happening well before that work was done, and after the work was done the problem was the same (or maybe even worse). Rocker cover gaskets were also all replaced. Running a finger inside the exhaust stack you get a very nice light grey dust, no gooey oily feeling at all - so if it's burning oil, it's not burning enough to gunk up the stack. Obvious places like the dipstick tube (which is on the other side of the cowling) look dry.
I want to fix the problem but budget is limited so a major objective is to learn as much as possible about diagnosing this kind of problem to help reduce the costs somewhat. I don't plan to actually try and fix it myself but if it's possible to pinpoint the problem on my own time, that might be worth it. I'd also like to be able to understand anything the AME tells me and decide on the likelihood of that scenario before pulling the trigger on getting it fixed. A friend of mine recently dropped $25K to have his engine rebuilt in the hope it would stop a pesky vibration he noticed while flying. It didn't make any difference except to his bank account.
An oil leak is maybe a little easier to diagnose.
If anyone can offer any advice, thoughts they'd be much appreciated and I'll eventually post the solution to the forum once it is known.
- Top Poster
- Posts: 5981
- Joined: Tue Jan 18, 2011 4:47 pm
- Location: Part of the "me, me, me" crowd, and loving every second of it.
You have an oil leak.the engine cowling on the pilot's side. The inside surface has a large area shining in the light from its coating of oil. Oil also comes out from under the left-side and small spots of it end up on the left main gear leg.
Wash the engine and bay throughly with gasoline or varsol. Run for 10 mins and try to find the source - something needs tightening.
An oil leak needs to get really serious before it shows up as increased per-hour consumption though!
You're kidding, right? Was the vibration connected to the rotation of the big fan up front? If so, it could be bad, really really bad... Also tell him I have a friend in Nigeria who needs a partner to shift some orphaned cash.A friend of mine recently dropped $25K to have his engine rebuilt in the hope it would stop a pesky vibration he noticed while flying.
Instead of asking these questions on an anonymous forum, discuss this with your AME and come up with a solution that works for both of you.
2-Then wash the engine, firewall, plane etc.. You can use varsol or mineral spirits in a spray bottle.
Be careful not to get any on the rubber engine mounts.
3-Clean as much as you can, with paper towels etc.
4- Now re-cowl and go for a very short flight say a circuit with high power on downwind.
5-De-cowl and have a good look everywhere with a mag-light or such.
This is likely the first step your mechanic will do and it takes a few hours so you just saved a few hundred bucks.
I was actually hoping (against hope) there was a way other than washing the compartment and engine with Varsol or Mineral spirits; I have big hands and it won't be easy to get into all the nooks and crannies. Since Photofly and CGZRO have kindly suggested a similar course of action, I'll give it a try. I've also heard of some kind of additive that glows in UV light - would be interested in hearing about anyone's experience using that.
Forgot to mention, this engine has an Airwolf separator but still gets lots of oil on the belly as I noted above. Two of the bottom plugs have accumulated oil since I bought the plane but they've been cleaned and swapped top for bottom regularly.
Anyhow, thanks for all the responses - I'll have a go at cleaning off the oil (and will mind the rubber parts in the process, thanks CGZRO).
I recently went on the hunt for my leaks. Did the cowl removal and clean up routine. I found I had a magneto that was leaking oil. We removed it had it repaired then put it back on and most of my leak stains went away. But i still have a drip from my oil quick drain. That will be addressed next change. Also my pushtubes seem to seep a bit of oil into the cowl.
A small leak can look like a real mess and finding it is a pain. I like to have stuff just so so i am still keeping an eye on the inside of the cowling.
And doing the cleaning routine is a great way to show the plane some love.
The cowl stains can often tell a story as to what's going on around the engine. Stain locations and patterns can sometimes help to pinpoint possible leaky areas.
I'm not sure what type of engine is in a Cardinal... however, Id have a good look at magneto, starter and/or vacuum pump mounting pad gaskets, rocker box cover gaskets, and oil drain return lines. I've seen on a few occasions the baffle springs shift and wear through the lower rocker box oil return lines. Also have a close look anywhere a rubber line is connected with a hose clamp.
additionally, you could check your lower spark plugs as well as completing a engine cylinder compression check if you feel that the engine may be burning the oil. These checks could help to determine if the oil is creeping past your piston rings or past the intake or exhaust valves.
Hope this helps and best of luck.
Use varsol, it's for cleaning oily parts.
You know, that has got to be the simplest, wisest, and most "spontaneous" answer I have heard in a long time! I will take that to heart!All you need is a little static electricity or other small spark and BOOM! You won't be worrying about an oil leak any more.
I take back my suggestion about using 100LL and rather recommend a good insurance policy and TNT !
More serious are little grey lines in the case that are actually leaking cracks. looks like a pencil mark against the paint. These ususally require a rebuild because the end result is catastrophic. Dangerous ares for these little grey lines in particular are near the cylinder hold down bolts.
The front seal can also be a problem and dangerous, its the seal where the crankshaft exits the case. Youll get oil everywhere in this case and it can be minor or serious but needs to be investigated properly if its happening.
Probably something trivial but good to know whats serious and whats not, especially in an IFR machine you put your family in.
It's strange that your Airwolf oil separator does not keep the oil off the belly. Are you sure it's installed correctly? Are the lines clear and flow to and from the crankcase? Are they in good condition? I'd have a really good look at the system that's supposed to keep oil in the engine. You might want to give them a call to get their opinion as to why it's not working correctly.
Let us know what you find.
