Engine Adjustments Mercury Grand Marquis III

ENGINE MECHANICAL

Note. Information for Escort also applies to ZX2, unless otherwise indicated.

Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

VALVE CLEARANCE

Note. All models except Taurus 3.4L are equipped with hydraulic valve lifters; valve adjustment is not required. If valves are noisy or incorrect clearance is suspected, components are worn. Check collapsed valve lifter clearance. See appropriate article in ENGINES in the appropriate manual.

3.4L ENGINE

1. Remove engine cover. To remove right valve cover, remove right side of cowl vent screen. Disconnect vacuum hose from EGR valve. Remove EGR pipe from bottom of EGR valve.
2. Remove power steering pressure hose. Remove 2 intake manifold supports. Remove front and rear intake manifold surge tank stays. Disconnect necessary vacuum and fuel vapor management hoses to remove intake manifold surge tank. Loosen intake air connector hose clamps and remove surge tank from intake manifold assembly. Remove ignition coils from right cylinder head. Remove bolts and right valve cover.
3. To remove left valve cover, disconnect harness connector from Intake Manifold Runner Control (IMRC) deactivation motor. Remove IMRC deactivation motor from left valve cover. Remove ignition coils from left cylinder head.
4. Remove radiator air deflector. Disconnect and position aside engine control sensor wiring as necessary to access left valve cover. Remove bolts and left valve cover.
5. Rotate crankshaft in normal direction of rotation until camshaft lobe is directed 90 degrees or more away from valve tappet. Insert feeler gauge between camshaft and tappet. (Scheme 1)
6. Ensure clearance is within specification. See «VALVE CLEARANCE SPECIFICATION (3.4L)»(/mercury/grand-marquis/iii-1997-2002/remont/adjustments/#engine-adjustments) table. If clearance is not within specification, remove and replace shim with correct thickness shim. VALVE CLEARANCE SPECIFICATION (3.4L) (1) Application In. (mm) Intake.006-.010 (0.15-0.25) Exhaust.010-.014 (0.25-0.35) (1) Clearance is checked with engine cold.
7. To remove shim, insert lifter compressor (T89P-6500-A) between camshaft and tappet. (Scheme 1) Rotate lifter compressor to compress valve spring. Insert lifter holder (T96P-6500-AH) between camshaft and tappet bucket.
8. Remove shim by blowing compressed air through hole in tappet shim. Install shim of correct thickness with number facing downward. Remove lifter holder. Recheck clearance. Rotate crankshaft and repeat procedure for all valves as necessary.
9. To install valve covers, replace any damaged valve cover gasket(s). Apply silicone gasket sealant at 4 places on each cylinder head (valve cover sealing surface) where front cover and camshaft seal retainers align. Install valve covers and tighten to 71-106 INCH lbs. (8-12 N.m.). To complete installation, reverse removal procedure.

Scheme 1

IGNITION TIMING

Note. On all models with distributorless electronic ignition, manufacturer does not recommend checking ignition timing, as faulty readings are common and timing is not adjustable. Timing specification given is for reference purposes only.

IGNITION TIMING

IDLE SPEED

Note. Idle speed is controlled by Powertrain Control Module (PCM) and is not adjustable. Idle speed specifications are for reference only. If engine idle concerns are present, check for contaminated fuel, vacuum leaks and incorrect ignition timing. Ensure throttle bore, EGR system and PCV system are clean. If these are okay, check PCM for Diagnostic Trouble Codes (DTCs). See SELF-DIAGNOSTICS - EEC-V article. If no DTCs exist, go to TROUBLE SHOOTING - NO CODES - EEC-V article.

IDLE RPM SPECIFICATION (1)

THROTTLE POSITION (TP) SENSOR

TP sensor is not adjustable. If testing is necessary, see SELF-DIAGNOSTICS - EEC-V article.

See also:
• VALVE CLEARANCE SPECIFICATION (3.4L)