Reviving Your Honda CRX: The Engine Rebuild Guide

The Honda CRX, a compact sporting marvel, carved out a unique niche in automotive history with its nimble handling, impressive fuel economy, and surprising performance. From its debut in 1983, often hailed as the 'Civic Renaissance Experimental', it quickly became a favourite among enthusiasts in the UK and beyond. However, like any cherished vehicle, time and the relentless British road conditions can take their toll, particularly on the heart of the car: its engine. If your beloved CRX is showing signs of fatigue, such as hard starting, hesitant acceleration, or unusual engine noises, you might be considering a remanufactured or rebuilt engine. This article delves into what these options entail and why they could be the perfect solution to breathe new life into your CRX.

Understanding Remanufactured vs. Rebuilt Engines

When faced with an ailing engine, two common terms often emerge: 'remanufactured' and 'rebuilt'. While sometimes used interchangeably, there are distinct differences worth noting. A rebuilt engine typically involves disassembling the engine, cleaning its components, inspecting them, and replacing only the worn or damaged parts. This can include new piston rings, bearings, gaskets, and seals. The process often brings the engine back to functional specifications, but not necessarily to 'as new' condition.

A remanufactured engine, on the other hand, usually implies a more comprehensive process. It involves disassembling the engine completely, cleaning all parts thoroughly, and then machining or replacing components to meet original factory specifications. This often includes resurfacing the cylinder block, boring cylinders oversize, polishing the crankshaft, and installing all new wear parts such as pistons, rings, bearings, and valve train components. The aim is to return the engine to 'as new' or even better-than-new condition, often with updated components or design improvements. For example, a D16a6 block rebuild, as detailed by enthusiasts, involves meticulous steps:

• Complete disassembly and thorough cleaning of the cylinder block, often via 'hot tanking'.
• Deck resurfacing to ensure a perfectly flat mating surface for the cylinder head.
• Boring cylinders, perhaps 0.5mm over, to achieve precise dimensions (e.g., 75.5mm diameter) and create a fresh surface for new piston rings with a cross-hatch pattern.
• Polishing the crankshaft to ensure smooth operation and correct clearances.
• Installing new piston rings, carefully gapping them (e.g., between 0.006" and 0.014") and spacing them 180 degrees apart to prevent compression loss.
• Ensuring correct crankshaft end play (Standard: 0.004-0.014", Service Limit: 0.018") and connecting rod end play (Standard: 0.006-0.012", Service Limit: 0.016").
• Assembling the engine with new gaskets, seals, and critical components, ensuring proper lubrication with suitable fluids like WD-40 for cylinder walls during ring installation.

These processes are crucial for restoring engine performance and longevity, addressing common issues that arise from wear and tear. When considering a supplier, a company like 'Eric' with a 4.5 out of five-star rating on Trustpilot suggests a reputable service, but always look for detailed information on their specific rebuilding processes and warranty.

The Honda CRX Engine Line-up and Common Issues

The Honda CRX, despite its compact size, housed a range of capable engines throughout its production run. Initially, in 1983, it offered an economy version with a 1.3-litre CVCC engine and a sports variant featuring an aluminium 1.5-litre four-cylinder engine. By 1985, the economy model was replaced with an enhanced 1.5-litre engine, and the Si variant was introduced with a more powerful SOHC PGM-FI engine. The complete redesign in 1988 brought new engines, including the 16-valve 1493-cc D15B2 with dual-point fuel injection (DPFI), an eight-valve D15B6 for the HF model with multi-point fuel injection (MPFI), and a new 16-valve 1590-cc D16A6 for the Si, also with MPFI. The D16A6, for instance, delivered 105 hp, later increased to 108 hp in 1989.

Owners often report that around the 110,000-mile mark, CRX engines may begin to show signs of wear. These symptoms include:

• Hard starting or failure to start
• Hesitant acceleration
• Decreased fuel economy
• Visible white or grey oil smoke from the exhaust
• Unusual engine sounds (knocking, ticking, grinding)

Should these symptoms arise, it's prudent to check components like the oil filter, timing cover, rod bearings, and piston ring set. A remanufactured or rebuilt engine directly addresses these issues by replacing or refurbishing these critical components, offering a cost-effective alternative to a new engine, which might not even be available for these classic cars.

