Out of the way, commuters! This modified Ford Sierra, which started life as a humble GLX, has been reinvented with a BMW 330d engine and a whole bunch of luxury upgrades.

Back in the day, Ford manufactured diesel-powered Sierras… but they were nothing like this! Dan McKelvie’s ’92 GLX may take on an innocent, unassuming look, but don’t be fooled as under the skin lurks a six-speed BMW M57 3.0D with air-ride, traction control and a plush Bavarian interior. Yep, this is a 330d swapped Ford Sierra!

We should firstly explain that Dan works as an Electrical Design Engineer for M-Sport in Cumbria, and it seems he’s been inspired to take on one or two ambitious projects in his spare time too. His previous build, a Bedford Rascal running a Kawasaki motorcycle engine and home-brew suspension, has become a well-known creation on the modified car scene, unsurprisingly creating quite a stir.

front on shot of modified ford sierra

Spicing up his daily driver

Having enjoyed that lairy Rascal project, Dan came up with the idea of adding a little spice to his daily commute by combining a retro car of some description with a modern diesel powerplant. “I had an E91 BMW 330d Touring at the time and loved it,” he says, “but it just blended in far too much, I’d often see around fifty clones on one single long journey.” Initially there was talk of a 2.0TDi transplant into a Mk2 Jetta, which would have been a cool build for sure, but compared to that silky smooth BMW 3.0D he’d got used to, the four-pot would have been something of a compromise. “In many ways, slotting an M57 3.0D into an E30 would have been ideal,” Dan says, “but the price of E30s soon put me right off the idea!”

Without realising it at first, Dan already had the perfect donor retro shell in his possession – well, almost. “My dad bought a 1992 Sierra 1.8 GLX when it was still almost new,” he explains. “It was our family car while I was growing up and I used to travel to school in it every day.” Despite buying a replacement some fifteen years or so ago, Dan’s dad never sold the Sierra, opting to leave it in his garage as a storage device while gathering dust. “I did get the chance to drive it around our garden a few times before passing my test,” Dan smiles. “It did get moved, just not very far.”

modified ford sierra interior

Plans for the Ford Sierra start

It was while visiting his dad one weekend that Dan had the chance to reacquaint himself with the family Sierra, and soon noticed how sorry for itself it looked. “I had a good look around the car and was reminded how little space the CVH engine took up inside the bay,” he says. “It got me thinking, this was a perfectly good retro car with potential currently going to waste.” He promptly asked his dad how much he wanted for his old family car and was happy to hear he could take it for free: “He was pleased it would be put to good use, but asked if he could have a go in it once I’d done the conversion,” Dan grins. “Now I just needed to find a cheap, rusty BMW E46 or E90 donor with low mileage, full service history and a six-speed manual gearbox!”

Turn the clock back five or ten years, it seemed E46 BMWs were lurking on every street corner (usually full of drugs), but they’re seldom seen these days. Fortunately, Dan was able to bag himself a 2006 204bhp M-Sport convertible that fitted his criteria perfectly. “I paid a very good price and, in many ways, it was too nice to break up,” he says. “At least this meant that it boasted lots of desirable goodies to sell on to put towards my project.”

air filter

Preparing to build the modified Ford Sierra

As ever, preparation was key when it came to this build and even before bringing the Ford Sierra home, all the research had already been done. “All the measurements had been made and all the BMW parts I’d need had been boxed,” Dan explains. “The rest of the parts were sold off and the shell was scrapped.” Meanwhile, the M57 engine and six-speed box were stored on a pallet on wheels, ready to be rolled into the Sierra’s engine bay when the time came. “The wiring had also been prepped inside the donor shell and placed inside a box, ready to be installed when required,” he adds.

Although it had spent most of its time off the road in dry storage, the Sierra had still suffered with the usual rust to the floors, sills, chassis legs, wings and arches, repairs being carried out as the project progressed. “The CVH engine was smoking due to leaky valve stem oil seals, none of the electronics functioned properly and the brakes and suspension had seen better days,” Dan recalls. “On the upside, being a GLX, it made a great base as it came with electric windows, sunroof and mirrors, and the late-spec three-spoke steering wheel.”

steel wheels on modified ford sierra

Exterior modifications on the Ford Sierra

Opting for a stealth look which includes the conveniently standard late-spec tinted rear lights along with a Cosworth front bumper, grille and Rouse splitter, Dan’s GLX manages to look both mean and understated, which was all part of the plan. Meanwhile those 17” Peugeot steel wheels hide a wealth of chassis upgrades, such as BMW E38 7-Series Brembo calipers at the front matched with Cosworth calipers at the rear, while an E46 power-assisted quick-rack replaces the original Sierra rack.

air compressor tank

Air ride for the modified Ford Sierra

“I decided I wanted a basic air-ride suspension system, and designed myself a controller and screen to handle the airbag pressures for each corner along with the compressor and driver’s display,” says Dan. The system itself comprises GAZ dampers and Compbrake adjustable top mounts with a bag-over-coil design at the front. “This involved replacing the steel spring for an air spring,” he continues. “As the GAZ coilovers used an imperial thread, I had to machine my own brackets for the air spring as nothing was available off the shelf.”

