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.)
[EDIT] Yes, bolts are re-usable unless visibly stretched or otherwise damaged. The "safe" thing to do is replace them. I did not.

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.
[EDIT] I had to shave the heads .015 to clean-up low spot where head gasket popped. I believe the heads have a weak area that "collapses" and reduces the crush on the head gasket fire-ring. Then the gasket fire-ring squeezes out from under the collapsed section of the head. I am HOPING that this is a once-and-done deal, and the head does not continue to give way in that localized area.

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.
[EDIT] Yes, replacing alternator is EASY with the rear head removed.

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.
[EDIT] Used that Fel-Pro set. Worked great.

5. Anything else I should do while I'm in there and have it apart?
[EDIT] Timing belt/pulleys, serpentine belt, block heater, O2 sensor, and OIL PUMP DRIVE O-RING are all good candidates when the heads are off. Push enough coolant down the exhaust pipe, and you'll need a catalytic converter, too. REMOVE at least one of the exhaust valves, if they're as pitted as mine were, you'll want a valve job. DO NOT replace ONE head gasket. The rear gasket was actually leaking, the front gasket was damaged, would have leaked in a few thousand miles. Both gaskets failed in the same place. Common problem???

[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/showthread.php/49680-1993-3-4-DOHC-quot-Lifters-quot

Performing the service bulletin to fix " cold engine lifter tick " '91 to '95 3.4 VIN X:

http://60degreev6.com/forum/showthread.php/49738-LQ1-Service-Bulletin-57-61-09-Lifter-tick-%28cold%29?p=450416#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.

[Dave96z34]

Having the 5 speed makes this job supper easy like 45min from below

[Schurkey]

Having the 5 speed makes this job supper easy like 45min from below

Supper easy? Like "done in time for dinner?"

I don't expect many four-doors have the five speed. Neither of mine do, anyway.

First replacement alternator was a Delphi. Wrong alternator in the correct-part-numbered box. No tab for latching the spring clip on the duct. Second replacement alternator showed up just before we were leaving town. Wilson rebuilt, not Delphi.

Unproven Suspicion: Neither Delco nor Delphi supply a CORRECT alternator for these vehicles. The photo of the Delphi on the store's computer shows the snap-lock tab, but the alternator supplied did NOT have the tab.





Frost plug removal is kicking my ass. Will not push in far enough to get it turned around to pull back out. Gonna have to make a puller tool that uses screw threads to grip and remove the plug. Once the block heater is in, the "real" reassembly begins.

Second replacement alternator--"Wilson" brand of reman. Has correct housing to accept duct. Somewhat different internals, I don't know if this is an upgrade or a downgrade based on smaller heat sink fins on the internal rectifier.




At this point, the alternator, block heater, and knock sensor are re-installed. I think this engine knocked so badly either from the lifter tick or from piston slap that the knock sensor was pulling timing.

Re-gasketed the oil pump drive, and reinstalled.


Resealed rear cam carrier. Need to reinstall lifters.

Need to disassemble and clean/inspect cylinder head, and then reassemble the rear bank. Project continues...


[EDIT] Frost plug removal, block heater warning:

http://60degreev6.com/forum/showthread.php/49839-3-4-VIN-X-LQ1-Engine-Block-Heater-Warning?p=451419#post451419

[Dave96z34]

Heads up unless you live in a hot hot climate don't bother with the docket.

[Schurkey]

Heads up unless you live in a hot hot climate don't bother with the docket.

Docket???

[pocket-rocket]

Alt. can be done once rear head is off.

Head bolts are your call. I've reused them without problems before.

I've yet to see cracked block/heads, but you should expect some warpage from aluminum heads.

Also, from my experience, the fallen exhaust guides only happens on the 96/97 style heads. The two sets I have here both have fallen guides, but I've yet to see it on a 91-95 head.

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