Hot and Cold

[Perks7210]

Hi guys.

Anyone advice with this will be greatly appreciated.

I recently changed the thermostat on my SEAT cordoba. Since then the engine is taking forever to heat up and when warm I only need to turn on the heaters for a minute, maybe less and the temp drops through the floor. Thought it may be a sensor but after an hours worth of " spirited driving" I could comfortably rest my hands on the block.

Surely this isn't good for oil distribution/engine longevity.

I'm confused.

 

[Lemond2008]

Sounds like you have fitted a duff, jammed open thermostat - just out of interest why did you change the old one?

 

[^neo^]

Could just be a bad airlock in the system

 

[Perks7210]

The engine was overheating, changed the duff water pump and it still got too hot. Changed the thermostat and problem solved. I honestly thought once the thermostat's open it stays open for most of the day, but you think the rapid cooling is because it's open for too long or opening to early? Will it cause any damage???

 

[Lemond2008]

Kind of - the thermostat is not so much a 'binary' on-off device, but changes how much it is open dependant on temperature. So, if jammed open (although seems strange for a new one), the coolant will be flowing at full rate and the engine will not get up to normal operating temperature.
However, I am unsure of your "comfortably rest hand on block" statement? After driving a long way in a spirited manner, I would have thought even with full flow through the thermostat, the block should be pretty damn hot.
So - Two potential issues, and two potential solutions.
1) Along the same lines as neo - If the engine is actually getting hot, but the temperature gauge is not reading it, and the heater is not staying hot - it could well be that there is air in the system which needs bleeding out (due to your loss of water when changing the pump & thermostat) or
2) The engine isn't getting hot, therefore the thermostat is jammed open and needs to be changed.

 

[igotalake]

i would suggest the latter (stat is bad) as if you cannot feel a fair amount of heat (off the head anyway maybe not the block) then the thing is not reaching the 80ish degrees it should be.