Common Engine Issues on the McLaren 650S
One of the main issues observed with the 650S engines concerns oil levels. As highlighted by Thorney Motorsport, an independent McLaren specialist, the M838T engine used in the 650S is particularly sensitive to oil levels and engine temperatures. Insufficient lubrication, especially during cold starts, can lead to premature wear of cams and rocker arms. It is therefore crucial to regularly check the oil level, especially after servicing or track use.
Failure to follow these precautions can result in extremely costly repairs. For example, an engine suffering from poor lubrication may require a cylinder head replacement, with parts alone costing up to €8,000 for the McLaren 12C, a closely related model to the 650S.
Complete Engine Rebuild
What You Need to Know
Rebuilding an engine is a complex process, especially on a supercar like the McLaren 650S. This procedure may involve replacing pistons and piston rings, machining the cylinders, and refurbishing the cylinder heads. At Thorney Motorsport, repair work can range from basic cam phaser replacements (around €9,800) to full engine rebuilds (up to €45,000), depending on the condition of the engine and required parts.
For owners looking to avoid even higher costs at an official McLaren dealership, Thorney Motorsport offers a more affordable alternative with components such as forged pistons and steel cylinder liners for enhanced durability.
Upgrades and Preventive Maintenance
One of the simplest ways to prevent premature wear is to ensure that the engine is always up to temperature before pushing it to high revs. This advice is especially relevant for drivers using their McLaren on the track, where the engine is pushed to its limits. It's also essential to properly monitor the engine oil level. Since the procedure can be somewhat tricky, we will be publishing an article and a video on this topic in the coming days!
The McLaren 650S Spider we recently worked on required a delicate operation involving engine removal. Following this intervention, the engine is being shipped to Thorney Motorsport in the UK for a complete rebuild. This decision was made due to the complexity of the repair and Thorney Motorsport’s renowned expertise in rebuilding McLaren engines — particularly with the use of reinforced parts such as forged pistons and steel cylinder liners.
This will ensure optimal engine restoration while maximizing performance for both road and track use.
Conclusion
The McLaren 650S is an incredibly high-performance machine, but its maintenance—especially engine rebuilding—requires specialized expertise. Thanks to workshops like Thorney Motorsport, owners can not only address common issues but also optimize their vehicles for intensive use. By following simple tips, such as regularly checking oil levels and allowing the engine to warm up before high-performance driving, it is possible to avoid costly repairs while fully enjoying the exceptional driving experience that the McLaren 650S offers.