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Head Gasket


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#1
98626v6

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will it be hard to replace a head gasket.....

cause unfortunately there is a crack or whatever in it thats causing water to leak into the motor...
which is causing my car to overheat.....

so if possible, if it is easy to replace, then ill do it, cause a shop i went to, is asking $1600 to $1800 to replace it......

#2
mrslcom

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Replacing the head gasket is one of the most labour intensive jobs around therefore it will be expensive.
You practically have to take the whole engine apart to get at the head gasket. While you are at it you might as well overhaul the engine. Sorry!

#3
98626v6

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sorry but im not too familiar with cars, but what do you mean overhaul?

i looked up head gaskets for the car and i noticed that there is a left-front and right-rear head gasket..
now would i have to replace both of them??

thnx for response mrslcom

#4
snailman153624

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Replacing the head gasket is one of the most labour intensive jobs around therefore it will be expensive.
You practically have to take the whole engine apart to get at the head gasket. While you are at it you might as well overhaul the engine. Sorry!

Well, sorta. Not really. You only have to remove the HEADS, not the whole engine. Pistons, crankshaft, etc., all stay in there, unless you want to overhaul (complete engine rebuild) the engine. To remove the head, you have to take the valve covers off, remove the timing belt, and remove the intake manifold. It really is not the difficult, but expect to take some time. However, USUALLY it is a VERY good idea to have your head machined (the head is the top of the engine, the part with the valves in it), and the valves re-ground to spec. This will ensure good compression and power. Also, if you remove the head and notice excessive wear on the cylinder walls, this is a good time to rebuild. If not, then don't waste your money rebuilding, just machine the heads, replace the head gaskets (the gaskets between the head and the engine), and reassemble everything. Machining only costs ~$80 for a 4 cylinder head. This includes the valve regrind, new valve seats, and coolant plugs. The gasket kit will usually run about $100. The rest is just turning wrenches, cleaning, scraping, and some more cleaning and scraping.

#5
98626v6

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sweet.... B)

but i still dont understand how there is a left-front and right-rear head gasket..
i found this out on... http://www.mazda-eng...ngineparts.html

very confusing.....

#6
mrslcom

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but i still dont understand how there is a left-front and right-rear head gasket..

I would guess because it is a V6 there is a head gasket for each cyclinder bank.
If only one is bad you don't have to replace the other one.

#7
snailman153624

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Exactly. The engine is a "V" 6, meaning there are 3 cylinders per head, and the block makes a V shape. So like mrsclom said, you only have to replace the bad one (but it's not a bad idea if the engine is high mileage to do both, since you can get the heads machined, etc.). And by high mileage, I mean 150k miles +

#8
blackshine007

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What exactly do you mean by water leaking into the motor? Are you saying that coolant is on the engine oil dipstick, because if it is, then you're gonna need a new engine. Either the head is cracked at one of the head's oil passages or the block is cracked and the only way to fix either of the 2 is to replace both. No rebuilding here.... nope...... You can rebuild on a steel block like the 4 banger's, but definately not the V6 because it's all aluminum and only it's sleeves, crankshaft and connecting rods are made of steel. You can try to rebuild the engine but you will forever have problems out of it. Might as well start saving up for a new engine. Now, you can start thinking about if you want to add some preformance parts onto it since you'll have to put an engine in it.

#9
snailman153624

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I dunno bout this car, but in the VW, a head gasket alone could introduce water into the oil.

#10
blackshine007

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Well, another way to test if the head's crack is to relieve the pressure from the coolant system and crank it up for 30 seconds, then cut it off. If the pressure is high and starts to squirt out only after a short time of running, the head is cracked. if there is no engine coolant in the engine, take the radiator cap off and start the engine and feel for air coming out of the radiator, that's a real good indication of a cracked head. Now, if you were to do a compression check, if the middle cylinder is losing compression and the others are slight low and/or OK, then that's a possibity that the head gasket is born, but we're talking about an aluminum head and block so the chances of that thing cracking is slim to a shot in hell of happening

#11
98626v6

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well, one of the main problem is the overheating part....i can cruise for about no more than 2 miles at about 35-40 mph.... then as i stop to turn the car off, i can hear the resevoir bottle just boiling away......good thing my work is down the street or else it be a biatch to drive to work..

the cars got about 90k on it.....i dont know if it would be worth fixing....

i still have until next year for the lease to be up.....

and on top of that, its still got $10,000 on the lease.... :mellow:

any suggestions -_-

#12
snailman153624

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You sure it's not just a bad thermostat?

#13
Spartan626

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Please let us know whatever you may have not mentioned so far. For instance, what is your temp guage telling you (what's it reading), and when (relative to type of driving). Have you tried purging air from your coolant system? To check this, look at the small radiator cap over the belt drive area while cold (and flat). If not topped off, you've been loosing fluid. Top off with 50/50 here, and at the radiator cap.

It could be your problem is as simple as the radiator's pressure valve cap (sic?). That is what controls the hot (expanded) coolant leaving the radiator and heading to the overflow tank. If that valve was weak, you would experience a boiling discharge (frequently) and an overall loss of coolant since the tank only holds so much before it spills on to the pavement. Confirm that your block has sufficient coolant and check the pressure cap valve (a cheap part).

Also, you should get a second mechanic's assessment before you do anything monumental.




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