Coolant problem

[C8PPO]

Unusual one for the time of year, but any opinions on this?

Haven't used the car for a couple of days so it's been sitting outside in the low temperatures. Went to use it earlier, and because it was so iced up, I left it running for a while to warm up and clear the windows. The windscreen didn't clear, and the temperature started creeping up towards the first red mark - way too high - so I stopped the engine and checked the coolant level.

There wasn't an obvious trace of coolant on the yellow "dipstick" so I added some - approx 30% antifreeze, the rest water. Put around 2 litres in and still no sign on the dipstick, but then water started running out from under the car, under the water filler point, so I assume the level is full and it's coming out of the overflow?

Anyway, warm air then coming out of the vents so I drove off.

First set of lights, the temperature climbed up beyond half way then suddenly dropped back down again. I drove about 3 miles, fairly slowly, then stopped and left it running to see what happened. After about 2 mins, the temperature started climbing, (whilst stationary) and this time didn't drop off again. Turned it off, waited a bit, then started it again. Drove home, temperature gauge stayed below half, but the car blew out scorching air for a bit, then blew out lukewarm air.

No idea what it is but I'm thinking maybe the thermostat is dodgy. Doesn't explain the apparent loss of coolant though - am I right in thinking it should show on the yellow dipstick? Or maybe an airlock in the system, but that still doesn't answer why, unless the car was short of coolant in the first place. Has a full Vauxhall S/H - surely that would have been checked? I'm assuming it won't be anything more serious - presumably antifreeze content would have been checked during the service?

Anyway, it'll be a call to Greens in the morning to see if they can take a look, but opinions welcome in the meantime.

Edited by C8PPO on Thursday 13th December 20:17

[S600VXR]

No alot of experiance on V8's but simptoms similar to smaller engine thermostate problems.... Greens will diagnose it for you no doubt.

[well_fans]

dipstick??? Engine coolant doesnt have a dipstick, least not on a cv8 - the fill point/expansion tank is the white plastic bottle at the back right of the engine bay and should be approx half full. Only thing on my car with a yellow dipstick is the windscreen washers and thats at the front right on the car, on newer cv8s etc its just the cap that shows in a gap in the black plastic radiator cover.

Now as for the car blowing hot air etc into the cabin - mine does that every now and again, I put it down to one of those things but it shouldn't be connected to the engine temperature. Cabin temp is controlled by the air conditioning/climate control which runs off its own coolant system. One problem with that which appeared to happen to several owners was the air temp sensor at the front of the car failing and as I recall the cheapest, easiest fix was to buy the one from a Vauxhall Omega as they were the same part.

[mackie1]

Sounds a bit like you've lost some coolant somehow and there's air in the system. I'm no expert though.

[C8PPO]

Just been and double-checked mine. There is a yellow screw cap on the nearside, right at the front, in front of the airbox, which is clearly marked "Coolant" and has a dipstick-like attachment on the underside of the cap. Screenwash is on the other side of the engine bay, behind the battery, and is a flip-off cap, not a screw. Whether or not the dipstick is, in fact, a dipstick, I don't know, but there's a long strip of plastic about the size of a large cable tie, the sme colour as the cap, fixed to the underside of the coolant cap.

Green's can't take a look until Tuesday which means I'm stuck without it until then - I don't want to chance driving it and potentially getting stuck somewhere if there's a problem.

[MikeGF]

Hi C8PPO

That's right, that is the place to fill the coolant & the "dipstick", I was also very surprised when I first topped it up as it is very hard to judge how full it is using the "dipstick".

MogV8 on here had a similar problem too, ie dumping the coolant out, after it happened he left the car for a couple of house (whilst we were at the Top Gear test track!) then filled it up with a good couple of litres and it seemed fine, but it may be worth dropping him a mail.

Cheers
MikeGF

[C8PPO]

Thanks Mike. Greens have called back and said they can take a look at it at the Rainham branch, so I'm off there shortly.

[well_fans]

C8PPO said:

Just been and double-checked mine. There is a yellow screw cap on the nearside, right at the front, in front of the airbox, which is clearly marked "Coolant" and has a dipstick-like attachment on the underside of the cap. Screenwash is on the other side of the engine bay, behind the battery, and is a flip-off cap, not a screw. Whether or not the dipstick is, in fact, a dipstick, I don't know, but there's a long strip of plastic about the size of a large cable tie, the sme colour as the cap, fixed to the underside of the coolant cap.

Green's can't take a look until Tuesday which means I'm stuck without it until then - I don't want to chance driving it and potentially getting stuck somewhere if there's a problem.

ok my mistake on the coolant reservoir with the newer cars. hope the leaks nothing more than that - a simple loose connection or split in a hose.

[L2VXR]

The yellow screw off cap with the dipstick is only the expantion pickup bottle and should be about half full on the useless dipstick,the important coolant level that i would check is at the radiator itsself under a flap on the lefthand side on the front panel cover here you should find a traditional radiator cap which you can remove (when cold!)and check the coolant

[C8PPO]

Thanks for that, I didn't spot the flap so assumed the cover had to come off - anyway, it's a Greens now so I await their verdict!