Let's baseline my grandma's neglected, (20 year old to us) 1997 LX450

[avdeveloper]

I just took it for a drive and I noticed that the radiator hose no. 1 (driver side) is steaming hot and and the engine coolant on my obd2 scanner shows it oscillating between 208 to 217F when it usually runs constant at 190F.

It is sputtering coolant onto the battery and leaking down into the ground after driving.

I checked the reservoir and its normally empty right after driving but will reach above the maximum line once its cooled down.

What is happening?

 

[avdeveloper]

I just took it for a drive and I noticed that the radiator hose no. 1 (driver side) is steaming hot and and the engine coolant on my obd2 scanner shows it oscillating between 208 to 217F when it usually runs constant at 190F.

It is sputtering coolant onto the battery and leaking down into the ground after driving.

I checked the reservoir and its normally empty right after driving but will reach above the maximum line once its cooled down.

What is happening?

my guess is that I have a bad pressure control valve inside the radiator cap. It's not releasing pressure when there is a build up that's why it's not releasing any coolant out to the reservoir when it's hot. Does that sound right?

 

[gummycarbs]

I checked the reservoir and its normally empty right after driving but will reach above the maximum line once its cooled down.

That sounds like the opposite of how it should work, minus the empty part. It should never be empty, to my knowledge. Coolant expands as it heats up, so you should have more in the overflow at operating temperature than when cold.

In my opinion, replacing the radiator cap (with genuine Toyota) should be a standard part of maintenance on a newly acquired rig, just like replacing all the fluids.

Open the radiator cap when the engine is cold. Is the coolant right near the top? It should be.

 

[avdeveloper]

That sounds like the opposite of how it should work, minus the empty part. It should never be empty, to my knowledge. Coolant expands as it heats up, so you should have more in the overflow at operating temperature than when cold.

In my opinion, replacing the radiator cap (with genuine Toyota) should be a standard part of maintenance on a newly acquired rig, just like replacing all the fluids.

Open the radiator cap when the engine is cold. Is the coolant right near the top? It should be.

yup. by normally I meant the last time I checked not knowing how it's designed to work. there should be coolant in there if there's too much pressure in the coolant system right? otherwise there would be a burst in the weakest point in the system.

 

[gummycarbs]

there should be coolant in there if there's too much pressure in the coolant system right?

Well, yeah, there should be coolant in the overflow tank at all times. More when hot, less when cold.

 

[avdeveloper]

Radiator blow out

Natcruiser said : "Yes, I'm pretty sure it is the front main seal on the crank.---the dealer said it takes an hour and a half off labor to do that seal" This is another reason you don't want to use the dealer, as mentioned above they often aren't familiar with the 80 series. The major oil leak...

forum.ih8mud.com

what does the color tell you? My radiator looks about the same. Is it mainly the radiator cap or has the top tank worn out and is a ticking time bomb literally?

 

[avdeveloper]

That radiator is hanging on for dear life, I'd replace that along with the heater valve near the firewall. Coolant/heater/vacuum hoses, are also a good idea while the throttle body and VC are off. Consider replacing the fuel filter too, and give the upper intake and TB a good clean.

I'm looking into ordering the Denso radiator off rockauto at 225. but why is the one from the dealer around 400?

 

[gummycarbs]

what does the color tell you? My radiator looks about the same.

If the top of your radiator is plastic, and it's turning yellowish like that, then the plastic is extremely brittle.

Same thing with the heater control valve. Sometimes the body of the valve looks okay, but when people try to pull off one of the hoses, the nipple just disintegrates and is similarly yellowish. That's why it's a good idea to change it out as part of preventative maintenance when dealing with a newly acquired vehicle.

I can't tell you *why* the plastic yellows. I don't know if it's the polymers actually breaking down, or some chemical component leeching to the surface. You'd have to ask someone who works in the industry. What we do know is that it's an indicator that the plastic has seen a lot of heat and is significantly degraded.

 

[avdeveloper]

If the top of your radiator is plastic, and it's turning yellowish like that, then the plastic is extremely brittle.

Same thing with the heater control valve. Sometimes the body of the valve looks okay, but when people try to pull off one of the hoses, the nipple just disintegrates and is similarly yellowish. That's why it's a good idea to change it out as part of preventative maintenance when dealing with a newly acquired vehicle.

I can't tell you *why* the plastic yellows. I don't know if it's the polymers actually breaking down, or some chemical component leeching to the surface. You'd have to ask someone who works in the industry. What we do know is that it's an indicator that the plastic has seen a lot of heat and is significantly degraded.

welp. it's been with us for 22 years now. I guess it's about time to replace it just in case. Is there any difference between the Denso from rockauto which is 225 vs the one from the dealer which is almost twice as much. I would expect that it's also by Denso.

 

[gummycarbs]

Is there any difference between the Denso from rockauto which is 225 vs the one from the dealer which is almost twice as much.

Not sure. If you search the forum, you'll find a TON of threads debating the merits of various radiators. Denso, CSF, Koyo, TYC, genuine Toyota, Ron Davis Radiator for the fancy lads, eBay Chinese aluminum radiators for the heathens...

