Water Pressure

[steve@cornwall 100]

Just checking, I should have good pressure in the top hose when car is hot, yes?

I have no real pressure although the rad is new and the heater works fine It's on a 205 auto which has a slightly weird system, a small pipe omes from where the bleed valve is by the 'stat on the gti, and routes through the auto choke valve, manifold and then to a pipe I havn't had opportunity to track yet! This seems to be keeping the auto choke on at all times

[welshpug 1,651]

there would be some pressure in there when its hot but not excessively, the Expansion tank cap releases at 1bar (14 odd PSi) so there would be some margin for overheating in there.

[steve@cornwall 100]

there would be some pressure in there when its hot but not excessively, the Expansion tank cap releases at 1bar (14 odd PSi) so there would be some margin for overheating in there.

 

It barely dribbles with the pipe off at 1K idle (apparently should be 750 for the auto) and at 1st fan cutting in temp I have to get my head around the layout of the system as it's totally different to the gti one but thinking about it - From the pump, water flow goes through the distribution block, through the bottom hose, through rad, past 'stat and into engine - so worth checking for kinks in bottom hose, and stat operation? One of the pipes from the dist. block goes to the heater, and straight to the stat housing (looks like before stat). Suspect 'stat again? The other pipe from the dist. block is a little different...... comes around cam belt end and splits in 2 - 1 to the manifold I'm guessing to the holes in the head that are not used on the gti and 1 through the carb, to the auto choke activator and back to the stat housing where the pipe goes to the gti t.body. also after the stat. (this one stays cool when running)

 

Sorry for the rambling description, but I think it's helped me get an idea of how it all works. So I'm thinking sticky 'stat - anyone agree? The car 's only really been driven steadily within a 10 mile radius of home, so hasn't had much chance to overheat - only once, apparently when the rad was replaced following a trip to Wales.

 

Fancy having a choke arrangement which is fully ON when it fails I guess the Germans (Weber carb) couldn't help f*c*ing with the French I reckon I can get it through emissions by jamming the choke closed once it's warmed up, but i'd like to sort it - only really bought it for the challenge. Once sorted it's already sold for whatever it's cost me to my wife's mate. I also have absolutely nowhere to keep it so I need to sort it quickly -

[welshpug 1,651]

hmm, I'd be tempted to just bung a new stat in it anyway if its going to a new owner so soon.

 

does the rad heat up at all? I dont think the fluid expands THAT much, though I cant think wether i've run and engine for any length of time with the Cap off.

[steve@cornwall 100]

hmm, I'd be tempted to just bung a new stat in it anyway if its going to a new owner so soon.

 

does the rad heat up at all? I dont think the fluid expands THAT much, though I cant think wether i've run and engine for any length of time with the Cap off.

 

Hmmm.. didn't check the rad for heat (what a plonker ) I'll try it tomorrow, minus the stat - and stick the stat in an old pan on the hob. My only real point of reference is from bleeding the gti - you get a 2-3" head of water out of that point with the pipe off- the auto barely drips.

 

Come to think of it, the rad must heat up if the fan thermoswitch is activating?

 

It's a strange system, no sign of an expansion cap. The water level switch is in the rad and the expansion bottle is just a plastic bottle with small bore (like the t.b water pipes on gti) from the bottom to the overflow on the rad. How can you realistically fill a coolant system through a bore that goes down to 1/4"

 

Strangely, the only parts this car has in common with a gti seems to be switches, lights, locks and grille even the block has different sensors fitted! Spec'd at 80bhp, I believe. Shows the development that originally went into the gti, eh?

[steve@cornwall 100]

Thermostat looked like a new one, but with it removed I've got better pressure, so I guess the wrong stat had been fitted. Next problem was that water was not flowing through the choke activator, so removed this and cleaned out the gunk. Water flowing though it - and leaking from the seal, so removed it again - resealed with some silicone around the seal and an extra washer to keep it in place. Then stripped and cleaned through all the auto choke mechanism now there's a cnut of a job! I don't think the activator is moving, even now it does get hot, but the choke is now in the open position and it drives so much better. Maybe without the stat it's not getting hot enough? Should also be ok for emissions. If it will start tomorrow after the predicted frosty night - it's good enough for me! Will be booked for mot asap - can't see anything else for it to fail on - which is more than can be said for my gti.