Factory maintenance schedule OEM · verified
Normal service, condensed from the factory interval matrix.
| Every 30,000 mi | Oxygen Sensor (replace) |
Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1988 635CSi.
The 1988 BMW 635CSi represents a mature-era entry in the model's production run, its engine carrying a 5.3-quart oil capacity and calling for 20W-50, 15W-50, or 10W-50 API SL viscosity grades that reflect the substantial powerplant BMW deployed in this platform. In the broader reliability history of the 635CSi, the 1988 model year stands as one of the cleanest on record, with just a single owner complaint logged — centered on the air bag system — and zero recalls ever issued. That near-spotless complaint volume and absence of recalls indicate that by this stage, BMW had largely sorted the model's mechanical and safety issues, making the 1988 a relatively low-risk data point for researchers examining the 635CSi lineage.
Fluid capacities, tune-up values and fuel economy at a glance.
0–60 mph, quarter-mile, horsepower and torque from independent road tests.
Independent road tests for the 635CSi of this era, listed by trim and engine — this page spans more than one engine, so no single horsepower figure is shown.
| Year | Trim / engine | 0–60 | ¼ mile | HP | Drivetrain |
|---|---|---|---|---|---|
| 1986 | Coupe 3.4L I-6 | 8.30 sec | 16.30 sec | 182 hp | RWD |
| 1985 | Coupe 3.4L I-6 | 8.20 sec | 16.00 sec | 182 hp | RWD |
Capacities, torques and tune-up values from the factory service manual.
This engine holds 5.3 qt of 20W-50 / 15W-50 / 10W-50 API SL engine oil, DOT 4 brake fluid.
| Brake Fluid | DOT 4 |
| Differential Gear Oil Capacity | 4 Pints |
| Engine Coolant | ETHYLENE GLYCOL |
| Engine Oil | 20W-50 · API · 15W-50 · 10W-50 · 5W-30 |
| Engine Oil Capacity | 5.3 qt |
| Power Steering Fluid | ATF |
Normal service, condensed from the factory interval matrix.
| Every 30,000 mi | Oxygen Sensor (replace) |
Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.
Owner complaints about the 1988 BMW 635CSi dominate in one area — the air bags, 1 of 1 reports (100%), well ahead of the next concern. NHTSA has issued no recalls for this vehicle, so these are owner-reported concerns only. 0 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the air bags pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.
All 1 complaints on record, top 1 components.
Source: NHTSA Office of Defects Investigation complaint database.
No recall campaigns on record with NHTSA for this vehicle as of the last data refresh.
Showing 1 of 1 bulletins on record with NHTSA.
| Bulletin | Date | Component | Summary |
|---|---|---|---|
| B510819 | 2024-01-16 | Electrical System | The basic conditions for initializing the power windows are not met. |
The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.
Decode factory build data for a specific vehicle by VIN.
Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.
Cross-vehicle references for the kinds of data on this page.
5.3 qt of 14 degrees F TO 122 degrees F: 20W-50 API SL OR GREATER, -4 degrees F TO 104 degrees F: 15W-50 API SL, -22 degrees F TO 68 degrees F: 10W-50 API SL OR GREATER, -40 degrees F TO 23 degrees F: 5W-30 API SL OR GREATER, per the factory manual.
NHTSA lists 0 recall campaign(s) for this model year. Check your specific vehicle by VIN.