Is there a maximum speed for high 4x4 on the 2008 f-150 supercrew?

Call it 80 miles per hour with a strong tailwind.

Cars of that era/engine size were all 'wheezy and asthmatic' once they got to 60mph and to be perfectly honest, they weren't designed for high speed motoring.

Google is your friend in such cases. I have done two for you, you can do the rest :>)

Google
maximum speed renault 16, 54 hp 1965

Can you replicate this in the workshop by raising the engine revs with the pressure gauges attached to he high and low sides? What is the maximum high pressure you see before the system shuts off?

Hi M, Please describe in more detail what problem you are experiencing. Vibration is not correct at any speed. The gears can be changed at more or less any speed, as long as the engine maximum RPM is not exceeded and at slow speeds the engine does not labour by selecting too high a gear. Regards John

blower motor resistor.

U could try turning if on high and smacking the fan with a rubber hammer under the passenger side dash, if no go, try checking for power and ground at the fan motor, if you have no power to the fan check for power at the fan speed resistor, then finally check for power out of the switch, always check all your fuses prior to troubleshooting electrical problems , it will most likely be a bad fan motor, then the switch, then the fan speed resistor please rate

The noise is caused by the engine running on after the ignition is shut off. It makes noise because the pistons are rattling in the cylinders from incorrect timing. This has nothing to do with the mechanical or electronic timing of the engine. The engine runs on either because of hot glowing carbon deposits in the cylinder head or because the engine was shut down when it was running too fast. Sometimes the carbon can be literally blown out by running the engine at high rpm for a short time. Put it in second gear and run it for a couple of miles on the highway. If this does not work the heads will have to be removed and the carbon cleaned out manually. The shut down when running too fast problem can be caused by the idle being set too high or by shutting the engine off before it has reached idle speed. If you can adjust the idle speed try reducing it. If not always hesitate before shutting the engine down to let it reach idle speed. Good Luck!

Item Part Number Description 1 — Tachometer 2 — LH turn indicator 3 — Oil pressure gauge 4 — Overdrive (O/D) off/tow haul indicator 5 — Engine temperature gauge 6 — Air bag warning indicator 7 — Safety belt warning indicator 8 — Fuel gauge 9 — Tire Pressure Monitoring System (TPMS) warning indicator 10 — Speed control indicator 11 — Transmission temperature gauge 12 — RH turn indicator 13 — Speedometer 14 — Malfunction Indicator Lamp (MIL) 15 — Message center indicator display area 16 — High beam indicator 17 — ABS warning indicator 18 — Brake warning indicator 19 — Message center display area 20 — Anti-theft indicator

that sounds like the blower motor resistor. on high it bypasses the resistor for maximum speed. but on low or medium speeds, the resistor slows down the blower motor. when the resistor goes out, the blower motor will only work on high. it is an inexpensive part and easy to replace. it should be located on the black box under the dash on the passenger side. there might be a plastic cover over it, but it will have a 3 or 4 wire connector plugged into it