A Mercedes SL65 AMG that had sat outside for years cost its new owner just $3,000. Getting the twin-turbo V12 running was only part of the job, though. Its hydraulic suspension had dropped so low that even getting it onto a lift took work.
In a September 26 video, LegitStreetCars host Alex took on the stalled project. He said the former owner had parked it after the engine began to misfire and went into limp mode, which limits performance.
Fear of the repair bill had helped bring the price down. Alex put the cost of a used replacement engine at about $20,000, while a single hydraulic strut could cost around $2,000. Those were his estimates, and he had yet to learn what this car needed.
Fresh battery power brought the dash back to life. The car had about 60,000 miles, and there were spare parts inside, too. Alex began checking whether it could run again before taking on the bigger repairs.
A Little Encouragement
With a small inspection camera, Alex checked inside several cylinders and liked what he found. He put the spark plugs and ignition parts back, then added water to the very low cooling system to check for leaks.
The first start brought smoke, rough running, and a ticking sound. Only part of the suspension rose, leaving the car leaning. After an engine flush, Alex could no longer hear the lifter tick. But the misfire returned, and he shut the engine off to check further.
Suspecting a stuck fuel injector, he tapped the injectors and fitted the second new battery. On the next start, the engine ran smoothly and the exhaust smoke cleared. He liked the result, though it did not prove what had caused the fault.
An oil change brought another useful check. Examining the old filter, Alex found no visible metal in its folds, then fitted a new filter and seals.
Up, Then Down
Underneath, the rear height sensors needed attention. Alex tried borrowing parts from his CL65, but they did not fit as planned. He ordered new sensors and another small part for a quoted total of $122.
For testing, he moved the sensor arms by hand and secured them with zip ties. The car began to rise and fall. When it later took too long to rise, he stopped to work on more of the system.
Two new pressure reservoirs, called accumulators, had come with the purchase. Alex installed them and changed the hydraulic filter and fluid. A loose bleeder caused a leak during testing; he owned the mistake and tightened it before going on. The folding hardtop worked, too, opening the way for a drive with the roof down.
Two Blocks Later
Out on the road, a scraping sound first sent Alex back to check the car. He later found a loose fender liner. He had left it partly unfastened while checking for leaks.
Then the check-engine light came on and the V12 began running rough. A scan returned misfire codes for cylinders seven and eight, both on the side with the original ignition coil pack. Alex suspected that pack, but left the diagnosis open for more testing.
Restarting the engine let it run smoothly for a while before the fault returned under load. Alex headed back to the shop and said it ran without a misfire for the last five minutes of the trip.