Testing thermostat with torch

[Mc Tool]

Hard to see in the pix ..... any chance that the head has been removed before you got the motor , looks like someone has applied some sealer to the head gasket and those " o rings " are sealant that got squeezed out when the head was torqued and set hard .
I used compressed air to suss out just how the water flows around the whole cooling system . One thing I found is that there can be small orifices in the water jacket that , if deep in , can be hard to see specially when things get a nice (cammo ) coating of crud . May be there to prevent air locks or aid in circulation ..... whatev . Wouldnt take much to block one . I only found the 1st one with the compressed air .....I couldnt figure why the air was coming out where it did .... then found the hole

 

[maineiac5586]

Hard to see in the pix ..... any chance that the head has been removed before you got the motor , looks like someone has applied some sealer to the head gasket and those " o rings " are sealant that got squeezed out when the head was torqued and set hard .
I used compressed air to suss out just how the water flows around the whole cooling system . One thing I found is that there can be small orifices in the water jacket that , if deep in , can be hard to see specially when things get a nice (cammo ) coating of crud . May be there to prevent air locks or aid in circulation ..... whatev . Wouldnt take much to block one . I only found the 1st one with the compressed air .....I couldnt figure why the air was coming out where it did .... then found the hole

Possible the head may have been off and makes sense the rtv may have spread out to those little holes. Thanks. I'll keep digging

 

[maineiac5586]

Well found the issue. Owner told me the pump was changed 2 years ago and it actually produced a decent telltale but looking here lol. Only found the tip of one impeller fin. Rest look like they were smeared into oblivion inside the impeller cup.

 

[maineiac5586]

I do have another question. Looks like the temp sensor moved away from the head from the heat. Do I leave it alone or replace it? I didn't see any water dripping from it

 

[Mc Tool]

Um , looks sorta melted aye . I would replace it not only because the threads look melted and it might develop a leak or pop right out but also because getting that hot may affect its reliable operation .

 

[jimmbo]

Since the Pump is missing a lot of Material, who knows where the stuff is residing. As for the Temp Sensor, that head must have got quite hot for it to pop out like that, or someone took it out and didn't reinstall it properly, as it does look cross theaded. Remove it and examine the Threads, of it and the Head. If it had been exposed to serious Heat, it may or may not be functioning. Attaching an Ohm Meter to it and placing it in some water, and heating the Water should result in a change in Impedance.

 

[Mc Tool]

Since the Pump is missing a lot of Material, who knows where the stuff is residing. As for the Temp Sensor, that head must have got quite hot for it to pop out like that, or someone took it out and didn't reinstall it properly, as it does look cross theaded. Remove it and examine the Threads, of it and the Head. If it had been exposed to serious Heat, it may or may not be functioning. Attaching an Ohm Meter to it and placing it in some water, and heating the Water should result in a change in Impedance.

Resistance in a DC circuit

 

[jimmbo]

Resistance in a DC circuit

I don't know where you learned Electrical Theory, but yes

 

[Mc Tool]

I don't know where you learned Electrical Theory, but yes

I have done 3 apprenticeships , 2 mechanical and one adult app as an "electrical service tech " both single and 3 phase , mostly domestic and commercial appliances and refrigeration , some car air con . Must admit I havnt worked as such since a m/c crash in 09

 

[maineiac5586]

I have done 3 apprenticeships , 2 mechanical and one adult app as an "electrical service tech " both single and 3 phase , mostly domestic and commercial appliances and refrigeration , some car air con . Must admit I havnt worked as such since a m/c crash in 09

Question. If I apply heat directly to the metal part of the overheat warning switch (switch removed from cylinder head ) should I be able to sound the warning horn? Heat from a heat gun.

 

[jimmbo]

As in Boiling Water, yes. If you are thinking about a Torch, do so at your own Risk.
Since you say it is a Warning Horn, it is likely just a Thermostatic Switch, not a Variable Resistance Device.

 

[chrisgt]

Question. If I apply heat directly to the metal part of the overheat warning switch (switch removed from cylinder head ) should I be able to sound the warning horn? Heat from a heat gun.

don't heat engine parts with a torch or a heat gun! They are not designed for this abuse.