Need some DIY input to replace a headgasket on my 93' Civic DX

The symptoms sure sound like a head gasket, and possibly a warped head. Cracked heads are rarer. The shadetree test for head gasket trouble is to remove the radiator cap (engine cold!) and start the engine. Pinch off the hose to the reservoir and place the palm of your hand over the radiator opening for a few seconds. If you feel steadily rising pressure or (worse) pulsations the head needs to come off for repair.

Replacing a head gasket is a fairly advanced DIY job, but it is more work than skill that makes it a challenge. Some important points:

*Don't rush. Expect the car to be down a week or two as you sort out snags, in expertise or tool availability. Before the new head gasket goes on be sure the surfaces are really ready (flat and clean). Check for guidance frequently. *Ask around to find a friend of a friend who has replaced a head gasket before. Having a local source of expertise is both emotional and technical support. *Rent the special tools you need, which will certainly include a torque wrench. Some parts chains offer what amounts to free rentals for up to three days - it amounts to buying the tool and returning it for a refund, but they expect you to do that. *A good manual is a good friend. You can get a Haynes manual for under $20 US the last I saw, but the Helm manual at $62 will serve you much better. DIY repairs can make up the difference in price very quickly.

Mike

Hey Mike, Thanks for the response. Turns out pops knows a bit more about head gaskets than I thought. He has all the tools, and we have a mechanic who's gonna come over and remove the head, and take it to an auto shop to get it milled. I guess from then on it's a matter of a new gasket and putting everything back together? Should have the Haynes manual in the house somewhere...I really think I'll be able to get through this, but I'm keeping your response to look back on if need be. Thanks Loads...

Sincerely Chris

do NOT get the head milled unless it is warped. i've seen many an alloy head screwed up this way. and they get slapped back on the block regardless so the owner has to go back again in 6 months and gets soaked for a new motor.

1. remove head.
2. do a rough check for flatness.
3. if ok, clean it up /carefully/.
4. check for flatness again.
5. finish cleaning.
6. re-use.

google this group for recent talk-through of this procedure on an accord.

oh, and the reason milling is such a gamble is because if the cutting piece picks up a piece of crud, it drags it all the way across the head gouging a deeper and deeper furrow in the surface as it goes. in old cast iron heads, this doesn't happen, so in the old days, it was ok to do this as a routine service procedure. old habits die hard, and in this case, can be very destructive. the head needs to be finished to near mirror finish to give a long term seal. if you really /must/ skim the head, make sure you inspect the work of the shop on other heads before you let them touch yours. if they produce near mirror, go ahead and use them. if they produce stuff with milling marks and ridges on it, move right along. and don't believe any story about the head needing milling marks to "grip" the gasket - that's bunk.

Some shop that fouled up a milling must have come up with that and described it as a "feature."

Yeah, feature, that's the ticket... it needs those scratches. Hate to have the head slip plumb off the gasket because it's so smooth, right?

Mike

I defer to the group experience on this. I've had the luxury of stumbling across a first-rate cylinder head shop (Arizona Cylinder Head for those in the Phoenix area) and never had to worry about unnecessary work or bad work. I agree, if a shop falls short in either of those areas it could make a slightly bad situation much worse. A slightly gouged mating surface is the path to perdition.

Mike

People have been resurfacing head or aluminum alloys for years and only the inexperience would drag the crud all the way across the head.

A near mirror finishes are too expensive for the average car owner could afford. Unless the car manufacturer requires a near mirror finish, don't bother with it.

My retired ex-partner has done some milling for me in his garage, and the output of the milling machine can be described as "near mirror finish." If a milling machine isn't producing that sort of output, it's because the head hasn't been dressed lately. That's the sort of neglect that can weaken the head gasket seal as combustion gasses insinuate their way through the gaps.

Actually, I don't think debris produces the milling marks. The cutter head is an abrasive disk spun at high speed that is scanned across the surface in the plane of the disk The edge of the disk cuts a flat groove at a preset thickness, then is moved laterally to cut an identical groove beside that, and so on. Milling marks appear if the wheel edge is not true.

Mike

the point for both of you is that a /lot/ of head shops out there simply use the same cutter on an alloy head that they use for cast iron. the best case result is a grooved head that is a /long/ way from smooth. and worst case is the gouging i'm warning you about - i've seen it many times guys, so beware.

and the biggest point in all this is that for most repair shops that use these kinds of milling services, they never get to see the consequences so they never learn any different. most cars are high mileage when the head goes the first time. if it goes a second, the car gets sold or junked. for my personal vehicle, i want the repair to last at least as long as the original - that's 140,141 miles. that's never going to happen on a grooved head because gas channels along the groove base. it's slow at first due to gasket sealant, but that sealant erodes, and then you get leakage again.

unless you have access to a shop that can produce a bona-fide high quality near-mirror finish, milling a head that is not warped is simply "monkey see, monkey do".