Gents, I'm driving my c230 when all of a sudden I get a burning oil smell through the vents. The triangle hazard icon comes on on the dashboard, I pull over, pop off the engine covers, and there is an oil leak.
In some places, the oil leak has caked onto the engine (see pics). In other places, it appears fresh. The oil burning smell is occurring when it leaks onto the passenger right side exhaust headers. But there also appears to be oil on some part of the alternator. I'm trying to determine the location and cause of the oil leak. I'm hoping the attached pictures will help.
Does anyone think it could be from the oil cap? There seems to be a small puddle of fresh oil right next to it, and there is also caked oil that high up on the engine. I was also wondering what else the oil could damage, for example can it damage the alternator?
I once had an oil leak on another car and it damaged the starter solenoid which was under the leak. What could be causing a dummy light warning from this kind of oil leak? Thanks -Sev
I can't see your full-sized pics, but knowing the M272 engine, there are three common sources of leaks.
Cam plugs: These are on the back of the left side head, covering where the camshafts go through the head. They just snap in place and are $15 or so for the parts:
Oil centrifuge: This is the modern version of the PCV. It attaches to the back of the right side head with three bolts. It is also fairly inexpensive and easy to replace:
Camshaft adjuster solenoids and sensors: These are on the front of the heads, two on each side. You can replace just the seals. However, for the solenoids (a.k.a. cam magnets), they also have an inherit problem on your engine that can cause other faults, so I'd replace them - about $100 for all four parts. The sensors rarely fail, so if they are leaking, then try just the seals. The full sensors are fairly pricey ($165 each):
Rodney, what is the possibility that it's just the oil cap that's leaking oil?
Reason I ask is that it's the highest point on the engine where there is oil leaking, there is a fresh puddle of oil next to it, and there is oil on both the passenger and driver's side of the oil cap.
Would any of the items you mentioned cause the dummy light:
Intake cam plug
Exhaust cam plug
Oil centrifuge
Camshaft Solenoids
Camshaft Sensor Seal
Camshaft Sensor
Finally, could oil leaking anywhere on the alternatoror the alternator regulator cause a fault in those and a dummy light?
Pics 1 and 4 show the camshaft adjuster solenoid and it could be the culprit, although the oil filler is there so it could be that as well. Pic 6 shows the oil centrifuge and it looks dry (other than the surrounding grime). It's possible that oil can get into connectors and cause error, but leaking oil in and of itself won't cause errors (well, unless the crankcase is empty and then you have bigger problems).
Joe's advice is good, although you may not need to buy any dye. Just clean it up and then look for fresh oil. The most likely culprits are the solenoids. Also, get codes pulled - it may be that it point to those as being defective (that problem is unrelated to the leaks, but replacing them would fix both problems).
Gents, I have replaced the oil cap, and pressure washed the engine as recommended.
Since the original post, I have driven the car only 30 miles, but let it run at idle for a good hour on top of that.
So far I have not gotten any more oil leaks, but maybe the previous oil leak took a long time to develop, since I recently inherited the car from my aunt.
Separate issue:
I have also replaced the MAF with a brand new Bosch one, since I was getting a CEL for intake too rich on both sides (i forgot the code #, but that's what the translation was). However the CEL is still present and still giving me the same error code.
Is it possible that the camshaft adjuster solenoids (aka camshaft magnets?) of which there are four on the engine, which may be responsible for the aforementioned leak, are also responsible for the CEL of intake too rich on both sides?
Upon checking the part # on my camshaft adjuster solenoids, it is the older part number units, which have been superceded by a newer part number. Perhaps they were re-designed to function better with the new part #. The car has 160K miles on it, so I figured I would change the MAF with a new one as both a precautionary measure, and to potentially remove the CEL in question.
Does 160K miles also justify a precautionary replacement of the camshaft adjuster solenoids as well?
Additionally, as it pertains to the Engine Oil Separator, would one from brand Koolman be acceptable, or do I want to go genuine MB for this part? Normally I always go genuine, but the part just seems like plastic, with the only wear item being the rubber gasket/o-ring.
First of all, what's the error code? As for proactive replacement of the camshaft solenoids, unless they are the known bad ones, or if the error codes point to them being the culprit, I'd leave them be.
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