4.7l V8, heating when idle (1 Viewer)

[ibrahimbasheer]

Hey!

Note: my car is 200 series but I’m posting here since some markets did not get the 200 series in 4.7l V8 option.

So, recently my land cruiser started overheating when idle for extended period of time. Accordingly i have replaced the following parts with new genuine toyota parts:
thermostat, waterpump, temperature sensor, fan clutch (radiator/engine), fan motor (ac/the fan inside the grille on the corner).

The radiator is new and was changed around an year ago and maybe 30k kilometers before.

But the problem still persists, and my mechanic doubts for it to be air bubbles causing the issue.

This issue is non-existent while driving, and when idling using only front ac it takes a long time to heat but while using both front and rear ac, the car heats up around 10 minutes of idling.

 

[OEMGUY0720]

I would normally check the fan clutch, but that’s interesting considering you replaced it recently.

 

[SteveH]

Get an infrared thermometer and check engine temperatures all around the engine compartment (and radiator) as it warms up. Something is failing to reject heat. I would also be sure your new fan clutch feels right and/or seems to operate as it should. If the radiator is very hot (pending overheating) the fan clutch should be strongly engaged and the fan roaring (due to air resistance). Beware that infrared thermometers do not read accurately in fast-moving air, so you may have to shut off the engine temporarily to get an accurate reading. I would check upper and lower radiator hoses, the thermostat housing, the engine heads, etc.

 

[ibrahimbasheer]

I would normally check the fan clutch, but that’s interesting considering you replaced it recently.

I’m surprised too. And my mechanic opened the radiator cap and put a plastic bottle on top and said that there are bubbles coming sometimes. Is it of any help?

 

[OEMGUY0720]

I’m surprised too. And my mechanic opened the radiator cap and put a plastic bottle on top and said that there are bubbles coming sometimes. Is it of any help?

When you remove the radiator cap (engine off), how clear is the coolant fluid or does it have sediments?

Are you also losing coolant fluid in the reservoir?

 

[ibrahimbasheer]

When you remove the radiator cap (engine off), how clear is the coolant fluid or does it have sediments?

Are you also losing coolant fluid in the reservoir?

it’s all clear. i even did a flush, using water and the water that came out was completely clear.

I am not loosing much from the reservoir.

 

[OEMGUY0720]

it’s all clear. i even did a flush, using water and the water that came out was completely clear.

I am not loosing much from the reservoir.

I think (I may be wrong) but your fan clutch maybe faulty. Do you still have your old fan clutch? Try that on see if the symptom persist.

Did you have overheating issues on idle prior to the most recent service/parts replacement you mentioned above?

 

[ibrahimbasheer]

I think (I may be wrong) but your fan clutch maybe faulty. Do you still have your old fan clutch? Try that on see if the symptom persist.

Did you have overheating issues on idle prior to the most recent service/parts replacement you mentioned above?

Yes, i did the servicing because of overheating. But it was more severe before and now it seems to be reduced but still present..

 

[ibrahimbasheer]

I think (I may be wrong) but your fan clutch maybe faulty. Do you still have your old fan clutch? Try that on see if the symptom persist.

Did you have overheating issues on idle prior to the most recent service/parts replacement you mentioned above?

What about the condenser being clogged? it’s the original condenser from 2009. Can it be the cause of this?

 

[J1000]

I’m surprised too. And my mechanic opened the radiator cap and put a plastic bottle on top and said that there are bubbles coming sometimes. Is it of any help?

Do a combustion gas test on your coolant. Bubbles when running could mean blown headgasket, especially if it's been overheating lately.

 

[ibrahimbasheer]

Do a combustion gas test on your coolant. Bubbles when running could mean blown headgasket, especially if it's been overheating lately.

What is a combustion gas test, and the car only ever heated once near 3/4th of the gauge. And never red lined.

 

[J1000]

What is a combustion gas test, and the car only ever heated once near 3/4th of the gauge. And never red lined.

Something like this: https://amzn.to/487vETp

Most auto parts stores will rent them out also.

 

[awesomeissquid]

What is a combustion gas test, and the car only ever heated once near 3/4th of the gauge. And never red lined.

The factory gauge is known to not be accurate and it is why most default to installing some type of external monitor, i.e. a scanguage or something similar. If you have a head gasket leak and combustion gasses are making their way into the coolant system it could explain the elevated temperatures.

 

[hiCountry Girl]

Get an infrared thermometer and check engine temperatures all around the engine compartment (and radiator) as it warms up. Something is failing to reject heat. I would also be sure your new fan clutch feels right and/or seems to operate as it should. If the radiator is very hot (pending overheating) the fan clutch should be strongly engaged and the fan roaring (due to air resistance). Beware that infrared thermometers do not read accurately in fast-moving air, so you may have to shut off the engine temporarily to get an accurate reading. I would check upper and lower radiator hoses, the thermostat housing, the engine heads, etc.

What would operating temp be on the block?

 

[SteveH]

On other Land Cruisers, I see head temperatures around 201-205 F or so. The block is typically cooler than that.

What I would look for is temps in the system (any part of the cooling system where you can get a temperature reading with an IR gun) that are considerably higher than the thermostat temperature - like 25 degrees hotter, rather than 5-10 degrees hotter. I would also start and run the truck for 5 minutes and get some readings, and then turn on the dual A/C setup and let it start to overheat, and then take readings in the same places. You need to learn what parts are getting too hot.

 

[ibrahimbasheer]

On other Land Cruisers, I see head temperatures around 201-205 F or so. The block is typically cooler than that.

What I would look for is temps in the system (any part of the cooling system where you can get a temperature reading with an IR gun) that are considerably higher than the thermostat temperature - like 25 degrees hotter, rather than 5-10 degrees hotter. I would also start and run the truck for 5 minutes and get some readings, and then turn on the dual A/C setup and let it start to overheat, and then take readings in the same places. You need to learn what parts are getting too hot.

Can the air bubbles be caused by other issues other than head gasket?

 

[ibrahimbasheer]

Can the air bubbles be caused by other issues other than head gasket?

The mechanic says that the radiator seems to be clogged as he checked through a camera.

I did not get it cleaned yet though to make sure if that is the cause.

But my question is why did the radiator get clogged within 2 years and it’sa genuine Toyota radiator?

 

[awesomeissquid]

Is the mechanic referring to clogged on the air side or on the water side? It is common for radiators to require cleaning of the fins to ensure the air transfer is maintained. Radiators and other coils that pull air across them act as giant filters so any sand, bugs, branches, leaves that cross over it get stuck and can cause blockages reducing the effectiveness.

That does not account for the air bubbles you are seeing though. Air would be entering from somewhere. A combustion gas tester like @J1000 recommended would confirm if you have a blown head gasket or something else causing the bubbles.

 

[ibrahimbasheer]

Is the mechanic referring to clogged on the air side or on the water side? It is common for radiators to require cleaning of the fins to ensure the air transfer is maintained. Radiators and other coils that pull air across them act as giant filters so any sand, bugs, branches, leaves that cross over it get stuck and can cause blockages reducing the effectiveness.

That does not account for the air bubbles you are seeing though. Air would be entering from somewhere. A combustion gas tester like @J1000 recommended would confirm if you have a blown head gasket or something else causing the bubbles.

Clogged in the water side/inside. The bubbles were coming when i changed the gear from P to D etc. and on idle they were almost non existent.

Is that of any help?

 

[Trunk Monkey]

I would still rule out air in the system, there are these nifty tools that pull vacuum on the whole coolant system, collapsing the hoses, and then draw in coolant from a tank and pretty much guarantee no air. Easy thing to check off.