Recommissioning Felix.... issues!

I am finally getting round to putting Felix back on the road... It's been unbelievably seven weeks a half years since his MOT ran out! 

I've sorted the petrol pump by replacing it with a new one from a Frontera 2.0i (same pump)... And he now fires up fine. 

Next other is the cooling system.  The expansion tank had a weird mouldy film on it (with pink clear coolant underneath), so I took it off and washed it out, then topped up the coolant.  

 

 

 

I ran him for about 30 minutes and the front can kicked in, but the radiator never warmed up.  The inlet pipe got slightly warm, but the outlet was cold.  The water rose in the expansion tank and had some bubbling.  The carol didn't give up though.  I'm assuming the PRT is not opening?  Tomorrow I might get round to draining all the fluid, shoving the jet wash into the pipes, then refilling.  Do the PRTs sieze up if not used?  ilI might have one in the shed... Need to check.

Any help appreciated.

Its surprising how things just get in the way and time passes by. I finally washed my 135 the other day and realised that was the first wash this year

Anyone have as pointer (or pointers) to check on the blockage?  Would back flushing from the rad backwards dislodge any crud?  I assume hosepipe inn the radiator top bleed hole would pump water back into the expansion tank? 
Sorry it's been so long since I did anything on my car!

A Mk1 F I had suffered from a blockage which took some while to pin down. Spigot on the outlet (front of the engine) to one of the bypass pipes blocked solid with crud which had accumulated in the casting around the temperature senders. Unlike more conventional setups, the K series thermostat is on the coolant inlet to the pump hence it depends in a flow of heated water from the bypass circuit from the outlet side, to tell it when to open. Weird effects when that gets blocked, goes straight from appearing cold to overheating all at once.

Ok so here's how far I've got today before the rain stopped play....

(Before I go on I realised that it was actually the outlet from the rad that was slightly warm the other day, not the inlet to the rad!)

1. Water is definitely moving as when the cap is off you get the squirt from the little pipe (was even more the other day when he bubbled). Plus the heater gets hot (more on that later).

2. Took off the radiator, back flushed and a few bits of crud and lumps of pink muck came out, but not loads. Back filled the rad inlet pipe.... No crud came out.  Did the same to the rad outlet pipe and the expansion tank started filling as expected.

3. Noticed some rusty looking sediment in the ultra clean expansion tank when it emptied down a bit when I first undid the rad bleed. So some crud has built up inside - needs a flush.

4. Refilled, and bled at the heater matrix and the radiator... Didn't bleed the engine as when I took the rad off little or no water came out the rad feed pipe..  just a small dribble!  Might need to do that but..... Suggests closed PRT?

5. The heater blows hot!  So hot engine water is getting that far!

6. After about 25 minutes running there was no boiling/bubbling BUT water feed to radiator was still not warm, rad was cold.  Temp was sitting between 1/4 and 1/2.... No rad fan came on like before.  

It started raining hard so I came in.... So not sure if he hasn't warmed up enough to let hot water to the rad, or if something is wrong.  But it's weird that the heater is blowing hot...