Random spike in temperature

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yogibear18

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2018
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Had a random spike in temperature around 240° the other day temps outside around 45° shut off my truck at the nearest store about 10 minutes after drove home and was fine, thinking an air pocket or thermostat hung up somewhere when it should be opening any other thoughts?
 

Jeepwalker

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Could be a sticking T-stat. Maybe not. IDK if a t-stat would close in 10 minutes, but maybe enough to unstick.

Do a full analysis before you turn on the parts canon (i.e. waste time):
- Any codes? If so, what are they.
- Sufficient coolant in the system?
- Any obvious radiator obstructions?
- Belt tight?
- No leaks? Looks dry under the water pump?
- Lower radiator hose stiff? (Spring in there?). They can 'suck-in' if flacid.
- Any 'gurggling' in the heater core upon morning start-up? That could indicate low coolant or air (or even an early-failing head gasket).
- Look under the oil fill cap for a milky substance?
- Sniff in the coolant bottle for any combustable smells as engine runs. Any bubbles in there (or radiator) if someone give it a little throttle? (if so, probably an early head gasket issue).
- Verify the temp sensor/s are reading fine 'cold', and also 'warm'. Your tk might have two sensors. Google to verify yours. You could use an ohm table (google it) and a multi-meter to check them, if you don't have a scan tool. Verify engine temp with an IR temp gun at the t-stat outlet and that the sensor ohms correspond to the engine warm temp. Check the sensor's wiring connectors. If you have a scan tool it makes verifying readings quicker. Sensors can drift so verify it's (or they are) good.

Those things don't take long to inspect and rule 'good'. Ultimately I'd probably replace the t-stat with a new MOPAR one (not parts store), bit if you see something during those other tests, then you might have another issue. Good luck. Let us know what you find.

:waytogo:
 
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yogibear18

yogibear18

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Looks like I’m going to need a water pump, I’m seeing discoloration around the weep hole , surprised it gone bad at just under 61,000 miles and 8 years old
 
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yogibear18

yogibear18

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New update on yogi (truck) Left bank needs a head gasket, I re checked with my pressure tester and seen it dripping off the edge of the head and block, water pump just was showing a small outline discoloration where there weep hole is so probably might be on its way out
 
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yogibear18

yogibear18

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2018
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Hemi 5.7
Another update took to dealership to verify the head gasket and would you know not … found nothing wrong, only went there for my windshield to be replaced and emptied my last $198 for a diagnostic fee and nothing for windshield,I can remember when I was working in the garage and charged $49 what a change through the years
 
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