Overheating while towing (1 Viewer)

[ATXyodaLifer]

I have a 2000 LC and the towing performance is unbearable. 1500 lb boat + 700lb trailer makes it overheat. Loaded dual axel trailer at 3000lb, overheating. I have flushed the radiator, use the toyota pink from the dealership, replaced the thermostat, meticulously cleaned the radiator. Confirmed all fans work and the AC compressor situation is all in working order. The odd thing is I replaced my 1998 T-100 with this truck and it had the exact same issues towing. Ended up replacing the 3.4 V6 on that truck and even with a new engine it was still a dog.

Two additional odds facts.
I ran into another guy at a gas station visiting Austin from Florida with a 2001 LC with a travel trailer behind it. I asked him how the hell is he towing that. He has been traveling the country, no problem. ARG.

I just bought a 2005 Sequoia 4x4 for my wife and while I have yet to tow with it, it feels significantly more powerful. I couldn't spin the tires on the LC if I wanted too. The Sequoia will spin tires if you push too hard on the pedal.

I have had to replace 2 ignition coils on the LC since I bought it last year (it has 225k miles) I replaced with Denso, but the remainder are an off brand. Should I do the rest?

Should I replace the Water pump? It is about time for a new timing belt.


The Sequoia has made me think maybe it is an engine/horsepower/torque issue. This LC kind of bogs down when you floor it, just like my T100 did. The Seqouia jumps up and spins rubber when you floor it.

Thank you as always for your replies.

 

[SHIfTHEAD]

Explain what happens when it overheats. Because none of what you talk about has ever happened with my 05 towing anything. The worse thing I've had to deal with is the abysmal gas mileage,but that was expected.

 

[2020 Rocks]

I have a 3500lbs pop up camper that I've towed several times, one trip into SW Pennsylvania and did not have any issues, granted I was careful. OD off for most of the real hilly stuff, etc. I'd be curious to know if you have tiny head gasket failure somewhere. Within a reasonable weight, the 100 series tows just fine IMHO.

 

[94SRUNNER]

Yes, As @SHIfTHEAD stated explain what happens during overheating.

What is the status of your coolant system? i.e. condition/age of coolant, radiator, thermostat, etc...

 

[bigredmachine]

at your mileage you should probably do the t-belt unless you have a matainance sticker showing the mileage that it was done at, and do the water pump at that mileage theres no reason not to. does it have lack of power all of the time or is it just noticeable when towing?

comparing the ability to light up the tires between the sequioa and 100 is not a fair comparison. 100 is permanent 4wd youd have to do a pretty sweet 4 wheel burn out, sequioa is part time so your only spinning up the rear making it easier to do

 

[ramangain]

Let's get down to brass tacks. Do you have the ability to monitor your coolant temps real time with something like a ScanGauge or an OBD2 reader that does bluetooth and you can monitor it with an app like Torque?

Do you tow with OD off? Your rig should easily cruise at 60-70mph with OD off with the 4spd tranny. Are you sure the thermostat is opening fully before it hits 195F?

I've towed a 6500lb dual axle trailer across the country more than once. I have never had an overheating issue, even on steep inclines when I need to be driving in 1st gear to complete the climb; the temps never rose above 220F. Besides your water pump, have you tried to get the radiator flow tested?

Your system came with Toyota red mixed with half water. Why the switch to Toyota pink?

 

[2001LC]

I have a 2000 LC and the towing performance is unbearable. 1500 lb boat + 700lb trailer makes it overheat. Loaded dual axel trailer at 3000lb, overheating. I have flushed the radiator, use the toyota pink from the dealership, replaced the thermostat, meticulously cleaned the radiator. Confirmed all fans work and the AC compressor situation is all in working order. The odd thing is I replaced my 1998 T-100 with this truck and it had the exact same issues towing. Ended up replacing the 3.4 V6 on that truck and even with a new engine it was still a dog.

Two additional odds facts.
I ran into another guy at a gas station visiting Austin from Florida with a 2001 LC with a travel trailer behind it. I asked him how the hell is he towing that. He has been traveling the country, no problem. ARG.

I just bought a 2005 Sequoia 4x4 for my wife and while I have yet to tow with it, it feels significantly more powerful. I couldn't spin the tires on the LC if I wanted too. The Sequoia will spin tires if you push too hard on the pedal.

I have had to replace 2 ignition coils on the LC since I bought it last year (it has 225k miles) I replaced with Denso, but the remainder are an off brand. Should I do the rest?

