Losing coolant into #2

[Schurkey]

OK, before I go any farther with the alternator...which I installed yesterday:

Has anyone put the '96--'97 alternator onto an earlier vehicle?

From on-line photos, it looks like the '96--'97 alternator is the newer, more reliable CS130D. Again, based on on-line photos, it appears that it may be possible for the earlier duct to connect to the later alternator. The main difficulty is that the lower/main mounting lug is entirely different. I'm not sure if the new alternator also requires a change to the giant aluminum accessory mount plate on the end of the engine.

Is the accessory mount plate different from '95 to '96?

There is a small bracket on the firewall side of the engine that the main/longer alternator bolt screws into. Is that different between '95 and '96?



All of these questions relate to the possibility of installing the later alternator on the earlier bracketry; can it be done with minor fabricating or does it require the newer mounting plate and such?

I'd be really thrilled to get rid of the P. O. S. early CS130 alternator!

Later CS130D: From napaonline.com p/n RAY 134715


Earlier CS130: Also from www.napaonline.com p/n RAY 2134532D

[robertisaar]

Crazy K has mentioned to me that the only difference between a 3100(or was it 3.1?) and 3.4 alt is the back plastic section that allows the cooling duct to attach. or at least i think he did.

i can't confirm this myself, but it's worth a look, if you happen to find one to compare.

[Schurkey]

Crazy K has mentioned to me that the only difference between a 3100(or was it 3.1?) and 3.4 alt is the back plastic section that allows the cooling duct to attach. or at least i think he did.

i can't confirm this myself, but it's worth a look, if you happen to find one to compare.

Pretty sure that is not true for the older-style alternator.

I'd certainly believe it could be true for the '96--'97 style.

[robertisaar]

probably, i don't remember the conversation too well, but it's worth looking into.

[Schurkey]

Service manual says to install "new" flat rings and "new" lock rings into the sprocket when tightening the camshaft sprockets to the camshafts.

Just got back from the local dealership; flat rings and lock rings are discontinued. They were sold as "Kit 1"; both rings and a new sprocket (four kits per engine!), but THOSE are discontinued also. There are a few "Kit 1"s floating around at various dealerships--they're discontinued but not sold-out yet. Dealership price is ~$50 each, plus freight.

I have absolutely no inclination to drop $400 in sprockets onto my two LQ1s. ($200 each engine; plus freight)

Has anyone had experience (good/bad) with reusing the flat rings and lock rings when installing the timing belt on '91--93 LQ1s? (94-up uses a different sprocket locking system--I guess.)

Is there a source for the flat and lock rings in the aftermarket?

[pocket-rocket]

Out of the many early style LQ1 timing belts I've done, this is the first I've heard about getting new hardware. I never had any fail from reusing old hardware either.

[Schurkey]

Out of the many early style LQ1 timing belts I've done, this is the first I've heard about getting new hardware. I never had any fail from reusing old hardware either.

Thank you. I'll be reusing the lock rings. I don't expect problems.

The flat rings do show some "indentation" from use. I suppose the lock rings are now compressed some. They look kind of like the inside of corrugated cardboard--the metal has been pressed back and forth, and then installation between the camshaft and flat lock ring provides a controlled press-fit between the corrugations. So...maybe...there'll be reduced press-fit. I'm willing to take that risk.

[pocket-rocket]

You are welcome

Also, if it's any comfort my 91 is the one Ben and I experimented on with cam timing trying a few different combinations, and the pullies were pulled (except the rear exhaust) so they've gone through many removal/installation cycles- more than I would expect the run of the mill LQ1 to go through, and they are still holding to this day.

[Schurkey]

OK, I'm parked in the hotel, looking out at the Atlantic ocean; and reading my newest book, which showed up the day before we flew out.

http://www.amazon.com/David-Vizards-Cylinder-Heads-Design/dp/1934709646/ref=sr_1_1?ie=UTF8&qid=1331690109&sr=8-1

Vizard makes a big production out of flowbenches; specifically suggesting that $100 in parts, along with some "sweat equity" will produce a flow bench capable of determining whether or not a change to the heads produced a gain in flow, or a loss.

As of a few days ago, I bought a pair of heads 'n' cam carriers from a nice guy in Minneapolis. He was kind enough to deliver the parts to my brother-in-law in Saint Paul. They'll be waiting for me when I go home.

SO: I now project that this head gasket failure is going to morph into a head-porting and valve job; with the spare heads becoming port-shape guinea pigs. Like I need another delay...

Next up: Finding a valve and seat grinder in my price range. Been looking for about six months; stuff is either worn-out junk or too far away; or too expensive for me.

If I had any sense--or self-control--I'd throw this engine back together and do the porting job on the OTHER Lumina. No promises on how this pans out.

[Schurkey]

Next up: Finding a valve and seat grinder in my price range. Been looking for about six months; stuff is either worn-out junk or too far away; or too expensive for me.

