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Leveled F-150
I have had my '93 Ford F-150 4x4 since it was new, and there is one thing about it that still bugs me: The frontend is lower than the rearend, giving the truck a nose-down rake. I'd like to install 32-inch-tall tires on 15x8-inch rims and raise the frontend up a few inches, but I'm unsure of which suspension kit would be best for my type of driving, which is mainly on the street, except for weekend outings to the local trails near my home. Can you offer any suggestions?Ryan FitzgeraldAlto, Texas
Sure, we can offer a suggestion, Ryan. Tuff Country manufactures two excellent lift kits for '81-'96 F-150s: the EZ Ride and the Heavy-Duty. Either kit will lift your F-series 2-1/2 inches in front through the use of radius arm drop brackets, which produce improved wheel travel and ensure that proper frontend alignment and geometry are maintained. The difference between the two systems is in the coil springs: The EZ Ride setup uses your Ford's OE coils, which deliver a smooth ride; the more-expensive Heavy-Duty kit includes replacement coils that are stiffer than stock, producing a taut ride and the capacity to carry a heavy winch without sagging. Both kits can be ordered with or without a rear 2-inch lift add-a-leaf. For more information, contact: Tuff Country Suspension, Dept. OR, 4165 W. 8270 S., Salt Lake City, UT 84088, (800) 288-2190, www.tuffcountry.com.
Inline Power Parts
I was wondering if there are any performance parts that I can buy for a 235ci inline-six engine. I know you may be wondering why anyone would want to build a high-performance straight-six; it's because there aren't many out there. I have the block waiting for a complete overhaul, but I can't find any performance parts. I would appreciate any help you can give me.Tom BrookshireSan Diego, California
Tom, we don't think the idea of a performance-oriented I-6 is strange. In fact, we've driven more than a few of those old 235s that were downright impressive. Once properly rebuilt, those I-6 engines are smooth runners with gobs of low-speed torque, which is precisely what the General had in mind when they were designed.
As to power parts for GM's I-6, check with Clifford Inline Performance Parts. Clifford builds an impressive array of performance I-6 components, including a Ram-Flow intake manifold - which can be used with a two-barrel or a four-barrel Holley carb - a set of headers for inline Bow Tie engines, camshafts for the 235 powerplant, and two induction systems that are as trick as anything we've seen. A sidedraft intake manifold breathes through a trio of Weber twin-throat carbs, and a multiport fuel-injection system uses an OE GM computer, airflow sensor, and injectors, and includes a complete wiring harness, a fuel pump, and installation hardware. For more information, contact: Clifford Performance, Dept. OR, 2330 Pomona-Rincon Rd., Corona, CA 91720, (909) 734-3310, www.cliffordperformance.com.
I Hear You Knocking
I recently purchased a '94 Jeep Wrangler that has very low miles (30,000), is in excellent overall condition, and appears to have been regularly maintained. There is only one problem: When the 4.0L inline-six engine is idling, I can hear a slight knocking noise. As soon as the engine is revved, the noise goes away. I've changed the oil and the filter, and the oil pressure gauge reads normal. Is this noise typical for these engines, or is there a problem? If so, what's the fix? Conrad GarrettPhoenix, Arizona
We remember that particular engine's at-idle knocking, Conrad. The folks at then-Chrysler knew about it too and issued a service bulletin detailing the problem. The noise is generated by piston slap, or the pistons rocking within the cylinders. The problem is caused by either incorrect cylinder bore diameter or by the coating flaking off of pistons designed with negatively tapered skirts. The fix isn't quick or simple; it involves a complete teardown of the engine. Chrysler stocks redesigned pistons and connecting rods - in seven different cylinder bore sizes - which, once installed, will solve the knocking problem. Check with the service manager of your local DaimlerChrysler/Jeep dealer; the factory may pick up all or a large portion of the repair cost.
Diagnostic Details
I have a question about on-board engine computers, but I can't seem to get a straight answer. What is meant by the computer's self-diagnosis mode?Jack WagnerReno, Nevada
Basically, when a engine's computer enters its self-diagnosis mode, it checks the operational condition of various sensors and circuits, then displays (on a code-reading tool) types of codes (numbers), which indicate the source or nature of a component's problem. There are two types of self-diagnostic tests: engine off and engine running. The engine-running test checks the operational status of the engine's sensors, the wiring harness, and the computer's basic functions after the engine reaches its operational temperature. The engine-off tests check the same components, but are performed with the ignition in the on position and without the engine running.