Replace both head gaskets or just the leaky one?

[chevyaddict]

Ok... this head gasket project on my 90 is a PAIN IN THE BUTT. Mainly because I keep running into bolts that just don't want to come undone. The driver's side head gasket blew so I'm replacing it. Seeing as this is probably more than I should have bitten off, I'm contemplating replacing only the driver's side and not both because the ac compressor removal and emission crap on the pass side is going to be a nightmare. Also having a bad back due to a post-surgery reherniated disc is not helping matters much. So what would you do?

Replace only the leaky gasket?
Replace them both while the car is 80% apart?

I've already decided I'm going to replace the water pump while I have everything apart. One less thing to have to deal with later....

 

[Toms007]

Well, I'm kind of crazy about these things, but beings it is that far down anyway, I'd probably go ahead and do them both. My luck would be, if I only replaced the one, a week after I get the one changed the other side would let loose, and then I'd be pulling it all apart again. But again, that's me. I'd probably change teh hoses as well...and probably the plugs and wires too...

 

[gmjunkie]

Ok... this head gasket project on my 90 is a PAIN IN THE BUTT. Mainly because I keep running into bolts that just don't want to come undone. The driver's side head gasket blew so I'm replacing it. Seeing as this is probably more than I should have bitten off, I'm contemplating replacing only the driver's side and not both because the ac compressor removal and emission crap on the pass side is going to be a nightmare. Also having a bad back due to a post-surgery reherniated disc is not helping matters much. So what would you do?

Replace only the leaky gasket?
Replace them both while the car is 80% apart?

I've already decided I'm going to replace the water pump while I have everything apart. One less thing to have to deal with later....

I say replace them both!!
Besides,Corvettes are easier than a Z-71,You ain't going to let this little girl out do you are you???All I did was grind the valves while the heads were off and adjust them when she was done!!!

 

[chevyaddict]

ha ha ha Junk!! Well, I've been rebuilding cars and engines my whole life... but without having something to lean over (IE a fender) and chronic back pain it makes one look at the whole thing differently. I'm normally hyper anal about doing a job fully and frankly am quite surprised that I'm contemplating the quick way out but I'm almost sure I'm going to forget how it all goes back together as it is!!! ha ha ha.......

 

[gmjunkie]

I'm almost sure I'm going to forget how it all goes back together as it is!!! ha ha ha.......

Thats what they make Digital Cameras for!!
Besides,"No Pain,No Gain"!!

 

[vetteboy86]

Ultimately I think the decision is yours. You can play the what if game all day long, but in the end, nobody knows when the other head gasket will start leaking. I know what everyone is saying though, with that much gone off the top of the motor, it is an excellent time to do it.

 

[bill5674]

add me to the go ahead list..same thing with my 90 couple years ago.drivers side blew so i figured what the heck, lets do both.last head bolt near the heater broke off.i guess i was lucky it broke almost flush! dont think you can pull the heads high enough to clear a stud that high. but i am getting carried away,i think the exhaust manifold has to come off with the head on the pass side. not tooo bad you`ll be glad you changed both especially if you are gonna keep her.......

 

[chevyaddict]

I just have to complain to someone who can empathize. This is a NIGHTMARE. I'm now trying to take the AC compressor off along with the brackets and because so many things are in the way I can't use sockets on many of the bolts.... or the bolts are too rusty to turn... or there isn't enough room.... or I don't have the right tool..... VERY FRUSTRATING! I've been turning the bottom ac bolt for 30 MINUTES a quarter turn at a time and its still not out. GGGGGRRRR!!!!!!!!!!!!!

Question though - that bolt on the tensioner pulley... if I undo that will the tensioner come undone? I'm assuming I have to separate that away from that entire huge bracket assembly on the passenger side where the ac bolts to it, correct?

 

[gmjunkie]

Question though - that bolt on the tensioner pulley... if I undo that will the tensioner come undone? I'm assuming I have to separate that away from that entire huge bracket assembly on the passenger side where the ac bolts to it, correct?

All the pressure should be off of the spring if the belt is off,It won't jump out and get you!!
It may come apart,but it wont be no big deal!!

 

[SPANISHVETTS]

All the pressure should be off of the spring if the belt is off,It won't jump out and get you!!
It may come apart,but it wont be no big deal!!

I think that there is an impossible to see nut on the back side of the bottom bolt. I remember that one of the compressor bolts had a nut on it.

You only need to move the compressor a bit forward. I have had Thunder's off so many times that it should be attached with quick disconnects.

90% of the tear down of the topend of the L98 is the intake. Be sure to use plenty of the right stuff on the plenum when you put it back together.

BTW I am in LA at the moment getting my knees and kidney rebuilt. If I can be of any use am glad to help.

