Exploding Thermostat......KABOOM

[zhoey]

Took the RR out today. Started from cold, drove about 3km down the road and into a traffic jam. Must have been a start-stop situation for about 30mins or thereabouts, then KABOOM!

Didn't think much about that until I noticed that the water temperature gauge was almost back in the blue region. Drove into the nearest gas station, opened the bonnet and noticed a bit of smoke from the engine. Was dark so couldn't see what was going on, but realized that the coolant reservoir was empty.

Well, it was dark at around 8pm and I wasn't going to attempt any roadside repairs in my outing clothes. So I got the RR towed into my fave workshop.

Next morning I popped the bonnet and had a closer look. Could not see anything wrong at first. Oil level - normal no coolant contamination. Oil filler cap - clean as a whistle. Exhaust - no moisture. Engine starts and runs as normal without missing a beat. Switched off engine and looked really carefully....thermostat was in 3 pieces, each piece dangling off its respective hose.

The thermostat had either jammed in the closed position, or the plastic thermostat housing had catastrophically failed. Hmmmmm......so much for a reliable off-road vehicle.....till now 16 years later and the 1st time it had to grace the back of a tow truck.

[wayneg]

Seems odd it broke into 3. Once you have got a new thermostat on I would be looking closely at the pressure in the cooling system, there could be a blockage not thermostat related causing excess pressure. ( Hopefully it was the Thermostat at fault )
Once sorted I would be fitting a low coolant alarm, you were lucky the failure happened when you wern`t cruising on a motorway, that would have been expensive.

[Blknight.aus]

Ive seen one that split of and went to visit the fan... It was in substantially more than 3 pieces.

[zhoey]

Ive seen one that split of and went to visit the fan... It was in substantially more than 3 pieces.

..........thereafter. :twisted:

[zhoey]

Just refitted with a brand new thermostat.
Idled the engine on the driveway and all was normal.
Drove at high speed down the highway, no signs of distress either.
Hence, it was a duff thermostat after all.

[bee utey]

Plastic components on all cooling systems will fail catastrophically given enough time. Obviously there's a use-by date built into every vehicle. Heater taps on Falcons and Commodores are notorious for exploding at between 150 000 and 200 000km. Radiator tanks, expansion tanks, thermo housings, water outlets, heater fittings, bypass pipes etc can all follow if the engine survived the coolant loss. This is where the auto repair industry makes its money!!!

[zhoey]

3 days of hard running.
No problems so I am going to put this issue to rest.

[PhilipA]

I saw a post on AFAIR a UK site showing how some people reinforce the housing by placing a band of epoxy aroiund the seam.
Apparently the seam is the point of failure.
I was looking at the posts which were AFAIR links from the post on "its Hot" or similar only last week about relocating a D2 thermostat.

http://www.aulro.com/afvb/discovery-2/148325-runs-hot.html

Regards Philip A

[DT-P38]

ROTFLMFAO