Cause of cooling issues (update 8/3)

[braderz]

as explained below ive changed the thermostat and the temperature sensor, but ive just checked the hose going to the thermostat and its cold, all the others are hot, been using the car all morning. Whats the underlying issue here? GTTDI 110 engine 109k. Any help please!!




changed my thermostat and temp sensor, the stat was jammed in and stuck, doesnt look like it worked, and the sensor was corroded big time!! Glad I changed them!!

[alex160]

well worth doing then, they seem to be a weak spot on the mk4 engines. Ive just ordered a new thermostat and temp sender for my golf. only had it 3 days lol.

[braderz]

mine is a tdi 110, and must admit considering how hard i had to pull on the stat to get it out, im sure it wasnt working, it was almost like a blockage as i had drained all the coolant out, which was pretty clean, behind the stat it was the same colour as whats in pic!!

[braderz]

new parts same problem...

[T_J_G]

Waterpump? My stat was stuck in the bloc when my pump went.

[braderz]

how can i find out if it is that? my heaters work fine, car doenst overheat, ive searched forums all over. belt was done at 70k according to book, but no idication as to whether or not pump was with it

[T_J_G]

When the stat was off you could have put your fingers in to feel the impeller. My coolant by the stat was a funny colour too.

Whn you rev the car, can you see water being put back into the expansion tank via the top hose. If it hasn't failed it could be on its way out.

[braderz]

ill check next time, i dont want the system drained again ive already done it twice to sort these 2 problems out!! i will check the bottle later cheers

[T_J_G]

I"m not saying is definitely gone but worth checking. You didn't find any plastic in the coolant did you? Did you flush the system?