2LTE Overheating Issue + Future Roadtrip = Questions (2 Viewers)

[Fraughton]

Got a question for the community:

I've been working slowly on trying to mitigate the overheating issue with my 2lte. The guy who owned the vehicle before me replaced the cracked head with a new one, replaced the factory radiator with an aftermarket rad and two electric puller fans (currently Jerry-rigged to an under-the-hood switch), removing the clutch cooling fan in that process, and changed out the glow plugs. I've been following the "Ideas for improving the 2LTE" thread (https://forum.ih8mud.com/threads/ideas-for-improving-the-2lte.680759/) and have done the obvious oil change, fuel filter change, and air filter change; then I did a coolant flush (as I noticed the coolant was quite murky) and it definitely dropped the engine temperature a bit (but not enough for hot days or long hills).

I had a bit of an issue with the fuel filter housing letting air into the fuel and am waiting for a new one to come in from 'rocky mountain imports". As such, I have postponed all work on the truck until I have it running again.

My next course of action (after replacing the filter housing) is to replace the oem thermostat with an 82C, add a freeze plug block heater (winters can get as cold as -40 up here), do a full coolant flush in the process (using oem red toyota coolant), and add redline water wetter to the coolant to help prevent steam.

I am going on a 750km roadtrip (really not that far) but with lots of climbs. The last climb is ~1000 meters over a span of 120km and I'm worried this ~2hr climb will end up being 5hrs+ or just not possible. As it is I have trouble with a 200 meter climb over 9km when I drive to town to hit up Napa (usually having to stop twice up the hill when the engine gets uncomfortably close to overheating).

Does anyone have any suggestions or ideas on how I can make this trip not a huge hassle? (other than renting a car) Should I just try to get as much of the suggested work in the "Ideas for improving the 2LTE" thread done as possible?

Cheers!

Fraughton

Sidenote: Has anyone installed a block heater in the 2lte? I'm having trouble finding the correct size.

 

[GTSSportCoupe]

What are the symptoms of your overheating problem? I'm surprised you are having problems given the new head/radiator/fans etc. The murky coolant sounds concerning though.

Before I did any of the stuff in the "Ideas for improving the 2LTE" thread, I did not have coolant overheating problems with the regular driving that you are describing. So you should not have to do that all that stuff to make your truck handle normal drives. That said, once you have your vehicle baselined in terms of basic maintenance, the "improving the 2LTE" stuff will help a lot though (most especially with lowering EGTs and greatly improving power/driveability.)

Coolant flush and new thermostat should help a lot. Maybe there is some debris (rust?) that has come from the engine and clogged your new radiator? Might be worth trying to check that. In Japan they sometimes run straight water instead of a coolant mix; this seriously corrodes the coolant passages and contributes to the head and overheating problems. Could be this was the case with yours back in Japan.

I've you are ever in Victoria BC, let me know, and we could chat about cruisers. I could show you some of the improvements I've made to mine.

 

[Fraughton]

I'm not sure what you mean by symptoms?
and I am surprised as well; hopefully the problem is something small and overlooked. I am concerned that I may have cracked the head driving from Cranbrook to Hudson's Hope when I first bought it. I was ignorant to the overheating problem and the truck overheated on two occasions when driving up through Banff. I was also teaching myself to drive standard on this drive, definitely contributing to the initial overheating. Is there an easy way to check if the head is cracked without removing the engine? or are there any other tell-tale symptoms involved with a cracked head?

Ya I'm hoping the coolant flush and thermostat will make a difference. and debris is possible, but how would I check that? Visually in the top of the rad there doesn't seem to be any debris.

I may be in Vic late October. I'll let you know if so.

 

[Trinidad]

This may or may not be relevant to the issue you are having but it what I experienced with my truck...

I have a 70 series with the 2LT engine and on long hill climbs the temp gauge would spike (shoot up 3/4 of the way to the red mark) by which time I would have eased up on the throttle to let the engine idle which brought the temperature back down. I had gone through eliminating the usual suspects (changed the coolant, thermostat, fan clutch, etc) and still had the problem. I noted that driving around the city or on long highway runs with shallow inclines for long periods on very hot days did not cause the engine to exhibit this problem.

I later found out that this was happening because the 'light duty' 2LT engine's thermostat was not allowing enough coolant to flow through to cool the engine when it was under load during long hill climbs. That is, the bore of the OEM thermostat doesn't allow enough coolant to flow through when opened. The issue was resolved by installing a thermostat with a much larger bore (from a Tacoma) to allow more coolant to flow through when opened.

Now, during long hill climbs, the temp needle 'blips' when the engine is under load during those long hill climbs, revving high whilst going through mud tracks, towing, and recovering stuck trucks. I haven't experienced the temp needle shooting up as it did before.

