YODAONE

Lexus lists two radiators for 1998-2000 LS400;

1640050130 stamped "5013", and
1640050150 stamped "5015"

I had a look on Rock Auto website and they only list Denso w/o tow package "5013"....so am asking if anyone knows whether the 5015 is in fact a tow package or heavy duty radiator..AND if so whether it has a thicker core...or larger transmission cooler...

What are its' attributes...

Denso was unable (read unwilling) to provide information....

UNCNOR

iTrader: (1)

Could the 5015 be a separate cooling radiator for the transmission?

YODAONE

I spoke to Lexus and they indicate they are both radiators which transmission coolers are an integral part in both...

Asking if anyone has information on whether the 5015 stamped radiator has thicker core. Thanks

MK386

Just get a KOYO...

YODAONE

What KOYO radiator do you refer?
Can you provide a P.N. or URL?
Meanwhile...the inquiry continues whether anyone knows the difference between the two OEM radiators....

Attempting to ascertain whether the 5015 stamped radiator has a thicker core...

Anyone know?

billydpowe

iTrader: (1)

I'll find out tomorrow and let you know, John Teckley TRD parts will know..

PureDrifter

iTrader: (10)

Denso rads are hit or miss in getting the correct pn for your application, may be worthwhile to call them and confirm.

billydpowe

iTrader: (1)

yes: the 1640050130 is made in Japan
the 1640050150 is made in USA for USA & Canada
radiator specs are the same

and now you know.

YODAONE

So I don't know...

South Atlanta Lexus offers online parts diagrams, descriptions with corresponding part numbers for LS400.

A link to radiator information for 1995-2000 LS400..:

http://www.lexussouthatlantaparts.co...rimLevel=19107

As you read there is descriptive text "W(Towing Package)".

A radiator subassembly component breakdown lists a radiator core (only) "W(Tow Package)" and transmission oil cooler(only)"W(Tow Package)"

Can anyone with firsthand knowledge make any sense of why two different P.N.'s would apply for the same radiator, while Lexus applies towing package adjective to one of them?

What I mean by that is has anyone physically examined the 16400-50150 radiator white-stamped (on top) "5015"??....and can verify the core thickness.

Thanks.

billydpowe

iTrader: (1)

you want to know, you buy one and fill it up and drain it and compare the fluid level with yours and then we will all know, but most of us dont really care... my info came from Lexus.. specs are the same.

YODAONE

Ok.

The older LS400 (1993) that I looked at has a much thicker core(not counting dual electric OEM cooling fans) than does the 1998, 1999 and 2000 LS400 radiator core thickness. (Have not fully investigated how the second cooling fan is engaged...for engine or A.C.)

I also observe that a 1993 LS400 water pump has fewer impeller blades than does 1998 LS400 ...so 4.0 litre displacement engine, not taking into account 50 HP differential, achieves adequate cooling.

Plausibly greater impeller blade count on the 1998-2000(1995-1997?) LS400 waterpump achieves adequate cooling through greater coolant flow/cycling through the thinner radiator...(Not dismissing that it may be more efficient design...but it has to pump more water to dissipate the heat through a thinner radiator..some law of thermodynamics is at work here)

Increasing coolant flow suggests greater horsepower draw.(why racers on domestic engines use larger pulleys to slow waterpump speed which is not practical on 1UZ-FE)

However....

What I am investigating and contemplating is using a thicker radiator on the 2nd generation, a 2nd generation waterpump fitted with a 1st generation water pump impeller that pumps less coolant.

Arguably this would reduce flow but waterpump power loss without diminishing cooling system effectiveness. Waterpumps consume a lot of power...which explains the proliferation of electric water pumps for American performance aftermarket and engine power competitions.

Or, in the further alternative, with a stock waterpump, the fan clutch would not engage as often.

Perhaps membership has access to water pump flow data for 1st and 2nd generation. (Or a cooperating contact at Aisin).

Denso informed me that the 1998-2000 OEM radiator does not employ the higher efficiency radiator fins, nor does their aftermaket 5013 stamped radiator offer the latest higher efficiency radiator fins.

So, this whole excercise is to determine what is available from the Toyota parts bin..starting with a thicker radiator.

I have asked my Lexus contact to check the dealer database for inventory on the Denso brand OEM radiator stamped 5015, and then have them provide core thickness and weight data.

Meanwhile, thanks to all who have contributed thus far.

billydpowe

iTrader: (1)

Well I have learned a lot by following this, dont have anything to do with it, but I like learning.. mine runs so good I would not change a thing.. Just got back from Park Place with a wash job.. over 200k and still looks great

spuds

You mean if it isnt broke dont fix it? I agree.

Losiracer2

I've got the RockAuto replacement Denso in my 97' and its survived AZ summers without any issue for over 50k miles.

YODAONE

Amazing answers...

Anyone with thickness measurements on standard vs. tow package radiator option on 1995-2000 LS400??

Profile images welcome...

Thanks