deanshark

Uh-oh, I'm at 219K still with original. Does that mean I'm in trouble? JK
I agree with RA40 on where the leaks could be and would also add the heater core itself. (inside under passenger side dash) This can go unnoticed if you don't have any passengers, or if they're just not observant. If the HC leaks the floor would be wet and you might hear the coolant sloshing around in the heater ducts under the dash.
If the tank was empty and you added a gallon I would say you have alot of air in the system which needs to be bled out. With the air in there it will make the gauge go to the top like it's overheating, but actually not be that hot.

RA40

iTrader: (6)

With good coolant service routines they can probably go quite long. Ours was in for the 200K TB service when the top tank seal had just started to leak.

For the OP, get a good radiator if needing to be replaced. I have an aftermarket Denso which was about $100 difference from a Toyota Denso. While bleeding make sure the heater is turned on so that the whole system is purged of any air.

FlufferNut

I had the same issue. changed the thermostat. Issue resolved.
It's like when at a friends house and their tv won't turn on. Is it plugged in?

spuds

How is that denso doing? I broke the infamous nipple off OEM and rockauto rad isnt cooling.I have 100F heat and drive up a mtn from 1200 feet to 5500 feet in 20 minutes,pretty severe duty.OEM was rock solid being just above centerline on gauge,new rad its getting up there,not driving it in heat presently.Only goes wonky in very hot drive up hill,otherwise fine.

oem is going to cost 516 dollars,is it what i need? if so,i will get that.I ordered from LexusPartsNow and after reading reviews i wonder just how oem a 'genuine lexus' part is,shouldnt it be toyota? 417 bucks with them right now and they are only 40 miles from me,if i get their infamous 2 weeks to ship im smelling a slow boat from china involved....?

cj98ls

Curious, is the rockauto radiator you mentioned the Denso branded radiator? It is significantly cheaper (@ $107) than the "Genuine Lexus" that is listed at LexusPartsNow. LPN has it listed for $365 for the -50150 version but that part doesn't appear to be available at "normal" Lexus parts outlets that I've looked at. Is $50 their shipping charge for the radiator? And where did you find the oem for $516? Asking because my '98 may well be needing one before long.

400fanboy

RE: LPN

2 weeks is not enough time to ship on a boat from china. Shanghai to Long Beach is 12 days, plus handling time at both ends. It's closer to 3, usually 4 weeks since it might not load onto the boat on the final stop before it departs to the USA. These boats often make multiple stops at different Chinese ports, loading cargo at multiple ports before departing.

I've never had that experience from LPN. Typically I'd say it's 3-5 days for me to get it, 1000 miles away from their California warehouse.

________

Also, on the topic of radiators, anyone have any tips for cleaning out the fins? Mine are clogged full of 25 years of dust\bugs\grime. My plan was to just low pressure garden hose it with my thumb to not damage the fins, like I do to my household a\c radiator. I can drive the car @ full tilt up a 6% grade & never have temp issues, but in traffic I have started noticing the cooling fan clutch starting to engage more and more often to keep the car cool.

Shipping costs for such a big\heavy part mean it will be expensive. I'd be wary of the $150 special, since half of that cost is going to shipping... If you can score one from a local warehouse\dealer with local pickup that might make a lot more sense. But when you have to ship an enormous 20lb metal box cross-country, that **** isn't cheap. amayama wants $420\465 for the OEM radiator, plus shipping. I would imagine the crazy price discrepancy is that the OEM unit isn't in production anymore and stocks are getting low, thus, driving prices up. Keep up with your coolant changes! Or you'll pay for it in the end...

bradland

Check the basics first Spuds the rad might not be the culprit.
I’d prob replace the thermostat first, it could be sticking and they’re cheap.
Also, as fanboy mentioned start paying close attention to the fan/clutch operation pre post and during the ascent.

spuds

yes,it was a 60 dollar denso from rock auto.Guess i answered own question on will denso work.Again folks,im putting a serious load on car coming up this mtn.I did the engine fill trick,hot water heat is fine.Amayama has the oem for 516 with shipping.Ran perfect changed radiator,now not cooling right from get-go,doesnt jive with a thermostat failure at same time but cant hurt replacing it for sure,when job done i will start with that,fluid level on line,toyota premixed fluid.Also I will
recheck filled properly,but heater is a monster,works great.Only overheats under hard load,pretty much OK, up a little in town 100f temps.Seems both fans running last i checked coming up hill,will check again,the fans are loud like normal when both running and blowing off a LOT of heat.LPN is 319,75 shipping,plus tax,419 total.

