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26 votes

Is my head gasket cracked?

It is totally possible. Combustion chambers are quite small and it doesn't take much fluid to fill one up. As the piston goes down during the intake cycle, a vacuum is created and anything in the ...
Thomas's user avatar
  • 708
19 votes

Is my head gasket cracked?

Yes. If the engine ingests water, you have a big problem: water is incompressible. When water gets into a cylinder, it will be forced out through the path of least resistance: the head gasket. And ...
Hobbes's user avatar
  • 4,412
14 votes
Accepted

If there are only two symptoms of a blown head gasket, is it really a head gasket problem?

My rule for blown head gaskets: if you have to ask if it's a blown head gasket, it's a blown head gasket. There are other ways than the head gasket that combustion gasses could get into the coolant, ...
R.. GitHub STOP HELPING ICE's user avatar
10 votes

Blown Head Gasket always goes hand-in-hand with Engine damage?

I've had some cars where simply changing the head gasket was a complete solution, on other cars there has been cylinder head damage which required skimming. On one, I had a melted piston and two ...
Steve Matthews's user avatar
10 votes

2006 wrx overheats going slow but not at speed

I don't think there's any reason to suspect a head gasket right off the bat like that. The first thing that comes to mind is the electric cooling fans. They are on the car specifically to keep it ...
JPhi1618's user avatar
  • 13.2k
10 votes

I've got oil in my coolant but no coolant in the oil - Ford Triton V10 Motorhome

If it has an engine oil cooler, that is most likely the problem, a faulty oil cooler, some are made into the radiator, others have heater hoses running to a remote oil cooler, and a few I have seen ...
Moab's user avatar
  • 7,990
9 votes

Does increasing head gasket thickness make it more failure-prone?

with all other factors held constant, is it true that a thicker head gasket is likely to fail? Yes. A thicker head gasket impacts how headbolt torque is distributed between the block and the heads. ...
race fever's user avatar
  • 3,353
9 votes

Head gasket sealer or head gasket replace

If this is a car you are planning on keeping, I'd highly suggest just paying the money to get it fixed. A stop leak may work for a period of time, but it's only temporary. A couple of things to ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes

2003 Subaru Outback Legacy, Blown Head Gasket

Coolant can definitely leak into the combustion chamber with a blown head gasket. Whether or not this is the cause of your power loss is hard to say. The amount of coolant going into the cylinder ...
Dalton D's user avatar
  • 1,958
7 votes
Accepted

Overheating at idle - mechanic says head gasket

It would be good to ask the mechanic to explain to you how they are sure that it is the head gasket – head gasket problems often share symptoms with other problems. One way that a head gasket failure ...
dlu's user avatar
  • 14.5k
7 votes

If there are only two symptoms of a blown head gasket, is it really a head gasket problem?

Given the symptoms, is it a bad head gasket or what else could it be? It is not conclusive it's a blown head gasket, but realistically, I'm doubting it's anything else ... let's give it a 99.9% ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes

Does increasing head gasket thickness make it more failure-prone?

It turns out that multi-layer head gaskets can be OEM as well. In this Hot Rod Garage video the presenter makes mention of the LS9 head gasket, which consists of 5 layers. This would seem to ...
Zaid's user avatar
  • 39.2k
6 votes

Overheating at idle - mechanic says head gasket

There are so many things that could explain slow overheating A compromised head gasket is just one of them. Other (less involved) reasons include: a radiator fan that doesn't turn on when it should ...
Zaid's user avatar
  • 39.2k
6 votes

Oil in the cooling reservoir

Welcome to Mechanics SE! A white milky, mayonnaise like substance is indicative of oil and water mixing. This could be down to a failed cylinder head gasket or a failed oil cooler. I'm not sure if ...
Steve Matthews's user avatar
5 votes

Why should I back off all valve lash adjusters until valves are closed when changing a head gasket?

They want you to back of the lash so you don't ruin your rocker arms The system in which this head depresses the valves is the reverse of many heads. The cams (the shaft at the top of the photo) is ...
DucatiKiller's user avatar
  • 32.9k
5 votes
Accepted

Why should I back off all valve lash adjusters until valves are closed when changing a head gasket?

