03 Q45 Oil Pan Leak

[loystock]

My wife's 03 Q45 with 49K miles has a leaking oil pan. I initially thought it was the drain plug that's bad so I bought one from Joe-IoS. However, upon closer inspection, I found a hairline crack on the area just where the drain plug goes in. I'm not sure why it cracked since I only use OEM gasket and just tighten the plug until the gasket is just compressed. I don't even torque the drain plug. The leak is not that bad. I did an oil change a month ago and so far the oil level is holding steady.

To me, it looks more like a weak design as the pan is made of aluminum with the plug coming in at an angle. Replacing the oil pan looks like a major job. Has any one experienced this problem? I don't think it's covered by the power train warranty.

Rod

[maxnix]

Wonder if some minimum wage pit monkey used an air wrench on it?

[elwesso]

If its just an external crack, what I might try is draining the oil out, cleaning it off really good and putting some JB weld on it... If it holds for a while, great, if not you're not out a lot of time..

I would personally do something about it since the crack will probably only get worse with time (heat cycles, removing the bolt, etc)

Im sure someone cranked the bolt on too hard, oil pans dont randomly crack on Nissan.

[1990QOwner]

Wonder if some minimum wage pit monkey used an air wrench on it?

Hey, I like your choice of words.

That JB weld stuff is good stuff, it should do good. Just make sure that you don't get the quick dry kind, it is not good on automotive, it is not heat resistant like the other stuff is.

[loystock]

After inspecting the oil pan last night, I took out both front rotors so they can be turned by my mechanic (he owns the shop especializing in Japanese and European cars). I noticed the car has some vibrations during high-speed braking. I also would like to ask his opinion on how to go about with the repair. Unfortunately, he was not there so I just left the rotors to his assistants. I ended up at a Kragen-Milpitas and took a chance with the guy at the counter. I was surprised that he knows about the Q45. He even said that the oil pan in the 03 Q is a structural component of the engine supporting accessories...right on the money. He also said that it will be expensive to have it replaced or repaired by a car shop. The guy is probably a retired mechanic. I was really shocked, no offense meant, but I have been to such shops before - Kragen, AutoZone, PEP Boys and never met any one who knows about Infiniti.

He gave me instructions on how to repair it and just like what Wes mentioned, he recommended J-B Weld, specifically J-B Stik. The performance data on this product looks very good - works on wet and dry surfaces, most metals, including aluminum with temp limit of 250 degrees F (300 peak). I hope it works.

I do most of of the servicing and minor repairs on our cars - 5 Infinitis and 1 Toyota. I do oil change, brakes, brake flush, ATX pan drop and refill, etc.. And now I remember, I was overseas for several weeks in January when the car became due for oil change. So I asked my wife to bring it to a lube shop - $79 for Mobil 1 sythetic. That shop probably over-torqued the drain plug.

Thanks,Rod

[elwesso]

Ive used JB stick before and I didnt like the way it went on. It was more of a hard clay that wanted to fall off rather than a semi liquid (toothpaste) sorta thing..

Make sure the surface is clean and ideally at room temperature. It does NOT stick to wet/cold surfaces trust me!

[loystock]

Post Mortem...Thank goodness my initial analysis was incorrect. The hairline cracks were superficial. With the drain plug removed and the area thoroughly cleaned, I didn't find any crack on the threaded area. However, there was a slight indentation at the base of the slot (pan probably hit something before). Further inspection with a magnifying glass indicated a small bump/protrusion on the sealing surface, probably caused by the earlier impact. This bump prevented the drain plug from going all the way in, and thus the oil leak. Filed the hairline cracks and the bump, followed by a 100 grit sand paper and then 30 micron finishing paper - everything looks so smooth and all cracks gone. Changed oil and filter (just 1 month old) with Mobil synthetic, OEM filter and gasket, run engine for while - not a single drop of oil.

Installed new pads on newly turned front rotors. Did some braking at 50-60 MPH - vibrations gone.

Cleaned the car, polished with Zaino and and leather seats treated with Lexol - car in showroom condition again.

It's a very long but productive day.

Thanks Wes for your input about the J-B Stick. I will keep it as souvenir,

Rod

[maxnix]

Installed new pads on newly turned front rotors. Did some braking at 50-60 MPH - vibrations gone.

One should never neglect the rear rotors as they perform more braking on most cars. A lot of cars on this board have had problems aft because of improperly lubricated caliper pins. Even more neglect to adjust the parking brake correctly.