Cooling System Specifications & Drive Belt Routing Audi A4 B5

ENGINE IDENTIFICATION

ENGINE/MODEL IDENTIFICATION

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COOLING SYSTEM IDENTIFICATION

Note. Three letter code indicates engine identification code. For location of engine identification code, see ENGINE IDENTIFICATION under IDENTIFICATION.

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COOLING SYSTEM PRECAUTIONS

Use only coolant additive G 12 meeting specification VW 774 D. G 12 coolant is red in color. G 12 must not be mixed with any other additives. If the fluid in the expansion tank is brown, this is an indication that G 12 has been mixed with another type of coolant. In this case the coolant must be changed. Also, if radiator, heat exchanger (heater core), cylinder head or cylinder head gasket, have been replaced, flush cooling system and replace engine coolant.

G12 coolant additive may be used in older vehicles when original coolant is drained and cooling system is flushed. Contaminated coolant must be drained immediately and cooling system flushed. See SERVICING .

DRAINING, FILLING & BLEEDING COOLING SYSTEM

Note. Servicing of cooling system can be made easier by removing front bumper and moving lock carrier assembly away from engine. For bumper removal and lock carrier procedures, see appropriate procedure in REMOVAL & INSTALLATION article in ENGINE PERFORMANCE.

1.8L Turbo (Engine Code AEB & ATM)

1. Turn engine off, and allow to cool. Raise and support vehicle. Remove noise insulation panel, from below engine. (Scheme 10) Open expansion tank cap. Place appropriate drain pan underneath vehicle.
2. If bumper has been removed, open radiator drain plug. (Scheme 11) If bumper was not removed, remove retaining clip from lower radiator hose, and drain coolant from radiator. (Scheme 12) Also, remove drain plug from water pump. (Scheme 13)
3. After coolant is drained, install lower radiator hose or tighten drain plug. Using NEW O-ring install water pump drain plug. Tighten drain plug to 22 ft. lbs. (30 N.m).
4. Screw Adapter (VAG1274/1) small cap, or (VAG1274/8) large cap, onto coolant expansion tank. Attach Special Tool (VAG1274/10) to adapter. To fill without using special tools, loosen coolant expansion tank and lift about 4" (100 mm). Remove grommet holding clip at heater core and pull back grommet. Loosen coolant hose on heater core and pull back hose sufficiently so that bleeder hole is no longer sealed by connection. (Scheme 14) Add coolant until it flows out of coolant hose bleeder hole. Push coolant hose on connection and tighten. Install coolant expansion tank cap.
5. Start engine, and raise engine speed to 2000 RPM for approximately 3 minutes. Allow engine to idle, until lower radiator hose is hot. Check coolant level, and top off if necessary. When engine is at normal operating temperature, coolant level must be at MAX mark on expansion tank. When engine is cold, coolant level must be between MIN and MAX marks, on expansion tank.

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1.8L Turbo (Engine Code AWM)

1. Turn engine off, and allow to cool. Raise and support vehicle. Remove noise insulation panel, below engine. (Scheme 10) Open expansion tank cap.
2. Place appropriate drain pan underneath vehicle. If bumper has been removed, open radiator drain plug. (Scheme 15) If necessary, attach a auxiliary hose. If bumper has not been removed, remove lower coolant hose retaining clip and remove coolant hose from radiator. (Scheme 16)
3. Disconnect lower coolant hose from oil cooler, and drain off remaining coolant. (Scheme 17)
4. Install lower radiator hose, and secure hose clamp or close radiator drain plug. Screw VAG adapter 1274/8 to expansion tank. (Scheme 18) Fit VAG special tool 1274/10 onto adapter. Remove seal from plenum chamber cover, in direction of arrow. (Scheme 19) Remove plenum chamber cover (1) from front of vehicle.
5. Push back protective cover for heat exchanger coolant hose. Release coolant hose, and pull back hose until bleeder hole in coolant hose is no longer covered by connection. (Scheme 14) Fill with coolant mixture. See «COOLING SYSTEM SPECIFICATIONS»(/audi/a4/b5-1994-1999/remont/accessory-drive-belts/#cooling-system-specifications-drive-belt-routing). Top off until coolant flows out bleeder hole.
6. Push coolant hose onto connection, and tighten. Install expansion tank cap. Start engine, and raise engine speed to 2000 RPM for approximately 3 minutes. Allow engine to idle, until lower radiator hose is hot. Check coolant level, and top off as necessary. When engine is at operating temperature, coolant level must be at MAX mark, on expansion tank. When engine is cold, coolant level must be between MIN and MAX marks, on expansion tank.
7. Check coolant level, and top off as necessary. When engine is at normal operating temperature, coolant level must be on MAX mark, on expansion tank. When engine is cold, coolant level must be between MIN and MAX marks, on expansion tank.