Should I replace the Water pump? It is about time for a new timing belt.


The Sequoia has made me think maybe it is an engine/horsepower/torque issue. This LC kind of bogs down when you floor it, just like my T100 did. The Seqouia jumps up and spins rubber when you floor it.

Thank you as always for your replies.

You've have something not to spec.

Check list:

1. Cleaned fins of all 3 radiators. No air flow obstruction in or in front of grill.
2. Cleared reservoir flow tube. This one is so often missed.
3. Flush block when radiator flushed. 2UZ has two block drains. I get 3.5 gallons out. With a few tricks I have, I've gotten as much as 3 3/4.
4. Toyota SLL (Pink) in 00, is not spec, but can be used. Although unless every drop of Toy LL (red) was removed (not possible), you must keep to Red PM schedule. I'd use red over Pink personally in 98-03. Red lends itself to flushing with distilled water, pink not so much as is a premix.
5. New OEM radiator cap. So often missed.
6. OEM thermostat, installed with jiggle value up. Big deal!
7. Bleed air from system and recheck by looking under radiator cap. To make sure no air (fluid to top of goose neck, after 8 hour cool down. Cool down and checked with front of vehicle higher than rear. Make sure to check, in the early morning before OAT or sun heats.
8. Fan clutch tested and working as it should.
9. Air filter clean.
10. Spark plugs gaps within spec and plugs tights.
11. Throttle body clean.
12. No vacuum leaks.
13. EVAP working to spec.
14. Long term Fuel trims, cursing on HWY ~+2% (+-2%)

No power: Your not turned well or have some compression or CAT issues

Also keep in mind that 00 does not have the same rear wheel HP as 03-. So you need to be a little more mindful of RPM vs speed pulling up hills, by using transmission down shifting when appropriate.

Additionally if any modification to factory design, they must be considered. Heavy, lifted, winch, underbelly pans, etc...

 

[94SRUNNER]

This is the recipe that needs to be followed!

You've have something not to spec.

Check list:

1. Cleaned fins of all 3 radiators. No air flow obstruction in or in front of grill.
2. Cleared reservoir flow tube. This one is so often missed.
3. Flush block when radiator flushed. 2UZ has two block drains. I get 3.5 gallons out. With a few tricks I have, I've gotten as much as 3 3/4.
4. Toyota SLL (Pink) in 00, is not spec, but can be used. Although unless every drop of Toy LL (red) was removed (not possible), you must keep to Red PM schedule. I'd use red over Pink personally in 98-03. Red lends itself to flushing with distilled water, pink not so much as is a premix.
5. New OEM radiator cap. So often missed.
6. OEM thermostat, installed with jiggle value up. Big deal!
7. Bleed air from system and recheck by looking under radiator cap. To make sure no air (fluid to top of goose neck, after 8 hour cool down. Cool down and checked with front of vehicle higher than rear. Make sure to check, in the early morning before OAT or sun heats.
8. Fan clutch tested and working as it should.
9. Air filter clean.
10. Spark plugs gaps within spec and plugs tights.
11. Throttle body clean.
12. No vacuum leaks.
13. EVAP working to spec.
14. Long term Fuel trims, cursing on HWY ~+2% (+-2%)

No power: Your not turned well or have some compression or CAT issues

Also keep in mind that 00 does not have the same rear wheel HP as 03-. So you need to be a little more mindful of RPM vs speed pulling up hills, by using transmission down shifting when appropriate.

Additionally if any modification to factory design, they must be considered. Heavy, lifted, winch, underbelly pans, etc...

 

[ATXyodaLifer]

Thank you all for replies.

On the dash, the coolant temp indicator slowly rises from the middle to red over the course of towing use. I regularly tow my trailer back and forth from Austin west to Blanco which includes some short but steep elevation. Highway speeds are not possible with the trailer loaded, have to baby the hills 55mph or it is straight to red line. On the Torque app I tow around 208f and pull over if it reads above 230f. My mechanic tells me to trust the dash no the app. The only way I can keep temp down is to stay low in RPM's over the hills which works out to dropping from 65mph to 50mph on average.


