Hi all. I went to change the oil in my wife's 2006 400h...all went well with that. However, after I started the car to inspect my work and check for any oil leaks, coolant all of a sudden started to leak from the frame right under the radiator on the passenger side. It was coming out of a small hole in the frame just behind one of the threaded holes used for holding up the plastic skid plate. I cut the engine as soon as it started leaking which stopped the leak. I'd say about a 1/4 cup came out.







I started to investigate further and could not find the source of the leak. I didn't see much evidence that it had been leaking prior to this incident - no trail of dried coolant on the backside of the skid plate and I poked around the frame in a few holes I could get my fingers in and it was only wet right where it was leaking. I noticed the drain plug is on that side of the radiator but no trail of wetnes leading from it (although it did have some dried pink crystals around it). When I couldn't find anything, I started the car again and no leaking. It's just dropping a drop here and there at the moment sitting in the driveway.

Haven't had any cooling system issues before. I'm actually taking it into the shop for a timing and water pump change tomorrow, but this leak doesn't seem to be coming from the pump.

I'll have them take a look tomorrow but wanted to see if anyone else has had experience with this or have any ideas on what it could be. Radiator maybe?

 

Could be engine radiator or hybrid radiator. Engine radiator is last in the stack. Hybrid radiator is first.

 

Do you have between 80K-140K miles on your Rx? My wife's 07 Rx400h started with a very slow coolant leak. I saw pink crystals along the radiator's end tank on the passenger side. At 125K miles, I decided to replace the radiator while my mechanic did the timing belt change. It doesn't seem too uncommon for the radiator to leak around 100K miles on these cars.

 

i love my 2006 400h, and it never overheated or lost coolant on the ground but the radiator failed at 75K, and was covered under my extended warranty. Those radiators are plastic on top and fused to metal below and often fail at that seam, not the best design in the world. What frustrated me was the plastic cover on the top of the radiator for no reason other than decoration, covered the slow leak or I would have seen it. Make sure u use the Toyota world antifreeze, and there are aftermarket radiators that are half the cost of the dealer.

 

Are you sure it was coolant and not some water from a recent bath merely finding it's way to the hole after the car was tipped up on the ramps and nudged by the fan?