Engine over heating (1 Viewer)

[DesertLCruiser]

222,000 miles on the 100 series. My engine is over heating. Looked it up, could be the thermostat or the water pump mainly. No signs of fluid leakage. Could there be any other issues?
How do I know if my water pump is the one that's broken without disassembling, if possible? I'm overdue on the timing belt and water pump by 8000 miles though.

 

[Sixspeed]

Heat will kill all engines; even the 2uz. If you're overdue in timing belt/water pump and likely coolant; you should change it immediately, especially your situation overheating. If the thermostat is faulty it remains closed not letting cool coolant to engine block. If the water pump is bad it is not pumping adequately. If the timing breaks, engine is junk.

Essentials for engine reliability
Coolant every 50k
Timing/water pump 90k

 

[elhombre]

Is there anything in the overflow bottle? That's the first place to start. Then pull the radiator cap and see if there is antifreeze.

Water pump has a weep hole that antifreeze will drip out of when it goes bad. Look for stains under the water pump. Many times the fluid will evaporate before it hits the floor.

If the thrmostat won't open, the engine will continue to get hotter as idling time goes on. Does it get hotter no matter the speed you are driving? Or does it cool down when you start moving?

 

[jLB]

Overheating, in Massachusetts, this time of year?

I’d be doing the past due timing belt, water pump & thermostat, at a bare minimum. Probably a pressure test too.

It might be more effective to get someone to look at the vehicle, instead of random strangers guessing though.

 

[bmwjnky]

Take care of your overdue parts and see if that takes care of it. If it is overheating at low speed and idle you could also need a new fan clutch.

 

[nissanh]

How old is the radiator? Probably clogged tubes inside the radiator. Drain coolant and inspect the channels inside the top cover: Use a camera to inspect.

 

[riffman12]

so many variables. start with the simplest:
- Coolant - is there coolant in the rad and in the overflow tank? If not, add some and/or figure out where it went
- Fan clutch - when you start the vehicle is there a substantial roar from the fan pushing air? Is there resistance when you turn the fan with the engine off? If not, get a new fan clutch
- Thermostat
- Water Pump
- Clogged radiator - this would give you other symptoms. Potentially a weak cabin heater

 

[DesertLCruiser]

so many variables. start with the simplest:
- Coolant - is there coolant in the rad and in the overflow tank? If not, add some and/or figure out where it went
- Fan clutch - when you start the vehicle is there a substantial roar from the fan pushing air? Is there resistance when you turn the fan with the engine off? If not, get a new fan clutch
- Thermostat
- Water Pump
- Clogged radiator - this would give you other symptoms. Potentially a weak cabin heater

Fan seems to be fine. And there is sufficient amount in the overflow tank. The heater has stopped working. Can I narrow it down to the thermostat since the heater isn't working? Or could it still be the water pump?

Take care of your overdue parts and see if that takes care of it. If it is overheating at low speed and idle you could also need a new fan clutch.

While idling it isn't over heating.

Is there anything in the overflow bottle? That's the first place to start. Then pull the radiator cap and see if there is antifreeze.

Water pump has a weep hole that antifreeze will drip out of when it goes bad. Look for stains under the water pump. Many times the fluid will evaporate before it hits the floor.

If the thrmostat won't open, the engine will continue to get hotter as idling time goes on. Does it get hotter no matter the speed you are driving? Or does it cool down when you start moving?

Even on the lowest speed it is heating up, so didn't try going any faster. My cabin heater stopped working. Can I narrow the issue to something or could it still be various possibilities?

 

[nissanh]

Are you sure you have enough coolant inside the engine?

On a cool engine, oen the radiator cap and inspect the coolant level. Add coolant if it is low.

 

[riffman12]

Fan seems to be fine. And there is sufficient amount in the overflow tank. The heater has stopped working. Can I narrow it down to the thermostat since the heater isn't working? Or could it still be the water pump?

Sorry just saw this. I had these exact symptoms on my 80. Including the weak or non functioning heater.

I would assume either a clogged radiator or clogged heater core. These items being clogged restricts proper coolant flow through the system.

Start with buying a radiator flushing kit and fush the whole cooling system (or have a shop do it). I would assume a bunch of nasty gunk will come out.

If that doesn’t fix it replace the radiator.

If that doesn’t fix it replace the heater core. I put this last because it’s apparently not fun.

 

[flyingscot]

Sorry just saw this. I had these exact symptoms on my 80. Including the weak or non functioning heater.

I would assume either a clogged radiator or clogged heater core. These items being clogged restricts proper coolant flow through the system.

Start with buying a radiator flushing kit and fush the whole cooling system (or have a shop do it). I would assume a bunch of nasty gunk will come out.

If that doesn’t fix it replace the radiator.

If that doesn’t fix it replace the heater core. I put this last because it’s apparently not fun.

To build on riffman's note:
Might seem unlikely but flushing the heater core fixed my 'no heat' situation on my Yukon. Simple YouTube video - .

 

[Sno bored]

Change your heater T-s whenever you do this work if they haven't been changed out yet. I'm sure it's not the cause of any of this, but if you have the cooling system taken apart, that's the time to do them.

 

[abuck99]

8000 miles past your TB service interval is hardly an emergency cause for overheating. Water pumps on 2UZ rarely seize so it’s probably working fine, the sign it’s failing is weeping coolant. Check for that as previously suggested here. If the water pump wasn’t replaced at the last TB service- it def should be replaced this time around along with the fan bracket, fan clutch, tensioner, and both pulleys.

I’d first rule out externally clogged radiator. Remove engine undercover, inspect the front side of the lower radiator area - looking at the gap between radiator and ac condenser- look for crud-mud- grass- debris built up on the lower radiator. Inspect the rest of radiator fins for build up of dust & dirt. Rule that out-

Check coolant color-in main tank is it clear or cloudy? Is it filled up to the top of the neck- squeeze large radiator hose and check for bubbles.

Check fan and fan clutch for proper operation- (search the forum)

You can pull the thermostat with out too much trouble- check that for proper opening temp- (read FSM for this procedure)