My '03 LX470 with 190K miles experienced the infamous heater tee failure and overheated. With the system repaired I now have an engine that runs beautifully but consumes coolant. As a hail-mary I tried K-Seal, to no avail, so it's time to fish or cut bait. I figure that I"m looking at $2,500 - $7500 in repairs. The LX is in otherwise very good condition. I'm in the Little Rock area and don't know of anyone that I can trust to take on the repair so my first thought is a Toyota dealer. I'm hoping to gain wisdom from those that have experience in this regard so all input is appreciated!
Engine Overheat Damage - Now What?
- Thread starter BonS
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
- Thread starter
- #2
One "truth" that I gleaned from The Car Care Nut is that VVTI Toyota heads can't be resurfaced. Since the '03 2UZ engine doesn't have VVTI then there's a chance that I can save the heads if they're warped?
Where is the coolant leak?
- Thread starter
- #4
I just rented a combustion leak detector and will attempt to learn which cylinder(s) are affected. Please stay tuned.
awesomeissquid
SILVER Star
Have you checked the spark plugs? If you pull them and some appear cleaner than the others, you have likely found your coolant leak. The coolant steam cleans the spark plugs.
Other option would be to use a leak down tester to verify that you have a connection from the specific cylinder into the coolant passageway.
Other option would be to use a leak down tester to verify that you have a connection from the specific cylinder into the coolant passageway.
- Thread starter
- #6
I changed all the plugs and all the plugs were the same coffee brown. Cylinders 2&4 plugs had the very, very smallest amount of a whitish deposit on both the anode and electrode tips. When I used K-Seal I pulled both of those plugs and ran the engine for a while without them (the Scotty Kilmer method). Prior to using K-Seal I could smell coolant outside the car. No coolant smell inside or outside afterwards.
I just ran a combustion leak test and the fluid remained blue after the engine was thoroughly up to temperature. The oil level is normal with no hint of water.
I cannot find any external leaks. No dried coolant on the radiator, hoses, or fittings that I can find.
The only indication of a problem is a decreasing coolant level in the surge tank with driving. Maybe 1/2"-1" per 100 miles. What am I missing?
I just ran a combustion leak test and the fluid remained blue after the engine was thoroughly up to temperature. The oil level is normal with no hint of water.
I cannot find any external leaks. No dried coolant on the radiator, hoses, or fittings that I can find.
The only indication of a problem is a decreasing coolant level in the surge tank with driving. Maybe 1/2"-1" per 100 miles. What am I missing?
awesomeissquid
SILVER Star
Check the valley between the cylinders where the starter lives to see if there is any coolant in there. Might be an external coolant leak.
After the overheat did you burp the coolant system properly? Maybe you just have some remaining air bubbles that are working themselves out of the system?
After the overheat did you burp the coolant system properly? Maybe you just have some remaining air bubbles that are working themselves out of the system?
- Thread starter
- #8
I thought that I got all the air out of the system. But as my surge tank levels drooped, I thought I might be dealing with residual air in the system. I continued to add coolant to get the surge tank back to the level line many times. Since I was smelling coolant outside of the car I used K-Seal. Over the past several days I've driven a few hundred miles a day so I had a lot of opportunity to look for continuing consumption. I'm slowly abandoning hope that it's air in the system. I'll peek under the intake manifold and give it a look. By the way, there's no smell at the tailpipe and now white cloud/steam to be seen.
- Thread starter
- #9
The valley is dry. I wish it wasn't.
My 4R slowly burped out air for about a month after my Indy did a timing belt years ago, my drives were typically short 6 mile drives 8 hours apart.
I too was concerned but after the initial processes of finding nothing large (i didn’t leak down or anything because it never overheated) I eventually stopped topping it off and for years it’s been fine. Total add was less than one overflow tank though.
I too was concerned but after the initial processes of finding nothing large (i didn’t leak down or anything because it never overheated) I eventually stopped topping it off and for years it’s been fine. Total add was less than one overflow tank though.
Interesting, why can't they be resurfaced?
I'd keep adding coolant and get a Blackstone test done after changing the oil and giving it a few hundred miles. They'll find trace amounts of coolant and give you a better pass/fail than the dye tester.
I've rebuilt a lot of bhg Toyota engines. Never a 2uz. Generally not a terrible job, but requires careful labor.
You can also do a compression test and a leakdown test on the engine to further verify the presence (or lack thereof) a head gasket leak. I would go that route since the plugs on the 2UZ are pretty easy to get to - first a compression test on all 8 cylinders (with and without oil), then the leakdown test (will require compressed air and a specific tester).
Also typical resurfacing for a cylinder head takes off a very nominal amount of material - heads on interference engines are resurfaced all of the time. That being said it's probably pretty easy to find another 2UZ as they often last longer than the vehicle they are installed in; I'd personally go that route (good used motor) rather than trying to rebuild one.
