What causes a GM V8 engine to leak coolant?

Knowing where to look helps and often a cracked cylinder head is the source of the problem. Between 2001 and 2006 GM manufactured millions of engines, many with defective cylinder heads castings. The cylinder head castings are weak in the area where the head bolts pass through.

What happens when coolant goes out in a GM Truck?

Still trying to find the answer but have recently found an article illustrating the problem. If your General Motors SUV or truck is losing coolant, with no visible signs of a leak, the source may shock you Worse, allowing the problem to go on often results in a new engine.

Where does the coolant go when the expansion valve is stuck?

If the expansion valve becomes stuck open, it allows a constant flow of pressurized coolant to enter the reservoir, where it turns to steam. The steam, which has coolant in it, is forced out of the the reservoir cap vent hole or loosens the cap. Steam and coolant are released into the engine compartment.

Can a leaking coolant cause oil to cloud up?

Coolant is leaking into the engine oil and a great deal of engine damage can quickly occur. False beliefs that mask the problem: People often dismiss this as a possibility, because the engine oil looks normal. The old ‘water causes the oil to cloud up’ test is false. Enough water may cause oil to turn milky over time.

Why does my GM engine keep losing coolant?

Worse, allowing the problem to go on often results in a new engine. Often General Motors vehicles, with the 5.3L and 4.8L engines have come to us because they continue to lose coolant. Normally the owner has tried in vain to find the leak and sometimes, multiple auto repair shops have been unable to find a source.

Are there any problems with the Chevy 6.0 engine?

If you are a user of Chevrolet 6.0 Vortec Engine, you must have the ideas of common Chevy 6.0 Engine Problems. In any vehicle, the engine is regarded as the most essential component. The Chevy 6.0 engine, similar to any other component, might develop some technical problems – which can make owners look for ways on how to fix them.

What happens when coolant is leaking into the oil?

Coolant is leaking into the oil which is a mixture of glycol and water. Engine oil temperature is far above 212 degrees Fahrenheit. Water boils, turns to steam and leaves through the PCV system. Glycol remains and mixes with the oil. Modern oil will often not turn milky:

What happens if you lose antifreeze with no apparent leak?

Losing Antifreeze With No Apparent Leak. Whenever a vehicle loses antifreeze, also known as coolant, the usual expectation leads the owner to check for evidence of leaks at all the coolant connections and components. Obvious coolant leaks can usually be found in the form of puddles left on the pavement.

What should coolant temp be when engine is hot?

With a good OBD2 code reader, you can also check the live data and the parameters of the CTS sensor. Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm.

What happens when your coolant temperature sensor is bad?

The engine is very sensitive to wrong air-fuel mixtures at idle and this is a condition when you might notice that something is wrong with your engine coolant temperature sensor. The engine coolant temperature sensor can have a hard impact on the air-fuel mixture. A bad air-fuel mixture can also cause the engine performance to drop drastically.

Why does my GM V8 engine misfire when cold?

Because, GM V8 engines are very prone to a rough idle and engine misfire when cold. The check engine light may also come on, with codes P0300, P0171 and PO174. But, as the engine warms up, the engine misfire or rough idle tends to go away; which seems confusing.

What should the coolant temp be on my Chevy?

I though the thermostat might be broken, so I replaced it with a 180 (was a 195). Problem continues except now it goes from 180 swings up to 210, then back below 180, then to 180 and repeates this all the time regardless of how long I drive. Anyone have any other ideas?

Is there an engine misfire code on a GM 4.8L?

Engine Misfire or Rough Engine Idle on GM 4.8L, 5.3L, 6.0L is becoming; more common and getting harder to diagnose. Because, GM V8 engines are very prone to a rough idle and engine misfire when cold. The check engine light may also come on, with codes P0300, P0171 and PO174.

Why is my GM 4.8l engine running too lean?

The engine may be running too lean, due to a leaking intake manifold. Too lean means too much air and not enough fuel; according to the power control module (PCM) calculation. When the engine is cold, not all sensors function. As the engine warms up the oxygen sensors report the lean condition.

What to do if you have a coolant leak?

Check for any external coolant leaks under your vehicle. If you can’t find any external leaks but are still losing pressure, check the oil pan either with the dipstick or tap out the engine oil to see if you get any coolant in the engine oil.

What causes coolant to leak on GM Vortec Spider?

One of the most common problems on the GM Vortec ‘Spider’ 4.3L, 5.0L, and 5.7L engines is coolant leaking from the intake manifold gaskets.

What causes coolant to mix with engine oil?

On V6 and V8 engine’s the intake manifold gasket can leak allowing coolant down into the engine’s crankcase and mix with the engine oil. To check for this failure the intake manifold will need to be removed and the gaskets inspected.

What happens when coolant leaks from the oil cooler?

As with the above symptom, it’s important to contact a professional mechanic as soon as you notice a coolant leak. If enough coolant leaks from the radiator or oil cooler, it can result in engine overheating problems and mechanical component failure. 3. Oil in the cooling system

Where does the coolant leak on a Chevy Silverado?

They are very hard to see without a pressure tester and getting under the truck with a good light. When they leak the coolant migrates along the pan rails and drips off of the bottom of the oil pan. I don’t know if you can buy the gaskets or not but with the mileage on it the water pump is on borrowed time anyway.

Can a bad oil cooler cause an engine to overheat?

If enough coolant leaks from the radiator or oil cooler, it can result in engine overheating problems and mechanical component failure. 3. Oil in the cooling system If the oil cooler adapter fails internally, you may notice engine oil in your cooling system.

How often should you change the oil in a GM Vortec?

Changing the oil about every 1,000 miles, for three successive changes, usually works. Any coolant or sludge left in the engine can destroy the oil’s ability to prevent wear. Coolant in the oil will also greatly increase a sludge buildup. Don’t take a chance, if your General Motors 4.8L or 5.3L Vortec engine is losing coolant.