Odd overheating problems

allstaruk · January 25, 2006, 10:37:13 AM

Maybe I\'m gonna get it up on ramps 1st and see if the rediator appears to be getting hot and whether the fans are comming on, I was thinking maybe for some reason the air con being turned on was stopping the fans from working?

nikp · January 25, 2006, 10:38:48 AM

Air con should turn the fans on!

allstaruk · January 25, 2006, 01:25:47 PM

Thats what I thought but maybe if one of the relays is fooked then its actually turnign the fans off?

Any one got any idea where would have thermostat in stock, can\'t seem to get hold of reworx on the e-mail at the moment.

nikp · January 25, 2006, 01:33:22 PM

Any of the specialist stockists have them in. I got mine from Clive company Shyauto. Best to ring, instead of email though.

allstaruk · January 25, 2006, 01:40:34 PM

Cool, i\'ll give reworx a bell later as i\'ve just got in from work and might grab a half hour nap, How much coolant does the RX take and is there any special procedure using coolant flush?

nikp · January 25, 2006, 02:13:06 PM

I can;t remember how much coolant the FD takes. There are docs on the web, shouldn\'t take too much to find out. Also - read the procedure on removing trapped air pockets - as they can prove to be a real pain in the butt!

As to the coolant flush: read what it says on the bottle!

Martiny · January 26, 2006, 09:21:09 AM

Quote from: nikpThat seems plausible.

You could try relocating the sensor to the entry to the radiator, instead of below the filler neck. Thats where most people put their after market coolant sensors.

This seems very strange to me.
When the thermostat is closed, the coolant is pumped around the engine and not the radiator. So, when your thremostat is closed, your aftermarket gauge is telling you the temperature of the radiator hose, which is not the same as the engine temperature.

Surely we are interested in the engine temperature, not the radiator\'s temp?

nikp · January 26, 2006, 09:30:43 AM

Yes, when the thermostat is closed the gauge will not read anything - however, a thermostat is only closed on an engine when the coolant around the engine is not up to temperature. Once it is up to temperature, the thermostat will open, and regulate the amount of water going around the radiator. when the coolant reaches a certain temperature, it will be fully open letting all the coolant through to the radiator. but between those two temps, it will always be partially open. I didn\'t think i\'d have to explain how a thermostat worked to you martin!

I have found that there is a temperature differential between the after market gauge and the regular sensor, but this is probably more to do with the cooler water from the radiator taking longer to reach the engine than the after market gauge.

allstaruk · January 26, 2006, 10:49:29 AM

Well I\'m going to have a go as sorting this this afternoon, reworx have got a thermostat so I will seek some advice while i\'m down there picking it up, this is going to be one boring drive in my mums 106

Martiny · January 26, 2006, 12:05:09 PM

Nik, I know how a thermostat works, although I must admit, there is something about a rotary which says you should never remove the thermostat, but I havent investigated that fully yet.

Well, now I am really shocked by your post , because you have confirmed my suspicion. You are monitoring the radiator temp and not the engine temp?

So, if your thermostat was to get stuck closed, you would be looking at your gauge, saying "ah, look how nice and cool my car is running". Meantime your engine could be toast because its overheating. Nooooo, PLEASE tell me this is not true !!!!!

nikp · January 26, 2006, 12:12:54 PM

Actually, no, in fact I recently used my gauge to confirm that my thermostat was stuck open! So ner! I know from experience that it takes a while for the heat in the engine coolant to build up and open the thermostat. However, occasionally, before christmas I was noticing that only after a couple of minutes the gauge was registering a temperature. Most of the time it would register a temperature after about 10 minutes or so, but there was the odd occassion when it did it after a couple of minutes. This made me realise that my thermostat was sticking open (or at least, opening prematurely) - I replaced it.

Oh, and by the way, I have a PFC, so I can monitor the temps from the aftermarket gauge, and the standard FD sensor. As i said, there\'s sometimes a slight differntial between the two - but most of the time they read the same temperature, within a couple of degrees of course - while the thermostat opens and closes.

I believe to get both our points over in a easy to explain manner, it\'s probably best not done via the forum: I think we\'re both misunderstanding each other, as i think we are in fact singing from the same hym-sheet!

allstaruk · January 26, 2006, 02:39:17 PM

Still in the middle of trying to fix it as we speak, geoff ar reworx has confirmed that the readings from the radiator filler neck will be well out. He recomends tapping the sendor into the waterpump.

nikp · January 26, 2006, 02:48:06 PM

Well, keep us informed!

Martiny · January 26, 2006, 03:00:11 PM

Quote from: allstarukStill in the middle of trying to fix it as we speak, geoff ar reworx has confirmed that the readings from the radiator filler neck will be well out. He recomends tapping the sendor into the waterpump.

Allright, now THAT sounds like a good place to put a sender unit.

allstaruk · January 26, 2006, 03:13:44 PM

It certainly does it also sounds like an absolute pain in the ass to

I have drained the old coolant and removed the thermostat and am about to change the thermostat over.

The only problem is while removing the pipes that go to the airbox the pipe that connects to the dumpvalve or charge relief valve (the brown one) where it connects to the airbox it snapped of the male part of the airbox it fits to.

Gonna try glueing it back in a sec but struggling to get it out the ind of the pipe.