2009 CHRYSLER 300 SRT8

Typical onset: 70,000-110,000 mi

Symptoms: Transmission fluid leaking at cooler lines or external cooler, Burnt ATF smell, fluid darkened significantly, Harsh shifts or delayed engagement when fluid runs low, Check engine light with trans temp codes

Fix: Replace transmission oil cooler and lines, flush system thoroughly. The cooler lines crack at crimps and the external cooler develops pinhole leaks. This is a 3-4 hour job if caught early, but if you've cooked the transmission from low fluid expect a full rebuild—add 12-16 hours labor for rebuild.

Estimated cost: $800-1,200 for cooler/lines only; $3,500-5,500 if rebuild required

Typical onset: 80,000-130,000 mi

Symptoms: Blue smoke on cold start that clears after warmup, Oil consumption 1 quart per 1,000-2,000 miles, Fouled spark plugs on certain cylinders, Carbon buildup on intake valves

Fix: Valve seals harden and crack on these Hemis. Proper fix requires heads-off, 10-14 hours labor depending on shop efficiency. Some try in-chassis seal replacement but results are hit-or-miss. Budget for valve cover gaskets, spark plugs, and PCV system refresh at same time.

Estimated cost: $2,200-3,800

Typical onset: 100,000-150,000 mi

Symptoms: Rattling noise on cold start for first 10-20 seconds, Chain slap sound from front of engine under acceleration, Check engine light with cam/crank correlation codes, Metal shavings in oil filter if guide has disintegrated

Fix: The plastic chain guides wear and tensioners lose pressure. If caught early with just noise, replace guides, tensioners, and chains—14-18 hours front-wheel-drive access is tight. If guides break and chain jumps timing, you're looking at bent valves and potential full engine rebuild. Do NOT ignore rattling.

Estimated cost: $2,800-4,200 preventive; $8,000-12,000 if internal damage occurs

Typical onset: 60,000-90,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Excessive driveline vibration at idle in gear, Visible separation or tearing of rubber mount, Transmission feels like it's moving excessively

Fix: The trans mount takes a beating from the Hemi's torque. Straightforward replacement, 1.5-2 hours on a lift. Do NOT use cheap aftermarket—OEM or quality polyurethane only. Inspect engine mounts at same time.

Estimated cost: $280-450

Typical onset: 90,000-140,000 mi

Symptoms: Coolant weeping or dripping from sides of engine block, Sweet coolant smell after driving, Slow coolant loss with no visible external leaks elsewhere, Rust staining on block behind motor mount area

Fix: Freeze plugs corrode from inside out, especially if coolant wasn't changed regularly. Rear plugs require transmission removal for access—that's 8-12 hours total. Front plugs are easier at 3-5 hours. If doing rears, smart to do clutch of transmission service while in there. Some shops quote all plugs preemptively to avoid comebacks.

Estimated cost: $600-1,200 for accessible plugs; $1,800-3,200 if trans must come out

Symptoms: Hesitation or stumble during hard acceleration, Loss of power above 4,500 RPM, Rough idle after spirited driving, Long crank time when hot

Fix: Not a common daily-driver issue, but SRT8s that see track days or aggressive driving accumulate fuel system debris faster. The in-tank filter and high-pressure filter both need service. In-tank requires pump removal, 2-3 hours. If the car's been run hard or on questionable fuel, do both filters and consider injector cleaning.

Estimated cost: $400-700