 

[chevyaddict]

90% of the tear down of the topend of the L98 is the intake. Be sure to use plenty of the right stuff on the plenum when you put it back together.

BTW I am in LA at the moment getting my knees and kidney rebuilt. If I can be of any use am glad to help.

Ouch! That doesn't sound pleasant. By the "right stuff" you mean something so the bolts don't break off like ANOTHER ONE just did? I think someone else mentioned putting something on the bolts before I reassemble so I don't have this problem in the future.... At least the head broke off this one so I could remove the water neck. Broke another torx socket too.... that's number 3. This is just lovely. At least I've almost got the manifold off........

 

[SPANISHVETTS]

Ouch! That doesn't sound pleasant. By the "right stuff" you mean something so the bolts don't break off like ANOTHER ONE just did? I think someone else mentioned putting something on the bolts before I reassemble so I don't have this problem in the future.... At least the head broke off this one so I could remove the water neck. Broke another torx socket too.... that's number 3. This is just lovely. At least I've almost got the manifold off........

No, use the RTV named Right Stuff when you put the intake manifold back on. I have tried other products and they always start leaking. Never had a leak with the right stuff.

Have you tried banging the bolt a few times before trying to remove it?(use the torx with a long extension and tap the extension a few times with a fair size hammer)

Are those Snap-on or Craftsman torx that are breaking?

 

[chevyaddict]

They aren't craftsman... the ones I had but I'm replacing them with craftsman. Its different sizes that have busted so now its the 45 I'll replace. Thanks for the "right stuff" tip.

 

[bill5674]

its` been a while but i think the whole a/c tension assembly ,was unbolted and just pushed forward. there is alot of stuff in the way .why all the rust? I thought things didn`t rust in sunny az? sorry dont mean to kick ya when your down, as far as breaking torx sockets ..if you can find a snap-on truck any where they have the best torx drivers i have found..keep us posted one bolt at atime....bill

 

[vetteboy86]

They aren't craftsman... the ones I had but I'm replacing them with craftsman. Its different sizes that have busted so now its the 45 I'll replace. Thanks for the "right stuff" tip.

If, your using the right stuff, you will not need the front and rear seal when you put the intake back on. Just use a generous amount. I have used it for several builds, and never had any problems.

 

[tmkassin]

Great opportunity to freshen up the heads. It only takes a couple hours with an air grinder to open the ports a little. And check the valves for wear. It is well worth the $100 or so to get them hydro tested and decked. And put new seals on the valves too.

 

[chevyaddict]

Ok, so after a couple week break I'm back at this job. I have a question... when removing the a/c bracket that bolts to the head in the front (and also overlaps over the water pump), it seems I have to remove the tensioner from it. Right now that tensioner is hitting against that front frame piece and won't allow it to slide off. Is that what you guys have done? Or is there some other kind of trick?

And four of the 12 manifold bolts won't come off.... two of them were already stripped (I don't know what dweeb put stripped screws back in there) and the other two are just too tight. Been doing the penetrating oil and tapping to no avail. I absolutely don't want to drill these out because they are into the aluminum heads... but least to say I am very frustrated. Why in the hell did Chevy decide to use these damn torx bolts anyway? Lame idea I think. I don't think I'm going to put those back on when (and if I ever get it apart) reassemble it.....

 

[Mac]

Why in the hell did Chevy decide to use these damn torx bolts anyway?

My best guess is they wanted to improve the vocabulary of grease monkeys. Most of us have invented new swear words trying to remove torx bolts. The only thing worse is the torx security bolts with the lovely little pin in the middle.. ad

Chevy wasn't the only one; most of the manufacturers were using them for a while. I'm not sure why since they're such a nuisance. Unless you're perfectly straight onto them, they strip so easily!

If penetrating oil and a couple firm smacks doesn't jar them, you might try heating using a heat gun. Once it's hot, squirt more penetrating oil on the threads and then the hammer again.

-Mac

 

[chevyaddict]

Thanks you two... a friend of mine suggested heat too although he said using a small torch. I'm a little afraid to do that with aluminum manifold and heads. hnoes

 

[SPANISHVETTS]

Time to get nasty with the torx

At this point it is probably safe to say that the manifold is going to have to be re-tapped and have heli-coils installed in a lot of the threads. It will not cost much more to re-tap and heli-coil all of the threaded holes and that will end this problem forever.

So (I love starting paragraphs with And & So) get the bolts out anyway you can. I despise extractors and do not allow them in the shop.

To remove a frozen bold we weld another larger bolt to it. One with a nice big head to get a wrench on. The heat generated in the bolt while welding helps to break the threads loose.

Then we wiggle the wrench back and forth until the bolt finally breaks free. Often the welded on bolt breaks free. Just weld it back on and keep trying. This method is about 90% effective for us. The other 10% are not coming out for love, money or an act of any god of your choosing.

Good luck