: UUC Yesterday, Dead Today?



leap229
02-02-06, 07:52 PM
I had my UUC shifter and bushings installed yesterday. A local mechanic friend did it for me. Fantastic. Absolutely a must have mod. This is the shifter the car should have had from the start.

Now the problem.

On the way to work this morning the car just died. I pulled up to a stop sign, pushed in the clutch and the engine stopped. It would then crank, but not start. Plenty of gas, and the MIL is not on.

The dealer has had it all day and can't find what's causing it to not start. :bonkers: Any thoughts? The wife and I are supposed to be leaving town tomorrow for a weekend trip, and I would hate not to be able to take the V.

Thanks.

roadracerx72
02-02-06, 07:55 PM
Uh oh :bonkers: . This does not sound good at all. Please keep us posted...

ewill3rd
02-03-06, 07:25 AM
On what do you base the term "plenty of gas"?
You mean it shows fuel on the gas gage?
You could have a problem with the fuel pump or the transfer pump, that would make it where you can have plenty of fuel, but no fuel pressure.
I have an SRX in the shop right now that had no fuel pressure because the wiring and terminal inside the pump have melted.
The CTS uses an identical fuel system. Ask them what the fuel pressure is while cranking.

Seems like they should be able to tell why the car won't start.
If they have had it for a day and don't know why it won't start tell them to get someone else to work on it.

leap229
02-03-06, 11:38 AM
Thanks for the note about fuel pressure. Good point. The point I made to the dealer yesterday afternoon was: fuel, compression, timing, spark???? If you've got these it should fire.

Turns out it's compression. Apparently there is a "broken valve spring." The service advisor didn't know which valve spring or if it was only one valve spring, but she is checking with the tech. Seems it still would have run on 7 cylinders, just badly. But maybe not.

Any word on if this is common. Anything else to look out for as collateral damage?

10secvette
02-03-06, 11:40 AM
Thanks for the note about fuel pressure. Good point. The point I made to the dealer yesterday afternoon was: fuel, compression, timing, spark???? If you've got these it should fire.

Turns out it's compression. Apparently there is a "broken valve spring." The service advisor didn't know which valve spring or if it was only one valve spring, but she is checking with the tech. Seems it still would have run on 7 cylinders, just badly. But maybe not.

Any word on if this is common. Anything else to look out for as collateral damage?

It should fire and run with a broken valve spring. Very strange. I would be at the dealership looking under the hood to make sure the valve covers are off....

obzidian
02-03-06, 12:06 PM
right, even with a broken valve spring, she should still at least try to start. I would also get over there and see this valve spring....with these single springs, it would be very easy and the fact that there isnt a cowl covering the back half of the motor like in my camaro, should be very easy to see which spring is broken..

Im witht heidea that it could be fuel related of a faulty spark fuse.

Hey, when we depress the clutch to start the car, those that work on a sensor or is it mechanical? That could be it if it was a sensor or something like that and went bad...

heavymetals
02-03-06, 02:01 PM
Broken valve spring?

Sounds strangely familiar to two other failures (one here and one on the Z06 forum) that resulted in lunched motors.


threadjack:

I think I am going to replace all my valve springs.

Does anyone have any recommendations as to dual vs single?

I am considering SLP/Manley.

10secvette
02-03-06, 02:05 PM
Broken valve spring?

Sounds strangely familiar to two other failures (one here and one on the Z06 forum) that resulted in lunched motors.


threadjack:

I think I am going to replace all my valve springs.

Does anyone have any recommendations as to dual vs single?

I am considering SLP/Manley.

Patriot Gold's all the way.

urbanski
02-03-06, 02:09 PM
oh crap

Mat347
02-03-06, 04:26 PM
Someone else here dropped a valve, but I believe the car would at least try to start. They denied his warranty due to a CAI and a CPU tune..but since a broken valve spring could in no way be caused by this, they covered it under warranty.

heavymetals
02-03-06, 04:31 PM
Oh boy!

