General Motors — Coolant Replacement and Cleaning
Maintenance · Coolant system
From a General Motors operator's manual covering: 181 CID, 3.0L L4, GMG-430, LW6. Check it applies to your exact model before use.
Applies to: General Motors 3.0L L4 (181 CID) engine
Before you start
- Use soft water. Use of well water or river water may cause scaling or rusting.
- Add anti-corrosive in hot season, anti-freeze in cold season.
Procedure
- Open radiator cap and open drain cocks of engine crankcase and radiator to remove coolant.
- Close drain cocks and pour coolant into radiator. Run engine until coolant heated to about 80°C.
- If considerable scale or rust, pour in cleaning solution and run engine until solution heated to about 80°C.
- Continue to idle engine for about 30 minutes.
- Stop engine, open drain cocks and drain coolant completely.
- Close drain cocks and pour in coolant to rinse system thoroughly until dirty water no longer runs out.
- Use soft water and fill until it flows out from overflow pipe.
- After filling, run engine for awhile. Stop engine, check coolant level and replenish if necessary.
Specs & values
- Replace coolant and clean system every 500 hours.
Source: General Motors operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.