Tech Tip: Chevy Blazer's Engine May Rattle Between 1,800 and 2,200 rpm

Tech Tip: Chevy Blazer’s Engine May Rattle Between 1,800 and 2,200 rpm

Some customers may comment on a rattle-type noise coming from the engine at approximately 1,800 to 2,200 rpm. The spark, rattle-type noise may be caused by torsional vibration of the balance shaft. If detonation noise is present, perform detonation/spark knock diagnostics first.

Some customers with the vehicles mentioned below may comment on a rattle-type noise coming from the engine at approximately 1,800 to 2,200 rpm.

Models affected:
• 1996-2003 Chevrolet Astro, Blazer, Express, S-10, Silverado;
• 1996-2003 GMC Jimmy, Safari, Savana, Sierra, Sonoma; and
• 1996-2001 Oldsmobile Bravada — with 4.3L V6 engine (VINs W, X – RPOs L35, LU3).

The spark, rattle-type noise may be caused by torsional vibration of the balance shaft. If detonation noise is present, perform detonation/spark knock diagnostics first.

Install a new tensioner assembly kit using the procedure below.

  1. Remove the engine front cover.
  2. Remove the crankshaft sensor reluctor ring and line up the timing marks on the crank gear and camshaft gear.
  3. Remove the camshaft gear and chain. For model years 1996-’98, remove the crankshaft sprocket using J 5825-A.
  4. Pull the shipping pin and discard. Remove the nylon timing chain tensioner blade from the timing chain tensioner bracket.
  5. Position the bracket on the front of the engine. The upper two attaching holes of the bracket will line up with the center two engine front cover bolt holes. The lower bracket holes will line up with the engine front cover alignment holes. See Figure 1.
  6. Use a hammer and the J 46165 Pin Driver to install the dowel pins through the two lower holes in the bracket and into the engine block. Make sure that the bracket is held firmly in place before proceeding.
  7. For model years 1996-’98, install a roller-type timing chain set. Install the crankshaft sprocket using the J 5590 Crankshaft Gear Installer.
  8. Install the timing chain around the crankshaft sprocket and position the timing chain to the driver’s side of the engine.
  9. Install the nylon timing chain tensioner guide onto the timing chain tensioner bracket pin and position the top of the guide under the tab at the top of the bracket.
  10. Install the camshaft sprocket into the chain and then to the camshaft. Install the bolts finger-tight. Make sure the timing marks are aligned, then tighten the camshaft sprocket bolt to 25 Nm (18 lb.-ft.).
  11. Install the crankshaft reluctor ring.
  12. Install the engine front cover and place a washer under the two center cover bolts that extend through the tensioner bracket. These washers are required to maintain the proper crush on the engine front cover seal. Tighten the bolts to 12 Nm (106 lb.-in.).

Courtesy of ALLDATA.

For additional information, visit www.alldata.com.

You May Also Like

Wrenchers Doubles Repair Tool & Equipment Offering

More than 25,000 lifts, tools, and equipment from 39 brands available online or by phone.

Wrenchers has more than doubled the vehicle repair tools and shop equipment available in its new catalog, offering over 25,000 car lifts, specialty tools, tire changers, shop fans, and more from 39 brands. 

“We are committed to continuously improving our product lineup to make Wrenchers a one-stop-shop for tools and garage equipment,” says Karla Zarate, director of sales operations. “When we launched Wrenchers as an improved version of long-time distributor Garage Equipment Supply in 2022, we had about 12,000 product numbers in our catalog. We’re at more than 25,000 now, with more in the pipeline. This means our customers can get more of what they need with just a click, rather than having to waste time shopping around.”

Myers Tire Supply Introduces MTS Xpresstm

The innovative solution to consolidate purchases and control inventory costs.

Experiencing What the Tool Industry Has to Offer

ETI held its annual ToolTech conference April 17-19 at the Hyatt Regency Tamaya Resort in Santa Ana Pueblo, New Mexico.

Sandia Mountains
LIQUI MOLY Develops Liquid Thermal Manager for EV Batteries

The automotive chemical specialist is expanding its range for all-electric vehicles with Battery Coolant EV 200.

May 2023 Vehicle Care RockStar: Johnny Weber

Johnny Weber exudes confidence in his abilities to lead the band through proficiency over pageantry.

Other Posts

Variable Valve Timing Systems

Variable valve timing systems allow today’s engines to maximize performance and drivability.

Continental Tire Upgrades Test Tracks for EVs

Continental expanded its EV charging infrastructure at three company-owned test sites in Sweden, Germany and the U.S.

Streamlight Names E.A. Langenfeld & Associates 2022 Automotive Sales Rep Agency of the Year

The company received the award yet again in recognition for outstanding national sales achievement.

MAHLE and Midtronics Join Forces for Battery Service 

The goal of the cooperation: holistic battery diagnostics and maintenance from a single source in a growing future market.