Coulthard, who is being replaced by Williams driver Juan Pablo Montoya next season, had to push his stricken car through the sand in 50 degrees Celsius heat until marshals belatedly arrived to help.

The Monaco-based racer was one of three Michelin-shod drivers to suffer tyre damage along with fellow Brit Anthony Davidson of BAR and Renault’s Fernando Alonso.

The tyre company launched an investigation discovering that some of the drainage covers at the state-of-the-art track south of the capital Manama, which was built in just 468 days, had worked loose from their concrete bases.

Coulthard’s team-mate Kimi Raikkonen did not last a lap of second practice after a fire broke out in his Mercedes engine.

Raikkonen, who was runner-up in the championship last year, has failed to score a point this season after suffering two retirements and the team are languishing in fifth spot.

“We are on the back foot, I don’t think anyone can hide from that,” admitted Coulthard, who has scored McLaren’s four points so far.

“We are at the bottom of the hill in terms of our competitiveness with our rivals and we are trying to climb our way back up.

“At various points we show pace but we just cannot harness it over one lap. We cannot get the right grid place and until we do that we are going to struggle.”

Coulthard eventually finished 11th fastest but Raikkonen saw his hopes of launching a title fightback suffer a severe blow.

The 23-year-old Finn was forced to stop on the track with flames licking from his Mercedes engine.

The blame was laid by a problem with the air tray and McLaren mechanics have been forced to change the engine.

Raikkonen will lose 10 places on the grid from his qualifying position under the new one engine per weekend ruling and will probably start Sunday’s race from the back of the grid.

“I have not had the best start to the season,” said Raikkonen, who only missed out on the title by two points last year, with massive understatement. “Our position could be better.

“But that’s the way racing goes sometimes. And everybody is pushing hard to try and improve.”

Raikkonen already trails Ferrari’s Michael Schumacher by 20 points and even with 16 races left this season is looking out of title contention.

Schumacher will be looking to maintain his perfect start to the season in Sunday’s history race by claiming his third straight win.

The six-time world champion is on course to extend his seven-point championship advantage even though he posted the fourth fastest time in second practice.

Schumacher, quickest in the first session, was less than 0.3 secs adrift of team-mate Rubens Barrichello who edged out Montoya’s Williams-BMW by only 0.001secs.

“It has been an interesting start on this circuit,” said Schumacher after his first taste of the Formula One’s newest venue.

“I have to say the track layout is very demanding. It looks like the rest of the weekend will be a great challenge and I am looking forward to that.”

Davidson, BAR’s reserve driver, was third fastest after a late flying lap having also made one trip across the gravel when he ran into tyre trouble.

Team leader Jenson Button was seventh fastest behind Jaguar’s Christian Klien and Ralf Schumacher in the other Williams.

Button, less than half-a-second off the pace, is looking to follow up his maiden podium appearance from Malaysia a fortnight ago.

“Ferrari still have the advantage,” said Button, third in Sepang. “We have just got to maintain our progress this season and get as close to them as possible.”

Coulthard, meanwhile, has raised question marks over whether the new track will improve overtaking opportunities fearing the dust and sand at the edge of the circuit will penalise drivers.

“If you want drivers to overtake, at every corner there should be a carrot dangling above it to make that possible. There are no carrots here.”