Daytona Shelby V6-181 3.0L SOHC (1991)
Hydraulic Lash Adjuster: Technical Service Bulletins
Engine Valve Lash Adjuster - Bleeding Procedure
NO.: 09-06-91
GROUP:
ENGINE
DATE:
Nov. 18, 1991
SUBJECT:
Tappet/Lash Adjuster Noise - Testing/Bleeding Procedure - Vehicles With MMC Engines
NOTE:
THIS BULLETIN ONLY APPLIES TO VEHICLES EQUIPPED WITH THE FOLLOWING MMC
ENGINES:
1.8L, 2.0L, 2.4L AND 3.0L WITH AUTOMATIC LASH ADJUSTERS
MODELS:
1992
(B8)
VISTA (2.4L SOHC)
1991-92
(AA)
ACCLAIM/SPIRIT/LE BARON SEDAN (3.0L SOHC)
(AC)
DYNASTY/NEW YORKER SALON (3.0L SOHC)
(AG)
DAYTONA (3.0L SOHC)
(AJ)
LE BARON COUPE/LE BARON CONVERTIBLE (3.0L SOHC)
(AS)
CARAVAN/CARAVAN C/V/VOYAGER (3.0L SOHC)
(B4)
RAM 50/POWER RAM 50 (2.4L SOHC, 3.0L SOHC)
(BD)
LASER (1.8L SOHC, 2.0L DOHC)
(B7)
STEALTH (3.0L SOHC, 3.0L DOHC)
1991
(AQ)
CHRYSLER'S TC (MASERATI COUPE) (3.0L SOHC)
(B3)
VISTA (2.0 SOHC)
DISCUSSION:
When diagnosing a customer complaint of Automatic Lash Adjuster (Tappet) noise, the following diagnostic test procedure should be used to determine
which lash adjuster is defective. Recent analysis of returned lash adjusters show a high number of good parts being replaced. Using the following Air
Bleeding/Testing procedure will assure only defective lash adjusters are being replaced.
Before replacing noisy Lash Adjusters (Tappets) the following items must be checked:
Verify the condition of the engine oil, and the oil level. Deteriorated engine oil will increase the chance of air being trapped in the lash adjuster.
Overfilled engine oil will increase the amount of air trapped in the lash adjuster. Change the oil and/or correct the oil level as required.
REPAIR PROCEDURE:
This procedure involves bleeding the air from the lash adjusters, and determining which adjuster is bleeding down.
1. With the engine fully warmed up, verify the lash adjuster(s) are still making noise.
2. Gradually raise the engine speed in small increments up to 3000 RPM and hold for 30 seconds, then slowly allow the engine speed to decrease to idle
in small increments taking approximately 30 seconds.
3. Repeat step 2 several times (not more than 10 times) and confirm whether the noise is still present.
4. If the noise is still present, remove the valve cover.
5. Check each lash adjuster by pushing on the rocker arm directly above the lash adjuster.
NOTE:
THE ROCKER ARM MUST BE ON THE BASE CIRCLE OF THE CAMSHAFT, NOT ON THE LIFT OR TRAILING SIDE OF THE
CAMSHAFT.
6. If the lash adjuster compresses while pushing down on the rocker arm, replace that lash adjuster. Repeat this process until all the lash adjusters have
been tested.
NOTE:
IT WILL BE NECESSARY TO ROTATE THE CRANKSHAFT TO ASSURE THE ROCKER ARM IS ON THE BASE CIRCLE OR
THE CAMSHAFT.
