Losing coolant into #2

[Schurkey]

'93 Lumina Euro 3.4 (DOHC)

Will be removing rear head to inspect coolant loss into #2 cylinder; and pressurized cooling system (combustion gas into water jacket.)

I intend to install a block heater while the head is off and I have access to the core plug. I'll install a fresh oil pump drive O-ring and distributor gasket. I expect the O2 sensor is poisoned. Will investigate the catalytic converter--I think it's broken internally and rattling. Will clean the plenum and EGR passages, and clean/test the EGR valve. Will ohm-test the injectors. (Engine ran pretty good until the cooling system filled with air and the engine overheated.) [EDIT]Timing belt has only 25K on it; it looks good, I'll re-use it. Leakdown test shows good cylinder sealing except for bubbles into the water jacket for #2. [/EDIT]

I intend to investigate the "cold knock" oil system TSB. The kits are not available any more, but it may be that I can find parts separately. Since the cams have to be drilled, now would be the perfect time to dick with this.

My questions are:

1. Are the head bolts re-usable? Service manual says to clean the bolts (does not say to replace them.)

2. Does the 3.4 engine have a history of warped or cracked heads/warped or cracked blocks? I'm really hoping this is a head gasket problem. Won't know for sure until it's apart.

3. Is there room to replace the alternator from above while the rear head is off? Alternator works good...so far. I'm thinking if the head and exhaust manifold is off, it might be easy to get to.

4. Is there a "favorite" gasket set? I'd be very likely to buy the Fel-Pro HS9113PT1 Head Set unless there's a specific recommendation otherwise.

5. Anything else I should do while I'm in there and have it apart?

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[jman093]

1. They are reusable if not "necked" at all. I went ahead and bought some for mine as I'm doing a complete rebuild, but if they look alright and you wanna keep it cheap you should be alright.

2. I've heard of heads warping. I don't think its a real common thing, but if you have a head gasket sealing problem, I would definitely have the head milled. A machine shop can smooth them up pretty cheap.

3. I'm not sure if it'll fit out or not as I left mine on the engine when I pulled the engine out, but the bolts will become much more accessible at the very least.

4. I think that's the only one available. It's what I bought for mine.

5. Pull off your exhaust valves from the head and make sure the valve guides aren't falling down. I just found 7 out of 12 of mine have fallen. It seems to be fairly common. If you have any falling out, pull the other head and check all those to. That's definitely something you'll want to have repaired.

[Schurkey]

4. I think that's the only one available. It's what I bought for mine.

There's a Victor-Reinz set also. As it turns out, Amazon sells the Fel-Pro set for about $60 less than the Victor.

5. Pull off your exhaust valves from the head and make sure the valve guides aren't falling down. I just found 7 out of 12 of mine have fallen. It seems to be fairly common. If you have any falling out, pull the other head and check all those to. That's definitely something you'll want to have repaired.

Wow. I would not have expected the guides to move in the head. Definitely on the "watch list".

Shouldn't need to remove the valves for inspection--wouldn't this be seen through the ports? How much did yours move?

Thanks for the reply!

[jman093]

There's a Victor-Reinz set also. As it turns out, Amazon sells the Fel-Pro set for about $60 less than the Victor.


Wow. I would not have expected the guides to move in the head. Definitely on the "watch list".

Shouldn't need to remove the valves for inspection--wouldn't this be seen through the ports? How much did yours move?

Thanks for the reply!

I suppose that's right that you could see them through the ports. I'm not really thinking I guess.

There's maybe a quarter to half inch of movement on them. Enough that my valve stem seals won't stay on.

[Schurkey]

I suppose that's right that you could see them through the ports. I'm not really thinking I guess.

There's maybe a quarter to half inch of movement on them. Enough that my valve stem seals won't stay on.

If they were moving a quarter-inch to half-an-inch--WOW--I'd think they'd practically fall out. I will be looking for signs of movement on mine!

THANK YOU!

Put it off long enough...time to pull the cam carrier and the head. Ripped off the intake and timing belt covers last night.

[Schurkey]

Eleven percent leakdown on THIS tester is amazingly good--and yet I could hear the coolant bubbling.



Don't let anyone tell you that water (and coolant!) won't do a fabulous job of cleaning the combustion chamber. Anyway, I guess I found the problem...



The head is not too bad. I will have to get the area where the leak was (right beside the copyright symbol) checked to see if it's a low spot; and have the whole surface checked for warpage. Planing (milling) the head will not break my heart.



The block worries me more than the head. I can talk myself into thinking I can feel that the leak area is a low spot. Milling this flat will require complete engine tear-down, and I'm NOT looking forward to that. Maybe it's in my mind, and the surface is acceptably flat...



How tight are the head bolts??? They look "about" the same diameter (metric vs. inch) as a small-block Chevy (7/16"), although I didn't measure them. A SBC head is torqued to about 65 ft/lbs. My torque wrench is a few percent less accurate counter clockwise vs. clockwise (5% instead of 3%) but what the heck. I set my torque wrench to 65, and none of the four bolts I checked would loosen before the torque wrench clicked. Set the torque wrench higher, and tested four bolts at a time before setting the torque wrench higher still. The first bolt broke free with the torque wrench set to 160. The rest needed between 160 and 170 ft/lbs to crack free. HOLY CRAP! And yet the bolts look beautiful. Not obviously stretched or distorted.


Speaking of "crack", how tight are the head bolts??? They're so tight I busted a socket trying to loosen them! When they say "SNAP-on" they mean it. Sounded like a .22 round when it let go.

[jman093]

Torque spec is 37 ft/lbs and then another 90 degrees.

The sequence is

6 2 3 7
5 1 4 8

[Schurkey]

Making slow progress. Dis-assembled and cleaned the lifters for the rear bank.
http://60degreev6.com/forum/showthre...t-Lifters-quot

Performing the service bulletin to fix " cold engine lifter tick " '91 to '95 3.4 VIN X:
http://60degreev6.com/forum/showthre...416#post450416

[95SleeperAcheiva]

Replace the head bolts! They are cheap in comparison to doing the job again.

Alternator has to come out axle hole, passenger side. sometimes dropping the cradle on the passenger side helps in removal.

I use a 3"x5"x1/2" flat hunk of steel wrapped in emery cloth to "dress" my blocks. You should use a straight edge and check for warpage with feeler gauges, just like you do heads. Shouldn't exceed .004". I've run into blocks being out more then once, you can do most of it by hand if your patient and keep measuring as you go. Make sure to clean REALLY well after sanding, use a blow gun to help get any emery out of cracks, like the piston and such.

[Schurkey]

Alternator has to come out axle hole, passenger side. sometimes dropping the cradle on the passenger side helps in removal.

Alternator comes out the top when the head is off. No problem at all. Pulled the alternator WITH the duct still assembled. Took about fifteen minutes to remove.



Replacement alternator should be here tomorrow. Still have to install block heater. Having trouble getting the core plug out.