2001 ETC with only 40,000 leaks oil after an oil change? smell at rat?

[therobski]

I have an 2001 ETC with only 40,000 miles. Needless to say it looks and drives like new. Took it to good friend of ours of over 25 years for an oil and filter change. He runs the service Depatment for a Toyota dealer. Got the car home leaks oil all over. Took it back they put another oil filter, still leaks, they changed the oil pressure switch above the filter, power washed the underneath got the car home leak big time. My buddy took it over to the Buick store they claim it could be either the rear main seal or a "half case" leak. Now it's really strange that all of a sudden this car started leaking after just and oil and filter change. Main seals start to leave a drop here and there and progressively get worse. This car was bone dry underneath. I have not have gotten the car up on jack stand and looked at myself. I wonder if I pull the filter off, maybe the oring or seal is still on there fro the old filter? I am a " 60's 70's gearhead" but this was my wifes driver and never touched a Northstar. I am wondering if one of my buddies screwed up something and they are telling him? I need to take the car somewhere in Dallas area to have it diagnosed. I tried Carroll Custom Cadillac and all I get is a recording no one picks up.

[Texas Jim]

Carroll Custom Cadillac is "NOT" a Cadillac dealer.

Take it to Crest Cadillac if you need a dealer in Dallas.

Take it to Frank Kent if you need one in Ft. Worth.

They both have a good service dept.

I am in Ft. Worth and use Frank Kent.

[rockfangd]

If they missed a double gasket twice that would be a record. This is weird. How much does it leak?

[KHE]

It is not a rear main seal or a case half leak... Not if it is leaking as bad as you say it is. It's a strong coincidence that the leak developed immediately after an oil change... Did they use the correct filter? It should be easy to pinpoint the leak if the car is cleaned and then idled while on a hoist. I wonder if it could be one of the oil cooler hoses?

[Logan]

Don't know....maybe overfilled with oil?

[therobski]

Buddy of mine at a Chevy store has a very good friend at Crest Cadillac in Plano ( Dallas area). When I get to it I am calling him for an appointment to drive the car over there. It leaks down and hits the exhaust-then some smoke. But still very driveable.

[KHE]

It could be the oil manifold plate has developed a leak. The oil manifold plate is between the oil pan and the lower crankcase half. To replace it requires the transmission to be removed from the car. Many times, the lower crankcase half seal is blamed when this part is really the leak source. I sort of doubt that is the issue since the problem happened right after the oil change.

[sprucegoose]

It could be the oil manifold plate has developed a leak. The oil manifold plate is between the oil pan and the lower crankcase half. To replace it requires the transmission to be removed from the car. Many times, the lower crankcase half seal is blamed when this part is really the leak source. I sort of doubt that is the issue since the problem happened right after the oil change.

Interesting... I have never heard of this "oil manifold plate" leak. Mine has always this exact same symptom since I bought it 3 years ago, and I assumed it was the case half seal...It leaks down the back of the block from an area I can't see well and drips on the crossover pipe and guard there. Will have to look at a diagram of this and decide if its worth takling myself as I hate th burning oil smell every time I stop.

That is strange, Therobski that yours would suddenly start leaking after the oil change. I would suspect they may have used wrong oil or filter? I am a firm believer in choosing the correct oil and filter and staying with it, not deviating by price or availablity. Perhaps they bumped something like oil cooler hose as KHE suggested...

[KHE]

Interesting... I have never heard of this "oil manifold plate" leak. Mine has always this exact same symptom since I bought it 3 years ago, and I assumed it was the case half seal...It leaks down the back of the block from an area I can't see well and drips on the crossover pipe and guard there. Will have to look at a diagram of this and decide if its worth takling myself as I hate th burning oil smell every time I stop.

The case half will just seep and not leak to the ground. When the oil manifild plate leaks, it drips to the ground and on the exhaust system. Most of the time, the case half gets blamed for the leak when it is actually the oil manifold plate.

In order to change the oil manifold plate, either the engine has to come out or the transmission has to be removed. The shop manual states that transmission removal is easier than engine removal. Once the transmission is out, it is not that much more work to drop the lower case half and re-seal everything. If the car has the lip style rear main seal, replace it with the cartridge seal and it will be good for a million miles.

Use the GM Engine sealant - it is made specifically for GM and there is NO aftermarket equivalent.