View Full Version : How hard is it to change the head gasket?

05-31-2001, 10:59 AM
i think that is what is wrong w/ my 90 240sx. it was overheating b4, and i drained, rinsed, and filled the radiator. it was ok for about a day. then it was overheating again. now i've found water in the motor oil. i've heard from others that these are symptoms of a blown head gasket.

how many ppl have done this before? any tips? thanks in advance

05-31-2001, 12:21 PM
I've done only the ka24e head gasket in car once and I am currently in the middle of my second ka engine rebuild. So here goes the longest single FA post ever (being at work is great isn't it) http://www.freshalloy.com/ Also this isn't necessarilly directed at you, as you may have much more mechanical experience just a general writeup that I have cut and pasted together from old e-mails I've sent previously.

I am assuming if you are thinking about attempting the job that you are fairly mechanically inclined b/c things can get interesting.

First thing to do is at least a compression test to determine what you are going up against, you can buy a tester for no more than $30 at the parts store. The factory spec for the ka24e (89-90) is 192 PSI, the key here is the difference per cylinder. Anything geater than +- 10 PSI can indicate a leak across those cylinders. You can add oil to check the rings to get an idea of what condition the engine is in. Also figure out why the headgasket went... overheated? Problems in your coolant system? If you don't fix that it'll happen again. Could it be the infamous ka24e timing chain problem? maybe the head is ok but the front engine cover was damaged by the timing chain. Maybe both are at damaged now. In short find out what went wrong and why before you start pulling heads off engines.

Once you have confirmed the head gasket has gone south. The actual removal of the head is not that difficult, but you will remove all of the upper engine. Bolts may be rusted/ could break but in general a good set of tools can get you through it in a apprehensive couple of hours. Basically pay attention, and follow removal steps in the Chiltons and double check with the Factory Service Manual.. (you are really going to need one). If you don't follow them you can easily warp or crack your head if it isn't allready at this point.

Once you have the head off. Start the inspection process. Determine if the head is warped/cracked. Check the block to see if its warped. etc.

Take it to a machine shop to get the head decked if necessary, then slap it back on there with new gaskets are you're all set. Of course you've marked everything you've removed and you carefully reset the timing and lastly didn't damage anything else in the process. Also torqued everything to spec etc.

It'll cost you nearly $75 for the necessary gaskets. New head bolts are probably a good idea $35. Another $40 to deck the head if needed. Plus... well you can replace nearly everything in the upper engine easily at this point and should consider getting at least some of the things done. The timing chain on the ka24e basically sucks. The original guides break and can destroy otherwise perfectly good engines for no reason (Maybe this is what caused the head to overheat). This is another ~100 that is well worth it and easier now that the head is off(trust me). The valves should probably be done while the head is out ( a head recondition, with valve job and head deck is $200). Why not consider aftermarket cams, head port and polishing while you're at it ($$$$ but no extra labor on your part).

In closing... Its not that "hard" but if you mess up at the few tricky parts you'll have a mess on your hands. I wrote this up as a guide for explaining what kind of work is involved. There are some huge leaps of faith. When I get around to it I might just put a web page together with pictures on doing this kind of job. In the interm send an email my way.. afm@duke.edu

PS: Is it time to go home yet?

05-31-2001, 05:19 PM
Esporque, I live in Raleigh, NC. (North Raleigh) I see you are located in Durham. I would like to meet with you if you are up for it. Let me know.


92' 240sx

05-31-2001, 09:26 PM
HKS makes a metal one, carpart.com sells it.~$200 I belive.

05-31-2001, 11:22 PM
Along with the above question...for future reference when going to rebuild a motor I know that using a metal head gasket is usually used. Are there any available for the DOHC and if so who makes them...Tomei, ect...??

05-31-2001, 11:38 PM
call beatty and woods...they found one for me


sorry i don't know what make it was...i did not look at the package, and my mechanic just put it in.

06-01-2001, 11:58 PM
Nobody makes metal headgaskets for the KA. Carparts.com doesn't list any 240sx applications for the HKS metal head gaskets.


<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by vortex240:
HKS makes a metal one, carpart.com sells it.~$200 I belive.<HR></BLOCKQUOTE>