Coolent running low but no leaks?

[Themasteryeti]

Drove my 480s over to the shops earlier and noticed that it was getting really hot on my way home , now I only got the car about a month ago and topped all coolent up, so I thought I'd check it and it was just below the low mark already, I daily the car and there hasn't been any leaks nor overheating issues apart from today, wondering if anyone else has come across a problem like this and found a solution?

[WillC9303]

Unless there is a leak or (god forbid) the coolant and oil are mixing, I don't see where the coolant could be going.

The most likely cause is that the levels have just settled since the coolant was last changed. My advice would be to top up the coolant back up to 'max' on the expansion tank, and check on the levels in a couple days time to see if its changed much. If the level hasn't changed, then nothing to worry about.

What were you doing when the car overheated? I was on my way back from Milton Keynes the other week in very slow moving traffic on a warm-ish day on the M1 and my Info centre temp warning started flashing at me. Put the heater on full and in a few seconds, the temp returned to normal and I had no problems for the rest of the trip.

[jifflemon]

Coolant leaks are tricky little buggers. So firstly, when was the coolant last flushed and changed? Coolant goes acidic with time hence why we change it.

Next, look for the signs of pin hole leaks - around clamps is a typical source. You also need to do this under pressure (with a coolant testing kit) or whilst the engine is running (usual safety measures taken).

I had one on the turbo that didn't show up until I reached full 1.5 bar pressure (see here)

[Jay-Kay-Em]

The elephant in the room is H/G but lets not go there yet. They are pretty bullet proof (only with a history of good coolant, thus minimising that corrosion element that Jeff mentioned).

Another thing to check is the expansion tank cap or "rad cap" as it were. If they vent too early then they lose coolant with no trace (as steam). Also, if it can't maintain a decent enough pressure then this lowers your boiling point, explaining your running a tad hotter than normal.

Also check for interior leaks from the heater matrix rather than in the engine bay. The interior doesn't need any extra sources of moisture than normal!

[Alan 480]

Also check for interior leaks from the heater matrix rather than in the engine bay. The interior doesn't need any extra sources of moisture than normal!

yes been there, leaks from heater to UNDER the mat/soundproofing
lift edg eof carpet at doors and slide hand underneath, not always very pleasant . . .
matrix is a bummer to change and at least two flavours of heater matrix, I reckon it is the first thing they installed when built

[Themasteryeti]

Unless there is a leak or (god forbid) the coolant and oil are mixing, I don't see where the coolant could be going.

The most likely cause is that the levels have just settled since the coolant was last changed. My advice would be to top up the coolant back up to 'max' on the expansion tank, and check on the levels in a couple days time to see if its changed much. If the level hasn't changed, then nothing to worry about.

What were you doing when the car overheated? I was on my way back from Milton Keynes the other week in very slow moving traffic on a warm-ish day on the M1 and my Info centre temp warning started flashing at me. Put the heater on full and in a few seconds, the temp returned to normal and I had no problems for the rest of the trip.

Coolant has been topped up, seemed fine this morning then on the way home it started getting really hot again so I did as you said and blasted the heater and that brought it down to a more reasonable temperature (still a bit high but much better) then I just went to the shops again and it was perfectly fine on the way there but started getting hot again when I was waiting at the traffic lights, once again I blasted my heater and it went back to a normal temperature after that for the rest of the drive coolant is still at the same level I filled it up as and the fan is still kicking in, I'm wondering if maybe it's kicking in a bit late or cutting out to early? Not sure how I'd go about testing this tho

[Themasteryeti]

Also check for interior leaks from the heater matrix rather than in the engine bay. The interior doesn't need any extra sources of moisture than normal!

yes been there, leaks from heater to UNDER the mat/soundproofing
lift edg eof carpet at doors and slide hand underneath, not always very pleasant . . .
matrix is a bummer to change and at least two flavours of heater matrix, I reckon it is the first thing they installed when built

Did just this and it was dry (thank goodness) && hopefuy it won't come down to changing that then

[Themasteryeti]

Coolant leaks are tricky little buggers. So firstly, when was the coolant last flushed and changed? Coolant goes acidic with time hence why we change it.

Next, look for the signs of pin hole leaks - around clamps is a typical source. You also need to do this under pressure (with a coolant testing kit) or whilst the engine is running (usual safety measures taken).

I had one on the turbo that didn't show up until I reached full 1.5 bar pressure (see here)

Not sure when it would have been last done, but there was next to no coolant in it when I bought it about a month ago
&Oh that's interesting never seen one of those, I'll have to see if I can get my hands on one!

[Themasteryeti]

The elephant in the room is H/G but lets not go there yet. They are pretty bullet proof (only with a history of good coolant, thus minimising that corrosion element that Jeff mentioned).

Another thing to check is the expansion tank cap or "rad cap" as it were. If they vent too early then they lose coolant with no trace (as steam). Also, if it can't maintain a decent enough pressure then this lowers your boiling point, explaining your running a tad hotter than normal.

