Are my heads cracked or just gaskets on intake and manifold blown?

Car is blowing white smoke and water out of the tail pipe big time.

My car has 150000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
In order to know if the heads are damaged from the overheating or corrosion near the coolant passages you will need to have the intake and heads removed. The heads get corroded to the point the coolant passages do not seal on the intake and block. Have the heads and intake inspected when they are removed. You may need to replace the heads and intake manifold.

How to Identify and Fix Common car Problems ?

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There is an easy way to find out if your engine`s head gasket has blown. Simply check under the oil filler cap. If the gasket is not damaged, the inside of the oil cap will be mostly dry. If you discover a milky brownish-yellow substance that is similar to the thickness of a milkshake, you probably have a gasket leak.
Oil and coolant leaks are common issues on many vehicles. Just because you see a leak doesn`t mean you have a blown head gasket. If you see the majority of the oil or coolant seeping out from the engine block though, it could be an indication that the head gasket is no longer maintaining a seal.
Additionally, the blown head gasket may have caused further problems in other engine parts or caused irreversible damage to the engine. If the blown head gasket has caused catastrophic damage, a complete engine may need to be installed or a new vehicle purchased.
a cracked block is repaired by installing a fresh engine, the cracked block is not worth repairing. The crack enables something to leak, depending on where it is. a blown head gasket will require removing the engine`s head and gasket replaced.
When they blow, intake manifold gaskets and head gaskets will typically leak different substances. A blown intake manifold gasket may cause air or fuel to leak. A blown head gasket, on the other hand, will typically cause combustion gases, coolant or oil to leak.
If you continue to drive your car with a blown gasket then you risk damaging the engine further as the increase in heat can warp the parts connected to the gasket or cause even more problems because of leaked fluids and/or eroded parts.
One tell-tale symptom of an exhaust manifold that needs to be replaced, is a ticking noise in the engine. An exhaust leak in the manifold can cause a ticking sound much like hearing a musician`s metronome, especially when the engine is cold.
A leaking cold air intake will often make loud noises as air comes out of the damaged part. You may hear a hissing or whistling sound when your intake manifold has a crack in it. That will let you know that there`s a major problem.
In addition to a possibly rough, uneven idle speed, you may also hear whistling, sucking, gulping or hissing noises. Your check engine light comes on: Abnormal operating conditions and loss of performance can result from a bad intake manifold.
If you`re replacing the head gasket on your vehicle you should always replace both of them to make sure your engine stays balanced. Also, since you already have the majority of the engine taken apart to replace once gasket, it is cost effective to do the other one at the same time.
The answer is, they should last as long as the life of your engine. However, if you don`t properly maintain your vehicle or the engine, chances are you`ll be having the head gasket replaced in your vehicle`s lifetime.
The most effective and accurate diagnostic test to determine if the cylinder head gasket is sealing combustion gases is to check for the presence of combustion gases in the engine coolant. This must be done with the engine warm and the radiator cap removed.
Engine codes

Engine codes are one of the first signs that something is wrong with your vehicle. If you see error code p0300, it points to an issue with your head gasket.

Can you drive a car with a cracked cylinder head? While you can drive with a cracked engine part, it`s important to note that doing so is just like driving with any other issue. It will get worse and worse over time if you continue to drive without dealing with the problem.
Water in your oil will allow your bearings to rust and wear out very quickly. If your head gasket leak has caused this problem you are almost always better off replacing the whole engine as a new head gasket will stop the leak but bearing damage has probably already been done.
The first symptoms of a head gasket that is failing are usually a slow loss of coolant with no visible leaks, engine overheating and/or a Check Engine light with cylinder misfire codes.
You can also try performing a compression test of your engine to find a head gasket leak. If your head gasket is blown, it will allow the compressed air in 1 or more cylinders to bleed off into the cooling system lowering the compression in that cylinder.
If your car can run safely for longer than 15 minutes without overheating, there are chemical repair products designed to seal the leak without the need to disassemble your engine. In fact, even those with hardly any mechanical knowledge can install the fix themselves.
A cracked block will almost always cause a cooling system leak and start very slowly. Sometimes it will be so slow that you will only be able to notice the leak when your car is warm and it will just look like a small amount of steam.
Listen for a loud rumble, especially while accelerating. You may also hear intermittent popping or hissing noises while the engine is running. An exhaust leak can affect the performance of your engine. You may notice that your vehicle doesn`t have its usual pick-up-and-go when you punch down the gas pedal.
Hissing or Sucking Noises

Usually, when the leak isn`t too bad, you will hear hissing noises coming from the engine. This may also sound like whining sounds or whimpering sounds. For more severe vacuum leaks, the noise is sucking or suction, much like a vacuum cleaner.

