What causes the need for a new head gasket and is this job difficult and is it worth it to do?

Answer 1

Blown gaskets are usually caused overheating and are very difficult to replace. It is worth it replacing if you want to drive this car again. If you drive it without repairing it, severe engine damage will occur.

AnswerIf you're of average mechanical ability and the job doesn't have snags, no, it is not difficult. If you're going to tackle it, do exactly what you're doing for starters: research. Get the specs that are needed as well as a r&r procedure, and you're off. Depending on where you live, or more precisly, where the car has lived, you may need Torches.

The "manifold to head" bolts can be challenging, but shouldn't stop you from trying. The bigger question you face is "is it just a head gasket?" It is possible that the gasket may have been blown from warpage in the head, in which case the head should go to a machine shop for cleaning, pressure testing, maybe magna-fluxing for cracks, and machining if it is okay. You could put it together and still have a problem. So send it to a machine shop unless you are just going to get a reman head. I don't know what size engine you have, so I can't get too specific, I would guess a 2.2 or 2.5. Fair chance of a cracked head if so. Tightening specs and sequence are important for the head bolts. Plan on new ones, toss the old ones. Get a new thermostat while you're in it. Overheating can damage a thermostat.

Getting back to the original question, yes, you can do this, be patient. IF a bolt snaps a machine shop can help you. Continue to research this before you start. Good luck.

AnswerIt depends on the car. Years ago I did it every Friday night on a Corolla for a month - took about 4 hours. Then I finally realised the head was cracked. Overhead cams make it more tricky. For example, on some cars the cam chain has a tensioner located low down. The chain must be kept under tension the whole time, or the tensioner falls into the sump. Then it's off with the sump. A full maintenance manual giving the procedure and specs for clearances is essential. Of course, a tension wrench is a must. It's best to do this with someone experienced the first time. However, with the right tools, maintenance manual, and common sense, it's not too difficult. As with any car repair, have a few plastic containers for nuts and bolts, each labeled. Otherwise expect to have a few left over at the end - not nice.

Note that what seems like a blown gasket can also be a warped or cracked head. Get this checked out before re-assembly, particularly if the car has overheated.

AnswerWhat causes it is usually bad manufacturing or a design flaw, lastly bad maintenance, say an overheat/ bad thermostat on a aluminum head, or no oil. The head gasket is what keeps oil and radiator fluid separate. When they mix, death, quite quickly. Engine replacement. Can most people do a head? No. About 500 bucks vs a new engine. When you lose radiator fluid, and its not on the floor, check your oil. if that's foamy, pull over, or death to the engine will come quickly. its 500 bucks vs a new engine. AnswerI'd strongly recommend getting a service manual before doing it; preferably the factory manual. But maybe one of the car store manuals will do it; look up the head gasket section and see if it specifies torque for the head bolts, order to tighten them in, whether you can reuse old bolts or need new ones every time, etc.

It's not necessarily a tough job, but it's one of the more finicky; after all, the factory presumably did the best job possible, and the gasket still blew, so you don't want to do a sloppy job. Although, any reasonably good job will last a while.

Some cars are easier than others. Whatever Ford compact had a rash of head gasket failures like in the 90s sometime and the dealers learned they can just undo the bolts, lift the head half an inch, pull out the old gasket with a pair of needle pliers and slide in the new gasket, and put it all back together again, all within half an hour, and collect 4 hours pay from the warranty book. Last time I did one, it took me all winter, but that was because it was too cold outside most of the time. Worked fine though. Until I overheated again.

The thing is, that just replacing the gasket isn't always the best idea. If the engine has a lot of miles on it and is burning oil, etc. might as well put a rebuilt head on as long as you're doing the work. Plus if the gasket blew because the head warped because it overheated, you should probably not put the warped head back on or it will eventually blow again. Thus the rebuilt head, which is ground flat before they rebuild it. (Which in itself causes some problems with cam timing, but that's another matter.....)

If the rings are shot, then the engine needs a total rebuild don't bother with anything less.

Lately, it's become almost more practical to just swap a used engine (or engine/trans, if its a FWD) from a junkyard instead of doing the gasket; it's more work and you're not likely to do it yourself, but the mechanic will likely guarantee it, assuming he gets to pick the engine; whereas they're reluctant to guarantee a head gasket for very long, given how finicky it is.

As for the cause, like everybody says, if you have an aluminum head, as most (all?) compact imports do, overheating will do it. Not right away, usually, but within a few months. The aluminum warps, and the uneven pressure is enough to let the gasket blow out. And the overheating is often due to a clogged radiator, or a leak that loses coolant, or a blown hose, or some such. Could be a long period of mild overheating, or a sudden high overheating. With me, it was always blowing a hose (or a hose clamp) on the highway, because you can lose all the coolant real quick and not notice any steam, like you would on the street at low speed.

Answer:I would order up an engine from a Japanese engine supplier, and replace the whole engine. The labor is not a whole lot more than doing a head gasket with much lower risk of problems.

Your blown head gasket was caused by some other problem that may or may not still exist when you are done repairing the head gasket.