Any thoughts please.

[fay66]

Yesterday we took "Fay", or Fay took us! to the Kop Hill Climb at Princes Risborough, it was quite a hot day and afterwards had a drive around to cool down, eventually arriving home after about 110 miles of trouble free motoring.

This morning after cleaning her to get rid of all the dust from the Hill Climb field, I was taking her back to her lock up, when I noticed the temperature gauge had passed the 212f mark at the top of the scale;  as you have no doubt read at some point, my gauge is always reads too high, but this time it had excelled itself.
I stopped to find a puddle of water under the radiator where I had stopped, I was pretty sure the problem wasn't the radiator as it's not that long ago it was rebuilt.
I eased the cap to the safety position and let the pressure escape, or so I thought, then released it all the way, only to have hot antifreeze belch it's way all over the engine etc; after letting her cool down I refilled the radiator with 2.5 litres of antifreeze mixture that I carry, I looked around, poking and prodding, and feeling how hot the water manifold was, the hoses and the radiator were, I came to the conclusion that unless it was that the thermostat had stuck, I wasn't sure what the cause might be no nasty smells from the radiator, no signs of oil in the water,and when restarted was running fine with no missing at all. so a leaking head gasket didn't seem likely.
I then checked the fanbelt to find that I could turn the mechanical fan and belt, while the belt slipped around the dynamo pulley,  a good indication the the belt wasn't tight enough, I retightened the belt, then went for about a 6 mile drive, and everything was as normal.
Just surprised that this problem hadn't manifested itself yesterday if the belt was that loose, and that she had overheated with ram air going through the radiator, even if the fastest speed was only 40mph.
Just hope that's all it was.

Brian
8227

[chugga boom]

on the way back from an outing in my appia she boiled , was the result of a slack fan belt, matty / warby's appia started to over heat on the way to turin 2006, this was because the water level wasn't quite high enough in the header tank, the result was alarming, it only took less than half a ltr to fill to max again but the por car was nearly in the red and giving possible head gasket symptoms, this was only 5 miles away from wrexham, however with the little top up of water 3yrs on and its still going strong, so best of luck and hope your as fortunate as myself and matty 

[fay66]

Thanks Chugga,
Fingers legs and everything else crossed

Brian
8227

[nistri]

Hi Brian, yes, maybe it was all down to a slippery belt. Did you turn the heater on before removing the rad cap? Though unlikely, you might have had a large air lock. Just to be on the safe side, I would do an engine compression test.

My experience with rebuilt radiators is that they are good as much as the people who did the work. In the UK and in Italy there have been a few disappointments...with the work quality. It is very useful to measure with a thermometer the coolant temperature because this also gives a calibration for a faulty gauge.

On S1 Fulvias (and Appia as well), there is a rough way to find out if the fan is actually doing its work. You stop the engine and check whether the needle on the temp gauge starts climbing over the next few min.
Good luck and best regards
Andrea

[fay66]

Andrea,
No I didn't turn the heater on until afterwards I'll remember that if it ever occurs again, must admit I hadn't thought of that.

The small company who rebuilt the radiator do a lot of work on classic and vintage cars, so I'm pretty sure the rebuild from that point of view was fine, although they did manage to get the outer casing slightly out of line, and consequently the mounting bolts on my radiator shutter wouldn't line up so I had to leave it off, partly my fault as I should have told them how important the alignment was. next time the radiator gets rebuilt!

I've always suspected my temperature gauge as it has always read high and towards the top of the scale, although I suspected that it wasn't really as hot as the reading, since I bought a digital infrared point and shoot thermometer I now know it reads incorrectly, as at about 160f it reads an estimated 190-200f,  I'm not sure which sender it has fitted, although I remember part of the number stamped on it is 492, which according to the parts list would seem to be Jaeger.
Is it more likely to be the sender or the gauge that is incorrect, as I have 2 spare instrument clusters complete with temperature gauges.

I shall do a compression check as you suggest as soon as possible, I assume that's to check if the head gasket has blown?

Many thanks.

Brian
8227

[nistri]

Hi Brian,

Yes, for peace of mind a compression test will rule out any damage to the head gasket.

I also have one of those laser thermometers. They are very useful to diagnose if there are radiator areas of different temperature because of local obstructions, faulty thermostats, etc. They don't give you a very accurate reading of the coolant temperature which is often higher than the radiator metal casing. Thus, it might be premature to assume that the gauge is faulty. You can get a thermocouple probe to measure the coolant temperature even with a good quality multimeter, or use a suitable mercury thermometer.

Interesting comment on the rebuild of your radiator. To find really good people to rebuild radiators is a difficult task...All the best, Andrea

[davidwheeler]

Vintage Radiator Company  www.vintageradiatorcompany.co.uk totally rebuilt my Aprilia radiator (Not an easy job) for £1k and made an excellent job of it.  On the other hand Serck via Partco did both my Fulvias (recored) for about £100= each and again no problems at all.

[angelorange]

If you need a new rad - save your money and try these guys:



Alloy Racing Fabrications
Unit 1, Willoughby Sawmill
Tuxford Road
Walesby
Newark
Notts
NG22 9NY

Tel: 01623 835805 / 07968 329108
Fax: 01623 835805

website: [www.alloyracingfabrications.com]

[fay66]

Thank you
Gentlemen for your suggestions.

Brian
8227