Overheating

[SunlitComet]

Just like EZ's liver will soon

 

[chilango1986]

The thermostat was just replaced i wondering why it wouldnt open. but yeah the upper radiator hose is soft i can squeeze it real good. So would that be the thermostat ? what if i pulled the stat out and just ran it without one?

The lower hose would tend to make the car overheat?

 

[retorq]

No thermostat will probably make it over heat quicker, the thermostat is like a valve, it's controlling flow (ie holding water in the radiator longer) and cooling more efficiently by doing it that way.

Don't even get me started on the collapsing lower hose "theory" ...

 

[SunlitComet]

Unless there is hot coolant pretty much touching the thermostat it will most likely not respond. When I replace them I fill the coolant till it traces the top of mNifold thermostat opening burping along the way. Drop it in wet Nd finish the rest of the job. Burping it some more to get as much coolant in the upper hose too.

 

[tlamot01]

I'm not buying the clog theory. Coolant passages on these trucks are huge. You'd have to have dropped a stop-leak soaked rag in the water pump for a clog to even affect the system. The fan clutch is very probable if you're only overheating at lower speeds. You should have changed that out when doing the water pump. There should be enough airflow to cool the engine at highway speeds. Your problem is most likely with the thermostat or radiator (see below).

Test the Thermostat:
Pull it out and place it in a pot of water. Gradually heat the water to boiling and look for it to open up. If you can't see it because of bubbles in the water, get some pliers and pull it out of the water for visual inspection. If it is working properly, it should be open about 1/3 inch. As it cools, it will slowly close.
This test is more accurate if you have a thermometer you can plunk in the water while it's heating up. I think the OEM thermostat opens at 185 degrees. In any case, it should be fully open when the water is at boiling temp.

Also, look at the plastic ribs of your radiator on the drivers side engine bay just below the oil cooler inlet. The stock radiator is known to crack between the third and fourth rib. There will be a telltale 'clean' spot if there is a crack, which may also explain your overheating issue.
Rarely did I ever see a puddle under my truck because the coolant would leak out under pressure and the level would always be below the crack, so a static leak was not easily identifiable.

 

[LI BeachHoe]

No thermostat will probably make it over heat quicker, the thermostat is like a valve, it's controlling flow (ie holding water in the radiator longer) and cooling more efficiently by doing it that way.

Don't even get me started on the collapsing lower hose "theory" ...

Correct, and running without the flow restriction of a thermostat or flow restrictor such as http://www.summitracing.com/parts/MOR-63440/, used in race engines, you will run into a host of other issues.

To the OP: it's also very important to make sure that the tstat is installed in proper direction.

 

[chilango1986]

I'm not buying the clog theory. Coolant passages on these trucks are huge. You'd have to have dropped a stop-leak soaked rag in the water pump for a clog to even affect the system. The fan clutch is very probable if you're only overheating at lower speeds. You should have changed that out when doing the water pump. There should be enough airflow to cool the engine at highway speeds. Your problem is most likely with the thermostat or radiator (see below).

Test the Thermostat:
Pull it out and place it in a pot of water. Gradually heat the water to boiling and look for it to open up. If you can't see it because of bubbles in the water, get some pliers and pull it out of the water for visual inspection. If it is working properly, it should be open about 1/3 inch. As it cools, it will slowly close.
This test is more accurate if you have a thermometer you can plunk in the water while it's heating up. I think the OEM thermostat opens at 185 degrees. In any case, it should be fully open when the water is at boiling temp.

Also, look at the plastic ribs of your radiator on the drivers side engine bay just below the oil cooler inlet. The stock radiator is known to crack between the third and fourth rib. There will be a telltale 'clean' spot if there is a crack, which may also explain your overheating issue.
Rarely did I ever see a puddle under my truck because the coolant would leak out under pressure and the level would always be below the crack, so a static leak was not easily identifiable.

Im going to check the radiator but like i stated the issue is when driving not parked . I dont see any leaks coming from the radiator or engine bay , only thing i hear is a hissing noise from the radiator.

 

[SunlitComet]

If while driving them somehow your coolant must not be moving around. +1 on the thermostat position. That hissing sounds like some fluid fluid or steam that is meeting some resistance.

 

[chilango1986]

So could be that i either the thermostat was placed in wrong ? since sounds like the radiator is hissing?

---------- Post added at 01:53 PM ---------- Previous post was at 01:50 PM ----------

Lol this will be the last time I give my money to my mechanic friend and tell him to fix it and give it back over the weekend .I would have done it myself but during the weekend Im on a work release program lol

 

[SunlitComet]

That Nd because I think you said the upper hose stays soft. That would imply your pump is fine but something is holding up flow. Just wIt till it is cold before draining it out some to get below the thermo water line to pull it apart. And install it like I mentioned. Hope that is the solution.