Dear Ride Drive,

I have been left a late 1997 TVR Chimera 450, with 40,000 miles on the clock, by a friend of mine who has moved out of the country. He said I could use it for a bit and then sell the car for him in the New Year (knowing full well I would fall in love and end up buying it!). Living in London I drive a lot in traffic, whilst understanding the car would run hot, what happened next concerned me.

Recently I have been hearing loud short noises from the boot of the car, almost as if someone had slapped their hand on the boot lid. The other day I was taking advantage of a clear winter's night and had the roof off – and heard the loudest noise yet. Thinking this cant be right, I got out to find petrol pouring out from below the car, just behind the left back wheel. I looked in the boot and the left hand corner was soaked through with optimax.. I took the filler cap off and found there to be a huge amount of pressure in the tank. I then heard two smaller pops and noticed the tank expand and retract.

Once traffic got moving I got in and drove to a petrol station and found all leaks had stopped, but there was still lots of pressure when opening the fuel cap. It doesn’t appear to have done it again since, but then I have not sat in traffic for extended periods of time.

Is this normal? If not, what could it be? Should I get it looked at, as I don’t really want the tank exploding?

Cheers

Rob

Reply:

Hi Rob,

I have an answer for you. The consensus is that you have a blocked breather and that you are experiencing vacuum and not pressure (although cannot be certain on that without seeing the car). The tank on that age of Chimaera is made from steel and what is likely is that as the fuel is pumped out the air is not allowed in to replace it. A vacuum occurs and once the pressure inside drops to a certain level the tank is collapsing. The bang you can hear is the equivalent of a biscuit tin lid popping in and out if you push down on the middle of it.

What is suggested is that you ring Martin at Racing Green Cars, who are Near Guildford at Ash Vale, on 01252 544888. He will speak with you about it and will be quite willing to look at the car to give you a more detailed answer to your question. Whatever you decide to do you really do need to get the car looked at as this is potentially quite dangerous.

Kind regards

Julian

Ride Drive Limited