460LQ8

2011 LS 460L @ ~100k miles. Just bought it 2-3 months ago.

Issues I've found so far:
- One headlight points lower than the other
- Nav buttons are all dark except "Climate" that occasionally flickers on and off
- Volume **** doesn't work
- Recent sandstorm sandblasted my headlights so they are almost completely useless now. I should have expected that driving 90-100mph 40mi a day through a sandstorm for a week.
- High pitched whine from radio while something is plugged into any of the cigarette lighters. I assume bad ground somewhere.

Otherwise, it's been good...until yesterday. Backing out at a store, someone flying through the parking lot is irritated he had to stop and started honking. He tries to cut around me and I floor it like a child, passing him, and let off the throttle at the exact moment it was shifting resulting in a hard shift (maybe related, maybe not). A km or two down the road, I hear the pleasant beep, look at the dash, and see the warning that the engine has overheated and I should shut the engine off, look at the maxed out gauge, pull over and shut the car off.

I wait 10-15 minutes, turn the car back on, and it's only a little below the max. Drive a hundred feet and it's overheated again. Turn it back off. It's been 110-120F for the past week or two so no surprise it didn't cool down much. I checked under the hood and didn't see any liquid anywhere so don't believe there's a leak. Checked the radiator and it's not obstructed. Radiator fans work. Couldn't tell if the overflow tank was full or not. Someone showed up that only spoke Arabic and I pointed out what was going on, he started to open the cap. It vented maybe a bottle of water (yes, water) on the ground. We opened it all the way. Poured about 3 bottles of water in it. About 30-40 minutes had passed, I started the car, it was only slightly above operating temp, I limped it home.

Symptoms
- Car overheated QUICKLY after I drove it like a fool briefly. Maxed out temp within 2-5 minutes.
- After it half-cooled down and we added 3 bottles of water, I was able to drive another 5-6km home before it maxed the temp gauge again. Odd thing was it seemed to cool down slightly the RPMs increased (pump/belt?) and warm up as I was coasting
- No noticeable leaks or steam
- Didn't smell burning coolant, but it looks like some dumbass replaced the coolant with water. This is common at shops here...
- Radiator and fans appear fine

Tomorrow morning I'll do some further diagnostics:
- Check level in coolant tank
- Check level in radiator (once I figure out how to get to it)
- Check radiator cap
- Check the oil to see if it's milky
- Check that the belt going to the water pump is OK, although I never heard any squealing
- Watch radiator level as the car warms up to see if thermostat appears to be working
- Inhale some exhaust fumes to see if I catch a whiff of that sweet, sweet coolant
- Pray it's not a head gasket failure

Any other tips?

460LQ8

Funny coincidence:
- My LS 460L overheats last night
- Coworker's Volvo SUV blew a radiator hose at work today when me and Coworker #2 were getting lunch
- Coworker #2's BMW SUV cooling system blew up after he got home from dropping me off

colfax

I very much recommend to you that it is your time and mileage and the overheating seems to confirm that you
should have your radiator drained and refilled with new quality coolant and I would take this
opportunity to put in a new thermostat as your mileage suggests it is time for that.

Anfanger

Looks like a thermostat or water pump issue.

460LQ8

So I don't know.

Drained the radiator. Took off the thermostat. The old one looked and moved fine but I replaced it anyway. Was going to replace the water pump as well but I need a tool with enough leverage to release tension on the belt and remove it. All I have is a wrench with a 6" handle and while I was able to move the tensioner I wasn't able to remove the belt while doing so... The belt needs to be replaced anyway, so I'll do that once I get the proper tools.

Filled the reservoir, opened what I assume is the bleeder on the radiator, turned the heater on, let the car run while refilling the reservoir when it got low, revved to 2000RPM for a few minutes at a time. Reservoir was "foamy" at one point which I hope is just from air that was trapped in the system. After a while it all went away.