Guess it looks like install LPN,if not up to snuff get oem.I will photograph real well what lpn sends and folks can tell me their opinion if oem or not.Whatever is going on,hot wont cut it and do not want to kill this fine running car.

Have you seen real oem marked genuine lexus?I just ordered upper control arms,lower ball joints and strut mounts and all say TOYOTA.They get installed this week,about 1500 in parts from Longo Lexus but dang am i impressed with the quality.

400fanboy

While the fan clutch is important, even when I'm doing even more aggressive mountain climbs than Spuds does, my fan never engages fully. It's frankly never even audible in the mountains, at speed (30-60mph). The only times it's audible is in stop & go traffic in the summer, or other times with extended 0mph stationary periods.

My point being, Spuds, as long as you get the whirr of the fan after you take off from a stoplight after being stationary for 2 minutes, and it's otherwise quiet, I would hazard a guess that the fan clutch isn't the reason of your temps climbing up the mountain.

It's also my understanding that the fan clutch (should, but not always) fail in the fully engaged position. Where it is fully engaged all the time and sounds like a diesel box truck.

IIRC only small\lightweight components come in boxes. The boxes are all the standard red\white Toyota\Lexus we've all seen before. IIRC, the suspension components all come in plastic bags with a sticker on them.

spuds

I agree,fans seemed fine when ive checked,and quiet like normal until temp climbs and both working,then normal audible whrrrr.

And yes,OEM radiator never heated up going up hill,only to centerline, right past centerline and whhhrrr here comes the extra fan and functioned perfectly,never beyond that centerline plus a smidge.

spuds

Yes,I should do a diag on fan function,it may have changed.But its hotter than Hades here recently after a winter blizzard of worst in 50 years.

spuds

Im doing 15 to 55 mph,lots of slow steep switchbacks then up to 55mph and lots of tranny shifting.Much closer to Pikes Peak vrs interstate passes.Its a load and Lex handled it great,now its far from great.

I need oil and tranny partial change for sure,dang but dont like that killer heat.

So bottom line,assess fans,thermostat,lpn rad,new toyota fluid,use engine top plug fill.Will do,thanks peoples,appreciated.If new rad is crappy,OEM here i come.

400fanboy

Yeah I do roads like that all the time in my car. I usually leave it in 3rd the whole time except for the 10mph hairpins. Easier on the transmission so it's not shifting so often. And it's hard to force the 3-2 kickdown anyway.

Never had any overheating problems, even at 8000ft altitude and 90 degree temps and sunlight and air conditioning. 10 or 15 miles of full throttle pulls, running the car out to 4000 or 5000rpm gaining several thousand feet of altitude elevation. Never once had temp issues. Your car should be able to do it just fine.

If coolant is fine, no rust, no air in the system, if water pump is fine (probably is), thermostat is probably fine if you change that w\ timing belt but best to address anyway. It's possible it's instrumentation failure, but if the overheating is in-sync with your fan clutch engaging then I would rule that out. The only thing that's left after that is the radiator right? The cooling system is pretty simple.

spuds

Agree 100%,think thats exactly what we will find.Hell yeah,I NEVER managed to move that temp gauge from factory new level.And now heat is pouring off her,fans whizzing away,took groceries from trunk,engine still running and i was getting heat blasted,its hot!

Sure sounds like rad to me,especially the history of failing after oem replaced with rock auto denso.All fluids OEM and clean.Ive been treating this car well,needs something it gets it and trying to use only oem.I thought denso WAS OE,but i dont think its up to oem,not what my experience is turning into.Maybe its a dud denso?

Cool,lets hope new rad does the trick.

spuds

Might anyone have a picture or knows what markings we can look for on salvage yard radiators so we can find oem used in the wild?