4NGEL

Hey guys I got an issue today. So I have a 03 Es300 and I’ve had coolant problems in the past with a leak and found it was a clamp before. Now its leaking more now and I’m trying to find the leak and I just can’t find it. When I squeeze the hose connected to the thermostat housing I can hear the hole. But I cant see anything coming out. Only under the car I can see a constant drip! The location of the drip is almost directly under thermostat housing on driver side about parallel from the front left wheel. Any advice would be appreciated. Thank you in advance

oh and I don’t have any white residue under my oil cap.

LeX2K

Assuming your radiator is not leaking could be the bypass hose under the intake see here 16261G
https://www.japan-parts.eu/lexus/us/...t/2?pnn=16261G

Hayk

iTrader: (1)

Gotta be that pesky bypass hose, it's directly connected to the thermostat housing.

4NGEL

yeah I think that’s exactly what it is. Thank you very much for the diagram that helps me visually see everything possible and I never know where to find those.

im going to look up some videos on replacing I think it’s gonna be a tough job but I think I’ll be fine as long as I mark everything and take my time and video everything.

4NGEL

yeah I really think so too thank you for your opinion and input. Any advice is good advice.

4NGEL

damn you were right bro, I just took off the hose and it has a good little hole dead center!



I have a question in this photo. Am I supposed to have coolant in the area where it’s visible? Was I supposed to drain it before I started doing all this? I’ve been watching videos and everyone I’ve seen they didn’t have coolant in that hole in the bottom right? And is it 100% necessary to replace the gaskets every time you open it up?

LeX2K

What you're seeing is coolant passages in the head the larger openings are air intake. Please get rid of that green coolant and use Toyota Super Long Life if you don't your coolant system will rot out. Lexus should have used an all metal pipe older V6's have it.

Draining the coolant makes the job less messy also be very careful not to get coolant into the cylinders too much and you'll bend connecting rods.