Replacing an Oil Pan Gasket Without Disconnecting the Transmission!

Our 2004 Malibu LT had a slow oil leak. Over the Fourth of July, it progressed to a small puddle of oil in the driveway. It took some time to investigate the cause and a little courage to turn some bolts, but now the car is leak-free. Here’s a recap of what I did.

The car was leaking on the front of the engine, which in this car means the passenger side. Observing the area by the crankshaft was difficult because the splash shield is a two-part component. Upon inspection, the front seal looked like it was leaking. I cleaned it up and the boss around the seal, and put the liner back in place.

Cleaned front seal and boss.

Almost immediately, the car started leaking again. A week later, when I re-inspected the front seal, it was clean, as was the boss. I thought it could be the oil pan gasket, the timing cover gasket, or the oil filter adapter gasket. I cleaned the area around the oil pan gasket and near the oil filter adapter. I couldn’t easily get to the area near the timing cover gasket.

Cleaned oil pan gasket.

The car continued to leak, and the oil pan gasket appeared to be leaking. This is where the free advice on YouTube and the written advice in the Haynes repair manual differed. One video said that to avoid disconnecting the transmission from the engine, you need to cut off a tab on the oil pan for clearance. I wasn’t going to follow those instructions, but when I looked under the car, I could tell that this advice must have been for another model year because I did not see the clearance issue that the video had. Another video said the oil pan will clear the subframe if you lift the engine high enough. Haynes said to disconnect the driveplate and loosen the transmission-to-engine bolts 1/2 inch to provide clearance. I decided to go with the lift the engine high enough plan.

Prepare for liftoff!

I was hesitant to remove the engine mounts and lift the engine. I was worried about alignment when re-installing the mounts. I was very hesitant to remove the driveplate-to-torque converter bolts to loosen the transaxle-to-engine bolts. In the end, I did not need to touch the transmission.

I had to remove many components and drain the oil to get to the oil pan. I removed the serpentine drive belt, catalytic converter, air intake, A/C compressor (I left the refrigerant lines connected), starter, upper and lower engine mounts, and oil filter adapter. When I removed the oil filter adapter gasket, I saw that it had failed in addition to the oil pan gasket. When I went to remove the oil pan, I could not get it to clear the subframe. I temporarily put a bolt back into the pan so I could carefully use the pan and a jack to help lift the engine as I raised it with the engine support bar. Once the engine was high enough, I could get the pan out. Then, there was a lot of cleaning, and the remaining steps were “the reverse of the removal procedure.”

Parts that need to go back in the reverse of the removal procedure.

The leaking pan, freed from the car!

The oil filter adapter gasket.

New gasket.

I took my time with this job and waited for the gaskets to arrive at the local parts store. Around 9 p.m., I was ready to start the car. The car started without leaks, but the battery light was illuminated on the dashboard. I took out the voltmeter and confirmed that the battery voltage was lower than it should have been. It felt like an alternator issue, but I did not have a problem before the repair, and all I touched on the alternator was the belt, or at least at the time, I thought that.

The following day, I looked in the daylight and saw a lead with a red wire that was not connected near the starter. I was confident the cable went to the alternator, but to be sure, I checked the schematic, and I traced the wire back to the alternator. Once I reconnected the wire to the starter, the battery light disappeared. I did not see two wires connected to the starter when I disconnected it, and when I put it back together in the dark, I did not see a second wire.

Ultimately, I needed an engine support bracket and two gaskets. I had extra oil on hand, and the oil filter only had a few miles on it, so I reused it. The parts and tools ran around $150, and it took me about 12 hours. I learned a lot along the way and no longer fear working with engine mounts. My next preventative maintenance item is replacing the serpentine belt. When we changed the belt on the 2002 Saturn L300, it required removing a weight-bearing engine mount. It’s clear that the engine mount strut is not necessarily weight-bearing.

I have driven over 100 miles since the repair, and everything is still dry. I was able to get the repair completed at a time that was convenient for me. Had I taken the car to a repair shop, I would have had to wait for an appointment, and it would have probably cost me $1,500. I think the book time for this job is 8 hours. With every repair, I learn and get more comfortable doing the jobs that scare me.

What repair jobs scare you? Let me know in the comments below.