Cold weather oil leak?

[jokerl90]

Something odd happened a few weeks ago. Never experienced this before, but this is my first 3400, so thought I would ask even though I'm a little embarrassed to.
We had a cold snap, teens during the night and mid 30'sF during the day. After a 50 mile round trip to work and back, the oil level on the dipstick would drop almost "hole to hole". After a warmup to the 40's and 50's the oil level stays the same.
A few months ago had the oil pressure sending unit replaced that was leaking oil. Afterwards no loss of oil.
I know metal contracts during cold temps, but I have never even heard of this on any kind of motor and I know temps in the teens are not that severe.
Any thoughts?

[aleros_eat_rice]

Is the oil pan gasket leaking?

[jokerl90]

Not that I know of. The car is so low it's hard for me to get under it, even with ramps or a jack.
Other than that cold snap, it does not leak a bit.

[Starglow]

Check the new oil pressure sensor again to make sure it isn't still leaking. Also check the UIM gaskets on both ends of the engine for signs of leakage...use a good flashlight and inspect the engine under the power steering pump and under the throttle body.

Also check the front & rear engine crankshaft seals for oil leakage, but note that some minor signs of seepage is normal for these engines. You will need to jack up the front end to do a good visual inspection...that's the only way you're going to figure out what's happening and if you're losing that much oil then it should be easy to see since oil doesn't dry up. If you can get the front end up on jack stands then you should have plenty of room to get under the car to check things out.

[Redog]

Not really making sense. Oil would be thicker when it's cold.

I had a head gasket leak from the rear head. Wasn't worth fixing because I wasn't even losing a pint

[jokerl90]

Thanks for the replies.I don't drive the car that much and it's not leaking at all now. May just wait till we get some more temps in that range then get it checked out. January and February, it's a coming! lol
I'm a big 'ol boy still getting over a broke leg from march, So I'm not looking forward to fooling with it. I changed out a alternator on my Nissan 720 4x4 the other day...it wasn't pretty.. hahaha
Again, thanks!

[jokerl90]

Update;
Drove car to work at +2F last week and again with temps in the teens, no lost oil.
Had the oil changed by the same mechanic that change to oil pressure sender. He said he saw no leaking around that, no major leaks, the motor is "weeping" oil all over. Guess this would be normal for a 3400 with 92000 miles?
Asked him if he could tell if the LIMG had ever been replaced, he coulden't tell from looking...dammit... hahaha hoping that had already been done.

Don't want to start a new thread just for this;
There is a metal coolant pipe coming from the water pump around to the back of the motor. It has the bleeder screw in it. Whats the name for this pipe? Can't find the part anywhere. Is it called the Thermal Bypass Pipe or maybe heater pipe? It has a few spots of corrosion thats looking bad.

[Nas Escobar]

I think you're talking about the heater pipe. It's probably going somewhere where the heater hoses are. Either that or it goes to the block. My LQ1 in my Cutlass has a pipe like that going from the lower radiator hose to under the intake plenum. Very strange setup but it is what it is. When the engine is cold, follow it and see where it goes.

[jokerl90]

Ok, thanks!

[zzyzzx]

Coolant leaking due to cold weather makes more sense to me, especially at the metal to plastic seam at the radiator. Oil leak, not so much.