Oil on MAF Connector

[hbarrett]

'04 MM, 14,000 miles now, purchased one year ago new. Have noticed that an oily film collects on the outside of the MAF connector. Can't figure out where it comes from. I have cleaned it off a few times during the past year, but it comes back again. All stock under the hood, no mods except 4.10s. Never have disconnected the MAF and removed it, just wiped off the residue. I had a 2000 CV HPP, and did not have a similar problem for the 4 years I had it. The oil has to be coming from somewhere. Anyone have any ideas? Thanks

[BillyGman]

'04 MM, 14,000 miles now, purchased one year ago new. Have noticed that an oily film collects on the outside of the MAF connector. Can't figure out where it comes from. I have cleaned it off a few times during the past year, but it comes back again. All stock under the hood, no mods except 4.10s. Never have disconnected the MAF and removed it, just wiped off the residue. I had a 2000 CV HPP, and did not have a similar problem for the 4 years I had it. The oil has to be coming from somewhere. Anyone have any ideas? Thanks

What air filter are you using? Is that "stock" also? if it's a K&N filter, that's where it's coming from.

[hbarrett]

All stock. The oil is on the outside of the MAF connector, not inside the MAF. The oil is coming from the engine somewhere, but I cannot find the source, and the oil in the crankcase is good. I don't need to add oil between changes as I did with my '00 CV. No smoke at the exhast either. I just can't figure where is comes from to end up on the outside of the connector.

What air filter are you using? Is that "stock" also? if it's a K&N filter, that's where it's coming from.

[SergntMac]

All stock. The oil is on the outside of the MAF connector, not inside the MAF. The oil is coming from the engine somewhere, but I cannot find the source, and the oil in the crankcase is good. I don't need to add oil between changes as I did with my '00 CV. No smoke at the exhast either. I just can't figure where is comes from to end up on the outside of the connector.

Look at the driver's side of the engine, towards the firewall. You'll find a PCV connection coming out of the valve cover with a short hose leading to the bellows. This is a vent into the air induction path, and you may have some seepage collecting and running down the underside of the bellows until it reaches the MAF. Wipe it all down, and see what develops? You may have a clogged PCV system, and rather than vent, it's pushing out this end.

[hbarrett]

Thanks, I'll check this out later today. BTW I have noticed this oil film since the car was still very new, but always forgot to have the dealer take a look at it.

Look at the driver's side of the engine, towards the firewall. You'll find a PCV connection coming out of the valve cover with a short hose leading to the bellows. This is a vent into the air induction path, and you may have some seepage collecting and running down the underside of the bellows until it reaches the MAF. Wipe it all down, and see what develops? You may have a clogged PCV system, and rather than vent, it's pushing out this end.

[metroplex]

Look at the driver's side of the engine, towards the firewall. You'll find a PCV connection coming out of the valve cover with a short hose leading to the bellows. This is a vent into the air induction path, and you may have some seepage collecting and running down the underside of the bellows until it reaches the MAF. Wipe it all down, and see what develops? You may have a clogged PCV system, and rather than vent, it's pushing out this end.

That would be the crankcase ventilation tube. It directs filtered and metered air INTO the camcover. There should not be any oil seeping from that tube in the direction of the MAF connector.

[BillyGman]

Since you're talking about the outside of it, if it isn't what MAC said, then look at your power steering resovior. is there fluid on the outside of it? if so, then that might be a possible source too. I've noticed some fliud caked up on my alternator, and I think the power steering res is the source, but I don't understand how it's getting out.

[SergntMac]

That would be the crankcase ventilation tube. It directs filtered and metered air INTO the camcover. There should not be any oil seeping from that tube in the direction of the MAF connector.

My point exactly, thank you. However, since hbarret has added that this oil has been collecting since day one, it's unlikey that this vent is the source. Still, never hurts to rule it out as suspect.

[hbarrett]

Called the Service Manager at the FLM dealer today, and explained what I was seeing. He thinks a likely source may be the AC compressor leaking oil and throwing at the MAF connector, etc. I have since noticed a stain on the hood liner, aligning with the pulley system area. He told me that the oil contains a fluorescent material that will glow under UV light. They will check it out when I go in for an oil change next week.
Howard

My point exactly, thank you. However, since hbarret has added that this oil has been collecting since day one, it's unlikey that this vent is the source. Still, never hurts to rule it out as suspect.

[hbarrett]

Checked closely under the hood this morning for signs of AC compressor leaking oil. For one thing, the AC compressor is low mounted and on the opposite side of the engine compartment, and I see no sign of anything leaking. What does appear to be a (the) problem is the PS pump which is much closer to the connector. The fluid in the reservoir is lower than I remember it to be also, but just slightly. Perhaps just a very small leak at the seal is allowing a discrete amount of fluid to be thrown around?

Called the Service Manager at the FLM dealer today, and explained what I was seeing. He thinks a likely source may be the AC compressor leaking oil and throwing at the MAF connector, etc. I have since noticed a stain on the hood liner, aligning with the pulley system area. He told me that the oil contains a fluorescent material that will glow under UV light. They will check it out when I go in for an oil change next week.
Howard

[wchain]

If you do clean, use Electrical Connection Cleaner to spray off the 'fangs' of the Mass Air Flow Sensor, the ECC will not leave a residue.

[DEFYANT]

He should let the dealer do it. If he does, they'll blame him! Could this just be road grime? If you dont clean your engine often, it will get very funky very fast.

[hbarrett]

I will let the dealer do it because it is still under warranty. The engine compartment is still very clean after one year and 14,000 miles, so it is not just road grime. It is an obvious oily film accumulating on the connector and on the side of the plastic intake tube immediately under the connector, mixed with a little road grime. Several months ago, I wiped the oily substance off with a rag, but it has since come back.

He should let the dealer do it. If he does, they'll blame him! Could this just be road grime? If you dont clean your engine often, it will get very funky very fast.

[hbarrett]

Recently had the FLM dealer in Bel Air, MD look at the film on the connector. They agree that it appears oily with road dirt, but they were not able to pinpoint its' origin. My work order indicates that they will be looking at this again during future visits. They may have also put some fluorescent materials into the PS fluid - not sure. Bottom line - no fix yet!

I will let the dealer do it because it is still under warranty. The engine compartment is still very clean after one year and 14,000 miles, so it is not just road grime. It is an obvious oily film accumulating on the connector and on the side of the plastic intake tube immediately under the connector, mixed with a little road grime. Several months ago, I wiped the oily substance off with a rag, but it has since come back.