The Most Common 2008 BMW 750Li Problems Owners Should Look Out For

The BMW 7 Series is the pinnacle of the BMW luxury sedan lineup. With smooth handling, powerful engine options, and next-level tech features, these flagship sedans represent the best BMW has to offer. The long-wheelbase 750Li provides even more rear legroom for stretching out in ultimate comfort.

The 2008 BMW 750Li in particular was well-received when new. Reviewers praised its responsive handling and smooth ride quality. The powerful 4.8L V8 engine and 6-speed automatic transmission deliveredswift acceleration. Interior luxury appointments like 16-way power leather seats with heat, ventilation and massage made every drive sublime.

However, as a used luxury sedan approaching 15 years old, the 2008 BMW 750Li has developed some problematic areas that owners should look out for. What are the most common mechanical and electrical problems with the 2008 BMW 750Li that owners should watch out for?

Engine oil leaks, faulty fuel pumps, failing alternators, glitchy iDrive electronics, and sagging air suspension are among the top issues with the 2008 BMW 750Li. Repair costs for such problems can run in the thousands.

This article will cover the most widespread 2008 BMW 750Li problems from each part of the car – engine, transmission, electronics, suspension, and interior features. We’ll also look at any recalls and provide tips to prolong the life of your 750Li. Let’s dive in.

5 Common Engine & Transmission Problems

The BMW 750Li comes standard with a powerful 4.8L V8 engine, though a 6.0L V12 was optional. Paired to a responsive 6-speed automatic transmission, these powertrains deliver smooth and effortless acceleration. However, some problematic areas have emerged:

Oil Leaks

The 4.8L V8 is prone to oil leaks from the valve cover gasket, oil filter housing gasket, and front crankshaft seal. Oil leaks are unsightly and can drip onto hot exhaust components, causing burning oil smells.
Repair costs for valve cover gasket and oil filter housing gasket leaks run $500-$900 in parts and labor. The crankshaft seal can cost up to $1500 if the timing case needs to be removed.
Watch for oil drips under the car and burning oil smells. Catch leaks early before oil gets on belts and pulleys.

Timing Chain Guide Failure

The timing chain guides are plastic parts that can wear and eventually break, causing a rattling noise from the timing chain.
Replacing the worn timing chain guides can cost $1200-$2000 in parts and labor. The job requires removing part of the engine.
Listen for rattling noises on cold startup that last more than a few seconds. This indicates worn guides.

Faulty High Pressure Fuel Pump

Models with the 4.8L V8 suffered from issues with the high pressure fuel pump failing prematurely. This causes no start conditions.
Replacing the high pressure fuel pump runs around $900-$1200 in parts and labor costs.
Listen for abnormal buzzing or whining noises from the fuel pump area indicating potential failure.

Transmission Slipping

The 6-speed automatic transmission may eventually suffer slippage and harsh shifts, especially when cold.
A transmission service with fluid change can help, but a rebuild or replacement may be needed, ranging from $2500 – $4000.
Test for slipping by accelerating through gears. Rough and delayed shifts also indicate wear.

Whining Differential/Transfer Case

Some 750Li owners report a persistent whining noise coming from the rear differential or transfer case.
Replacing bearings and seals in the differential or transfer case to fix whining issues costs $600-$1000 in parts and labor.
Have whining noises coming from the rear of the vehicle inspected promptly.

Electrical System Issues

Like most modern luxury cars, the 2008 BMW 750Li is packed with electrical components that can sometimes cause annoyances:

Alternator Failures

The alternator charges the battery, but is prone to premature failure on the 2008 750Li.
Replacement alternator costs are $800-$1000 for parts and labor.
Signs include battery warning lights, dimming headlights, and eventually the car not starting.

Problematic iDrive Electronics

BMW’s iDrive system controls navigation, entertainment and car settings on a central knob and screen. But it’s plagued by glitches and freezing.
Out-of-warranty iDrive repair costs often exceed $1000. Complete replacements can run even higher.
Try resetting the system. If issues persist, BMW dealer diagnosis is needed.

Faulty Sensors

Various engine management sensors can malfunction and trigger dashboard warning lights. Oxygen sensors, crankshaft sensors and camshaft sensors are prone to failure.
Replacing most sensors runs $150-$350 in parts plus 1-2 hours of labor per sensor.
Diagnose faulty sensors promptly to prevent bigger issues.

Battery Drainage

Parasitic drains from failing electronics can drain the battery when the car sits for a while.
Diagnosing and fixing parasitic drains costs $150-$300 in labor at a shop.
Consider a battery tender/trickle charger if the car sits for long periods.

Suspension & Steering Concerns

The BMW 750Li comes standard with an adaptive air suspension system. This provides a smooth ride, but some common problems have surfaced:

Sagging/Leaking Air Suspension

Failing air struts and air suspension components lead to a sagging rear end and bumpy ride.
Replacing leaking air struts costs $450 each, plus $800 or more to fix other air suspension parts.
Watch for sagging rear suspension and listen for leaking air sounds.

Steering Column Noise

A knock/clunk when turning the wheel indicates a failing upper steering column joint.
The steering column upper joint costs $350-$500 to replace in parts and labor.
Diagnose steering noises early before more extensive damage occurs.

Excessive Tire Wear

Worn suspension and alignment issues causes premature inner tire wear. This is common on 2008 750Li models.
Front tires can need replacement every 15,000-20,000 miles at a cost of $300-400 per pair installed.
Inspect alignment and suspension components if tire wear seems excessive.

Recalls & Tips for Longevity

Avoiding common 2008 BMW 750Li problems comes down to staying on top of maintenance and addressing issues promptly. Here are some final tips:

Takata Airbag Recall

Older BMW models are part of the Takata airbag recall due to risks of airbag inflators rupturing.
Airbag replacements are free at BMW dealers based on your car’s VIN. Check the active recalls and schedule service immediately.

Oil Changes

Stick to 7,500-10,000 mile oil change intervals with full synthetic oil. This keeps the V8 lubricated.
Use OEM or Mann filters. Avoid cheap generics that can cause problems.

Fluid Flushes

Change brake fluid, power steering fluid, and transmission fluid every 50,000 miles or 4-5 years to maintain smooth operation.
Fluid flushes run $150-$250 each at independent shops. Worth the preventative maintenance.

Suspension Maintenance

Inspect bushings, ball joints, tie rods ends and other chassis parts while under for oil changes. Replace if worn.
Have wheel alignments done periodically to maximize tire life and prevent uneven wear.

The 2008 BMW 750Li remains an excellent used luxury sedan with its supple ride, powerful engine, and modern features. But like any aging luxury vehicle, it requires diligent maintenance and attention to detail to avoid expensive repairs. Watch for leaks, listen for noises, and don’t ignore any warning signs. Address issues promptly and keep up on services to maximize longevity. With care, your 2008 750Li can cruise for many more years in high style.