Aftermarket Parts and the Rebuild Process

Given that the Honda CRX ceased production in 1991 (replaced by the Honda del Sol, though many consider it a third generation), original equipment manufacturer (OEM) parts directly from Honda can be scarce for engine components. This is where the aftermarket industry becomes crucial. 'Aftermarket parts' are those not made by Honda but designed to fit and function in a CRX. The term 'CRX aftermarket parts' often refers to custom or performance parts, but it also encompasses replacement parts necessary for a rebuild. As experienced CRX owners like Christopher Hoffman note, finding OEM cylinder-head bolts, for example, can be challenging, making aftermarket solutions vital.

For carburetted CRX models, the complicated vacuum-line setup can be a challenge, and finding mechanics with the patience and knowledge to deal with them is key. Many cars might have Weber replacement carburetors, which, if properly set up with an automatic choke, can offer good drivability. For PGM-FI fuel injection systems, while generally reliable, finding injectors can be difficult. Cooling fan switches can also fail but are typically easy to diagnose and replace.

When rebuilding, it's paramount to ensure all clearances are checked and adhered to, and that components are installed correctly. For instance, pistons must be inserted with the "IN" stamp facing the intake manifold side, and rubber rod bolt boots should be used to prevent scratching cylinder walls during installation.

Beyond the Engine: Holistic CRX Maintenance

While the engine is paramount, CRX ownership involves addressing other common issues. Braking and suspension systems are frequently cited areas of concern. Owners have reported:

• Unusual brake pedal feel or strange braking sounds, often linked to a faulty brake drum.
• Suspension complaints like vibrations, poor handling, loose steering wheel, uneven tyre wear, and grinding noises while turning, commonly associated with the steering knuckle, ball joint, and coil spring insulator.

For suspension, stock-plus replacement struts and shocks are becoming harder to find, leading many to swap to coil-overs. Upper strut bearings/bushings are also scarce. Brake hardware is mostly available, but discs can be difficult to source, leading some to convert early drum-equipped CRXs to Acura Integra rear discs and hubs.

Rust is another typical issue, particularly in wheel arches and sunroof drains. The innovative HP-Alloy plastic panels (front fenders, mask between headlights and hood, side cladding) can become brittle over time, leading to cracks, though carbon fibre reproductions are available. Sunroof leaks from clogged drain tubes and hatchback gasket compression or misalignment can also lead to water entry and rust.

Interior-wise, early 1984 and 1985 door panels can wrinkle, while later moulded panels tend to hold up better. Dashes generally endure well, but poorly installed sound systems over the years can cause electrical issues.

Why Invest in a CRX Engine Rebuild?

The Honda CRX holds a unique status as a sought-after classic. Its small size, affordability, fun-to-drive nature, and inherent durability have cemented its place in automotive lore. Despite being discontinued, its popularity endures, leading to an increasing appreciation in the collector market. According to valuation experts, CRX values have seen an upward trend, making a quality engine rebuild a sound investment. For instance, a #2-condition first-generation CRX can fetch around £17,000, while second-generation models in similar condition command £18,000 to £19,500. The Si variants, especially clean, unmodified examples, are particularly prized.

This rising valuation, coupled with the car's enduring appeal, means that restoring your CRX's engine isn't just about keeping it on the road; it's about preserving a piece of automotive history and potentially enhancing its market value. Furthermore, a well-rebuilt engine ensures that the CRX retains its characteristic 'Economy Fast' ethos, a blend of efficiency and spirited driving that made it so unique.

Choosing a Rebuilder and Pre-Purchase Inspection

While a Trustpilot rating like 'Eric's' 4.5 stars is a good indicator, due diligence is key when selecting a rebuilder. Look for workshops with specific experience in Honda engines, particularly the D-series. Inquire about their rebuilding process, the quality of parts they use (OEM or reputable aftermarket), and their warranty policy. A comprehensive warranty on parts and labour provides peace of mind.

If you're considering purchasing a CRX with a rebuilt engine, or one that needs one, a thorough pre-purchase inspection by a trusted mechanic is crucial. As Christopher Hoffman advises, look for cars with the fewest modifications possible, as 'amateur swaps are common'. He also stresses the importance of obtaining a factory service manual and an electrical troubleshooting manual supplement, as Honda's engineers often knew best. These resources are invaluable for understanding the car's original specifications and for guiding any future maintenance or repairs.

Frequently Asked Questions About Honda CRX Engines

In conclusion, the enduring allure of the Honda CRX is undeniable. While its engines, like any mechanical component, eventually succumb to wear, the option of a high-quality remanufactured or rebuilt engine offers a fantastic pathway to extending the life of these iconic vehicles. By understanding the process, choosing reputable suppliers, and committing to ongoing maintenance, you can ensure your Honda CRX continues to deliver the spirited, economical driving experience it was famed for, keeping its legacy alive on the roads of the UK for many more years.

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