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2.8L 12-Valve V6 (AFC)

1. Turn engine off, and allow to cool. Open cap on coolant expansion tank. Raise and support vehicle. Place appropriate drain pan underneath vehicle. Remove noise insulation panel, below engine. (Scheme 10)
2. Remove locking plate, at bottom of radiator, pull off connection flange. Loosen drain plug, and drain coolant at radiator. (Scheme 20)
3. Open coolant plug on engine. (Scheme 21) Drain coolant from engine. After coolant has drained completely, close drain plugs at engine block and radiator.
4. Push on connection flange at bottom of radiator, and install locking element for connection flange. Screw on Adapter (VAG 1274/1), and extend with 42 mm diameter and 100 mm long auxiliary hose. (Scheme 22) Open hose clamp, pull back coolant hose sufficiently so that vent hole is no longer concealed by connection. (Scheme 23) Open bleed screw at coolant pipe below expansion tank. Fill with a mix of clean water and manufacturer recommended coolant. See «COOLING SYSTEM SPECIFICATIONS»(/audi/a4/b5-1994-1999/remont/accessory-drive-belts/#cooling-system-specifications-drive-belt-routing). Add coolant until it flows out at bleeder hole in hose. Tighten hose clamp to 132 INCH lbs. (15 N.m).
5. Add coolant, until it flows of at vent hole, then close bleeder on coolant hose. Close expansion tank cap. Set heater controls to HOT. Start engine, and raise engine speed to 2000 RPM for approximately 3 minutes. Continue running engine at idle until radiator becomes hot at lower radiator hose. Check coolant level in expansion tank, and top off if necessary.
6. Check coolant level, and top off as necessary. When engine is at normal operating temperature, coolant level must be on MAX mark, on expansion tank. When engine is cold, coolant level must be between MIN and MAX marks, on expansion tank.

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2.8L 30-Valve V6 (AHA & ATQ)

1. Turn engine off, and allow to cool. Open cap on coolant expansion tank. Raise and support vehicle. Place appropriate drain pan underneath vehicle. Remove noise insulation panel, below engine. (Scheme 10)
2. Remove front bumper. See FRONT BUMPER in «REMOVAL, OVERHAUL & INSTALLATION»(ref-11847) article.
3. Open coolant drain plug on lower left of radiator, by turning clockwise. If necessary, attach an accessory hose to connection. (Scheme 24) If bumper is not removed, loosen lower radiator hose clamp, and disconnect radiator hose from radiator. Drain coolant.
4. Drain coolant from engine drain plug. (Scheme 21) Close all drain plugs. Loosen bleeder screw, on lower coolant line, under expansion tank. (Scheme 25) If necessary, unbolt expansion tank.
5. Fill with a mix of clean water and manufacturer recommended coolant. See «COOLING SYSTEM SPECIFICATIONS»(/audi/a4/b5-1994-1999/remont/accessory-drive-belts/#cooling-system-specifications-drive-belt-routing). Add coolant, until it flows out from bleed screw. Close bleeder screw, and tighten to 15 ft. lbs. (20 N.m).
6. Loosen bleeder screw, on front coolant line, between power steering pump and left cylinder head. (Scheme 26) Add coolant, until it flows out from bleeder hole in coolant line. Close bleeder screw, and tighten to 15 ft. lbs (20 N.m).
7. Top off coolant to MAX mark, on expansion tank. Install coolant expansion tank cap. Set heater controls to MAX heat position. Start engine, and let idle for approximately 10 minutes. Raise engine speed to 2000 RPM, for approximately 5 minutes. Allow engine to idle, until lower radiator hose is hot.
8. Check coolant level, and top off as necessary. When engine is at normal operating temperature, coolant level must be on MAX mark, on expansion tank. When engine is cold, coolant level must be between MIN and MAX marks, on expansion tank.

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SERVICING

Coolant does not usually need replacing. In case of larger repairs when coolant needs to be drained, new coolant must be used because, old has been exposed to oxidation and dirt. Flush cooling system when replacing coolant. To flush, fill system with clear water, and run engine for approximately 2 minutes. Drain cooling system. See DRAINING, FILLING & BLEEDING COOLING SYSTEM under DRAINING, FILLING & BLEEDING. Flushing system should remove most coolant residue.

Coolant to water ratio must not exceed 60%. Frost protection and cooling efficiency will decrease if the percentage of coolant is too high. For coolant to water ratio, see COOLANT MIXTURE RECOMMENDATIONS table.

COOLANT MIXTURE RECOMMENDATIONS

ADJUSTMENTS

Note. For drive belt routing (Scheme 28)- see scheme 30.

Servicing of accessory drive belts is made easier by removing front bumper and moving lock carrier assembly away from engine into service position. For bumper removal and lock carrier procedures, see appropriate procedure in REMOVAL & INSTALLATION article in ENGINE PERFORMANCE.

Main Accessory Drive Belt

Accessory drive belt is adjusted automatically by self adjusting tensioner.

Air Conditioning Compressor (1.8L)

Using torque wrench on A/C belt tensioner, pre-tension belt to 18 ft. lbs. (25 N.m). Tighten tensioner fasteners to 15 ft. lbs. (20 N.m). Start engine and check belt running. (Scheme 27)

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Water Pump (1.8L AEB & ATW)

Note. Adjustment of V-belt tension for water pump is not possible.

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COOLING SYSTEM SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• ENGINE IDENTIFICATION
• SERVICING
• COOLING SYSTEM PRECAUTIONS
• COOLING SYSTEM SPECIFICATIONS
• DRAINING, FILLING & BLEEDING COOLING SYSTEM