jml_911

Hi chaps

Had a problem last night with my 2001 C5 Z06.
I was sat in very slow traffic - stop start for not much more than 5mins.

Traffic opened up went to accelerate away and immediately heard a misfire. Sounded like it was only running on 4 cylinders. Engine down on power. And the check engine light came on. I was only 1/4 from my destination so limped it in.

Had a service guy come out (I'm in the UK so nobody really knows corvettes apart from the few specialists) So they couldn't do anything and the car was lifted back to my house.

Ran through the DIC codes today nothing major. B2482, 0507 0502 - which I think they just relate to the UK light conversion

The right side exhaust tail pipes looks very black and sooty

Engine won't start - it tries, splutters and dies pretty much immediately.

As I mentioned I'm in the UK so any help that I can get a head start on this and hopefully get some early diagnostics before getting it lifted to a Corvette specialist would be very welcomed

Bill Curlee

When you have an engine or EBTCM issue,, always read the DTCs "BEFORE" you turn the ignition off.

Have someone help you diagnose spark You pull a plug wire on each bank and see if you have spark on both banks while someone cranks the engine.

You may have blown a fuse for fuel and spark and they are bank specific.

I had a shorted coil power wire and I was missing the spark on the drivers side. Drove 12 miles on FOUR CYLINDERS to get home. She did pretty good for half an engine..

Here are the fuses that you need to check:

jml_911

Well that doesn't sound too bad - we'll have a look tomorrow and try and figure it out.

Thanks so much - points us in the right direction

Bill Curlee

Where bouts in the UK do you live?

Bill

jml_911

Hey Bill
North London / Hertfordshire borders

Bill Curlee

Well,, the closest I been to you is The Navy Base in Faslane Scotland and that my friend is FAR away..

jml_911

Where the nuclear subs are !
Yep - it's like the other side of the world for us

3boystoys

Z06, bet it has broken valve springs! Pull valve covers and take a peek, better hope it didn't eat a valve.

jml_911

jeez I hope not.
Being looked at now

If it is and it's just the springs that need to be replaced/upgraded. What's the go to supplier/product ?

3boystoys

Do a search, this is a common issue with the Z's.

jml_911

Yep - broken valve spring
Going to get these sent over
https://sdparts.com/details/pac-racing/pac1218

3boystoys

Hope the valves and pistons are OK.

jml_911

They appear to be. Shouldn't have done any damage.
Fingers crossed

I'll add the car details to the thread about these failures.

3boystoys

As long as the keepers are still in place your probably OK, they can be changed without removal of the cylinder head.

jml_911

cheers buddy
They seem to be all OK.
Should have them in the UK by Thursday, hopefully I'll be able to bribe my mechanic to get them in for the weekend

Bill Curlee

3boystoys

EXCELLENT CALL!


jml_911

While you have the valve springs out, I recommend changing out the valve seals. Just another step and it isnt difficult.

jml_911

Do you mean the rocker cover seals ? Doing them and actually managed to find parts off the shelf in the UK
So going for this upgrade at the same time
http://www.partsworldperformance.com...80033?___SID=U

3boystoys

I think he means VALVE STEM SEALS, the ones that keep oil from going down the valve stem.

Bill Curlee

Your OEM LS6 cam specs are:
204/218 int/exh @ 0.05" duration
0.551" / 0.547" int/exh lift
117 LSA

New cam=
Duration @ .050” Lift (deg) I: 219 E: 228.

Maximum Lift (in) (1.7 rocker) I: .525 E: .525.

Lobe Separation (deg) 112.



That isnt that much of a change. BUT With stock heads it may be Ok.

You do realize that you will need or should:

-Change the oil pump. I used a Melling high volume pump.
-Change the Harmonic Damper. New OEM is fine but I used a Power Bond Damper.
-Install a LS2 or better timing chain
-Valve guide seals. Exhaust valves and intake valve require different seals. Make sure that you install the correct ones on the correct valve.
-New correct length pushrods. (optional but worth it)
-New timing chain cover front seal and gasket ( You can install the gasket in the wrong direction if not careful!)
- ARP Damper Bolt (optional) NEW OEM Damper Bolt MANDITORY!


Have you contemplated "HOW" you are going to position the lifters to remove the CAM. You have FOUR choices:

1. Remove the valve rockers. Insert dowel rods in the holes on the front of the block when you take the front cover off. Spin the cam to lift the lifters into their bores. (the lifter buckets should be able to hold the lifter UP to reinstall the cam. Hopefully!!!

2. Purchase 16 telescoping magnets and hold up the lifters.

3. Some people do method 1 & 2 just to be positive that they are not going to drop a lifter in the engine

4. Remove the heads and lift out the lifters and lifter buckets.





If you change out the cam, you will need a Professional “ PCM” tune. You can try a Mail Order tune but, it will be better to have an in the shop tune. Your cam may need bigger injectors. You tuner will be able to see if yours are above 80% duty cycle at WOT. If they are, he will have to scale in the new injectors. Most people go right to Ford 30 lb/hr injectors. That equates to 36 lb/hr with our increased fuel pressure.

SOME NOTES!

-Use HIGH STRENGTH locking compound on the cam plate retainer bolts!

-Make SURE that you get the timing chain gears DOT to DOT 100% perfect!

-Recommend using an ARP Damper bolt.

-Depending on your response and what you decide to do, I may have some more info for you!



If it were me, I would install new lifters but that’s an option. If you end up with valve noise, you will wished you changed the lifters.

I hope this helps and I’m not insulting your intelligence.

Just making sure that you have everything to make it happen CORRECTLY in one repair session and you get it done without any post build issues.

Bill

3boystoys

You might want to rethink the cam upgrade over there, without a shop that has a chassis dyno and tuning software you probably won't like the car much when it's done.