Here is where I am at:

1. Cleaned fins of all 3 radiators. No air flow obstruction in or in front of grill.
   Done
2. Cleared reservoir flow tube. This one is so often missed.
   Done. Some bits of radiator sealant material was found and cleaned out best we could from the system. The radiator looks to be recently replaced before I bought it.
3. Flush block when radiator flushed. 2UZ has two block drains. I get 3.5 gallons out. With a few tricks I have, I've gotten as much as 3 3/4.
   Done
4. Toyota SLL (Pink) in 00, is not spec, but can be used. Although unless every drop of Toy LL (red) was removed (not possible), you must keep to Red PM schedule. I'd use red over Pink personally in 98-03. Red lends itself to flushing with distilled water, pink not so much as is a premix.
   I will look into replacing with straight red.
5. New OEM radiator cap. So often missed.
   Done
6. OEM thermostat, installed with jiggle value up. Big deal!
   Done
7. Bleed air from system and recheck by looking under radiator cap. To make sure no air (fluid to top of goose neck, after 8 hour cool down. Cool down and checked with front of vehicle higher than rear. Make sure to check, in the early morning before OAT or sun heats.
   Done
8. Fan clutch tested and working as it should.
   Done
9. Air filter clean.
   Done
10. Spark plugs gaps within spec and plugs tights.
    As I have already had 2 coils go out, I am thinking this might be an area to focus.
11. Throttle body clean.
    Done
12. No vacuum leaks.
    Was a leak because of a broken hose connection on the throttle air intake. Sealed with plastic cement, just got a replacement throttle body air intake. Hope this is it.
13. EVAP working to spec.
    Need to look into
14. Long term Fuel trims, cursing on HWY ~+2% (+-2%)
    Need to look into this as well.
    
    

 

[JunkCrzr89]

On the Torque app I tow around 208f and pull over if it reads above 230f. My mechanic tells me to trust the dash no the app.

Your mechanic is wrong. The dash gauge is notoriously inaccurate.

 

[2001LC]

Thank you all for replies.

On the dash, the coolant temp indicator slowly rises from the middle to red over the course of towing use. I regularly tow my trailer back and forth from Austin west to Blanco which includes some short but steep elevation. Highway speeds are not possible with the trailer loaded, have to baby the hills 55mph or it is straight to red line. On the Torque app I tow around 208f and pull over if it reads above 230f. My mechanic tells me to trust the dash no the app. The only way I can keep temp down is to stay low in RPM's over the hills which works out to dropping from 65mph to 50mph on average.


Here is where I am at:

1. Cleaned fins of all 3 radiators. No air flow obstruction in or in front of grill.
   Done
2. Cleared reservoir flow tube. This one is so often missed.
   Done. Some bits of radiator sealant material was found and cleaned out best we could from the system. The radiator looks to be recently replaced before I bought it.
3. Flush block when radiator flushed. 2UZ has two block drains. I get 3.5 gallons out. With a few tricks I have, I've gotten as much as 3 3/4.
   Done
4. Toyota SLL (Pink) in 00, is not spec, but can be used. Although unless every drop of Toy LL (red) was removed (not possible), you must keep to Red PM schedule. I'd use red over Pink personally in 98-03. Red lends itself to flushing with distilled water, pink not so much as is a premix.
   I will look into replacing with straight red.
5. New OEM radiator cap. So often missed.
   Done
6. OEM thermostat, installed with jiggle value up. Big deal!
   Done
7. Bleed air from system and recheck by looking under radiator cap. To make sure no air (fluid to top of goose neck, after 8 hour cool down. Cool down and checked with front of vehicle higher than rear. Make sure to check, in the early morning before OAT or sun heats.
   Done
8. Fan clutch tested and working as it should.
   Done
9. Air filter clean.
   Done
10. Spark plugs gaps within spec and plugs tights.
    As I have already had 2 coils go out, I am thinking this might be an area to focus.
11. Throttle body clean.
    Done
12. No vacuum leaks.
    Was a leak because of a broken hose connection on the throttle air intake. Sealed with plastic cement, just got a replacement throttle body air intake. Hope this is it.
13. EVAP working to spec.
    Need to look into
14. Long term Fuel trims, cursing on HWY ~+2% (+-2%)
    Need to look into this as well.