Drove it up and down the road for about 20 min at up to 150kmh. Temp seems a little high, up to the 5th notch on the temp gauge, but spent most of the time around the 4th mark. Ambient temp is 48c so that could have something to do with it. Will drive it to work tomorrow but to be honest I'm a little nervous since I don't think that I "fixed" anything. Commute is literally ~40km through the desert so getting stuck is not entertaining.

bpddaddy

Crawl under car and check for coolant drip lines on the top of the transmission housing that don’t make it all the way to the skid plate covers. Or look at the back of the engine on both sides back to the firewall and check for coolant right below the intake manifold. The car exhibits spikes in overheating due to a gasket leak under the intake manifold (Valley Plate).

Search for that heat. I and others have posted about it here.

Doublebase

Alright, so if you’re not experiencing coolant loss, the fans work, and your coolant mixture is correct...head gasket or coolant temperature sensor, maybe.

Where you live, and it being so hot, actually makes me feel “better” because if it did overheat once, or come close to overheating, at least you have an excuse...the extremely hot temps. Perhaps it was just a one time thing and maybe everything is fine, especially where you say you’re not noticing any coolant loss.

I’d keep an eye on it and really start measuring coolant to inspect for loss. Radiator is clean and not obstructed? I don’t know if the impellers on the water pump are metal or plastic, but I have seen plastic impellers totally break off and melt away. I know that is a long shot, but it isn’t a bad idea to replace a water pump anyway. You could always try pulling a spark plug and checking for coolant...you could try a compression test. Just some ideas.

Anfanger

Maybe the system was not bled properly but compression test is a good idea. Check if the radiator is clean on outside. If you drive in sandy conditions, there might be some sand trapped in the radiator.

460LQ8

Thanks for the tips/pictures. Interesting on the "valley."

I drove it ~100km to work and back today. Temperature gauge stayed at the 4th and 5th notches. I checked the reservoir as soon as I got home and it did appeared to have a couple mm of foam at the top and the coolant level seemed a little lower. Of course, I didn't open it to check for sure. I will add more coolant once it cools down and run it with the cap off to see if any bubbles appear. Hopefully it's just residual air in the cooling system but of course I'm concerned about needing a head gasket replacement...

The temps have been 45-50c for at least a couple weeks. Never had a problem staying cool except the other night. Radiator is dusty but not clogged -- no clue how, to be honest. There were mini sand-dunes in the airboxes when I changed the filters.

The replacement water pump I bought has metal impellers. I'll change the water pump and serpentine belt myself, but if it turns out to be a head gasket it's going to a shop. 100k miles seems early to have one blow, no?

460LQ8

Just as a daily update...

I realized what I thought was "foam" yesterday was actually just one of the thicker plastic ribs on the coolant reservoir. Oil cap clean. Dipstick clean. This helps me relax from thinking it's a head gasket issue which is my primary concern...

Filled the reservoir a little above max yesterday morning and it was right at min when I got home. Same thing today. Somewhere coolant is being leaked or burned.

Friend is going to let me borrow his pressure test tool. I'll test cooling system pressure. How do you do this on an LS 460? I see it doesn't have a traditional radiator cap. From the plastic bleed valve on the radiator?

If pressure test shows a leak I will replace the water pump and belt this weekend and refill coolant. If it's still leaking then I'll bother with the "valley."

Nospinzone

I had to replace the radiator on my car at142,400 miles due to a slow leak.

460LQ8

Ordered some UV dye and a flashlight to check around. I can't see anything from a visual inspection. Thanks.

Anfanger

Seems to be a typical valley plate leak unless you have a problem with a head gasket. If you have a fiber-optic camera, you should be able to check for valley leaks.

460LQ8

Coolant even lower today than yesterday, which was lower than the day before that. Fill it a little above "max" each morning.

Looking around for where it may be leaking, I noticed the thermostat was a little wet and I forgot to move a hose clamp back. It was also a little wet above the plate that crosses over the radiator, and outside of the bumper where there are the plastic "plugs" there seems to be some liquid that comes out. This has been going on for a couple weeks. Hmm...maybe the radiator has some small holes? When it's cool in the morning I will fill it up again and try to look. Probably a week or so before dye gets here...

hfahmy

Check water pump. You will see pink crusting around it if it is leaking