Months later: Found, purchased, and reconditioned a Sioux model 680 valve grinder. Had to have a part reworked to accept the small-diameter valve stems of the 3.4 engine. Got the part back today from the machine shop. It appears that I can now hold runout of the valve in the chuck to under one-thousandth of an inch--approx. .0007 as measured with a dial indicator. As long as the runout is less than the valve stem-to-guide clearance, it should be OK, but "industry standard" for runout is .001 maximum, with less preferred.

The intake valves, and the intake and exhaust seats look pretty good. The exhaust valves look like crap. I've experimented with a couple of exhaust valves in the valve grinder; results were less than optimum until today with the reworked chuck shaft. The last part of the grinder reconditioning is to weld an angle-iron base with four casters. The grinder and cabinet together are heavy as hell. I want to be able to roll it around the shop (and out of the way when I'm not using it.) Once the wheeled base is complete, it looks like I'm ready to grind valves "for real".

Here's a photo of an un-ground exhaust valve as removed from the engine but cleaned on a wire wheel and with some solvent, and an exhaust valve freshly ground with the reworked valve grinder. I have inspected all the exhaust valves from the rear head of my 150,000 mile engine, and the valves from the two spare heads I got off of Craigslist with "unknown" mileage. All the exhaust valves look about the same. Frankly, I think they're made of poor material:


The valves have a 45 degree face, and a 30 degree back-cut for improved flow as manufactured by GM. You can see the two separate angles if you look closely--and of course it's very easy on the un-ground valve--the shiny area above the pitted 45 degree face is the 30 degree back-cut.

Two things surprise me:
1. This engine ran great up until the head gasket failure. Even the leakdown test did not indicate excessive valve leakage. Power may have been down slightly--I have a theory for that involving the knock sensor and overly-retarded ignition timing--but it idled smoothly and would bounce against the speed limiter if given a chance.

2. The exhaust valve seats don't look beat-up by the pitted valves. Must be hard as hell.

Finally, some progress on this hanger-queen.

[Schurkey]

Valve job completed; the valve grinder is now functioning perfectly--I dicked with it some more to get the runout down to less than .0005. As bad as the exhaust valves appeared, (photo in previous post) they would clean up by grinding only .003 to .004 from the faces; lapping the valve to the seat, and then grinding the back-cut ALMOST to the witness mark of the lapping. The intake valves cleaned up with a .001 to .002 grind, and again they were lapped to the valve seat, and then back-cut.

The seats were beautiful, only two needed to be touched-up with the seat grinding stone. When I was done, all valve tips met the height specification detailed in the service manual.

I obtained a vacuum-style valve sealing tester. After reworking and cleaning the machine, it would produce an 89% vacuum when completely plugged with a suction cup. When connected to the cylinder head ports, the valves would seal to the valve seats so efficiently that there was only a percent or three of leakage. There is no way to know how much of that was "true" valve leakage, and how much is leakage past the valve stem seal and up the valve guide. The worst pair of valves was sealing at 86%; a loss of only 3% from what the machine was capable of producing. (This is without the valve springs installed. Sometimes, the valve spring pressure can cause marginal valves and seats to seal better.) I consider these results "excellent".

Ultimate suction produced by the vacuum unit--note suction cup over the port adapter:


Suction when testing valve sealing against the valve seat--port adapter allows the vacuum to be applied to the port--and therefore to the valve and seat. This pair of exhaust valves is sealing within 1% of the capacity of the machine.


Discovered that the front head gasket was degraded and would have soon met the same fate as the rear head gasket that started this whole mess. The defect was in EXACTLY the same place; so I'd have had a coolant leak into #6 in perhaps a thousand miles. At the point that I took it apart, there was no leakage...caught it JUST in time.

I stacked the rear head gasket (actually leaking) on top of the front head gasket (not leaking...yet), but shifted the rear gasket a little to one side so you can see both defects.







First guess: The cylinder head may have a weak area at this location, after a hundred thousand miles or more, the head distorts and the gasket loses clamping force. My cylinder heads had "low spots" at the gasket failure, I KNOW that the gasket wasn't being clamped properly. As the gasket wiggles back and forth on the block because it's not being "pinched" properly, it etches the iron. Eventually the gasket "blows"; allowing coolant into the cylinder, and combustion gasses into the cooling system. This is my best guess at the root cause of the identical head gasket failures. Anyone else have a similar gasket failure and care to comment???

Both the front and the rear head were planed .015 to true the head gasket surface.

The block damage was very similar front and rear at the gasket defect.

Rear deck surface at the fire-ring defect:


Front deck surface at the fire-ring defect:


At some point in time, this engine swallowed a small screw. #2 cylinder has evidence of the screw threads pounded into the piston quench areas. The cylinder head has similar marks. Cylinder #4 had a couple of marks, but not as bad. Apparently the screw got pounded several times in one cylinder, got blown back into the intake manifold where it went to a different cylinder, got pounded some more before finally blowing out the exhaust. I did NOT find the screw inside the engine. There did not seem to be a problem with ring seal or oil consumption on any of the cylinders, so the piston damage does not seem to have pinched the top ring groove.


