Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/86539
RAM TOUGH If you are thinking of buying an older model Dodge Ram to add to your fl eet, these tips will help make that used purchase a solid one By G.R. Whale than old ones. The #4 injector isolator/hold-down bracket often wears a pin-hole leak in the line, yielding poor performance and a messy engine bay. TSB 14-004-11 details a Mopar fuel fi ltration kit, including fuel tank vents hoses, that costs about the same as one injector. 6.7 ISB Introduced to Dodge trucks in oil fi ller breather relocation kit useful (it loses lots of oil on steep descents) or the cold-idle refl ash that raises idle speed and drops three cylinders to build heat in sub-freezing ambient, < 140 de- grees F coolant, temperatures. 5.9ISB HPCR DIESEL In 2003 the Cummins added common-rail (CR) fuel injection, a system with plenty of benefi ts but one that demands clean fuel. Early engines with CR had the same TPS/APPS as '98-02 and lift pump issues, especially those mounted to the fi lter housing, and the 2003 trucks suff ered from corrosion at the PCM. A fuel transfer pump failure won't damage expensive parts in CR engines but it might not start either. In 2005 the pump was moved into the tank, and Dodge no longer sells 03-04.5 units, they use a retrofi t kit to 2005 style. As Patton notes, moving a potential wear item to a harder- to-service location is counterin- tuitive, and the aftermarket off ers better replacements. Many of these stock-style pumps will sup- port up to about 100hp increases. Though it has many sensors, say our experts, following proper starting procedures often cures phantom "problems. " Surging complaints typically indicate a bad fuel-control actua- tor; they've been known to fail. Less common, and occasion- ally overlooked, is a bad cascade overfl ow valve on the CP3 pro- ducing hard or no starts. Some techs recommend a lubricity additive for corrosion resistance. Redmond also fi nds some '04 diesels drop a valve seat insert (usually cylinder #4 or 5). Be sure to check service records to see if the truck you are buying has had these types of repairs. CR injectors fi re multiple times per cycle, at pressures beyond 20,000 psi, so they wear faster 2006, the 6.7-liter ISB, derived from the 5.9L, met 2010 emis- sions requirements and had an exhaust brake built-in. Many of the early "problems" revolved around lugging the engine: sooted turbos, EGRs and DPFs, and plugged NOx cats. All issues attributable to not working the engine hard enough. The variable geometry turbo has an electric motor to move vanes for better throttle response, boost and 150 braking horsepower. But excess soot could limit vane movement, impairing all those performance factors. So be aware of the soot issue when shopping for that used model. Software re-fl ashes solved sooting issues so be sure they're up to date. (In Redmond's ex- perience, emissions equipment problems were far fewer than Ford and GM diesels.) He does note, however, that "early 6.7s have a fairly rough cylinder head deck fi nish which sometimes leads to mysterious coolant loss, with combustion pressure seeping into the cooling jacket and misting out from the coolant recovery reservoir. " Scheduled maintenance is criti- cal to the 6.7s operation. Replace- ment injectors should be matched to the ECM, the EGR should be cleaned every 67,500 miles and fuel fi lter changes done every 15,000 miles or less are required. Our experts also suggest cleaning the DPF at 100,000 miles by washing and/or blowing com- pressed air backwards through it. GEARBOXES Automatic transmissions operated Scheduled maintenance is critical to the 6.7s operation. Replacement injectors should be matched to the ECM and the EGR should be cleaned every 67,500 miles. at OEM power and weight limits rarely fail. But pushing past those limits causes big issues. That's why there's a big aftermarket for strengthening them to hold up to the power generated by a tune. Leaks in trans fl uid cooler lines are not uncommon, especially since they usually hide behind propickupmag.com PROPICKUP 59