What`s more, plastic manifolds can easily crack by mishandling, over-tightening fasteners, excessive bending, flexing, overheating, vibration, or an engine backfire. One kaboom that blows back into the intake manifold can crack or even split open a plastic runner or plenum.
When it comes to air returns making funky noises, though, there are usually a few common culprits: Dirty air filters and/or air ducts: Typically, air returns are covered with vents or grills. Since the air return sucks air, they are prone to getting clogged, especially if your home is particularly dusty.
A loud noise coming from your vehicle when you accelerate, particularly one that sounds similar to a lawn mower is most likely due to an exhaust system leak.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Can bad intake manifold blow a head gasket? 2010 Toyota Prius
ANSWER : Hello – it is unlikely a bad intake manifold gasket will cause a blown head gasket on a Prius (different story for GM V6 engines). It is possible that a failing head gasket can cause a misfire over time – coolant can start to leak into the cylinders causing a misfire. The mileage level on your engine is within the range of reasonable head gasket failure. I would recommend an engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm the diagnose for this problem, give you an accurate assessment of damage and cost estimate for repairs.

i have a 1994 z28 and i did a head gasket replacement for some blown head gaskets. I then tried changing the timing gears and when
ANSWER : Hi there. It really depends on the location of the motor (meaning if it’s installed in the vehicle or loose and on an engine stand), that would factor into the price and whether this is a project one of our mobile mechanics can complete. We can complete the oil pan gasket replacement, but some of the other jobs like wiring harness, intake and rocker arm installation is outside of our scope of service. In regards to estimates for those services, I would suspect it would cost anywhere from $400 to $1,000 based on where it’s completed and what supplies would be needed.

Oil is geting into intake manifold and into all intake vavles.
ANSWER : Hi there. That type of oil volume inside the intake manifold is typically a sure fire indication of a blown head gasket. It’s also quite possible that this has occurred for an extended period of time. There are a few things that you can do to verify that this is the head gasket. First, check the oil itself. If it is milky or foamy then it means the head gasket is damaged and coolant is leaking into the oil galleys. If the head gasket is not damaged, excessive oil inside the spark plug well could also be a damaged O-ring but can also be the result of a failing piston or worn valve guides. Either way, the only way to correctly inspect and diagnose this would be to tear down the motor, so you might want to consider whether you are wanting to complete repairs or purchase a newer vehicle.

Roland, does the 2007 4.7 liter with the plastic intake manifold have coolant passing through to cool the manifold?
ANSWER : Hello. It does not appear that the intake manifold on that model has coolant passages, so it is unlikely that that is the cause of the issue.

I would still carefully examine the intake manifold for any signs of warping, however, as plastic manifolds are more susceptible to warping than aluminum ones.

If the compression test was performed on a cold engine, it may be possible that a cold engine helped seal the pressure. If it feels safe to do so, I would start the engine, warm it up to operating temperature, and then retest the cylinder compression. There are certain cases where the head gasket is blown or the cylinder heads are warped, however, only once the engine is warmed up and the metal expands. If you’d like a second opinion on the car, a certified expert from YourMechanic can come to your car’s location to inspect the overheating problem and diagnose the issue properly.

New exhaust gasket and manifold, still have exhaust leak.
ANSWER : The trouble with small exhaust leaks is that they always turn into large exhaust leaks. The hot gas leaking past the gasket will eventually burn up the gasket making the leak worse. If not corrected, it will also burn the surface of the exhaust manifold. It rarely goes so far as to burn the cylinder head, but that can happen in extreme cases. To make matters even more complicated. having an exhaust leak also allows air to enter the exhaust stream and messes with the oxygen sensor reading. Mixture too lean trouble codes will follow as the system shifts rich to try to correct. So, if you want to keep this truck, you need to get this fixed. I’m not sure I buy the line about the head being warped enough to prevent the manifold from fitting, maybe you should get a second opinion on this. You can have this done by contacting Your Mechanic. They will send a technician to your home or office to check out your exhaust leak and let you know what can be done about it.

I have coolant in my lower intake manifold after replacing the gasket in my upper manifold in my 1996 Chevrolet Suburban.
ANSWER : Hi there. If you have coolant in your lower manifold also then at the very minimum you need to blow it out with compressed air. I would recommend removing the lower manifold also to make sure that you get it completely clean. If you do not then you can cause some serious internal engine damage.

Will a very small crack in my intake manifold cause major damage if I wait about 3 months to fix it?
ANSWER : The intake has coolant cross over tubes that directs coolant from one cylinder head to the other. If you have a crack in the intake manifold and it is leaking coolant then when the engine is running and cooling system gets hot and pressurized it will leak coolant at a faster rate causing the engine to overheat and possibility of engine damage may occur.

It is not recommended to drive the vehicle with the coolant leaking. The coolant may get into the alternator causing it to short out. The coolant will also get into wire connectors and cause loss of electrical connection with possible drive symptoms like stalling or no starts.

When you’re able to, I highly suggest having the coolant leak diagnosed by a certified technician, such as one from YourMechanic. So that the right repairs can be made.

Is manifold gasket replacement a diehard requirement for manifold r&r?
ANSWER : The intake manifold gasket can be reused if it is not damaged in any way. The cost of the new gasket versus removing the intake again if it leaks is something to think about. Consider if it’s worth the risk to reuse it if you had to do the job twice. The manual for your Pontiac Grand Am says you can reuse it as long as it is not damaged, but I personally would not reuse it.

If you need some assistance with this, consider YourMechanic, as a certified technician can come help you with the repairs you’re making and service your intake manifold gasket as necessary. Good luck.