 

[torquedorque]

If you suspect a cracked head, is it because of loss of power? A compression test might be in order, but pressure testing the cooling system should put your mind at ease, no leak would mean no crack, almost always.

 

[Fraughton]

This may or may not be relevant to the issue you are having but it what I experienced with my truck...

I have a 70 series with the 2LT engine and on long hill climbs the temp gauge would spike (shoot up 3/4 of the way to the red mark) by which time I would have eased up on the throttle to let the engine idle which brought the temperature back down. I had gone through eliminating the usual suspects (changed the coolant, thermostat, fan clutch, etc) and still had the problem. I noted that driving around the city or on long highway runs with shallow inclines for long periods on very hot days did not cause the engine to exhibit this problem.

I later found out that this was happening because the 'light duty' 2LT engine's thermostat was not allowing enough coolant to flow through to cool the engine when it was under load during long hill climbs. That is, the bore of the OEM thermostat doesn't allow enough coolant to flow through when opened. The issue was resolved by installing a thermostat with a much larger bore (from a Tacoma) to allow more coolant to flow through when opened.

Now, during long hill climbs, the temp needle 'blips' when the engine is under load during those long hill climbs, revving high whilst going through mud tracks, towing, and recovering stuck trucks. I haven't experienced the temp needle shooting up as it did before.

Did the Tacoma thermostat actually fit properly in the original housing? Or we're some changes needed? I will definitely try this as I'm already going to replace the thermostat. Do you have the part number by chance? Or maybe the model of Tacoma it would've been for?

If you suspect a cracked head, is it because of loss of power? A compression test might be in order, but pressure testing the cooling system should put your mind at ease, no leak would mean no crack, almost always.

I'm just a learn as I go DIYer. Had no idea that a cracked head would cause a drop in power (it makes complete sense though). This is good news because I haven't seen any loss in power (that I can tell). However I still will be getting a pressure test done on the coolant system before the winter hits.


Thanks for the help guys!

 

[77cruiser77]

What's the cost difference I wonder between upgrading parts for a 2LTE to become more reliable and swapping in an already proven reliable motor such as a 3B, 13BT, or the more work option 1HZ? Also curious of the 2UZ-FE which I've heard gets better fuel mileage and gobs more hp and torque.

 

[Trinidad]

Fraughton,

I had the work done by John at ATEB in Burnaby.
The new thermostat's external diameter is larger than that of the thermostat housing... it had to be ground down to fit.
The thermostat itself cost $33

On Monday I will the part # of the thermostat they installed as it was on indicated on the receipt I got.

Check your PM.

 

[crushers]

let me get this straight.
you are having issues with a shorter less steep climb and want to know if it is smart to do a shorter steeper climb with a compromised engine? seriously?
if you over heated the new head then there is a very good chance it is cracked. it is still a cast head and yes, i have seen them fail.
compression test will tell you nothing about the cooling system
a coolant pressure test MIGHT tell you if you have a crack but if the crack seals back up as the head cools then it will give a false reading.
there is NO cure for the head cracking, it is a design flaw. you are going to be spending thousands trying to prevent the issue but in the back of your mind the concern will always be there. everytime you head off on a remote trip you will worry," is this the time the lump of cast leaves me on the side of the road or not"
the LJ78 is a sweet truck. nice ride, lots of room, great gearing for larger tires.
think of that very pretty girl next door, the one with a drop dead body, great personality but she has a drug problem. you can date her, you can spend money on her but she will still have the issues.
best just to walk away.
in this case you already put a ring on her finger so you need to find a way to cure the problem and the only REAL cure is a heart transplant. bank your money for a 1HZ or 1PZ and you will end up with a truck you can rely on and one that can actually move down the road with ease.
when less than 1% of the owners of LJ trucks have beaten the odds, that is not a good sign to keep dumping money into the crack whore.

sorry for the reality check.

 

[GTSSportCoupe]

Fraughton,

I had the work done by John at ATEB in Burnaby.
The new thermostat's external diameter is larger than that of the thermostat housing... it had to be ground down to fit.
The thermostat itself cost $33

On Monday I will the part # of the thermostat they installed as it was on indicated on the receipt I got.

Check your PM.

I'd be very interested in that part #. Thanks for looking into that.

 

[GTSSportCoupe]

What's the cost difference I wonder between upgrading parts for a 2LTE to become more reliable and swapping in an already proven reliable motor such as a 3B, 13BT, or the more work option 1HZ? Also curious of the 2UZ-FE which I've heard gets better fuel mileage and gobs more hp and torque.

