thermostat not opening (1 Viewer)

[ditidahtkitesurfer]

So here's a good one...little bit of history first

Truck sits for 1.5 years in a field.

Take it, drive it a bit, notice a hose bulging and a rad with some coolant leaking.

Do a full blown rad swap with a new skookum custom built amazing rad.

Replace all hoses, belts.

Do a 400km trip.

Everything runs amazing no issues.

Get home, and two weeks ago the belt makes a huge squaking noise. Thinking its the belt i spray the s*** out of it with belt lubricant.

Only to find out and diagnose that the water pump was the culprit. Great.

Replace the water pump.

ALso bought a spare thermostat because I suspected I might need it.

Today, I 'm driving around and after five minutes of steady driving the engine is steaming/smoking. I wait for it to cool down, pop the housing on thermostat, replace the thermostat, seal it all up with permatex red gasket maker sillicone. I think I'm off. WRONG> Thermostat still not opening.

What's next? I'm stumped, loving the experience of doing all of this work, but want to DRIVE!

Thanks,
Kevin

 

[dadinabarrel]

I'd have a crack without the thermostat, that eliminates that. It's getting hot because of no water flow, caused by something...

 

[Fantom]

You could remove the thermostat and throw it into a pot and boil some water to see when it opens. Have you replaced the rad cap? There could be an air lock in the system. You can run it, with the heater turned on and on hot to circulate the coolant, which normally (if everything works) gets the air bubbles out of it once the thermostat opens.

 

[MrMoMo]

Well a few things... Knowing exactly what the problem is before replacing parts is a good start. You said the water pump was replaced. Did the fins break off the old pump? If so, where did they go? Were they all removed or is there one/parts of one stuffed into a coolant passage now? Do you still get heat out of the heater? (FYI, a trick when you start overheating is to crank the heater, as that takes heat away the same way the rad does, but is not blocked by the thermostat, sometimes can get you home)

If the thermostat was faulty removing it completely should resolve it, but if you have something else blocking the flow then only removing that is going to help.

 

[ditidahtkitesurfer]

Thanks for all of the advice.

The rad cap was tested and found to be air tight.

None of the fins broke off to my knowledge off the old water pump. I will look though.

The thermostat is brand new so I assume it opens. THough I will test the old one when I get it home to see if it is faulty.

If I was running it to get the air bubbles out of it (assuming there's nothing lodging inside -- great thinking momo), i'd want to make sure the coolant was totally topped up, and once it was would I put the lid on the rad or leave it off? I think I could be a tad low on coolant.

One more question. I emptied out some coolant the other day when replacing the water pump. I dropped maybe 7 or 8 litres out of the hose at the bottom of the rad. The rest remained in the rad. This coolant has some (very small amount) oil residue in it---i put it in the old jugs in case its reusable. Yesterday when I dropped the same hose to do the thermostat there was only like 500ml. Does this mean anything to anyone? And can I reuse the coolant if there is a little oil in it?

 

[ditidahtkitesurfer]

AND when i opened the hose on the thermostat housing, though i had emptied the lower rad house, the top one was empty. bone dry nothing. i'm getting into the air bubble thing...

 

[Radd Cruisers]

The reality:

The original water pump was seized, so it doesn't matter if the impeller was broken or not.

No circulation means it doesn't matter if the thermostat was working or not, it can't do it's job of allowing water to flow through the rad at the right temp.

New Genuine thermostats almost always work - I only put that 'almost always' caveat in there to prevent someone from going in to a long-winded story about how one did fail at some point shortly after installation. My experience in pulling wrenches for a lot of years has been that new OEM parts failures are very rare indeed (more often a problem with the work or some other factor is at play).

So, it all really boils down (oops, pun not intended) to the fact that there has to be coolant in the system and circulating to cool things.... it seems as though the OP forgot to top the coolant up after the new 'stat went in to place.

All sorted out now, a bit iMessage and phone diagnostics helped with that.

~John

 

[MrMoMo]

The reality:

The original water pump was seized, so it doesn't matter if the impeller was broken or not.

No circulation means it doesn't matter if the thermostat was working or not, it can't do it's job of allowing water to flow through the rad at the right temp.

Well firstly without knowing why the water pump was seized, the true reality is it DOES matter if the impeller was broken, for all we know, it was seized because a broken fin was jamming it...

Secondly, nothing above in any way suggested that there was no circulation, until the comment of only 500ml of coolant coming out we had no reason to believe this was coolant level related, though the question could have been asked.


Stating the "obvious" to those who are not presented all the same info as you does not help anyone become better at diagnosing problems, or helping others out - but I am glad you were able to help my far away friend get this resolved - thanks for that.

 

[ditidahtkitesurfer]

filled the engine block fully with coolant, drove for a while and after no movement on the stat spoke wth John at Radd Cruisers who advised me to reconnect the wire to the stat...I now have a functional land cruiser.... :0)