Oil Leak Advice
11-16-2009, 02:03 AM
#1
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Oil Leak Advice
Latest project is attacking the oil leaks of a 1990 C2 with 74K miles.
I replaced the oil return tubes and put a new crush washer between the main oil line adapter and the engine case - those areas are now dry:
The passenger/right-side of the engine (cylinders #4, 5 & 6) is completely dry:
However, there is a continuing leak on the driver-side of the engine in the area of cylinders #1 & 2:
Both sides of the cooling air duct for cylinder #1 drip oil, the rear-most portion of the cooling air duct for cylinder #2 drips oil, and the driver-side engine case is covered with fresh oil - all marked by red arrows in the following picture:
The leading portion of the cooling air duct for cylinder #2 is dry (green arrow) and the further-forward cylinder #3 is also dry.
The cooling fins for cylinders #1 & 2 are not showing any oil.
From what I can see without removing parts from the top of the engine, the crankcase top breather cover and the oil sender areas do not appear to be leaking oil. There is some "old" oil around the intakes' sleeved connections, possibly indicating an oil overfill in the past.
Could there still be oil seeping from the intakes?
Would oil in the intake manifest itself in what I see from below?
What else should I check?
Dig deeper into top of the engine even though there's no visible oil?
Could this be a dreaded cylinder to engine case leak, even though the #1 & 2 cylinders have no oil on their cooling fins?
I replaced the oil return tubes and put a new crush washer between the main oil line adapter and the engine case - those areas are now dry:
The passenger/right-side of the engine (cylinders #4, 5 & 6) is completely dry:
However, there is a continuing leak on the driver-side of the engine in the area of cylinders #1 & 2:
Both sides of the cooling air duct for cylinder #1 drip oil, the rear-most portion of the cooling air duct for cylinder #2 drips oil, and the driver-side engine case is covered with fresh oil - all marked by red arrows in the following picture:
The leading portion of the cooling air duct for cylinder #2 is dry (green arrow) and the further-forward cylinder #3 is also dry.
The cooling fins for cylinders #1 & 2 are not showing any oil.
From what I can see without removing parts from the top of the engine, the crankcase top breather cover and the oil sender areas do not appear to be leaking oil. There is some "old" oil around the intakes' sleeved connections, possibly indicating an oil overfill in the past.
Could there still be oil seeping from the intakes?
Would oil in the intake manifest itself in what I see from below?
What else should I check?
Dig deeper into top of the engine even though there's no visible oil?
Could this be a dreaded cylinder to engine case leak, even though the #1 & 2 cylinders have no oil on their cooling fins?
Last edited by slips2; 11-16-2009 at 12:56 PM.
11-16-2009, 02:22 PM
#2
Rennlist Member
This would be great to know as I am in the process of tracking down some leaks for myself (similar to what you have). Maybe white car syndrome.
How was it replacing the oil return tubes? Your tubes look a bit scraped up.
How was it replacing the oil return tubes? Your tubes look a bit scraped up.
11-16-2009, 04:54 PM
#3
IHI KING!
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I would start by cleaning the everything. Then take the car for a drive and as soon as you get home, jack up the car and look for shiny or wet spots. Without cleaning first, you may be seeing oil on one part that may not be leaking. The engine's air cooling blows oil around making it hard to say definitively where the source of the leak is.
11-25-2009, 07:48 AM
#5
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Leaks at the top of the motor are hard to find because the hot oil flows easily, and exits the scene. It does wash dirt on the way down, so you see thick deposits near the bottom of the engine.
My car at 65 k miles was not leaking, but I did some "while you are in there" seal replacements. The O-ring on the oil sender crumbled. The 0-rings associated with the power steering were also very brittle. I would get those, and the valve cover gaskets sorted first, and then see if there is still a leak.
Stopping a leak is sometimes by process of elimination.
My car at 65 k miles was not leaking, but I did some "while you are in there" seal replacements. The O-ring on the oil sender crumbled. The 0-rings associated with the power steering were also very brittle. I would get those, and the valve cover gaskets sorted first, and then see if there is still a leak.
Stopping a leak is sometimes by process of elimination.
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11-27-2009, 12:03 PM
#8
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All helpfull input everyone, thanks!
I'm going to pull the intakes and replace the 20 year-old top-end seals, once they arrive from Sunset. I'll post pictures with my findings.
I'm going to pull the intakes and replace the 20 year-old top-end seals, once they arrive from Sunset. I'll post pictures with my findings.