Do you mean 1uz-fe? That is the gasser commonly swapped in New Zealand. Bolts to the existing transmission, which is a real bonus. I've thought seriously about swapping one into mine, and then would be able to do the job on the side for others if they wanted help. Sounds like the perfect engine from what the Kiwi's say. They do get similar economy, but get 260hp 260lb/ft torque. Sticking with diesel is great and all, but that engine would be a serious fix for a Prado. Not to mention a whole Lexus LS400 donor can be had for about $1000.

 

[crushers]

did anyone make a kit for the wiring for the 1uz-fe?
now that would make the swap soooo much easier for those of us that hate electrical.

 

[GTSSportCoupe]

did anyone make a kit for the wiring for the 1uz-fe?
now that would make the swap soooo much easier for those of us that hate electrical.

Those that have figured it out are the ones making money off swaps in New Zealand. They keep the wiring secrets to themselves for good reason. With the schematics from the Prado and the donor vehicle (LS400) it shouldn't be that hard to figure out though.

 

[Dprio34]

Resurrecting and old thread, Just got back from a 2000km round trip through Nevada, Wyoming, Utah, and Montana through Yellowstone and Grand Tetons. Temperatures were over 115F/ 46 Celsius in Nevada at times. My Water Temp gauge usually stays parked at the 8:00 position and may climb to 9:00 on steep grades. On this trip it would climb all the way to 10:30ish, just under redline. (never touched redline). Anyway, the curious part was it would also spike at idle with the parking brake set or going down steep grades in idle (higher than it would in the climb up a steep grade). My first impression was possibly a problem with the clutch fan. Then I burped the system at the radiator cap and added coolant. It seemed to cure the problem somewhat... Any ideas what is going on in this scenario?

 

[GTSSportCoupe]

Air in the system will cause the temp spikes you were seeing. A small leak will allow air into the system when the engine cools. It is supposed to draw back from the reservoir, but won't if there is a leak.

When the gauge is just under the redline the engine is at about 110C in my experience. I'd highly recommend swapping to Evans Coolant. This will protect your motor from head issues with all that heat. Not worth the risk. Evans swap costs about $200. New head about $2000. Labor yourself....

 

[tommybj73]

Check all your hoses,a tiny hole can open up at certain tempetures when there is more pressure in the system and cause the engine to run hot,you could also try and remove your thermostat for your trip for price of mind

 

[Jarrat]

I'd be very interested in that part #. Thanks for looking into that.

Me to.... I have the 3.0 4 Runner one in my truck now, and it works.... Ok...

 

[GTSSportCoupe]

Me to.... I have the 3.0 4 Runner one in my truck now, and it works.... Ok...

I learned now that ateb adds a custom spacer and uses the 1kzte stat. It's a pretty cold one tho. Prado does better economy with a 88c.

 

[GTSSportCoupe]

This may or may not be relevant to the issue you are having but it what I experienced with my truck...

I have a 70 series with the 2LT engine and on long hill climbs the temp gauge would spike (shoot up 3/4 of the way to the red mark) by which time I would have eased up on the throttle to let the engine idle which brought the temperature back down. I had gone through eliminating the usual suspects (changed the coolant, thermostat, fan clutch, etc) and still had the problem. I noted that driving around the city or on long highway runs with shallow inclines for long periods on very hot days did not cause the engine to exhibit this problem.

I later found out that this was happening because the 'light duty' 2LT engine's thermostat was not allowing enough coolant to flow through to cool the engine when it was under load during long hill climbs. That is, the bore of the OEM thermostat doesn't allow enough coolant to flow through when opened. The issue was resolved by installing a thermostat with a much larger bore (from a Tacoma) to allow more coolant to flow through when opened.

Now, during long hill climbs, the temp needle 'blips' when the engine is under load during those long hill climbs, revving high whilst going through mud tracks, towing, and recovering stuck trucks. I haven't experienced the temp needle shooting up as it did before.

Fraughton,

I had the work done by John at ATEB in Burnaby.
The new thermostat's external diameter is larger than that of the thermostat housing... it had to be ground down to fit.
The thermostat itself cost $33

On Monday I will the part # of the thermostat they installed as it was on indicated on the receipt I got.

Check your PM.

Hey @Trinidad , this is an old thread, but I think you still visit these forums once in a while. A few of us are playing around with different alternative thermostat options for the 2LTE. Much for the reasons you explained above. The ones we're honing in on are the 3RZFE Tacoma ones. It sounds like this is what may have been put in your old LJ71 by ATEB. I think you PM'ed the part number to Fraughton all those years ago. Can you please send me that PM also if you see this? I'd be very interested to know what thermostat ATEB put in there for you. Thanks! Nick.