I blew a head gasket tuesday, L98. My dad and I are tackling the replacement project tomorrow, any advice, or things I need to do while I'm at it?

 

advice - don't screw up

Honestly though the only other things that I can think of that you should check would only involve other problems your engine has. for example, you could clean the throttle plate or just replace all the seals in the engine.

 

If it blew for the typical reason - galvanic corrosion caused by a weeping head gasket that allowed exhaust gasses to mix with the coolant - then the cooling system is a mess and the radiator and heater core need to be flushed if not replaced. You also need to get everything out of the block so pull the oil cooler hose at the filter and the knock sensor. This assumes that the block is still good. Many early aluminum headed Vettes began to weep at #7 close to end of the warranty. Left undetected, it wears a groove in the deck of the block that will be fairly obvious when you take it apart. If you don't deal with it, you'll be replacing the head gasket again . . . . and again.

 

soak the exhaust bolts with a penatrating oil, and drain the coolant from the block...for starter's

 

Have the cylinder heads checked. Make sure they're flat....and no, you can't eyeball them...and have them pressure tested to ensure they aren't cracked. The shop can also check the valve guides and seats.

"While you're at it"....is solely dependent upon budget. Something easy and for durability would be to replace the valve springs. Another thing would be to replace the lifters. A few horsepower can be gained with the addition of roller rockers. A few more horsepower can be gained by adding 1.6 roller rockers and having the heads machined to accept springs that will work with them. Yet more power can be gained with basic cylinder head porting, chamber clean-up, and port matching to the intake. Next up would be adding Super Ram intake manifold. etc, etc, etc.

How fast you want to go? How much money do you have?

Btw...A Factory Service Manual is a WISE investment. Buy one if you don't already have one.

 

If this is something that comes up, what should be done to fix it and prevent recurrence?

 

How much do you think a shop would charge to have those things checked?
By "While I'm at it," I simply meant maintenance and preventative things. I'm a college student that just bought a house, I have no budget I'll keep this post in mind for future reference though

 

then make the Necessary repairs, but you will need to take the heads to a good machine shop for leak & flat surface testing, they will report on what is recommended.

 

$200 - $300 to clean them up, check the guides, pressure test, and surface them.

If you need guides, seats, valves, the price will increase. A cheap way to address worn guides is for the shop to knurl them.

In all likelihood, yours won't need anything more than cleaning/checking/surfacing.

 

Hope so. As far as I know, I didn't drive it much with the blown gasket. When it really crapped out on me, I drove maybe 4 miles to get it home. Temps never went above 230, assuming my temp gauge is accurate.

 

If the deck of the block is grooved, you can either pull it and have a shop mill it or you need a new one. Frankly I'd go for a new. You can try a boneyard for used, but so many '88 to '91 Vettes have this issue, you may find the same problem - assuming your Year is in that range.

 

My machine shop is about $240 to clean both heads, replace valve guides, flatten the heads if needed and check for valve seat wear.
Another $100 gets a valve job. If I supply springs, keepers, etc. they will do those at the same time they do the valve guides.

 

you probably know this already.....but.....

1) label each hose and wire that you take off without exception. Take pictures or make drawings to be sure where the parts came from. Place bolts in plastic bags with labels keeping them together as a unit.
2) label the bolts.....some are shorter than others on the runners to the intake.
3) ALWAYS use anti-seize on any steel bolt that threads into aluminum.
4) Use a center punch and dimple the china wall at the front and rear of the block. I also dimpled the intake manifold in these same areas. The dimples give the gasket material (Silicone or The Right Stuff) something to grab hold.
5) Use the Right Stuff instead of silicone.
6) I usually line up the timing marks before taking things apart. It makes it easier to tell where your distributor rotor should be pointing. Mark the position of the rotor.
7) You need to get some rubber push over plugs to cap off your fuel lines. They WILL LEAK if your don't (ask me how I know...).
8)....drain the block by pulling the knock sensor and then the drain plug on the drivers side. These holes sometimes rust over, if so then use a screw driver to break thru the rust....be ready for rushing coolant.
9) Use thread sealant on the head bolts. Suggest you use the same on the intake bolts where they enter the head if they will be exposed to oil from the galley.
10) While you have the TB/plenum and runners off clean the inside of carbon build up.
11) Take a cardboard box and punch small holes (or slots) in it to represent the each head marked front and drivers/passengers side. Then as you take out the push rods and rockers push the rod into the hole in the box to keep them in the exact position they came out of the heads. Then place the rocker over the rod.
12) Make sure that all your gasket surfaces are clean and oil free before assembly.
13) MAKE YOU DAD DO ALL THE WORK AS YOU GO FETCH BEER FOR THE TWO OF YOU....

GOOD LUCK ON YOUR PROJECT.

 

I know what budget is,been there, pull the heads , if you can see where the head gasket is blown your half way there. check your heads with a good strait edge if there good new head gaskets and button it up. do dry out the cyl.,clean the lifter gally drain and change the engine oil and filter. just drain the coolant through the petcock, don't pull the knock sensor,can open up a can of worms. if you can not see where the gasket is blown, have the heads checked out by a machine shop toverify. if he car was running ok before it will run the same after. i have seen to may people do a vave job on a high milage motor,ya it needed it, but making the top end solid you can plan on blowing the rings out of it. if it smoked on start up valve seals are probably shot. if you and dad have the means to replace the seals, go ahead ,just do them one at a time and dont mix up the valves. good luck just my 2 cents