v8 running hot

[mavrick1903]

Temps are bouncing between hot and normal. Looking for suggestions on where to start:

Thermostat?
Water pump?
Other?

 

[AuSeeker]

Since there's not enough info to really give good advice, I would first check to make sure it isn't low on coolant, when he engine is cold remove the radiator cap and make sure it's full, if not add coolant until it's full, replace cap and drive it and see if that's the issue, you also need to find where it's losing/leaking coolant and fix the leak/s.

If it isn't low then you have other issues, maybe air bubbles in the coolant system, the system needs to be "burped" until all air is removed.

There's other things that can cause your issue but the above is a start for now.

 

[mavrick1903]

Thanks [MENTION=149207]AuSeeker[/MENTION].

The overflow was basically empty. I added fluid last night on my way home but have not checked the radiator cold yet. That'll happen this afternoon.

Issue: Gets hot (needle all the way to H) but does come back down when the RPMs come up.

 

[AuSeeker]

Thanks [MENTION=149207]AuSeeker[/MENTION].

The overflow was basically empty. I added fluid last night on my way home but have not checked the radiator cold yet. That'll happen this afternoon.

Issue: Gets hot (needle all the way to H) but does come back down when the RPMs come up.

Sounds like it's low on coolant and the air pockets created by that will produce steam which will make it overheat, once the RPM goes up more coolant is moved in the system and it cools down.

You definitely must have a leak, if you are using the correct pink/red coolant you will see pink/red crystallization around wherever it's leaking, common areas are the corners of the radiator, around the thermostat housing, or any of the hoses.

Hopefully you find an obvious leak and it's not something more hidden.

Update what you find!

 

[Hungryhawk]

If you have a small coolant leak the overflow reservoir will slowly lower over days till the suction tube gets air not coolant. Then the radiator coolant level starts to lower till the engine get hot above normal. Hot/cold cycling of the radiator is normal and the overflow reservoir level goes up and down with this cycle.
The most likely leak is the water pump seal. Evidence is left by this leak which you can learn where to look. Or maybe an old hose has a pinhole leak, or a hose clamp seal has a leak. Rare is a worn out pressure cap on radiator that lets coolant boil into the air.

 

[mavrick1903]

So the coolant level was low. The overflow reservoir was empty in the 1.5 miles from autoparts store to home last night. Topped up both.

Now, to find the leak.

 

[AuSeeker]

So the coolant level was low. The overflow reservoir was empty in the 1.5 miles from autoparts store to home last night. Topped up both.

Now, to find the leak.

Run it some to help get any trapped air to work it way to the radiator, and recheck the radiator for being low.

Hopefully it's not the waterpump because it's buried in with the timing belt and will be hard to tell if it's leaking without taking stuff apart, if it is the waterpump you're going to need to also replace the timing belt out of caution, the reason being is that coolant will deteriorate the rubber belt and it could fail as a result, if the timing belt breaks it will do fatal harm to the engine, as in valves hitting pistons, etc.!

 

[Kevin G.]

I'd determine if the thermostatically controlled fluid fan clutch is in good working order.

Just an idea.

Kevin

 

[Hungryhawk]

Another suggestion - if you need to replace the water pump is also replace the thermostat while you have front of engine exposed.