Unhappy Cerbie - post Silverstone PH meet

[sshenton1975]

Hello All

Need some help diagnosing Cerbie Speed 6 problems...

Took the car out yesterday for a good run around - no issues all day having had the car off road for 6 months

When I got home having done around 30 miles in and out of traffic, I filled expansion tank up with water

Today took the car to the Silverstone PH meet and just as we arrived in the queue to sign it, it started overeheating - temp rocketed up to 110 and steam from tank. Small amount of water under car (could have been steam)

On way home it quickly (within 5 minutes) overheated again. Got it to the services on A43 and poured 2 litres of water into the car. The drove home normally with temp gauge at 80 - 90 degrees (no traffic - av speed 60)

I had a new water tanks put in the car a year ago so shouldnt be that. Could I have got an air lock into it when i topped up with water last night?

Car runs OK so I am (hoping) it is not head gasket - however 2 litres of water seems a lot?

Water under car seems to be coming out underneath passenger seat area/footwell - close to the water tank I think?

What alarmed me was how quickly it soundly overheated once car was in traffic. Fans OK

Has anyone got a diagram of the various hoses, water pump, rad? What are the basic checks I can make

Many thanks

Simon

[spongy]

How low was the tank the first time you filled it,and how high did you fill the expansion tank when you did fill her.Remember the expansion tank should not be filled to much....ive seen em filled to the brim.....not good.

[sshenton1975]

when i filled up the first time, it took about a litre and that left around 8-10cm from top of expansion....

[Allandwf]

My Cerb blew off a pipe down there, under the expansion tank, where it goes to the heater, exactly where you had water ie passenger area. Was a 4.2 but would think heater plumbing would be similar.

[Timja]

Were the fans coming on ok when it was overheating?

[natben]

It is possible that the expansion tank was overfilled and the excess water is being blown out the expansion tank cap. If the fans are coming in out would point to the fuses being ok, but might be a problem with the temp sender below the air box. I changed the temp sender on mine and it has made a big difference to the cooling on mine.

[nawarne]

"Water under car seems to be coming out underneath passenger seat area/footwell - close to the water tank I think?"

Have you run the engine up to temp and opened the bonnet? This to check for any obvious leaks - hoses, rad, connections to oil cooler....etc.

18 months ago, the heater matrix failed on my tuscan. The matrix is located on the pass. side of the engine bay, just in front of the bulkhead...don't know where it would be on a Cerby. Started off needing frequent coolant top-ups, then got to the point where I could hear the pressure/steam coming out of the leak. A local radiator repair shop re-cored the matrix for about 90 inc.

You shouldn't need to top-up more than 0.25 to 0.5 litres at any time. Sounds like the cause needs investigating.
Nick

[Gazzab]

Running the car with a water leak and therefore a lack of coolant is asking for overheating and hotspots which may damage the engine, gaskets etc...

[TVR_CS]

Are sure it's not leaking from around the Y piece under the tank, I had the same problem thinking it was coming from the cap, tightened up the jubilee clips underneath, all sorted.

[sshenton1975]

Thanks for all your posts guys - I need to get all the covers off and have a good look underneath!

V embarrassing at Silverstone, sat in a cloud of steam!!

[natben]

Also make sure the cap is on tight enough, I know it sounds simple enough but if it is not put on tight after you filled up the expansion tank the coolant will escape.

I would start by toping up the coolant and running the car on the drive up to temperature and see if the fans are kicking in. If the temp goes up to 100 turn of the engine, if the temperature gets to 90-95 and if something is wrong the temperature will very quickly climb above 100 so keep your finger on the red button!!.
Then start to check some of the things suggested above.

Good luck and let us know how you get on.

[Quentin1]

Sticking thermostat? Check if the radiator gets hot. If not, the thermostat does not open which will lead to overheating, then the cap will release water.
(The fans will come on anyway, but have no effect when no hot water is guided through the radiator...)

Just a thought, because of the six months off the road.

Björn.

[WhyTwo]

I had all sorts of overheating issues with my Tuscan. Turned out to be a faulty filler cap thread. Suggest for the sake of £10 - 12 you invest in a new one and see if that resolves the issue

[DonkeyApple]

Could be filler cap but if the car has been sitting around for 6 months the first thought that sprang to my mind is a sludged radiator not cooling efficiently?