QuestionWhen I start my 97' Nissan pickup (2.4 cyl) in the morning while the engine is cold, it makes a rattle noise for 3-5 seconds and then stops. It never makes this noise any other time except in the morning. Do you have any idea what might be causing this noise? Could it be the timing chain?
AnswerHi Jeff,
That's just one of those things with that engine. That's dry internal engine parts quieting down after engine oil pressure comes up. I found this on your truck that might be of interest:
Classification:
EM99-002
Reference:
NTB99-058
Date:
September 13, 1999
ENGINE RATTLE NOISE AT IDLE (WARM ENGINE)
APPLIED VEHICLE:
1990-97 Truck (D21)
APPLIED ENGINE:
KA24E
SERVICE INFORMATION
If the engine of a 1990-97 Truck exhibits a rattle noise, similar to the sound of a diesel engine, when the engine is idling at full operating temperature, the cause may be excessive clearance between the piston pin and the piston.
This rattle noise can be increased by temporarily blocking the exhaust pipe to increase back pressure.
CAUTION: Do not block the exhaust pipe for more than 3 seconds.
NOTE: This rattle noise is not present when the engine is cold or is run above idle speed, and cannot be isolated to one particular cylinder.
Use the following service procedure to resolve the incident noise, if it should occur.
SERVICE PROCEDURE
1. Confirm the rattle noise exists with the engine at idle and at full operating temperature.
NOTE: Do not confirm the rattle noise with the engine cold or with the engine running above idle speed.
A. If the rattle noise exists, proceed with step two.
B. If the rattle noise does not exist, look for other causes of the noise.
2. Install a set of four new pistons, connecting rods and connecting rod bearings (see the Parts Information table for the component part numbers). Refer to the EM section of the applicable service manual for the removal and installation procedure of the subject components.
NOTE: Pay close attention to the "Important Points" listed below when installing the subject components.
Important Points
^ Use the piston grade numbers to order the correct pistons. The piston grade numbers are located on the cylinder block deck and on the top of the pistons (see Figure 1).
^Use the crank pin grade numbers to order the correct connecting rod bearings. The crank pin grade numbers are located on the front counterweight of the crankshaft (see Figure 2).
^ Make sure the piston rings are properly installed on each piston and the piston ring end gaps are positioned correctly (see Figure 3).
NOTE: If the piston ring does not have a punch mark on it, the ring can be installed with either side up.
^ Make sure the oil holes are aligned when installing the bearings in the connecting rods (see Figure 4).
^ Inspect the cylinder walls and if necessary, use a ball hone (Kent-Moore P/N 319-BRMGBD3-1/2) to apply a cross hatch pattern to each cylinder for proper piston ring sealing. Follow the ball hone manufacture's recommendations, or if not available, apply a small amount of motor oil to the ball hone and work the hone up and down for approximately 30 seconds per cylinder.
CAUTION: Before using the hone, cover the crank pin with a clean rag to protect it from abrasive debris. After honing is complete, clean each cylinder with solvent to remove all abrasive debris from the engine.
^ Make sure the piston pin clips are securely installed into the grooves of the piston pin bore.
PARTS INFORMATION
CLAIMS INFORMATION
If the vehicle is in warranty, submit a Primary Failed Part (PP) line using the claims coding as shown.
The figures they are referring to I can't sent in this medium.
