Thermostat didn't open.....

Post by **Matt** » Fri Sep 02, 2005 10:02 pm

I collected our "new" convertible from Tunbridge Wells on thursday and drove it all the way home to Southampton. During the trip I thought the heater was very toasty. Anyway long story short the thermostat didn't open the whole trip, there is no obvious damage (the engine burnt quite a bit of oil though) should I look out for anything in particular?

Post by **Kevin** » Sat Sep 03, 2005 9:08 am

If it didnt seriously boil over you should be OK, what can happen if it gets seriously hot is that the oil thins down as well and the engine begins to become more rattly/noisier and this an lead to all sorts of problems, but it sounds as though yours didnt suffer from this.

Post by **rayofleamington** » Sat Sep 03, 2005 11:34 am

should I look out for anything in particular?

Fortunately the A-series is very robust agains overheating.
If it's not boiled all the water away then the oil loss is more likely to be from a worn engine than just from haveing vaporised a lot of oil.
As mentioned alreay the oil gets very thin causing a bit more more use but the thing to worry about is how long is has been like that

If it has been used like that for a long time the overheating can cause valve failure, worn top end and valve guides etc..

Riley had a similar fault with a failed thermostat (which i found on the first big run, together with heavily retarded timing causing a serious overheat on the motorway) . The engine carried on (an is still running - ask Gluck) and although it uses a bit more oil than ideal but the A-series is pretty hard to kill.

Post by **bmcecosse** » Sun Sep 04, 2005 5:26 pm

How do you know it didn't open ? Most unusual - they usually fail open. But just stick in a new one - and see if it is ok !

Post by **Onne** » Sun Sep 04, 2005 6:38 pm

Or put it in a pot of water, and bring it to the boil.

Post by **rayofleamington** » Sun Sep 04, 2005 6:51 pm

Most unusual - they usually fail open.

Really? The normal Minor thermostat has a wax element actuator with a return spring and as the normal failure of a thermostat is that the wax actuator packs up it would normally fail closed

Post by **Cam** » Mon Sep 05, 2005 12:26 am

Yes, I have had the odd 'closed' failure, but one 'open' failure which was not really a failure as it was like that when I bought the car. The centre pin had been bashed off the rail at the bottom of the stat and it was at an angle and stuck open. God only knows how it got like that but it must have been like that before it was fitted!

Post by **Matt** » Tue Sep 06, 2005 9:23 am

If it has been used like that for a long time the overheating can cause valve failure, worn top end and valve guides etc..

Well in the last 10 years its only done 6000 miles so I'm not too concerned about that, and when it has been used its only been used to go round the block...

How do you know it didn't open ?

Well, I took it out and put it in some boiling water and it didn't open!

Post by **lowedb** » Tue Sep 06, 2005 1:23 pm

I'd do an oil change too.

The excessive heat might have damaged the oil. When this happened on a friends Marina, when we opened the oil filler the oil was actually sizzling on the rocker shaft!

Post by **bmcecosse** » Wed Sep 07, 2005 1:33 pm

The few failures I have come across over the last 40 years have all been 'open'.

Post by **rayofleamington** » Wed Sep 07, 2005 1:46 pm

The few failures I have come across over the last 40 years have all been 'open'.

I guess that's probability for you - it rarely follows science.

Post by **paulk** » Wed Sep 07, 2005 1:51 pm

You Mean 1 million to one shots

happen 9 times out of 10?

Paulk

Post by **Cam** » Wed Sep 07, 2005 1:57 pm

Probably...