Thank you all for the encouragement, I'm pumped to go find where the oil's getting out!
varsol takes forever to dry and WILL mix with any fraction of oil when leak checking,,,, best to BLOW DRY ALL varsol this will remove any solvent from rubber parts as well !otherwise allow the solvent to dry naturally
In the summer I use Aeroshell 100+ and in the cooler months I switch to Aeroshell 80+. It always seemed like oil consumption was worse in the summer but I never had any way to quantify it. Sometimes it seemed OK and other times it seemed bad - didn't make sense. This year a buddy of mine has been using the plane so it's been getting more use with shorter rest intervals between flights than it would have had with just me flying it.
Recently the plane was flown to the Nanaimo fly-in breakfast (1 hour total airtime) on Sept 2 and before the flight a quart of oil was added pre-flight - dipstick was showing ~5 quarts before that. Two days later the plane was flown to Tofino and back and no oil was added but a note in the logbook shows the dipstick read 5.5 quarts after just 2.2 hours. A couple of days after that flight I dropped over the hangar and checked the stick and saw around 5 quarts. Total airtime up to this point was 3.5 hours - so it looked like 1 quart disappeared after 3.5 hours.
On Sept 16th I took the plane for a flight in two segments totalling 1.2 hours. Before the flight I checked the stick and was surprised to see it at a healthy 5.5 quarts! I think what had happened was during the 12 days since the previous flight the oil that was clinging to the interior of the engine had mostly settled back into the sump causing the stick to read an honest value.
The next day I went back to the hanger to start cleaning the engine as described in this thread; the oil read below 5 quarts.
The plane is grounded for the time being - engine cleaned now and I'm letting it sit, cowls off, without a run-up to see if any oil voluntarily appears anywhere. After a few days I'll go have another look and check the stick again. I bet it will be above 5 and if I leave it long enough it will be interesting to see how much oil really is in there. I'll check the engine for any signs of oil weeping out anywhere. If none is seen I'll run the engine for a few minutes and check again.
Long story short - although there's a leak, the apparent increase in consumption is due to the shorter time interval between flights and the longer time it takes the more viscous oil to settle back into the sump.
I will update the post with the results of the cleaning and subsequent inspection.
- Top Poster
- Posts: 5981
- Joined: Tue Jan 18, 2011 4:47 pm
- Location: Part of the "me, me, me" crowd, and loving every second of it.
Mostly the "used" oil leaks out of the crankcase breather all over the belly or gets burnt and sent out of the exhaust.
Both are expensive, loud, and noisy.
However, when handled properly both respond well and provide great pleasure
On Friday I went back and checked the engine. Everything remained clean except for one place where the sump bolts to the bottom of the O360 and at the front. Here's the shot as of the 17th followed by the shot after 5 days. The black shape on the right side of the images is the starter. In other words the leak faces the front of the aircraft.
I cleaned the area and went for a short flight today, circuits for 0.4 and removed the cowl for another look. It was messy again and more than what appears in the photo after the engine had been through 4 circuits. Other places still looked clean.
Looks like the leak is either from the sump's (correct term?) seam where it joins the crankcase or perhaps the split line of the crankcase. Seems more likely the sump which has a gasket visible (black line in the photo).
[Edit] - Figured out how to add images. Before and after shots:
- Oil cleaned and engine not started
- Before_s.jpg (351.89 KiB) Viewed 673 times
- 5 days later without engine start
- After_s.jpg (367.67 KiB) Viewed 673 times
I thought you could only torque down gasket-separated surfaces only so many times before the gaskets were compressed to the point they were no longer effective. True, I've never had this done in the 5+ years of owning the Cardinal and will talk to the mechanic about getting it done. Would be very nice to see this improved!cgzro wrote:That's very common. Most of those bolts will take a 1/4 turn every now and then. Have your mechanic go around the sump attach bolts and case 1/2 bolts and torque them down. Those things are worth checking every time you drop the cowl or change the oil.
I thought you could only torque down gasket-separated surfaces only so many times before the gaskets were compressed to the point they were no longer effective. True, I've never had this done in the 5+ years of owning the Cardinal and will talk to the mechanic about getting it done. Would be very nice to see this improved!
Dependson the gasket and mating surface area but the bolts are not there primarily to stop oil leaks. If they are not torqued properly the loads are not distributed properly which is much worse.
The cork valve cover gaskets are bad in that the cover on a Lycoming has a very narrow mating surface, a few mm and it will cut the cork in 1/2 if you over tighten them.
I was going to start a separate thread but since you mentioned the exhaust here - I noticed this while looking for the leaks. The brass spacer on Cyl #4's exhaust port appears to be warped and black soot is coating the cylinder cooling fins behind. The exhausts were removed and reinstalled at the annual in January so I assume those spacers were replaced. Only this one looks stressed. Anyhow CA, is this what you meant by your comment? Aside from CO leaking into the engine compartment is there any other reason why this is bad? Just curious, will get it looked at.crazyaviator wrote:Most gasket materials will "seat" after 1-2 heat-cool cycles and will need to be retorqued ( important with a new engine ) Then, I would suggest no more than once a year to check for torque on all the nuts/bolts firewall forward. I would even go as far as checking the torque on the crankcase mating bolts/nuts which don't have a "gasket" within 10 hrs of assembly. Same goes with exhaust flange nuts,,,, some systems seem to be designed to leak ,,, others will go a thousand hours and never leak. With all exhaust flanges on cylinders, NEVER let a leak progress beyond a trace amount before rectification.
Thanks to all on this thread for your help - I've gained valuable knowledge about my plane and how to troubleshoot oil leaks, much appreciated!
- Exhaust leak.JPG (334.05 KiB) Viewed 673 times