Head gasket replacement and head porting Q's

[lone73]

Looks like I may have a slight head gasket leak on my ZZ4 with about 70K miles on it, has the stock ZZ4 aluminum heads on it still. The left head at the left front below the exhaust manifold had two bolts loose and oil or something blackened leaking from underneath the bolt heads. I tried to tighten them down a few weeks ago (a few weeks of driving that is, had the car dn last 2 months for a trans rebuild) but looks like it didn’t take. Now I have a very audible tick-tick-tick coming from that area of the motor – after it warms up, doesn’t do it when its cold. I’m thinking blown head gasket. Any opinions on this?





If I do have to pull the head and replace the gasket, got a few questions for anybody that’s been down this road…

1. Do the head bolts in the described area enter the oil passages ?

2. Do I have to replace the head bolts or can I reuse the old ones?

3. I found Fel-Pro PermaTorque head gaskets at Summit (FEL-7733PT2) for 14.95 a pair. Are those adequate or are they too cheap?

4. I have some time to try my own porting in the next couple of weeks as well if it is not too time consuming. Anybody tried this? How do I go about it? How much time would just a pocket port job take?

5. Anybody know the torque amount and torque sequence for a ZZ4 aluminum head?



Thanks
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[JohnZ]

If I do have to pull the head and replace the gasket, got a few questions for anybody that’s been down this road…

1. Do the head bolts in the described area enter the oil passages ?

2. Do I have to replace the head bolts or can I reuse the old ones?

3. I found Fel-Pro PermaTorque head gaskets at Summit (FEL-7733PT2) for 14.95 a pair. Are those adequate or are they too cheap?

4. I have some time to try my own porting in the next couple of weeks as well if it is not too time consuming. Anybody tried this? How do I go about it? How much time would just a pocket port job take?

5. Anybody know the torque amount and torque sequence for a ZZ4 aluminum head?



Thanks
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1. Nope, the head bolts just go into the water jackets.

2. Yes, you can re-use the head bolts; clean their threads thoroughly, clean the threads in the block with a thread-chaser (NOT with a tap), and use thread sealant on each bolt.

3. Never heard of those gaskets, and they can't be worth much at that price; you need Fel-Pro FPP-1010 Perma-Torque Blue with the copper fire ring (so they don't brinell your aluminum heads).

4. If you haven't ported heads before, I wouldn't recommend you try it at home; either have a shop do it that's experienced at it, or forget it.

5. Head bolt torque is 65 ft-lbs., done in three steps (25-45-65), with sealant on the threads and oil under the bolt heads, sequence shown below:

 

[lone73]

Thanks for the info John

Have you ever seen black oily looking stuff oozing from underneath the bolt heads before?

I may try just retorqueing b4 I pull the head off. I really don't know why they would leak like that.

thanks

 

[JohnZ]

Thanks for the info John

Have you ever seen black oily looking stuff oozing from underneath the bolt heads before?

I may try just retorqueing b4 I pull the head off. I really don't know why they would leak like that.

thanks

Black oily stuff oozing from underneath the bolt heads would indicate coolant blackened by combustion gases, a symptom of head gasket failure.