Oops

[johnnyboy666 195 1 Cars]

decided to change the oil and filter in me roland today, and as it hasnt been done for a while i used some engine flush, instructions said pour it in and let it idle for 15 minutes, fair enuff so i put it in start her up and go and make a sandwich, come back about 10 mins later just as water starts to piss out the header tank... o bollocks... swiftly switch it off and notice the temperature lights on and the stop light etc, luckily there doesnt seem to be any hint of a headgasket problem as yet thank god, but it mustve been a close one. the question is why did it overheat so quickly?? was it because it wasnt moving and thus getting no air cooling? or should i be looking somewhere else? its not the first time its overheated, it has happened twice before in traffic jams.. any help would be gratefully appreciated

thanks

[28CRAIG 2]

What condition is your rad in that is the obvious thing.

[johnnyboy666 195 1 Cars]

it seems alright although the downpipe/manifold gasket was blowing onto it for a few miles but thats sorted now, having said that its probably the original radiator so might be best to change it, is there a possible upgrade radiator available whilst i'm there and would that be a worthwhile idea?

[johnnyboy666 195 1 Cars]

or maybe just some cold air feeds might help?

[jackherer 543]

Does your cooling fan work? Doesn't sound like it...

[Casanova 0]

My fan works but I initially thought it didn't as the car will often overheat before it comes on!

 

§

[Guest martyn_mcg]

I had mine sat for 10mins running with just water and that holts speed flush in it, no coolant in the water and it didnt overheat. You def got a problem, sounds like radiator or pump to me.

[Jrod 7]

See this is the weird problem my friend has.

 

His car always runs at the second tempature bar where as his last 1 and the 5 I've had all run at the next bar down.

 

We rebuild the whole engine and it still does it!

Replaced for a known good block, skimmed head, new headgasket, New rad, plugs, leads, oil, oil filter, carb, new hoses, bypassed heater matrix, water pump. Basically everything but it still runs just as hot. If you leave it sat the fan comes on very quickly, it doesn't actually overheat but is just always hot.

 

I think some just run hot but no idea why.

[johnnyboy666 195 1 Cars]

well thats more money then also just noticed the cv boot's split on the passenger side grr

[johnnyboy666 195 1 Cars]

would it be worth putting the fan on a switch so i can turn it on earlier than it would normally?

[PumaRacing 1]

My fan works but I initially thought it didn't as the car will often overheat before it comes on!

 

§

 

The engine can't "overheat" before the fan comes on if the fan control switch is working correctly. What it can do however is blow water out of the coolant tank but that's nothing to do with excess temperature. It's because the system isn't holding pressure and the coolant is boiling at a lower temperature than it should do so check the expansion tank cap seal or just replace it or have a pressure test done. If you have any leak in the rest of the coolant system or the smallest pinhole in the radiator you'll get the same effect.

 

If you paid attention in physics classes at school you'll know that fluids boil at higher temperatures at high pressure and lower temperatures at low pressure. That's why coolant systems are pressurised to about 1 bar - to raise the boiling point of the coolant to well above 100 degrees C. That's also why boiled eggs take longer to cook in a ski chalet in the Alps than they do at home. The atmospheric pressure is lower at high altitude so the water boils at a lower temperature and doesn't cook so effectively. A 3 minute boiled egg at sea level is an 8 minute egg at the top of Mont Blanc.

[johnnyboy666 195 1 Cars]

balls. upon further inspection it appears there is a lot of sludge in the header tank (but no sign of anything untoward under the oil filler cap) should i be assuming the headgaskets gone?

[Jrod 7]

I've seen loads with sludge in the header tank, take it to a garage and they can test the water for exhaust gasses.

[johnnyboy666 195 1 Cars]

thats a slight releif, seeing as im skinted at the mo lol, i thought i'd seen sludge in one of my previous 205s, i gotta take it up the garage in a few days anyway so i'll ask them to check whilst its there

cheers

[johnnyboy666 195 1 Cars]

is there any way i can check for definate if the headgasket has gone without having to go to a garage? any sure fire signs i should look for?

[g60-r 0]

check in the oil filler cap. if the oil looks like mayo she's a gonna. happened on my 1.9 405 sri also had a temp prob with her too. my rad was a bit shbby and had radweld in her more than once so i replaced the rad, thermostat and watertemp sender for the fan, never got hot again i know vw do different grade temp senders, i.e one that will make the fan come on at a lower temp. could be worth looking for something like that.

 

just thought, maybe you have an air lock some where? that would cause it to over heat quickly.

 

hope you sort it soon bud

[johnnyboy666 195 1 Cars]

i have been checking the oil filler cap regularly and no sign of any mayo (or in the case of my mates old rover , looked more like ham sandwiches in there)

[bren_1.3 1]

down on compression?

feeling down on power?

water in oil?

using water?

getting too hot?

[pugrallye 0]

check thermostat

[johnnyboy666 195 1 Cars]

i have at last figured out the problem (i think)the fan only comes on intermitantly hence why it overheats when stood in traffic or when stopped but not when doing 100 down the motorway (sorry i meant 70) so its sometimes working and sometimes not, how can i check whats at fault?

cheers

[gti-si 0]

sounds like a dodgyt water temperature sender or a dodgy thermostat, one of the two. Just replace them and see what happens, should sort you out