Potential coolant leak near oil filter/ oil cooler assembly

[5280 Lexus]

Hey guys trying to diagnose a leak I found on my 2003 GX470.

Yesterday was looking under the hood while the engine was running and noticed my coolant overflow was almost empty. The last time that happened my radiator was leaking so I checked the usual culprits radiator corners, hoses, thermostat housing, etc and didn't see any visual signs. Looking underneath from the drivers side I can see what appears to be a small leak coming from behind the oil filter housing and the pulley for the AC compressor. I attached a photo showing the spot, however i couldnt get the camera in close enough to get where it looks to be weeping, you can see it dripping and the residue below, but the actual leak seems to be tucked up in a corner behind the bolt for the filter and under the ac compressor. I havent been seeing coolant on the ground and no symptoms of overheating. Could this be a sign that my water pump is starting to go? Most of the water pump failures I see leak on the passenger side since its closer to that side. If anyone has ideas or had a similar experience would appreciate insight.

 

[5280 Lexus]

I should add that I had the timing belt, water pump etc replaced arund 60k miles ago

 

[aztoytec]

Toyota/ Lexus coolant is pink. That doesn’t look like a current coolant leak. Maybe residue from a previous repair. I’d clean it off and recheck it after a couple days

 

[HomersCanyonero]

Do you have toyota pink coolant or another color coolant?

Also, when engine/radiator is cool, remove the actual radiator cap and see if it’s low.

I know that the overflow has a low and max operating range. I’ve seen mine go low and then go back to normal while I was in the trails going up and down hills.

 

[5280 Lexus]

Hey guys, sorry I should have specified my truck doesn't have the toyota pink coolant. Previous owner had replaced it with a universal coolant. When my radiator broke last year I didn't have time to flush the system since it was an emergency so I just stuck with universal (bad I know). I am going to pressure test the system so that I can stop speculating. I will update this thread with my results.

I have a suspicion that my coolant leak is coming from somewhere else and that it is just dripping down into that spot or the water pump is failing and the coolant is coming out of the weep hole. I believe it is close to where im seeing the leak. The last timing belt job was done by a mechanic of questionable skill, the PO said that the water pump was replaced but I have no way to know for sure.

 

[5280 Lexus]

Did a pressure test on the cooling system. Held pressure for 5 mins and wasn’t able to see any coolant leaking from the area. Maybe it was a fluke I’m not sure. I ordered a new radiator cap from Toyota while grabbing some other parts just for the sake of it. Will keep my eye on it and if I find anything I’ll update this thread. Thanks for the reply’s guys

 

[5280 Lexus]

Was on youtube watching some toyota maintenance videos and one of them happens to be on a leak from the oil filter area on a sequoia with the same 2UZ-FE engine. This video was about an engine oil leak caused by a bad gasket behind the assembly. It showed a nice view of the area and how to remove the assembly. That one wasn't leaking coolant but it got me thinking that could related to my problem. The actual gasket is only $1 from my local toyota dealer ( PN: 1569250020). Reading the description for the gasket it actually says that leaking coolant could be a sign of failure. I am unsure if they are talking about that gasket specifically or the whole assembly in general. I also don't think I can definitively say that is the issue unless I pull the assembly and replace it then test again. Someone on GXOR recommended two other parts to replace, one is a $5 o ring and the other $14 drain plug of some sort. Its a lot cheaper and less labor than a water pump replacement and since it is such a small leak I'm going to order the parts and give it a shot. Will update post when I make more progress.

figure 8 gasket: PN: 1569250020
Oil cooler line drain valve : PN: 1569550010
O-ring: 9030167004

Video on oil cooler leak

toyota parts description

 

[5280 Lexus]

Was on youtube watching some toyota maintenance videos and one of them happens to be on a leak from the oil filter area on a sequoia with the same 2UZ-FE engine. This video was about an engine oil leak caused by a bad gasket behind the assembly. It showed a nice view of the area and how to remove the assembly. That one wasn't leaking coolant but it got me thinking that could related to my problem. The actual gasket is only $1 from my local toyota dealer ( PN: 1569250020). Reading the description for the gasket it actually says that leaking coolant could be a sign of failure. I am unsure if they are talking about that gasket specifically or the whole assembly in general. I also don't think I can definitively say that is the issue unless I pull the assembly and replace it then test again. Someone on GXOR recommended two other parts to replace, one is a $5 o ring and the other $14 drain plug of some sort. Its a lot cheaper and less labor than a water pump replacement and since it is such a small leak I'm going to order the parts and give it a shot. Will update post when I make more progress.

figure 8 gasket: PN: 1569250020
Oil cooler line drain valve : PN: 1569550010
O-ring: 9030167004

Video on oil cooler leak

toyota parts description
View attachment 2900784

Also i think the process may be slightly different on the GX470, will download FSM pages to verify

 

[5280 Lexus]

Problem ended up being a leaking water pump, after a few weeks it got big enough that I could see it dripping down out of the weep hole. I replaced the timing belt and water pump with the AISIN kit and no more leak. I could see the build up of coolant when I took everything apart.