In comparison, the rear proved to be far more straightforward as the Sierra uses a separate spring and damper setup; “I removed the springs from the GAZ coilovers and used a pair of universal airbags here,” Dan adds. All remaining components including the arms, brackets, driveshafts and custom subframes were all powder-coated and the floor fully Dynamatted and insulated. All reusable suspension parts were also sent off to be powder-coated, ready to be fitted with fresh bushes upon their return.

BMW 330d engine

Fitting the BMW 330d engine into the modified Ford Sierra

A dry build ensued with the BMW’s engine and transmission in place, and once Dan was happy, the underside and engine bay were fully stripped, ready to be treated, stone-chipped and painted – all of which he carried out himself. “I didn’t want any rusty petrol in my diesel pumps, so the fuel tank and lines are all new,” he says.

“The brake lines and custom hoses for all four corners and the ABS pump are also new, as are the brake discs, pads and all nuts, bolts and pipes, it’s basically a brand-new car underneath!” In comparison, various other components within the engine bay required for this ambitious transplant such as radiators, header tanks, OEM hose fittings, clips and pedals all came courtesy of Dan’s local scrapyard. “I just took along my toolbox and my tape measure, to ensure that everything I sourced would fit correctly in their new home.”

car information

Wiring everything up

Wiring up a fresh engine can often be the most daunting part of a full-on rebuild, but being an engineer by trade, this task proved to be the easiest and most enjoyable part for Dan. He’s not kept things simple either! “There were a few luxuries I wanted from the donor BMW,” he explains, “including cruise control, the instrument cluster, air-conditioning, climate control, ABS and traction control.” To us it sounds like a stressful nightmare, and we won’t go into every detail, but for the cruise control, Dan required four separate wheel speeds which meant using Sapphire ABS hubs which benefitted from ABS rings with the ability to accept a wheel speed sensor.

“In the end, I made my own ABS rings so that the speedo and mileage was correct to match the BMW cluster,” he says. “For the ABS itself and the traction control, it was as easy as adding in the ABS pump and extra BMW sensors such as steering angle and so on.” The air-con just requires custom piping for now, but the remainder of the electrical system all functions correctly which means the OBD-II functions and live data all work as they should, making any fault-finding simple.

bmw seats in modified ford sierra

Modified Ford Sierra interior changes

The Bavarian theme continues on the inside, as Dan wasn’t prepared to pay the high price tag a 30-year-old Sierra Recaro interior now commands. “As I’d be covering lots of miles, the seats had to be comfortable and plush,” he reckons. “After some careful measuring, I opted for BMW 3-Series M-Sport front seats and rear leather seats from a 2021 model.” The front seats are heated too, as you’ve probably guessed!

Ford Fair

Basic remap

The 204bhp six-cylinder M57 3.0 is a peach even in standard form, so Dan has so far resisted the urge to mess around with things here, other than the necessary addition of a custom stainless-steel exhaust. “It retains the original single turbo setup with a very basic remap,” he says. “The M57 is very tuneable, but I’ve not been tempted to increase the power yet as it drives so well as it is.” Matched to the M57’s BMW six-speed gearbox and diff, we’re told this Sierra feels just like a modern car behind the wheel; “the seats are comfy, the steering is light yet communicative, and overtaking is never a problem,” he assures us. “You soon forget you’re driving a Ford built in the early ’90s!”

bmw instrument cluster

Problems with the modified Ford Sierra build

Not every aspect of the build proved to be all plain sailing, as Dan had a few struggles aligning that BMW rear diff within the Sierra’s subframe. “I seemed to spend a lot of my time lying on my back with the car on monster axle stands on a winter’s evening,” he says. “It was a lengthy process combining the original unmodified BMW propshaft and diff with the Cosworth driveshafts, all of which were mounted in the Sierra subframe.” After all, the last thing he wanted was to drive five miles down the road to realise there was a minor misalignment with a resulting wobble in the driveline. “Measure twice, cut and weld once, then measure again with laser alignments and rulers,” Dan says. “This being a steel-cased diff, it was a heavy unit to be pulling in and out!”

modified ford sierra  rear 3/4

Conclusion

Incredibly, from barn find to MOT complete with BMW running gear, this project only took less than twelve months to complete. Well, we say ‘complete’, but we’re told there’s still work to do such as a fresh respray, the fitment of Cosworth sideskirts, while a set of LED-converted rear lights might make an appearance too. “And if I ever get the feeling this car is driving a little sluggish, it’ll be time for a bigger turbo,” he smiles. For now, it seems Dan has the best of both worlds – silky-smooth six-cylinder diesel power and economy, all wrapped up in the unmistakable shell of a classic ’90s Ford Sierra. The purists may frown, but we just love it!

Words and photos: Jon Cass.

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