Blown Head Gasket

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jgray152
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Joined: Wed Feb 10, 2010 2:53 pm

Blown Head Gasket

Postby jgray152 » Wed Feb 10, 2010 3:16 pm

My mothers pathfinder recently had clogged cats and after further inspection by our mechanic, he said the head gaskets were leaking which is why the cats clogged up so quick.

So my mother does not have money to spend on a mechanic to put in new head gaskets. I know I could do it, I have done one before on a much older vehicle with less stuff to remove but I am wondering if replacing the head gasket would cause any other issues?

Our mechanic told my mother that we would run into compression problems if we replace the head gaskets. I don't see why if its done properly and torqued correctly.

How long did it take YOU to replace a head gasket?

Any advice on this would be great. Thanks!


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JAHBLESSINGS
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Postby JAHBLESSINGS » Wed Feb 10, 2010 7:35 pm

take off the oil filler cap and see it looks like milk chocolate. if is is milk chocolate then the gasket is blown. if not then you can find someone to do a pressure test to truly find out. replacing a head gasket does not lower compression. you need to find another mechanic and get a second opinion. not everyone with tools are classified as a mechanic. good luck...

jgray152
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Postby jgray152 » Wed Feb 10, 2010 9:11 pm

Apparently, some how, both head gaskets are blown (so he says) and one of the heads are warped.

This doesn't make sense to me since the vehicle is never over heated and for both gaskets to blow at the same time, it seems a bit fishy.

He said it would be roughly $2000 to machine the head. I can buy a new one for $500.

How can you tell if the head is warped without taking the darn thing off?

I guess he saw coolant in the exhaust when he pulled the cats off.

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JAHBLESSINGS
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Postby JAHBLESSINGS » Thu Feb 11, 2010 5:49 am

only a machine shop can really tell if a head is warped. get another opinion.

jgray152
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Postby jgray152 » Thu Feb 11, 2010 7:05 am

I just found out that our mechanic sent the vehicle down the street to someone else that knows more about that area of the engine and he said it was definitely warped. I still can't tell how they have come to that conclusion

I have been trying to get a hold of the mechanic so I can talk to him since I understand a lot more about engines than my mother. So after I talk to him I will see.

How long you think it would take to replace two head gaskets? I am just looking to give my self a range of time my mother will be using my car.

jgray152
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Joined: Wed Feb 10, 2010 2:53 pm

Postby jgray152 » Thu Feb 11, 2010 1:12 pm

Welp,

I found a shop that will take our old heads, regardless of being warped or not, will resurface , pressure wash and pressure test them for $150 each. I misunderstood in the beginning about the cost being $2000 for machining, that was for the entire job and actually the job would be $3000.

We are deciding whether we will buy a new vehicle or just fix this one. I think fixing this one will be better if I do it myself since I know I can do it.

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Tech
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Postby Tech » Thu Feb 11, 2010 8:02 pm

get a second opinion. Does it run rough? Check to make sure the butterflies didn't fall into a valve. If you end up doing heads (and instake and exhaust manifolds and t-belt -if it's a VG) you could still end up needing cats and 02's. You'll be in for a few grand easy. If it's a VQ, you could definately end up with an oil burner. Your "mechanic" has the way of thinking which is that if you get a new valve grind and resurface, the next weekest point for combustion gases to escape will be your worn rings. If the matrix of your cats is crumbling (and it's a VQ) your cylinders might be toast already. I don't think he could possibly tell about warpage without taking anything apart, but sending the heads out is a good idea

jgray152
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Postby jgray152 » Fri Feb 12, 2010 9:54 pm

The cats are junk so we already bought new ones. The O2 Sensors I am sure will not be the best after this so they are on the list as well. I priced a bunch of stuff out and so far I am hitting $800 for most of everything including a new radiator since that has some pin holes.

The engine runs horrible. Practically stalls out when you drive it and it wont rev over 4000 rpm. Shifts all screwed up. I will be doing everything once I am in the engine.

What do you mean VQ?

He said the matrix of the cats were clogged up. I will be checking compression before I do anything. It idles fine, so I would probably let it warm up a bit before doing a compression test.

It ran perfect before this. This happened within a a week or two.

I used to work on engines all the time but I got out of it for a while, especially after selling my Mazda Rx7. Easiest engine to work on. So we usually bring it to our mechanic to have him check stuff out and do the work if its not to expensive.
Check to make sure the butterflies didn't fall into a valve.
Not knowing to much about this engine, only butterflies I know of is the throttle body. Any where else use butterflies I should be aware of?

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Tech
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Postby Tech » Fri Feb 12, 2010 11:20 pm

lets start with what year your truck is.
The plugged cats alone could cause a rough run, but depending on your driveline combo - there could be a lot of much easier fixes before head gaskets (not saying it isn't possible) - but on any pathfinder -not very common - xterra yes. Again, depending on your year/engine - you could have butterflies in the intake. if you drop a couple screws, the valve itself falls into the engine and can enter the cylinder and get into the intake/exhaust valves. shoot me some info. I'd hate for you to tear up the motor when you only have a bad MAF (causing miss-killing cats), or bad TP sensor or something.


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