CrazyHawaiian

The L98 in my 1989 IROC-Z (130K miles) has alot of problems. I'm saving up on the side to build another motor, but in the meantime I'm trying to keep this motor running for as cheap as possible so I can continue to enjoy the car. Recently the headgasket blew on the pass side head so I'll be taking the heads off to replace the headgaskets. And as long as I'm doing that I'm also gonna replace all the intake gaskets. But I'm not sure what I should do with these heads. The car blows smoke on startup ever since I got it (even before the headgasket went) and there is a good ammount of what I'm guessing is blowby. Every once in a while I'll get a good ammount of wet oil on the plugs when I check them. The compression tests indicated something wrong on the top end, so I'm also guessing there is something wrong with the valve seals or other seals/gaskets in the heads. When I put this thing back together I plan to replace the head, intake, and valve cover gaskets, and I'm going to redo the PVC system. I'm hoping this will help stop oil from getting on the plugs. But my real dilemma here is what to do with these heads. I want to do this as cheap as possible. My only real goal here is to have the engine run again. I dont want to make more power or anything like that. The heads will already be off the car, I figgure if there is a cheap/easy fix for whatever I might find then I might as well do it. Is this something the DIY'er can likely diagnose and fix? I've never done this before. Are there common seals/gaskets in the head that go bad above 100K miles? How would I diagnose this? Or does this require specialty tools/knowledge meaning I should send them to a machine shop? I'm just interested in replacing whatever seals/gaskets I have to so hopefully the engine lasts a little longer before finally exploding in a horrible death. And I wanna do it cheap if possible, these heads are not worth spending $$. I would really appreciate your guys advice on this, I'm not sure what to do in the worst case scenario (the heads need alot of work).

ZZ28ZZ

I would take the heads to a local trustworthy machine shop and have a valve job done. The seals will be replaced when they do that.

Check the heads for cracks before spending any real money on them. I would also have abt .005" milled off them since they may be warped after blowing the head gasket.

Depending on what kind of new eng you're building, you may be able to use the heads again and thus justify dumping a little more money into them now.

Kevin Vandevenne

iTrader: (3)

You could replace all the valve seals on the head. You should be able to do this yourself. You'll need to remove the valve springs, you can usually rent a tool at the local parts store to get the springs off. Vavle guide seals are cheap...probably cost $20-$30 for the seals. I'd do this first. If it still leaks after then you know you are in for bigger repairs down the road.

CrazyHawaiian

Thanks Kevin, thats exactly the type of information I was looking for. I'm guessing as long as I have to remove the valve springs I might as well replace them with fresh OEM replacement valve springs (these heads have 130K miles). I'll go price this stuff out and see what I'm in for. Thanks again!

CrazyHawaiian

Anyone else got ideas/comments?

RBob

iTrader: (1)

I second the valve stem seal replacement, easy & cheap, and will help a lot with the startup smoke.

I wouldn't replace the springs, just put the originals back in. No sense spending money on this motor when it will be put to better use in the new motor.

Another item would be to look at the valves. If any are burnt or cracked just replace the damaged ones. May be able to get some good used ones from a shop. Again, enough to get by without spending much money. If you replace any of the valves I wouldn't even do a valve job unless lapping showed it was required.

Sometimes the backs of the intake valves get carboned up. Can always wire brush them to clean it off. If you have some time maybe lap the valves to the seats.

Then put it back together with the new gaskets.

RBob.

CrazyHawaiian

Awesome, thanks alot for the advice!! I like your guys ideas on keeping this as cheap as possible but still effective. I hope to have the heads off by tonight so I'll have more updates on what I find. I'll have to do some research on the term "lap" in regards to the valves, I'm not familiar with that one. Thanks again!!

CrazyHawaiian

I got this far, gonna pull the heads tomorrow and see whats up.

D's89IROCZ

Another thnig I am wondering , what different has to be done to the PCV system in a forced induction setup , so it runs right ?

I was wondering if that had soemthnig to do with the blow by ?

CrazyHawaiian

On my boosted car I'm running breathers on both valvecovers and it seems to run perfect. This is something the previous owner did. I considered converting it back to the regular PCV system but since it works good I decided not to mess with it. If you do a search there are some good threads on the subject where people that know way more about it than me explain it. On this N/A car I'm working on here with the headgasket failure I'm running the stock PCV system, but I think my PCV check ball thingy might have been clogged.

CrazyHawaiian

Got the heads off, looks like I'm in business. Definately a head gasket failure between the cylinder walls (yay no exploded parts or anything). I'll post pics later after I get some sleep ...