You want to back off the valves so you don't damage the head when you pull the head bolts. If you have tension on the valves, you run the risk of warping the head. Likewise, when you put the head on, ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
5 votes

2006 wrx overheats going slow but not at speed

Cools at speed, but not at slow vehicle speed. Definitely an engine cooling fan issue. It's either the fan itself or the sending units that tell the fan when to come on. Best bet is to pick up a ...
zipzit's user avatar
  • 6,569
5 votes

2003 Subaru Outback Legacy, Blown Head Gasket

These engines are notorious for blowing head gaskets around +/-160,000 miles. It's highly likely you have already warped the head so no matter who does the work make sure the head is resurfaced. On ...
user288719's user avatar
5 votes

2003 Subaru Outback Legacy, Blown Head Gasket

Quite possibly, because the cylinder with coolant leaking into it will have low compression. When I ran my Subaru with two leaking cylinders, I found that on the freeway, the engine had to run at ...
PeteCon's user avatar
  • 8,712
5 votes

Oil in the cooling reservoir

Textbook root cause nr. 1 would be a damaged head-gasket, other possible issues are: Cracks in the engine head or, heaven forbid, the engine block. Some issues with the oil heat exchanger (if ...
Martin's user avatar
  • 8,458
4 votes

Coolant still in oil after head gasket change?

Please consider this answer as "food for thought" and not as a reliable expert advice. The most difficult part is to differentiate if the oil contamination is from the residual coolant in the not-...
Martin's user avatar
  • 8,458
4 votes
Accepted

Can you leave heads sitting on a gasket overnight before tightening down?

As long as you don't tighten any bolts on it, it will be fine. Even to pull the head off of the gasket should be fine. Realistically, while the head itself is or can be heavy, when you spread out the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes
Accepted

Using a thicker head gasket when the cylinder head resurface limit is reached

The pressure generated at Top Dead Center on the Power stroke is very high. A "taller" gasket will have a larger cross-sectional area exposed to this pressure, so high "pounds/sq inch" grows ...
SteveRacer's user avatar
  • 12.4k
4 votes

2002 Subaru Legacy coolant overflowed, relatively new head gasket

What you describe sounds the cooling system failing to hold pressure. There are two obvious causes of this: A failed pressure cap or its gasket. This would cause low pressure in the cooling system ...
dlu's user avatar
  • 14.5k
4 votes
Accepted

P2646 after Head Gasket Replacement....WRONG or NO OIL?

A straight answer to Did they use the wrong oil causing this to happen??? No. The wrong oil wouldn't, at leas not 10W30 instead of 5W20 would make no noticeable difference in 30 minutes. Maybe ...
kyle_engineer's user avatar
4 votes
Accepted

Why would a blown head gasket burst the coolant tank?

When an engine goes through it's four cycles, one of those cycles is combustion. Combustion creates a lot of pressure, which forces the piston down in the cylinder. Normally, the head gasket helps ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes

Bubbles in radiator despite several cylinder head overhauls

There are a limited number of places where combustion gasses can get into the coolant. A cracked head is the obvious one. It is also possible that it is a crack in the block going from the cylinder ...
HandyHowie's user avatar
  • 25.4k
4 votes
Accepted

Diagnosing Head Gasket Leak: Coolant bubbles, but doesn't squirt

Bubbles can usually be an indicator. Coupled with the oily coolant and coolant loss, it seems like a pretty cut and dry case. However the only way to know 100% is to get your exhaust tested or system ...
Coffee_Mug's user avatar
4 votes

2002 Subaru with strange smell, thin white steam

The most likely cause of these issues is a coolant leak. The strange smell could be coolant, which probably smells strange if you've never smelled it before. You could have a worn-out radiator cap, a ...
MTA's user avatar
  • 6,549
3 votes
Accepted

Subaru 2002 Impreza 2.5 TS - Head Gasket

What's the best course of action? Figure out where the coolant is going. Here are some ideas: Drain your oil and change it, and the oil filter too. Look for signs of coolant in the old oil. If you ...
Jason C's user avatar
  • 4,890

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