A group buy on valve springs?:histeric:

rand49er
02-03-06, 04:33 PM
Apparently there is a "broken valve spring." The service advisor didn't know which valve spring or if it was only one valve spring, but she is checking with the tech. Seems it still would have run on 7 cylinders, just badly.Had two intake valve springs go out on my '69 Vette 350/350, and it ran well enough to get me home from New York to Detroit ... a little lopy, but it did run. I think your problem is somewhere else.:hmm:

VELOSE
02-03-06, 04:43 PM
I hope it's not a valve spring. My wife will kill me if she finds out that I'm out of warranty because a supercharger miraculously found its way into the V. :D

ewill3rd
02-03-06, 06:44 PM
I haven't heard of many valve springs breaking on these engines.
I saw some rocker problems on early production models of the gen III motor.
Usually that was pretty harmelss but you'd end up with a bunch of needle bearings in the oil pan.

When a valve spring breaks it can potentially cause all kinds of damage, if the valve keepers fall off due to the broken spring it can "drop" or fall into the cylinder. This usually makes quite a bit of noise as the valve stem hits the top of the cylinder (head) and the flare on the end of the valve can snap off and drive the valve stem through the piston down into the engine.
You'd have heard something loud and ugly if that happened.
It could just bend up but it will stop the engine if it does that.

I hate to say this but it sounds to me like they are stalling for time.
A single broken valve spring would not stop the other 7 cylinders from working.
Not to say they are covering up, maybe they just want more time to tear stuff apart to find the problem.
Let us know what they find.

heavymetals
02-03-06, 07:04 PM
I haven't heard of many springs breaking either, but the ones that did caused catastrophic engine failures.

This is what happens when you become a mod junkie.:histeric:

I do think it is cheap insurance though considering the mods I have probably voided any engine warranty.:canttalk:

leap229
02-06-06, 09:24 PM
Well, I was at the dealer today and confirmed that it is the #6 intake spring, leading to as Heavymetals put it "catastrophic" engine failure. They pulled the head off, and there is a hole in the piston and the cylinder is trash.

Oddly enough, it was never got very noisy, and it wouldn't run on the other 7 cylinders. Unless something happened the night before that I didn't hear or notice, but I wasn't driving it hard then either, I was literally putting along to work at <30 mph in 3rd when I came to a stop sign, put in the clutch and the engine stopped.

With the exception of the UUC shifter, this car is stock with 4400 miles. While there has been some spirited accelaration, what this car was made to do, the car has not been drag raced and no visits anywhere near the rev limiter.

Anyway, a new engine is on order and expected later this week. Maybe I'll see the car back sometime next week.

heavymetals
02-06-06, 09:30 PM
That does it.

I am ordering springs.:yup:

leap229
02-06-06, 09:37 PM
There seems to have been a fair amount of discussion in the C5 Z06 forums about valve springs breaking leading to the same problem I've got. It doesn't seem to be widespread, but anyone with any serious engine mods is putting in different springs. You might check there for recommendations.

Frankly I don't drive that hard to justify it. If the new engine eats a valve because of a broken spring, GM will put another one in.

crowan
02-06-06, 10:13 PM
The LS6 is such a sweet motor that I feel like it deserves a formal funeral with an honor guard.:crying:

Glad to hear that your dealer is doing right by you.

CR

ewill3rd
02-07-06, 08:02 AM
Even abusive driving shouldn't really affect valve springs or cause an engine to drop a valve.
Short of floating the valves from over revving that is.
I am sure it was a defect in the spring itself.
It probably broke and the keepers fell out, then the valve dropped into the cyilnder and did what I described above, perforating your piston!

Hope they get it fixed soon!

leap229
02-08-06, 01:23 PM
I am just waiting on the motor and installation.

I am a bit nervous because my dealer, although they have always been great with all my cars, doesn't do much (any) work on V's. But swapping an engine is swapping an engine. We used to do it in the driveway on a Saturday afternoon. Of course, there was a lot more room and a lot less electronics.

The real bummer is another 500 mile break in period.

I'll report back when I've got it back.