Overheating :(
 

Hi all,

I broke down the other day, with the car overheating :(

Unfortunately, I didn't even notice the needle move, it was the red light and message centre notice that caught my attention!

I was expecting the usual empty header tank, but it was still full and I've not lost any coolant.

My initial suspects are thermostat, although this is both fairly new ( a few years old only) and a PRT. Other suspect would be water pump.

Do either of these seem more likely (I have a new thermostat in the garage) or is there something else to consider?

I've not had change to run diagnostics yet, I would like to see how the temp sensor behaves, there was no boiling over of the coolant or steam....but the gauge seems to perform normally....runs up to temp and then overheats after a couple more miles, it could be playing up though I guess and need replacement.

Lack of flow through the radiator seems a possible cause (failed thermostat). Was the cooling fan running full belt? It should have been. Does it operate as it should? Demist Test OK?


TC

I can't be sure if the fan was running on high speed, but I'm fairly sure it's OK.

I let everything cool down for a while and then restarted, fan ran on slow, and on fast as soon as air con was started, I left the air con on for the high speed fan just in case, but it started overheating again after just a few miles.

Called in the breakdown cover at that time and got it home.

I'll swap the Thermostat out as soon as I get the chance, and go for a drive with the laptop connected to keep an eye on the temperature.

My only other concern is that I dropped a wheel in a rather large hole in the road earlier in the day - I suspect I just clouted the lower arm on the o/s so can't see how that would have any effect - I'll take a look, but probably just coincidence, the overheating problem was hours later.

The aircon only requires the low speed fan. Run the Demist Test when you can to check. The operating parameters (with aircon off) are:

Low speed starts 104C
High speed starts 112C

I suppose you may have damaged/squashed the PRT by grounding the front end. The PRT sits on the subframe behind the radiator, so is potentially vulnerable.

TC

Good point, I'll double check with demist test.

I don't think I bashed anything in the PRT area, but I'll check.

Been travelling with work this week so got the first chance to look at the car this evening.

Took the undertray off, no obvious damage anywhere from where I hit the ground, certainly no marks on parts that sit lower than the thermostat anyway - PRT looks fine from the outside (I will probably swap any as currently main suspect).

I plugged in my PScan and got the following two errors - any ideas?

https://farm2.staticflickr.com/1937/...a04e659c_z.jpg

I think probably unrelated, I'll clear and see if they come back.

What is more concerning is that the car now won't start - hopefully the battery just needs a charge, but was spinning over but just wouldn't catch :(

PScan was also showing coolant temp at 20C so I suspect there is nothing at all wrong with the coolant sensor.

Help?
 

Hi Matt,

Sounds like the thermostat may have jammed shut .... why it would do that whilst happily driving along I dunno.....

Are compressions ok?

If you could use another pair of hands give me a shout.... I'm in Stevenage.

Good luck

John

Just to check Matt, you haven’t got a conventional thermostat and a PRT fitted at the same time have you?

Simon

Good spot about the possible fact OP has 2 thermostats fitted - which if the case may well be the cause of his problem.:}