 

[SaturnAscends]

I'm looking into ordering the Denso radiator off rockauto at 225. but why is the one from the dealer around 400?

I have a TYC in mine, seems to work pretty well.

 

[avdeveloper]

While I'm still waiting for the new radiator cap to be delivered, I installed a new stereo. I bypassed the factory amp and no longer hear the alternator whine that's been there for over a decade since 2004

Good thing for this forum and the stickies at the top for installing the head unit. It was tedious but it worked!

 

[avdeveloper]

Ok I've updated the list of items I've purchased (will purchase) on post #2

I've purchased a few parts last week and they're probably going to take a while to arrive.

Baseline Checklist​

Project	Component	Part Name (Part Number)	Installed On
Fix P0401 Code	EGR	Vacuum Hoses (90999-92003)	4/12/22
Tune Up	PCV Valve Kit	Valve cover vent hose #1 (12261-66021) (2) Clips for hose #1 (90467-14001) Valve cover vent hose #2 (12262-66021) (2) Clips for hose #2 (90467-20002) PCV valve (12204-35040) PCV grommet (90480-18001)	4/12/22
	Gas Filter	90917-11022	4/12/22
	Air Filter	1780166030	5/06/22
	Complete Tuneup Kit - NA Engine	(1) Distributor cap (19101-66010) (1) Distributor cap gasket (19127-66020) (1) Distributor rotor (19102-61240) (1) Spark plug wire set (90919-21557) (6) OEM spark plugs (90919-01176)
	Valve Cover Leak Kit	OEM valve cover gasket (11213-66021) OEM throttle body gasket (22271-66010) (6) OEM spark plug tube seals (11193-15010)
	Fuel System and Charcoal Canister Hoses	Fuel Hose (7727960020) Fuel Hose (7775460180) Fuel Hose (9533706020) Hose Clamps (9613230600) Fuel Filter (2330069045) Oil Filter (90915YZZD3) Oil Filter Gasket (9672335028) Oil Filter Union (9040419015)
	Drive belts	Fan belt (993321091083, 909160235383)
	Air Cleaner	Hose (1788166080) Wing Nut (9017508008) Filter (1780166030)	5/06/22
Cooling System	Radiator	Denso Radiator (1640066081) Cap (1640154750) Fan Shroud (1671166031) Coolant thermostat (9091603117) AISIN Fan Clutch (1621066010)
	Radiator Hoses	Coolant hose (9955510200) Water bypass hose #1 (1657166030) Water bypass hose #2 (1626466021) Water bypass hose #3 (1626766020) Clamps x3 (9046713128) Clamps x6 (9613551300) Radiator hose clamp x2 (9046743002) Radiator hose clamp x4 (9046641008) Clamps x6 (9046721010) Radiator hose #2 (1657266021) Heater clamp x2 (8712460070) T connector pipe (8724860460) Heater Control Valve (8724060170)
Seals	Rubber seal clips for hood	904670801183	4/01/22
Repairs	Driver Seat plastic gears	Gamiviti	5/11/22
	Hood struts	Amazon off brand	4/7/22

​

Preventive Maintenance Todo​

Maintenance Item	Performed On
Drain and Fill: Differentials and Transfer Case Fluids
Drain and Fill: Transmission Fluids
Coolant Flush (do before changing cooling system components)
Undercoating	5/07/22

Upgrades and Modifications​

Project	Component	Part Name	Installed On
Entertainment	A/V Receiver	Boss BE7ACP	5/13/22

 

[avdeveloper]

welp. I tried filling up my truck with coolant and it looks like I have a leak! Checked the radiator cap and it looks like there is a missing piece of gasket in the cap.

 

[SoCal80series]

subd

 

[avdeveloper]

All right! Just finished buying the parts I need to work on the cooling system. They should all arrive by early next month . By then, I'll disassemble a good amount of parts from the engine bay to work on the list items I specified on the Baseline checklist: valve cover leak kit, Tuneup kit I ordered from @NLXTACY a while back, Radiator and hoses, heater hoses (reverting the rear heater delete). It's almost time to address comment #6 by @Ozark80

So far I'm down $1807.23 on parts alone. I've amassed a bunch of tools since I started with practically nothing other than a couple screwdrivers and a pair of scissors .

 

[avdeveloper]

welp. this is becoming a PITA. if only I could get that clamp to slide a little bit to the top, I could get it unstuck. it looks like I'd have to remove the make some room by removing the battery and bay?

 

[avdeveloper]

well well well. just needed a different tool and different angle and I was able to pull it off before sunset.

tomorrow, it's time to replace the hose with the continental brand for now while I do a flush. fill it up with more distilled water to find out if there's another leak somewhere... is it worth doing before dismantling the rest of the cooling system?

 

[avdeveloper]

ok after filling it with distilled water and bleeding cooling system, I don't see any more leaks and it hovers around 190-194 now. I bought two 32oz blue devil to flush it with tomorrow

 

[avdeveloper]

I'm flushing the cooling system now and I'm on the 8th round of drain and fill. I don't recall when this was flushed last but I bet it hasn't been done since 2014. I'm flushing it now before I replace the hoses, radiator, etc al. Should I expect the water to run clear after several more rounds or do I just begin taking apart the cooling system now?