Also check for interior leaks from the heater matrix rather than in the engine bay. The interior doesn't need any extra sources of moisture than normal!

Gonna see if I can get ahold on one of those gauges to test that, does make me wonder why this problem didn't turn up before tho? I drive the car everyday and it never had this problem previously

[jamescarruthers]

480 coolant woes I have suffered:

- metal pipe from engine block rusting away (on back of engine, above gearbox)— this is very common and the only solution I have found is to pay to have the pipe copied)

- core plugs rusting away behind the timing belt

- water pump springing a leak, exiting through it’s weep hole

- automatic gearbox oil to coolant heat exchanger rusting away

All of the above probably from neglected coolant changes in the car’s history.

- feed pipe from coolant bottle

- T- (or is it Y-) shaped pipe at bottom left of engine bay holed

- heater matrix springing a leak (entirely metal on early cars but later ones still susceptible)

Of course yours could be anywhere but looking at others and where they have had a leak might help you home in on it.

[Alan 480]

Coolant has been topped up, seemed fine this morning then on the way home it started getting really hot again so I did as you said and blasted the heater and that brought it down to a more reasonable temperature (still a bit high but much better) then I just went to the shops again and it was perfectly fine on the way there but started getting hot again when I was waiting at the traffic lights, once again I blasted my heater and it went back to a normal temperature after that for the rest of the drive coolant is still at the same level I filled it up as and the fan is still kicking in, I'm wondering if maybe it's kicking in a bit late or cutting out to early? Not sure how I'd go about testing this tho

if temp is going VERY high, maybe the thing is 'boiling' because the fan isn't kicking in at all?? its not uncommon for the switches to fail, some had two stages.
you should be able to hear it 'hurling' when it does kick in.
testing switch is a PITA cos means opening up the radiator,

BUT you can check the fan works,
A that it turns by hand, might be stuck?
B hot wire it to make sure it works if it is free

if not already purchased you need HBOL (Haynes Book of Lies) some would call it HBOL (Haynes Book of BIG Lies)

[Jay-Kay-Em]

Keep in mind your diagnosis of “getting hot” is based on 480 instrumentation

Get it idling with the fan cutting in - out - in - out. On that basis at least you know it’s stable. If the fan cuts in, stays on and she boils over, then you know you have an issue.

[arthuy]

I had a loss which was the radiator side tanks. The plastic expands coolant escapes and it was hard to trace.

You can get dye and uv torch kits on ebay. Helps you spot it even when the coolant dries in.

[Themasteryeti]

Coolant has been topped up, seemed fine this morning then on the way home it started getting really hot again so I did as you said and blasted the heater and that brought it down to a more reasonable temperature (still a bit high but much better) then I just went to the shops again and it was perfectly fine on the way there but started getting hot again when I was waiting at the traffic lights, once again I blasted my heater and it went back to a normal temperature after that for the rest of the drive coolant is still at the same level I filled it up as and the fan is still kicking in, I'm wondering if maybe it's kicking in a bit late or cutting out to early? Not sure how I'd go about testing this tho

if temp is going VERY high, maybe the thing is 'boiling' because the fan isn't kicking in at all?? its not uncommon for the switches to fail, some had two stages.
you should be able to hear it 'hurling' when it does kick in.
testing switch is a PITA cos means opening up the radiator,

BUT you can check the fan works,
A that it turns by hand, might be stuck?
B hot wire it to make sure it works if it is free

if not already purchased you need HBOL (Haynes Book of Lies) some would call it HBOL (Haynes Book of BIG Lies)

The fan definitely work, I let it idle yesterday and the fan does kick in, but it's only on for about 10/15 seconds then turn off again, idk if that's normal or if it's cutting out to early?

&& I got a hbol with the car, been reading it like a Bible

[Themasteryeti]

I had a loss which was the radiator side tanks. The plastic expands coolant escapes and it was hard to trace.

You can get dye and uv torch kits on ebay. Helps you spot it even when the coolant dries in.

Oh I didn't think about dyes! That might be a good idea bcoz the coolest had gone from full to half full in the space of a few days now but while it's running there isn't any drips or anything noticable

[Themasteryeti]

480 coolant woes I have suffered:

- metal pipe from engine block rusting away (on back of engine, above gearbox)— this is very common and the only solution I have found is to pay to have the pipe copied)

- core plugs rusting away behind the timing belt

- water pump springing a leak, exiting through it’s weep hole

- automatic gearbox oil to coolant heat exchanger rusting away

All of the above probably from neglected coolant changes in the car’s history.

- feed pipe from coolant bottle

- T- (or is it Y-) shaped pipe at bottom left of engine bay holed

- heater matrix springing a leak (entirely metal on early cars but later ones still susceptible)

Of course yours could be anywhere but looking at others and where they have had a leak might help you home in on it.

That sounds like a very long expensive list
Idek where to start with seeing which bit it is, obviously I don't wanna just replace everything and it not sort the problem D: