Coolant leaking into engine - 2002 Buick Park Avenue

hi Jonathan.
leaks in your 2005 Volkswagen Beetle. Leaking coolant is one of the more common types of fluid leaks on Beetles. Engine coolant (which is also called antifreeze or anti-freeze) moves through the inside of your Beetle's engine and keeps it from overheating. Coolant can leak from the reservoir or from the hoses, in 2005 Beetles coolant leaks are most likely to occur where the hoses connect to the engine.
A few things to note about coolant is that it is sweet tasting and highly toxic, so it can end up in the dog's stomach pretty quickly. If you ignore a small coolant leak long enough, you will run out of coolant, which leads to an overheated engine and other serious, but highly avoidable, problems. In many 2005 Beetles, an anti-freeze leak can cause the temp sensor to record high engine temperatures. thermostat most likely culprit if it is taking a long time to heat up.
or read up some more at this link.

2005 beetle heater takes long time to heat up Google Search
or this one.
2005 beetle leaks coolant somewhere Google Search

It is common to see white exhaust smoke when first starting a car, especially on cooler days. This is generally steam caused by condensation. As the engine warms up and the condensation dissipates the white exhaust smoke (steam) is no longer seen. If excessive white exhaust smoke is present well after the engine warms up, it is necessary to have the car inspected for possible internal coolant leaks. Indicators of an internal coolant leak include billowing white exhaust smoke accompanied by a sweet odor or a low coolant reservoir level. An internal coolant leak can also contaminate the engine oil giving it a frothy, milky appearance. Even small amounts of coolant entering the combustion chamber will produce white exhaust smoke. One of the main causes of white exhaust smoke and coolant loss is a cracked or warped cylinder head, a cracked engine block, or head gasket failure caused by overheating. A cracked head may allow coolant to leak into one or more cylinders or into the combustion chamber of the engine. Dirty coolant, a poorly maintained cooling system, a low coolant level, or a non-functioning cooling fan can cause engine overheating. In addition, engine wear can eventually cause the gaskets to lose their capacity to seal properly allowing internal coolant loss. Intake manifold gasket and head gasket failures are two of the most common sources of internal coolant loss caused by engine wear.
Never remove the radiator cap or coolant reservoir cap while the engine is hot or running as it can cause serious injury; always allow the car to cool down completely first. Checking for a low coolant level in the reservoir is the first step in determining if coolant loss is causing the white exhaust smoke. If the coolant reservoir is at the proper level but excessive white exhaust smoke is present, a cooling system pressure check is required to determine where, if any, coolant leaks are located. THESE LEAKS WILL CAUSE SEVERE ENGINE DAMAGE! Have the car inspected immediately.

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Internal coolant leaks can and will cause

a leak in coolant system will cause air pocket in the coolant system around the engine coolant temperature sensor.coolant sensor is a thermistor in which when hot cool cause it resistance decrease which affect the voltage from sensor to pcm which will cause engine coolant to turn on.if coolant level okay,check coolant fan fuse and relay, if all is good,engine coolant temperature sensor could be bad or have vechicle code scan for pcm problems it control the coolant fan.fill coolant system to correct level make sure engine coolat reservoir is at full cold mark and not empty.fill coolant system check for leaks,refill coolant overflow jug back to full cold mark dont over fill, if coolant overflow stay empty you have leak either its leaking or you have radiator hoses or radiator leaking coolant.when coolant overflow jug run dry it cause air get in coolant system causing overheating problems.

1. External Leaks
You need to get the vehicle to a mechanic to check all flexible coolant hoses, hose connections, around the exterior of the water pump and the entire radiator. To do properly the vehicle also needs to be on a hoist. If there is an external leak you should find coolant dripping from the front of the car while the engine is idling and the cooling system is fully pressurized. However it depends how bad the leak is and it's location.

2. Internal Leak

If coolant is leaking into the engine this is a serious problem and needs to be identified by a competent mechanic. For example, if you have a blown head gasket coolant will blow into the engine and contaminate the engine oil. If you check the oil in the engine's sump it should be completely free from coolant contamination.
You should also check the coolant in the radiator for any signs of oil contamination. If there is coolant in the oil then there will also likely be engine oil which has blown into the engines coolant passages and then mixed with the coolant.
IF you can find traces of coolant in your engine oil (or oil in the coolant) the likely problem will be a blown head gasket and the head on the engine will need to be removed and inspected .

Blown head gaskets are usually a result of an owner allowing the engine to overheat as a result of low coolant level, failed water pump or faulty thermostat. Overheating can also cause major damage to the head on the engine.

TO FIX COOLANT LEAK.YOU HAVE TO LOCATE IT.BEST TIME FIND COOLANT LEAK WAIT UNTIL MORNING.ADD COOLANT UNTIL COOLANT LEVEL IN RADIATOR CORRECT. START THE ENGINE LET IDLE UNTIL START GETTING HOT.THEN TURN OFF ENGINE.COOLANT PRESSURE WILL PUSH COOLANT OUT WHERE LEAKS ARE.CHECK TOP RADIATOR HOSE AND BOTTOM RADIATOR HOSE.CHECK AROUND RADIATOR LOOK DOWN BELOW COOLANT FAN AREA BEHIND RADIATOR.LOOK FOR LEAKS AT RADIATOR CORES AND SIDE CONTAINERS.CHECK FOR COOLANT LEAKS AROUND WATER PUMP GASKET OR WEEP HOLE.CHECK FOR COOLANT LEAKS AROUND HEATER HOSES AND HEATER CORE.CHECK ENGINE CRANKCASE FOR COOLANT LEAKS.

Inside your car's engine, thousands of controlled explosions called combustion events occur. These explosions are created by igniting a fuel / air mixture inside the engine. Spark plugs are used to ignite the fuel / air mixture contained in the cylinders. These explosions are converted into power through the engine while producing a large amount of heat. These high temperatures are controlled with the help of the cooling system. A cooling system consists of a water pump, cooling fan, thermostat, radiator hose, hose clamps, radiator, radiator cap and coolant. Engine coolant is used to transfer heat from the engine to the radiator by the cooling system. The radiator removes heat from the coolant by forcing air through the radiator cooling fins. Without coolant your engine will overheat and if left unattended severe engine damage will occur. Engine coolant colors can vary from green, orange, blue, clear and yellow each having their own unique protective and environmental properties. Coolant leaks are a common car problem that can lead to overheating; we have listed some of the most common causes below.(Always inspect engine cold to avoid personal injury) (note: coolant and antifreeze refer to the same product, in below freezing, coolant lowers the freeze point hence the name anti-freeze and in warm weather coolant help raise the boiling point, "coolant").
Troubleshooting Procedure
Step 1: Check Engine Coolant Level, Test For Leaks - Engine coolant is used to transfer heat from the engine to the radiator; if a coolant leak is present the engine will eventually overheat. Inspect the engine coolant level in the coolant reservoir tank; coolant level should be between the hot and cold marks. Always check the coolant level when the engine is cold, preferably over night. If the coolant level is not between the reservoir marks the cooling system may have a leak.

If engine overheating has occurred the coolant level will naturally be low due to expansion of the coolant from the extreme heat of the engine. This heat expansion forces coolant out of the radiator and coolant reservoir. To test for an engine coolant leak move the car to a dry smooth surface and allow the engine to cool. Remove the radiator cap and carefully (do not spill) add water until full, then re-install cap. Start engine and allow to run for about three to five minutes (do not allow to overheat) while the engine is running inspect the ground below the engine, if an engine coolant leak is present observe the location of the coolant drops, this will help determine where to start looking for the coolant leak (shut the engine off before inspecting).

If no coolant is observed two additional checks are needed for a complete test. With the engine off remove the engine oil fill cap and turn it over, if a milky oil condensation is present the engine may have a failed cylinder head or intake manifold gasket allowing coolant to leak internally. To inspect engine gaskets disassembly is required. Next, the car heater core must be inspected; the quickest way to check the heater core condition without removal the heater core is to inspect the passenger's side foot well compartment carpet for the presences of coolant. If coolant is present the heater core has failed and must be replaced or repaired. After necessary repairs have been made refill the cooling system with manufacturers recommended engine coolant and recheck operation.

WHERE COOLANT LEAKS OCCUR
Coolant leaks can occur anywhere in the cooling system. Nine out of ten times, coolant leaks are easy to find because the coolant can be seen dripping, spraying, seeping or bubbling from the leaky component. Open the hood and visually inspect the engine and cooling system for any sign of liquid leaking from the engine, radiator or hoses. The color of the coolant may be green, orange or yellow depending on the type of antifreeze in the system. The most common places where coolant may be leaking are:
Water pump -- A bad shaft seal will allow coolant to dribble out of the vent hole just under the water pump pulley shaft. If the water pump is a two-piece unit with a backing plate, the gasket between the housing and back cover may be leaking. The gasket or o-ring that seals the pump to the engine front cover on cover-mounted water pumps can also leak coolant. Look for stains, discoloration or liquid coolant on the outside of the water pump or engine.

Radiator -- Radiators can develop leaks around upper or loser hose connections as a result of vibration. The seams where the core is mated to the end tanks is another place where leaks frequently develop, especially on aluminum radiators with plastic end tanks. On copper/brass radiators, leaks typically occur where the cooling tubes in the core are connected or soldered to the core headers. The core itself is also vulnerable to stone damage. Internal corrosion caused by old coolant that has never been changed can also eat through the metal in the radiator, causing it to leak.

Most cooling systems today are designed to operate at 8 to 14 psi. If the radiator can't hold pressure, your engine will overheat and lose coolant.

Hoses -- Cracks, pinholes or splits in a radiator hose or heater hose will leak coolant. A hose leak will usually send a stream of hot coolant spraying out of the hose. A corroded hose connection or a loose or damaged hose clamp may also allow coolant to leak from the end of a hose. Sometimes the leak may only occur once the hose gets hot and the pinhole or crack opens up.

Freeze plugs -- These are the casting plugs or expansion plugs in the sides of the engine block and/or cylinder head. The flat steel plugs corroded from the inside out, and may develop leaks that are hard to see because of the plug's location behind the exhaust manifold, engine mount or other engine accessories. On V6 and V8 blocks, the plugs are most easily inspected from underneath the vehicle.

Heater Core -- The heater core is located inside the heating ventilation and air conditioning (HVAC) unit under the dash. It is out of sight so you cannot see a leak directly. But if the heater core is leaking (or a hose connection to the heater core is leaking), coolant will be seeping out of the bottom of the HVAC unit and dripping on the floor inside the passenger compartment. Look for stains or wet spots on the bottom of the plastic HVAC case, or on the passenger side floor.

Intake Manifold gasket -- The gasket that seals the intake manifold to the cylinder heads may leak and allow coolant to enter the intake port, crankcase or dribble down the outside of the engine. Some engines such as General Motors 3.1L and 3.4L V6 engines as well as 4.3L, 5.0L and 5.7L V8s are notorious for leaky intake manifold gaskets. The intake manifold gaskets on these engines are plastic and often fail at 50,000 to 80,000 miles. Other troublesome applications include the intake manifold gaskets on Buick 3800 V6 and Ford 4.0L V6 engines.

INTERNAL COOLANT LEAKS
There are the worst kind of coolant leaks for two reasons. One is that they are impossible to see because they are hidden inside the engine. The other is that internal coolant leaks can be very expensive to repair.

Bad head gasket --Internal coolant leaks are most often due to a bad head gasket. The head gasket may leak coolant into a cylinder, or into the crankcase. Coolant leaks into the crankcase dilute the oil and can damage the bearings in your engine. A head gasket leaking coolant into a cylinder can foul the spark plug, and create a lot of white smoke in the exhaust. Adding sealer to the cooling system may plug the leak if it is not too bad, but eventually the head gasket will have to be replaced.

If you suspect a head gasket leak, have the cooling system pressure tested. If it fails to hold pressure, there is an internal leak. A "block tester" can also be used to diagnose a leaky head gasket. This device draws air from the cooling system into a chamber that contains a special blue colored leak detection liquid. Combustion gases will react with the liquid and cause it to change color from blue to green if the head gasket is leaking.

Head gasket failures are often the result of engine overheating (which may have occurred because of a coolant leak elsewhere in the cooling system, a bad thermostat, or an electric cooling fan not working). When the engine overheats, thermal expansion can crush and damage portions of the head gasket. This damaged areas may then start to leak combustion pressure and/or coolant.

Cracked Head or Block -- Internal coolant leaks can also occur if the cylinder head or engine block has a crack in a cooling jacket. A combustion chamber leak in the cylinder head or block will leak coolant into the cylinder. This dilutes the oil on the cylinder walls and can damage the piston and rings. If the coolant contains silicates (conventional green antifreeze), it can also foul the oxygen sensor and catalytic converter. If enough coolant leaks into the cylinder (as when the engine is sitting overnight), it may even hydro-lock the engine and prevent it from cranking when you try to start it. Internal leaks such as these can be diagnosed by pressure testing the cooling system or using a block checker.

A coolant leak into the crankcase is also bad news because it can damage the bearings. Coolant leaking into the crankcase will make the oil level on the dipstick appear to be higher than normal. The oil may also appear frothy, muddy or discolored because of the coolant contamination.

Leaky ATF oil cooler -- Internal coolant leakage can also occur in the automatic transmission fluid oil cooler inside the radiator. On most vehicles with automatic transmissions, ATF is routed through an oil cooler inside the radiator. If the tubing leaks, coolant can enter the transmission lines, contaminate the fluid and ruin the transmission. Red or brown drops of oil in the coolant would be a symptom of such a leak. Because the oil cooler is inside the radiator, the radiator must be replaced to eliminate the problem. The transmission fluid should also be changed.

continue..

if there are no visible leaks ending up on the ground, check the engine oil level and see if it is overfilled or looks like there is coolant on the dipstick, could either be a head or intake gasket leaking coolant into the engine. Also check for white smoke coming from the exhaust which shows that the engine is burning coolant. If the engine has overheated recently there is a good chance that you have a cracked head and coolant is leaking internally in the engine

Coolant leaks can occur anywhere in the cooling system. Nine out of ten times, coolant leaks are easy to find because the coolant can be seen dripping, spraying, seeping or bubbling from the leaky component. So open the hood and visually inspect the engine and cooling system for any sign of liquid leaking from the engine, radiator or hoses. The color of the coolant may be green, orange or yellow depending on the type of antifreeze in the system. The most common places where coolant may be leaking are:Water pump. A bead shaft seal will allow coolant to dribble out of the vent hole just under the water pump pulley shaft. If the water pump is a two-piece unit with a backing plate, the gasket between the housing and back cover may be leaking. The gasket or o-ring that seals the pump to the engine front cover on cover-mounted water pumps can also leak coolant. Look for stains, discoloration or liquid coolant on the outside of the water pump or engine.Radiator. Radiators can develop leaks around upper or loser hose connections as a result of vibration. The seams where the core is mated to the end tanks is another place where leaks frequently develop, as is the area where the cooling tubes in the core are connected or soldered to the core headers. The core itself is also vulnerable to stone damage. But a major factor in many radiator leaks is internal corrosion that eats away from the inside out. That's why regular coolant flushes and replacing the antifreeze is so important.
oses. Cracks, pinholes or splits in a radiator hose or heater hose will leak coolant. A hose leak will usually send a stream of hot coolant spraying out of the hose. A corroded hose connection or a loose or damaged hose clamp may also allow coolant to leak from the end of a hose. Sometimes the leak may only occur once the hose gets hot and the pinhole or crack opens up. Freeze plugs (casting plugs or expansion plugs in the sides of the engine block and/or cylinder head). The flat steel plugs corroded from the inside out, and eventually eat through allowing coolant to leak from the engine. The plugs may be hard to see because they are behind the exhaust manifold, engine mount or other engine accessories. On V6 and V8 blocks, the plugs are most easily inspected from underneath the vehicle.
Heater Core. The heater core is located inside the heating ventilation and air conditioning (HVAC) unit under the dash. It is out of sight so you can�t see a leak directly. But if the heater core is leaking (or a hose connection to the heater core is leaking), coolant will be seeping out of the bottom of the HVAC unit and dripping on the carpet. Look for stains or wet spots on the bottom of the plastic HVAC case, or on the passenger side floor.
Intake Manifold gasket. The gasket that seals the intake manifold to the cylinder heads may leak and allow coolant to enter the intake port, crankcase or dribble down the outside of the engine. Some engines such as General Motors 3.1L and 3.4L V6 engines as well as 4.3L, 5.0L and 5.7L V8s are notorious for leaky intake manifold gaskets. The intake manifold gaskets on these engines are plastic and often fail at 30,000 to 80,000 miles. Other troublesome applications include the intake manifold gaskets on Buick 3800 V6 and Ford 4.0L V6 engines.
INTERNAL COOLANT LEAKS
There are the worst kind of coolant leaks for two reasons. One is that they are impossible to see because they are hidden inside the engine. The other is that internal coolant leaks can be very expensive to repair.


visit for more info:

http://www.aa1car.com/library/coolant_leaks.htm

Had this same problem. The plenum has a coolant port for the EGR valve which lets in a small amount of coolant. The intake plenum is plastic and will leak coolant into the lower manifold. You will need to replace the warped leaking plenum with a new one, flush the engine, Coolant DOES NOT LUBRICATE THE MOTOR!!! CHANgE OIL & FILTER.I did this myself, lots of stuff to remove & replace. Runs like new after replacing the plenum.