Filed Under (Chevrolet) by admin on 15-04-2011
Subject: Models: EI10035 — Engineering Information –Front Suspension Noise, Clunk, Popping, Rattle 2010 Chevrolet Camaro Condition Important: If the customer did not bring their vehicle in for this concern, DO NOT proceed with this PI. Some customers may comment on a noise coming from the front suspension. Description of the noise can include suspension clunk, popping or rattle. Upon further inspection, the noise can be generally traced to the front strut assembly. Strut assembly components, including struts and top mounts, returned under warranty have been tested with no trouble found. Cause GM Engineering is attempting to determine the root cause of the condition above. Engineering has a need to gather information on vehicles PRIOR to repair that may exhibit this condition. As a result, this information will be used to “root cause” the customer’s concern and develop/validate a field fix.
Filed Under (Jeep) by admin on 03-10-2010
may experience an incident of engine misfire during certain vehicle operating conditions. The misfire may occur when the vehicle is operated between 80 – 112 KPH (50 – 70 MPH) and under light loading conditions, e.g. slight uphill road grades. This condition may occur at all ambient conditions, but is more noticeable when ambient conditions are less than 0°C (32°F). If the vehicle is equipped with On-Board Diagnostic (OBD), a MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 – Multiple Cylinder Misfire. Various single cylinder misfire DTC’s may also be present. If the frequency of misfire is high the Powertrain Control Module (PCM) may place the engine in “Limp-In” mode. The misfire condition may be caused by one or more engine exhaust valves that are slow to close. Late closure of an exhaust valve may be the result of no valve rotation and associated build up of carbon on the exhaust valve stem. This condition may occur when the engine is not allowed to run at engine RPM’s that are greater than 3,200 RPM. At 3,200 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM’s and high carbon deposits are associated with short trip driving where the vehicle engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and add to the opportunity of carbon deposit build-up on the stem of the engine exhaust valve. Verify that an engine misfire condition is present. Use of the DRBIII(R) during a road test, or a Co-Pilot data recording, may help to determine engine misfire and misfire counts. If carbon deposit accumulation is severe, then a cylinder leak down test may detect one or more cylinders leaking greater than 15%. Save any misfire DTC Freeze Frame Data that was stored for later misfire correction verification. Verify that the engine misfire condition is not caused by faulty engine mechanical or electrical components. If the engine mechanical and electrical systems are operating properly perform
Filed Under (Chevrolet) by admin on 18-09-2010
Exhaust System Installation 1. Place removed OE exhaust system on the ground and using this as a reference, arrange components of new exhaust (figure 6). 2. Place a clamp over the expanded end of the R/H Front Pipe and fit on right-side exhaust. Place a clamp over end of X-Pipe Assembly and fit into R/H Front Pipe (figure 7) . Verify orientation of X-Pipe Assembly with curvature as shown (figure 8). Do Not tighten the clamps. Repeat for L/H Front Pipe. 3. Place a clamp over the expanded end of R/H Intermediate Pipe Assem- bly and set it into position as shown in figure 6 making sure to install the hangers into the rubber isolators. Do Not tighten the clamp. Repeat for L/H Intermediate Pipe Assembly. 4. Install OE crossbrace support using original hardware. (figure 9) 5. Assemble R/H Rear Muffler Assembly making sure to install the han- gars into the rubber isolators (figure 10) and at mufflers. Repeat for the L/H Rear Muffler Assembly. Check your exhaust system for proper clearance under the vehicle and also for tip alignment. (figure 11) 4. Once position has been determined to be correct, tighten the Ac- cuseal™ clamp to 32-35 ft. lbs. making sure the clamps openings are not over any of the notches in the pipes. Tighten the flange hardware to 18-22 ft. lbs. 5. Before starting your vehicle, make sure to check all wires, hoses, brake lines, body parts and tires for safe clearance from the exhaust system. 6. Start vehicle and check for any leaks. If any leaks are found, determine cause (such as loose hardware or incorrectly positioned clamp) and re- pair as necessary.
Filed Under (Chrysler) by admin on 12-11-2010
OVERVIEW: This bulletin involves rotating all engine exhaust valves, replacing the valve spring retainer locks with a new design to increase valve rotation at lower RPM, inspecting/replacing the MAP sensor (as necessary), and decarbonizing the combustion chamber. MODELS: 2004 – 2006 2005 – 2006 (CS) (LX) Pacifica Chrysler 300/Magnum/Charger SYMPTOM/CONDITION: The customer may experience occasional engine misfire (rough running engine) during certain vehicle operating conditions. In addition, MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 – Multiple Cylinder Misfire. Various single cylinder misfire DTC’s may also be present. If the frequency of misfire is high, the Powertrain Control Module (PCM) may place the engine in “Limp-In” mode. The misfire condition may be caused by one or more engine exhaust valves that are slow to close due to a build up of carbon on the valve stem. DIAGNOSIS: 1. This condition may occur when the engine is not allowed to run at engine RPM’s that are greater than 3,500 RPM. At 5,000 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM’s and high carbon deposits are associated with short trip driving where the engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and increase the likelihood of carbon deposit build-up on the stem of the engine exhaust valve. Fuel detergent quality may also contribute to the condition; the customer may want to try a different brand of fuel. 2. Verify that the engine misfire condition is not caused by faulty engine mechanical or electrical components. 3. If the engine mechanical and electrical systems are operating properly perform the Repair Procedure.
Filed Under (Honda) by admin on 25-12-2010
Customer Concern: Tests/Procedures: Potential Causes: Tech Tips: Has a misfire on start up only. Sets cylinder #1 misfire code P0301 and cylinder #4 misfire code P0304. Sets pending misfire code P1399 as well. The problem only lasts a few seconds. Suspecting headgasket since the coolant level is low and smells anti-freeze when the engine is started. 1. Check for evidence of anti-freeze on the spark plugs or in the cylinders. Pressure test the cooling system and check for anti-freeze going into the cylinders. 2. If not anti-freeze, check fuel pressure and see if it holds in case a fuel injector is leaking down. 3. If pulling the cylinder head to replace the headgasket, have the cylinder head sent out and checked for cracks. Cylinder Head Cylinder Head Gasket Fuel Injectors Cylinder head was cracked. Other causes of a misfire like spark plug wires and incorrect valve adjustment are common but those wouldn’t likely be a misfire for just a few seconds on cold start up.