Engine Overheating - 2004 LC (5 Viewers)

[brake checker]

Hello all,

New to this forum, but have been lurking for quite some time.

Bought a 2004 with 210k miles, great service records up here in CO. I changed the heater tee's out last week and bought a scan guage, beacuse well, it is an old car and I wanted to drive it with a better understanding of temps, etc., and just make sure no weird underlying issues presented.

Current issue at hand:
The car overheats in the hot summer. Mainly stop-and-go on the freeway (96 ° yesterday) for an hour or two, AC on. Temp creeped up to 236, so naturally I shut the AC, turned on the heat, and let it cool. Car has been fine when moving quick down the freeway, was sitting at 186-190ish the whole way to work today. Around town on a hot day, a little higher, but not near the 236 range unless AC is on. I have been gentle and keeping the heat on and windows down in my new mobile sauna.

Findings & insights:
-Removed most residue well from older heater tees that crumbled a bit when swapping
-Coolant levels are good. Rad and Overflow (Maybe it needs to be bled?)
-OEM Thermostat was put in 10k ago, as well as a coolant flush
-99% sure radiator is original
-Points me to the fan clutch, fan clutch doesn't move freely when the car is cold
-Could it be as simple as a radiator cap... No, it couldn't be? Right!

Any advice would be great at this point! If I can't figure it out off it goes to a local Denver Mech.

Cheers.

 

[Mike NXP]

Sounds like you've checked the obvious stuff. Could be a radiator cap like you mentioned but probably not. More likely when we see temps rising in stop-n-go its related to fan/fan clutch or debris in radiator.

Remove skid plate and check radiator all over, spray it down and clean it up.

I forgot how to diagnose the fan clutch. When cold, you should hear it roar when the engine starts and slowly quiets down. When you shut down and its hot it should be hard / feel resistance when spinning the fan. (belt removed for testing)

Start easy and check radiator and replace cap with OEM but start doing research on replace fan clutch

Thread 'Radiator fins need cleaning! Alert Alert Alert'

Jul 22, 2019

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added radiator cap and thermostat to job, as best practice.

Got me to thinking about the radiators I've been replacing. All have debit built up on lower third.
This one hand some extra grasses along with general clogging on lower third.

Over the years/miles debit builds up in condenser and...

• 2001LC
• Replies: 35
• Forum: 100-Series Cruisers

• 

 

[Mike NXP]

Possibly relevant threads on fan clutch here and here

 

[Trunk Monkey]

If you changed the heater T's it's possible you've got air in the system.

 

[brake checker]

If you changed the heater T's it's possible you've got air in the system.

Sounds like you've checked the obvious stuff. Could be a radiator cap like you mentioned but probably not. More likely when we see temps rising in stop-n-go its related to fan/fan clutch or debris in radiator.

Remove skid plate and check radiator all over, spray it down and clean it up.

I forgot how to diagnose the fan clutch. When cold, you should hear it roar when the engine starts and slowly quiets down. When you shut down and its hot it should be hard / feel resistance when spinning the fan. (belt removed for testing)

Start easy and check radiator and replace cap with OEM but start doing research on replace fan clutch

https://forum.ih8mud.com/threads/radiator-fins-need-cleaning-alert-alert-alert.1151006/

Might as well throw a cap on, below are some photos of the rad/condenser. They don't seem too bad. Will look into the fan clutch next, thanks for the reference.

 

[brake checker]

If you changed the heater T's it's possible you've got air in the system.

Soda bottle bleed with car on an incline, run F/R heat?

 

[vipergrhd]

My vote replaces the radiator and new cap, if it is the original unit, you are on borrowed time. The 04 that I bought from a couple blew the bottom section of the radiator and didn't pull over right away and it cost them an engine failure, which I am replacing with a low mileage engine.

 

[excessive]

i think it's the thermostat

 

[Jack90210]

Might as well throw a cap on, below are some photos of the rad/condenser. They don't seem too bad. Will look into the fan clutch next, thanks for the reference.

View attachment 3975986

View attachment 3975987

To be clear, that's the trans cooler and the AC condenser coil. The radiator is behind the condenser, and it's hard to see unless you look up (from under the car) through the slim gap between the two. If it's original and has never been cleaned well (flushed from the rear, with the shroud pulled back) then it's highly likely that it has enough obstruction to affect its performance.

 

[2001LC]

While washing radiator fins. Test fan clutch.

Top radiator, in the AM before sun up. Park 8 hours on level ground. Best, park with vehicle front end higher than rear end.

Unless, we put in thermostat. We don't know, jiggle was placed up/at top. So during a coolant service, I at least look. Which requires new thermostat gasket.

I use BlueDriver or OBDmx, to monitor and log tech stream on my iphone. It's a good idea to monitor and log: Engine coolant temp, Fuel trims, Intake air temp AT temp, MPH, RPM.

 

[brake checker]

While washing radiator fins. Test fan clutch.

Top radiator, in the AM before sun up. Park 8 hours on level ground. Best, park with vehicle front end higher than rear end.

Unless, we put in thermostat. We don't know, jiggle was placed up/at top. So during a coolant service, I at least look. Which requires new thermostat gasket.

I use BlueDriver or OBDmx, to monitor and log tech stream on my iphone. It's a good idea to monitor and log: Engine coolant temp, Fuel trims, Intake air temp AT temp, MPH, RPM.

View attachment 3976297

Ok, will look into doing this next. I have a scanguage with engine coolant temp as a set on my dash.