• Cleared reservoir flow tube. This one is so often missed.
  Done. Some bits of radiator sealant material was found and cleaned out best we could from the system. The radiator looks to be recently replaced before I bought it. This is interesting as there is not or should be any sealant in the system. If a coolant stop leak has been used, you could have blockage. I like using BG coolant flush & super cool if I suspect rust, gunk build-up, etc. or a stop leak used. A sealant that is used, is 1282B FIPG at water inlet to water pump fitting. If excessive amount used during assemble. It squeeze out the sides. Both outside and inside. To much and chucks can be floating through the system. The places I've found and or seen pictures of chunks are; oil cooler and thermostat housing. Can also clog radiator. This can effect coolant flow and thus cooling. A clue if to much FIPG used, is simply looking at outside of inlet for excessive amounts.
• Toyota SLL (Pink) in 00, is not spec, but can be used. Although unless every drop of Toy LL (red) was removed (not possible), you must keep to Red PM schedule. I'd use red over Pink personally in 98-03. Red lends itself to flushing with distilled water, pink not so much as is a premix.
  I will look into replacing with straight red. Keep in mind Red is not used straight out of jug, It's mixed 50/50 with distilled water. Using Pink will not cause your overheating. Just not year correct.
• Spark plugs gaps within spec and plugs tights.
  As I have already had 2 coils go out, I am thinking this might be an area to focus. Not likely a overheating cause. But speaks to performance and general overall engine tune.
• No vacuum leaks.
  Was a leak because of a broken hose connection on the throttle air intake. Sealed with plastic cement, just got a replacement throttle body air intake. Hope this is it. Vacuum leaks may induce extra air into the intake manifold. This may yield a lean fuel to air mixture. Engine will run hot, if mixture is lean. Fuel trims offer clue here.
• EVAP working to spec.
  Need to look into. I'm seeing more and more often with age, EVAP vacuum line leaking. Again this can lead to vacuum leak (lean condition) and I've been suspecting some fuel pressure issue.
• Long term Fuel trims, cursing on HWY ~+2% (+-2%)
  Need to look into this as well. As mention they can be revealing/clues as to vacuum leaks. Also low fuel pressure, clogged fuel deliver system (like clogged fuel injectors, fuel filter, FPR, etc), weak fuel pump.

App reading ECT is much more accurate than your dash gauge. This tells me your mechanic is not a 100 series specialist, likely not a Toyota man. Did he work on the vehicle you "had" that overheated! What work has he done to this 2000 LC?

 

[ramangain]

On the Torque app I tow around 208f and pull over if it reads above 230f.

208F is abnormally high for simple flat-ground towing. On my recent trip from ABQ to Ohio, I never saw above 200F while towing 6500lbs, even going WOT on inclines to get the trip done between winter storms.

If you have a basic mechanics tool set, it is not difficult to remove the thermostat and check it is installed properly and operating correctly. Aside from that, is it possible to take and post a video of this overheating issue the next time you are properly hitched up?

 

[JunkCrzr89]

208F is abnormally high for simple flat-ground towing. On my recent trip from ABQ to Ohio, I never saw above 200F while towing 6500lbs

I agree - I towed a 6x12 cargo trailer, packed to the brim, over multiple mountain passes driving from AZ to CO with O/D off and hit 200*F just a couple of times...Most of the drive I was cruising at 188-192*F.

 

[SHIfTHEAD]

The temps you mention are exactly what I was seeing and could not track down the cause. I eventually decided it was a radiator gone bad and decided to replace it and do a timing job at the same time. When I did the job I found that the thermostat was original manufactured in 2004. I put it all back together with a new OEM thermostat and everything has been fine since.

 

[ATXyodaLifer]

Thank you so much for your replies. I will update the thread as I work on these excellent ideas.

I am afraid the lingering radiator sealant could be the culprit, makes perfect sense that some got stuck in other parts of the cooling system. The radiator looks to have been replaced right before I bought it, so it hurts to think it could be clogged, but it makes a lot of sense that too much sealant was put in the system at some point and when they put the new radiator in, the old sealant was not all removed. I actually bought BG coolant flush off of ebay a while back after reading another thread by you 2001LC, but I have not attempted using it yet.

I think the high temp on the Torque app is what led my mechanic to question that number. If that number is correct, no doubt this truck runs hot.

It has been 90K miles since timing/water pump so I know that is due. Weak water pump makes sense.

The EVAP vacuum leak/weak fuel filter is something I am going to try and resolve asap. This sounds exactly like the difference in how mashing the gas pedal feels between the LC and the Sequoia. The Sequoia jumps up and goes, the LC almost feels like pushing the gas pedal more bogs it down.

You all are amazing, thank you!

 

[Patassa]

comparing the ability to light up the tires between the sequioa and 100 is not a fair comparison. 100 is permanent 4wd youd have to do a pretty sweet 4 wheel burn out, sequioa is part time so your only spinning up the rear making it easier to do

Not to mention an electronic system designed to prevent wheels from slipping...