LS460 - is rad replacement commonplace?

[donkmeister]

I've spotted on a US forum that a radiator change on the LS460 is something that seems to be a necessity due to it being a single rad for ATF and engine coolant, and eventually corrosion will allow the two to mix and ruin the gearbox. However, when I look on LOC I've not found anything about this problem on the LS460.

Is this a problem with UK model LS460s, or perhaps was it an issue on an earlier model of LS that was resolved by the time the Mk 4 came out? If it is an issue on the Mk 4, is there a particular part revision or age we should be looking out for? Is there a better version of the rad that can be fitted? Any warning signs to be aware of that the rad needs to be replaced or is it an age/mileage thing?

 

ETA I just looked in the main bit of the LS forum and sure enough someone is talking about a leaking rad on an LS460, so that's at least one. I'd still be grateful to know if this is something that simply will happen and is better treated pro-actively.

Edited February 8, 2022 by donkmeister
Saw another post

[Malc]

It's been much mentioned here for the Ls430 and latterly with the Ls460 having a similar set-up

100k miles / 10 years might be the optimum 

The Ls400 never seemed to suffer from this design " progress " at Lexus thankfully

Malc

[donkmeister]

Righto, it seems to be a relatively straightforward job, one for the list!

Any ideas on whether the OEM part is best, or if there's a more durable version that is recommended?

[PJ Murphy]

When I had mine done on the LS460 I tried a good replacement but when it arrived it was not right so I settled for a genuine Lexus unit which with our membership discount I thought quite reasonable. My car was 13 years old with about 76k when done. 

[LexusRbest]

US spec radiator doesnt have the wee pipe for the overflow like the UK one

[LexusRbest]

US spec radiator doesnt have the wee pipe for the overflow like the UK one.

The radiator has a small cooler in the base that has been known to leak oil to water or .water to oil

Unless you are a gambler install a transmission cooler for £100.

If water gets into the gearbox oil it is game over. You wont know until it’s kaput.

[donkmeister]

Just realised I never updated this. 

I ordered one from Rock Auto and found that (despite the manufacturer themselves saying it was a replacement part for the correct part number) it didn't fit... The top pipe fouled the fan pack.

So, I ordered the part from LPD, perfect fit. I replaced the water pump, trans pipes and clips, and the large rad hoses whilst I was at it. Only one corroded fastener, holding the rad and condenser together at the bottom. The little thoughtfully placed hole in the undertray meant draining down was nice and easy. Hardest part was figuring out how to remove the radar.

Obvs the little overflow nipple snapped on the old one, because that's what they do 🤣

Also, Lexus kindly put the fill/ bleeding instructions right there on the header tank so I just followed those and it was perfect.

[Malc1]

Well done ......  another 100k miles and 10 years to rest soundly

Malc

[donkmeister]

I'll dig out a photo of the old rad later on; it was definitely getting rather crusty!

[donkmeister]

The first picture shows the old radiator I removed. This pink crust, both top and bottom, wasn't apparent before I removed it from the car, so I'd suggest any old LS460 owners who suspect they are still on the original rad should have a good look around with a nice bright torch and a mirror, phone camera, boroscope, just something to peer underneath the fan shroud as I couldn't see it beforehand from just nosing around.

The second picture is just the "bottom crust". Apologies for the brown grass, it was July. 

The third picture shows the incompatibility of the pattern part rad with the fan pack. I'm afraid I was rather annoyed at this point and this is the only picture I took, but you can see that the bottom clips are engaged (top of the pic) and the top hose (bottom of the pic) is fouling the shroud. It appears the rad itself is too short, top-to-bottom. My advice is to pay the Lexus premium and get the OEM part (16400-38192) - approx £300. The pattern part claimed to cover that part number but clearly doesn't.

Also, for the transmission cooler I'd recommend changing the following parts. 

32941-50040 (oil cooler hose) qty 1
32942-50040 (another oil cooler hose) qty 1
90466-16004 (clips for those hoses) qty 4

Finally, whilst you COULD do the waterpump with the rad in situ, for a novice such as myself I was thankful for the extra space once the rad was removed. So I'd recommend doing that too as I did find a small amount of leakage that was cleaned up with a scotchbrite before I fitted the new pump, gasket and belt.