Oil Leak Under Thermostat

[Kyogie]

Hey all, recently purchased a 97 4runner, SR5, 5spd with the 3.4 v6. I'm in the process of bringing it up to speed maintenance wise as the previous owner lived in the mountains and some items were neglected. I noticed an oil leak under the thermostat when I was changing the throttle body out.

Attached is a picture of where it's leaking from one spot (in between the two hex nuts to the left of the oil filter). I did just wash the car down so not all wet spots are oil/coolant.

As far as I can tell its not leaking from the head gasket, and the valve cover gaskets were replaced by the previous owner (don't trust his work, but i can't trace it that high up). From the best I can tell right now it seems to be leaking between what I assume is the oil pump and the block, right below and to the left of the oil pressure switch. The one thing this doesn't explain is why oil puddles on the front of the engine in the little space under the thermostat housing.

Any help would be appreciated as i've searched for oil pump/gasket leaks and haven't found any information on that.

 

[thatoneguygeoff]

I'd give your engine a thorough degreasing and drive it to get the engine warm to see exactly where it's coming from. It's hard to diagnose a leak when everything is covered in grime.

 

[Kyogie]

I'd give your engine a thorough degreasing and drive it to get the engine warm to see exactly where it's coming from. It's hard to diagnose a leak when everything is covered in grime.

That's what i'm trying to do today, as it's finally not freezing out. I can watch the bead of oil run down the split between the oil pump and block though, I just can't pinpoint where it's starting from.

 

[xspsi6]

A very common and often misdiagnosed leak is the oil cooler sandwich plate seals its cheap and easy to change out not sure if this your exact leak or not but I bet it is leaking and these seem to have multiple common leaks as they age, I had to totally re seal my entire 5vzfe at only 170k but I always run synthetic Amsoil and the previous owner ran mobil1 since the day it was new which m1 tends to find a marginal leak and turn it in to a big leak.

 

[JRZEE2000TR4LTD]

That's what i'm trying to do today, as it's finally not freezing out. I can watch the bead of oil run down the split between the oil pump and block though, I just can't pinpoint where it's starting from.

You must mean the WP and the block. May want to check your cam seals, but the most common leak on these engine is the VC gaskets and when they leak the oil goes everywhere depending on where they are leaking.

 

[Kyogie]

You must mean the WP and the block. May want to check your cam seals, but the most common leak on these engine is the VC gaskets and when they leak the oil goes everywhere depending on where they are leaking.

My first thought was Cam seal since the VC gaskets were replaced and looks like the timing belt was done sometime recently. But it's below the water pump. I was looking at some diagrams and from what I can tell that is the oil pump at the base of the block. Where the crank shaft pokes through.

It's another warm day out so i'm going to try and get it to a self service carwash to power wash out the sludge. I know the rear main seal is leaking as well :/ but I just wanna get them all nailed down before I start ordering parts.