I elected to re-use the head bolts. Service manual says to inspect them, clean them, and re-use if not visually defective. Works for me. REMOVING the head bolts took a fairly uniform 160 foot-lbs to crack them loose. The threads and under the bolt heads were completely dry of lubricant. I cleaned and inspected the bolts, then painted a stripe down the length of them. If I ever remove them, and that stripe has become a spiral, I know the bolts have twisted. With any luck, I'll never have to pull them out again!


I lubed the threads and under the bolt heads with moly-based assembly lube. The bolts were torqued to 37 foot-pounds in three steps--20 ft/lbs, 30 ft/lbs, and then finally 37 ft/lbs using the GM-specified sequence. Then each bolt was carefully turned another 90 degrees using a Lisle 28100 angle-meter, again in proper sequence.

Because I was curious, I then put a torque wrench on each bolt, starting at 50 ft/lbs, and increasing until the bolts "felt" like they were about to turn tighter. I DID NOT actually tighten any bolts further with the torque wrench; but they all began to feel "rubbery" at nearly the same torque--70 ft/lbs. This is way more in line with what I'd expected based on the bolt diameter--the metric equivalent of 7/16; similar to a small-block Chevy and it's head bolt torque of 65 ft/lbs.






Ran the engine today for the first time since February when the rear head gasket popped.

Still need to install the covers over the timing belt pulleys, the PS pump and tubing, the accessory belt, and a few other odds 'n' ends. Still not drivable, but will be as soon as I get back from yet another trip. I can hardly wait to get this car back on the road. I am just a little concerned about the etching to the block surfaces; and how that may--or may not--affect the head gasket seal. The only way to fix that would be to plane the block; that would require complete engine removal and disassembly, and I don't have another year to finish this project.

My second Lumina 3.4 is probably going to get the head gaskets replaced in the next year; along with the valve grinding and camshaft oiling modification detailed in other threads. It's a year older, but has about 30K fewer miles. It is my expectation that the second engine will not take seven friggin' months to complete. First, though, is to put a fuel pump on the thing. That'll be my next project.

THIS engine has ~150K miles on it. I bought it at 110K miles, I have NO idea of the service history prior to my purchase.

I will have a pair of rebuilt heads and cam-carriers for sale, with all oiling modifications and the valve-job completed, sometime after the second engine has it's new head gaskets.

[robertisaar]

interesting conclusions, hard to think of how a screw got dropped into the engine, managed to damage multiple cylinders, yet exited the engine without causing some type of immediate failure.

[Schurkey]

Hanging my head, drinking beer and crying.

Engine runs GREAT. No real improvement on the knocking; but I figured it to be piston slap rather than lifter tick. Transmission has been flaky ever since the car was test-driven after re-assembly. Seemed to bind in fourth gear; vehicle would actually slow down unless I gave it enough gas to downshift.

Earlier today, transmission went "bang" and now has no forward or reverse gears. Towed it home.

First Guess: Damage was done when I towed it ~70 miles home when the head gasket popped last February. The trans was already wounded when I took the engine apart--because it worked GREAT right up until the engine quit and left me stranded.

Is there a typical failure mode for the 4T60E? Splined input shaft tears out of a drum or somesuch?

Does a '94 4T60E from an LQ1 car fit and work in a '93 LQ1?

[robertisaar]

94 LQ1 4T60E has some differences compared to a 93 LQ1 4T60E.... mechanically, it will bolt to the engine just fine, trans to frame mount and bracket may or may need to be swapped for the alternate style.

shifter position switch will need to be swapped for the one that's correct for the PCM/car.
trans plug is wired different and actually has different circuits:

93 and earlier has two +12V feeds, 3 controlled circuits(TCC, shift solenoid A, shift solenoid B) and two status switches(shifter in 1st and shifter in 4th).
94 and later has one +12V feed, 4 controlled circuits(TCC, TCC PWM, SSA, SSB), then the 2 wires used for the temp sensor.

[Schurkey]

94 LQ1 4T60E has some differences compared to a 93 LQ1 4T60E.... mechanically, it will bolt to the engine just fine, trans to frame mount and bracket may or may need to be swapped for the alternate style.

shifter position switch will need to be swapped for the one that's correct for the PCM/car.
trans plug is wired different and actually has different circuits:

93 and earlier has two +12V feeds, 3 controlled circuits(TCC, shift solenoid A, shift solenoid B) and two status switches(shifter in 1st and shifter in 4th).
94 and later has one +12V feed, 4 controlled circuits(TCC, TCC PWM, SSA, SSB), then the 2 wires used for the temp sensor.

Greatly appreciated. Have a line on a '94 transmission; but I'm not willing to convert ECM and wiring harness.