Also typical resurfacing for a cylinder head takes off a very nominal amount of material - heads on interference engines are resurfaced all of the time. That being said it's probably pretty easy to find another 2UZ as they often last longer than the vehicle they are installed in; I'd personally go that route (good used motor) rather than trying to rebuild one.
You can also pressurize the cooling system with a cooling system pressure tester for an hour or so, and then see if the engine stumbles when started (indicating that this pressurized coolant snuck into a cylinder).
- Thread starter
- #15
Interesting. I haven't yet added anything like one overflow tank - yet.
The issue with resurfacing is that it messes up the valve timing in the VVTI setup. I'm just being a parrot on this one.
Oh how i miss my home shop. We full time in an RV and I have to make do sometimes. I guess I can use the chassis air in my coach to help with a leakdown test. I would love to get that data point. Since my engine has 190K on the clock a used engine does make good sense.
I've done both, but now I'm just adding to the surge tank when cold - to be consistent. The radiator is keeping itself full. I didn't pull the driver's seat out but I felt around for moisture and everything's dry. It's definitely putting out heat! And I don't smell coolant in the car when the heat is blasting.
I'll look into doing a pressure test on the cooling system Good idea. I guess I can borescope the cylinders while the cooling system is under pressure and look for weeping.
Thanks all!!
Ok, I think that's just referring to unusually high material removal. They have variable thickness head gaskets for most other engines to help with that. For typical rebuilds I think you're ok, but perhaps I'm mistaken. If I remember I can take a look at the Lexus service manual I have in the shop.
2001LC
SILVER Star
VVT or non VVT heads, can be recondition the same.
The 2UZ is a funny beast when dealing with purging air from coolant system. We must fill radiator and reservoir. Run engine at op temp getting RPM up to minimum 3K for 3 minutes. Turn both cabin heaters to max hot. You should feel very hot heat blowing. If not, you're low on coolant.
Let cool down overnight (8 hr's). Best if parked with front end higher than rear. This put high point at radiator cap. Air move to high point. We must check under the rad cap and top to the neck. If any needed, repeat checking/topping again the next morning.
If thermostat jiggle valve not at top. The system will not properly purge the air.
Cap and thermostat, must both be in proper working order also.
Reservoir hose must go straight down and be clear of blockage.
All bugs, grasses, cottonwood, dust, mud, feathers, etc., must be cleaned from radiator fins.
Once sure coolant is leaking/loss, check all the usual spots for the Toyota red or pink trials. If not found, check ever inch on head gasket. Still loosing, no coolant leak found and oil good. Do a compress test. Then leak down. While doing leak down test or just pressurizing a cylinder. Watch for air bubbles in radiator.
Never use a stop leak! The one time I'd use. Is when head leak is found and cylinder diagnostic show badly scored. I's may the use just buying some time until engine replacement. Which I'd then also replace radiator and pray heat cores not clogged.
The 2UZ is a funny beast when dealing with purging air from coolant system. We must fill radiator and reservoir. Run engine at op temp getting RPM up to minimum 3K for 3 minutes. Turn both cabin heaters to max hot. You should feel very hot heat blowing. If not, you're low on coolant.
Let cool down overnight (8 hr's). Best if parked with front end higher than rear. This put high point at radiator cap. Air move to high point. We must check under the rad cap and top to the neck. If any needed, repeat checking/topping again the next morning.
If thermostat jiggle valve not at top. The system will not properly purge the air.
Cap and thermostat, must both be in proper working order also.
Reservoir hose must go straight down and be clear of blockage.
All bugs, grasses, cottonwood, dust, mud, feathers, etc., must be cleaned from radiator fins.
Once sure coolant is leaking/loss, check all the usual spots for the Toyota red or pink trials. If not found, check ever inch on head gasket. Still loosing, no coolant leak found and oil good. Do a compress test. Then leak down. While doing leak down test or just pressurizing a cylinder. Watch for air bubbles in radiator.
Never use a stop leak! The one time I'd use. Is when head leak is found and cylinder diagnostic show badly scored. I's may the use just buying some time until engine replacement. Which I'd then also replace radiator and pray heat cores not clogged.
Last edited:
- Thread starter
- #18
That all sounds like good advice 2001LC. Some a bit too late for me. K-Seal says "The particles in our K-Seal products are very precisely designed to be large enough to repair holes up to 0.635mm in size but deliberately small enough to never block any passageways or tubes within the cooling system, including those inside the heater core and radiator." So I'm hoping they're not wrong or lying. I ran the heat today and it was incredibly hot. I'm don't know what a thermostat jig valve is. Please explain. Thanks.
I just drained, refilled, and burped my system after replacing the thermostat. Even after burping at idle then at 2-2.5k it still drank the reserve as it wasn’t fully burped until the thermostat was able to open, which I had to drive at highway speeds for it to do. Did another fill and it took just a bit more but has since equalized, about 3 days now.
When looking at a thermostat, one end has a jiggle valve. The system can't properly deal with any air if that valve isn't installed correctly (pointed up, or towards the hood).
In this picture, it's on the right:
