NEED LT5 TIMING FAIL HELP!!!!

[oricale]

Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!

[A26B]

Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!

There is no timing "belt' on the ZR-1 Corvette LT5 engine. It uses chains to drive the cams.

If indeed this is what happened, you will most definitely need to remove the cam cove to inspect. Cam chains do not "jump". It could be a broken cam sprocket bolt, broken cam, broken chain.

It needs to be inspected by someone with bonafide knowledge & experience with the LT5 engine. Where are you located? We can probably direct you to the closest service.

No Hp gain from a valve job if it was Ok before. There are a number of performance enhancement modifications that could be done at the same time as the repairs. Depends only on the depth of your pockets.

[oricale]

Hello,..yeah I meant chain,..here is a pic of the head with the cam cover off:

,..chains are tight still as I could tell,..apparently this happend at idle and they shut if off when it started to sound like a diesel engine,..I live in washington DC..

From what I gathered they just dont have the knowledge to identify what actually happend,..

[Pete]

Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!


Chains do not/can not skip/jump in our Z's unless there was a whole lotta of other issues.
Since your comp/leak tests good not the chains or cam timing.
Check for a miss.
I'm thinking your hearing flywheel/trans rattle or have a bad lifter which is very rare.
Most common issues for a miss injectors,wires,coils,check/change plugs easy and cheap.

Pete

[Kevin]

was it a backfire?

[oricale]

I wasnt there thats the problem,..they took the cover off and did the leakdown and compression found nothing,...cant fire it up due to that,..but they said it was at a low idle when popped and started sounding like a diesel...(their words...not mine)...so i am trying to figure our the best way to move forward,..but at this point i just want to make sure that no damage can or did happen to the block or anythign i cant fix or have fixed,..any ideas?

[oricale]

i also would like to know how to check/reset timing of the cam chains

[Pete]

i also would like to know how to check/reset timing of the cam chains

Have them stop all work put the valve cover back on with anerobic sealent,make sure you clean the surfaces good head & cover.

They will do more damage then you will be able to afford $$$ seen it too many times these techs think they know everything at your expense/loss this is not what they are use to it's not a small block chevy they hear a rattle and start taking things apart what the hell was he looking for rocker arms,has no clue about the motor/trans design freaking shmucks instead of manning up and saying i have no clue they start taking sh!t apart WTF.

Do not atempt to retime the cams it's impossible with the motor in the car.
JUST PUT THE VALVE COVER BACK ON.

Look at the MAP sensor at the back of the plenum make sure the vacuum hose is connected very common they blow off.

Like i said before most common are injectors,wires,coils.
Go to common issues/solutions.

Pete

[gbrtng]

Who is "they" and why did they have the vehicle - We need the rest of the story.
Did you just purchase it?

[Kevin]

I wasnt there thats the problem,..they took the cover off and did the leakdown and compression found nothing,...cant fire it up due to that,..but they said it was at a low idle when popped and started sounding like a diesel...(their words...not mine)...so i am trying to figure our the best way to move forward,..but at this point i just want to make sure that no damage can or did happen to the block or anythign i cant fix or have fixed,..any ideas?

yeah, get the car back, have the dc zr-1 crew look at the car, DON'T LET SOME JAGOFF AT A DEALER WORK ON IT

[oricale]

Yes i did just buy it,...just trying to get a game plan,...

PETE:,..LOL!,..yes I certainly agree,..I work on 35 million dollar airplanes daily and I am NOT yet qualified to rip ANYTHING apart!,...

I mostly want to get a few ideas to check without tearing the engine apart to make sure I didnt buy a dead vette,..but I am prepared either way,..this is my only chance to own such a great car...($$$)

Also this car just came back from california in 06 and had $4000.00 in exhaust upgrades for the smog requirements,..I cant imagine i need or want all that on for MD or DC..

[tccrab]

My diagnosis is a bad misfire and what you're hearing is the dual mass flywheel rattle.
It can be really scary, especially if the misfire is a bad one.
Misfires typically caused by:
1. Bad Injectors
2. Ignition (plugs, wires, coils)

If I were to be a gambling man, my bet would be on bad primary fuel injectors.

Your car came from the Sacramento CA area, I saw it a couple of years ago on the road not far from my house in Folsom.
Couldn't catch up with him in traffic, never got the chance to talk with the owner.

TomC
'Crabs

[oricale]

**YES**..YOU ARE CORRECT SIR!!!!..I have all the documents from the folsom dealer that did all the work on the smog!!...WOW small world!....

[Pete]

Does the rattle/knock only happen at shut down?

If so that's just the dual mass flywheel no biggie,flywheel just getting old.
If it rattles/knocks at idle and motor shakes,most likely you have a miss.

Before you go any further check MAP sensor back of plenum make sure vacuum hose is connected,easy and free.

Somebody post picture location of MAP.

Pete

[bdw18_123]

I agree with what the rest of the guys here are saying. I just recently finished reassembling/repairing the LT5 in the project '90 ZR-1 I bought over 2 years ago, so I am pretty familiar with the internals of this engine.

Like has already been said, probably not the chains; especially if it looks tight and the compression is good on all the cylinders. They can't 'jump' teeth like a belt can, there would have to be major things broken for that to happen (missing/broken chain guides, etc). Things are too tight in there, they either work, or they break (which was the case with mine, driver's side timing chain was broken when I bought the car).

Yeah, don't try messing with the timing, it is a VERY complicated process and it is not easy, especially if your not familiar with this engine. Not to mention the new parts & special tools you need you need. The whole front end of the engine has to be disassemble to do the timing.

Just get that cam cover back on with anaerobic sealant (Permabond A136 or Loctite 518) and clean the sealing surfaces really good as was suggested. It is VERY important that you follow the torque amounts and sequence in the service manual exactly (see my next post below), due to the cover having the bearing surfaces that the cams ride on built into it.

Also as has already been said, check the MAP sensor hose, coils, plug wires, spark plugs, injectors (if these are still original and your ZR-1 is a 90-92, they are definitely bad or going bad, the original injectors of those years can't handle the ethanol in today's fuel). Can't rule out the ECM as a cause either, as I had that problem; but that is a last resort after checking the usual stuff.


Here are a couple of pics to show where the MAP sensor is and hose that Pete is talking about:

http://i13.photobucket.com/albums/a292/bdw18_123/LT5toprearview.jpg

http://i13.photobucket.com/albums/a292/bdw18_123/STA70001-1-1.jpg

[oricale]

Awesome,..Thank you for the info,...I will do just that,...

I will look into injectors, plugs and wires!,...

I am wondering if there is tell-tale signs of a major issue ?..I am assuming that if its running rough and the timing cannot go out,..then it has to be a spark-fuel-miss- ISSUE?

OR a tell-tale sign that there isint a major issue?

[Kevin]

it's probably an injector or more going bad. i doubt there's any real issue

[bdw18_123]

I would check that MAP sensor hose first, as it is common for it to come off. When it does it makes the engine sound like it has a bad miss or something.

Here are two pages from the LT5 service manual supplement that shows the torque procedure and tightening sequence for the camshaft covers.

http://i13.photobucket.com/albums/a292/bdw18_123/cam_cover_torques1.jpg

http://i13.photobucket.com/albums/a292/bdw18_123/cam_cover_torques2.jpg

[secondchance]

May I ask where the car is at? Call me at 703 980 8814.

[tccrab]

<snip>
I am wondering if there is tell-tale signs of a major issue ?
<snip>

Not likely.
The LT5 was "Purpose Engineered and Built".
In plain English, it means that they designed it and built it to be "rode hard and put to bed wet", often.
She's a thoroughbred that was made to run, and built strong enough to take it all and ask for more.
Very few stock LT5's have detonated over the years.
As long as they are properly maintained, they just keep on running.
There are ZR1's out there with well over 100k miles that just keep on keeping on.
You need to read this book, "Heart of the Beast" by Anthony Young:
http://www.amazon.com/Heart-Beast-Anthony-Young/dp/0971146845
It will give you a real understanding of the Beast that you know own.

Fear not, the Brotherhood of the Beast will help you out.
I absolutely guarantee that a local Brother will be willing to stop in and help out.

For the love of god and everything holy, do not, and I repeat, do not take it to the local Chebby Stealership.
It's highly unlikely that they've ever seen a ZR1, much less diagnose and repair one.
It would be money and time wasted.
Trust me on this.

TomC
'Crabs

[oricale]

Hey all!!,...:) the car is in NY I have paid for it (Mostly) and I drove up from DC to inspect the vehicle,...I am picking it up next weekend or the weekend after,...I al dealing with a few things:

Getting it from NY to DC...Trailer ect...I was going to Trailer it,..but If I could drive it....!!!!awesome!!!.

anyway I am no star-dreamer...I am prepared for whatever is good or bad,..but I want a plan,..do we have any members in the Long Island area????

[FU]

do we have any members in the Long Island area????

Yes here, where is the car located ? Is this a white car with a red stripe ?

[oricale]

Uhhhhhh,....yeah????:confused:

[oricale]

Why???????????(nervous!!)God this is a small community!!!!Very cool

[Kevin]

Yes here, where is the car located ? Is this a white car with a red stripe ?

I thought you lived around there frank

[FU]

I saw that car sitting at a repair facility on Montauk Highway in Lindenhurst for a few weeks during the month of August. Caught my eye on the way to and from work. That shop is a good shop , but I doubt that they know much if anything about the LT5. I wondered why the owner took the car to that shop instead of the Vette Dr's ? The Vette Dr's are about the most knowledgable shop around here with the LT5's.
Next Saturday my green car will be making a trip from here to it's new home in South Carolina.

Well anyway , how can I be of help ?

[Kevin]

I saw that car sitting at a repair facility on Montauk Highway in Lindenhurst for a few weeks during the month of August. Caught my eye on the way to and from work. That shop is a good shop , but I doubt that they know much if anything about the LT5. I wondered why the owner took the car to that shop instead of the Vette Dr's ? The Vette Dr's are about the most knowledgable shop around here with the LT5's.
Next Saturday my green car will be making a trip from here to it's new home in South Carolina.

Well anyway , how can I be of help ?

YOU SOLD THE GREEN CAR! i'm actually sad now

[FU]

YOU SOLD THE GREEN CAR! i'm actually sad now
Yes.

Here is a copy of what was written on the e-bay add :

The car does need some mechanical work, the other day pulling out of the drive way the timing chain tensioner went bad on the passenger side. I had it checked by a shop and after doing a compression test and a leak down test it was found that only 4 lifters need replacing on the passenger side all else check out good.

[oricale]

yep apparently when thye pulled the cam cover and oil pan and found no evidence of an issue, they did the test and couldnt figure it out,...soooo they did NOT want to work on it....SO here we are...

yeah I had him pull it from ebay when I bought it,...I questioned the lifter comment,..

I think I am going to trailer it regardless. I have rebuilt from the ground up 2 corvettes and 1969 mach 1......BUT ZERO LT5's ,so I am tapping the collective genius here.

I would like to talk personally with someone close to the wantah area if possible

[Pete]

Lifters rarely have issues,not that it can't happen but i never seen or heard of a stocker having lifter issues.

I have seen tensioners freeze/lock up it sounds like lifters (like loose rocker arms in a small block chevy) i would guess this is why valve/cam cover is off.

I can say this your Z is most likely ok just something silly/stupid wrong just need to diagnose.

Also if the LT5 has a miss it sounds like a box of rocks.
Start with common issues.
You can do a search on this site.
or
Ask away.

Sounds like you can wrench do it yourself and save some money unless you have no time to mass with it.

Hope you fix her up right.
Pete

P.S.
Frank, WTF sold the Big Green Machine,let me guess making room for new C6 ZR1.
Does this mean we won't see you at BG anymore.

[QB93Z]

yep apparently when thye pulled the cam cover and oil pan and found no evidence of an issue, they did the test and couldnt figure it out,...soooo they did NOT want to work on it....SO here we are...

yeah I had him pull it from ebay when I bought it,...I questioned the lifter comment,..

I think I am going to trailer it regardless. I have rebuilt from the ground up 2 corvettes and 1969 mach 1......BUT ZERO LT5's ,so I am tapping the collective genius here.

I would like to talk personally with someone close to the wantah area if possible

If you would like to meet a bunch of Washington Area ZR-1 owners, we will be gathered at my garage in Westminster, MD on Sunday, 9 October:

http://www.zr1.net/forum/showthread.php?t=15641

We will also be at a local area car show on Saturday:

http://www.zr1.net/forum/showthread.php?t=15640


My phone number is 443-244-1347. Please call me if there is anyway I can help.

Jim Voter

[tccrab]

See?
I told you that the Brotherhood takes care of our own.
:salute:

The Brotherhood of the Beast is alive and well.

Nothing makes me more proud of our little family than when one or more of our own step up to help out the noobies.

TomC
'Crabs

[oricale]

AWESOME!!! THANK YOU!,...Although I will have to ride the Ducati there,..I am not sure I will be let in driving up in a Mach 1....

:jawdrop:[-X

[QB93Z]

AWESOME!!! THANK YOU!,...Although I will have to ride the Ducati there,..I am not sure I will be let in driving up in a Mach 1....

:jawdrop:[-X

You are welcome at the Westminster Maintenance Day (WMD) on Sunday in what ever you drive. We appreciate ALL fine machinery.

Jim

http://i407.photobucket.com/albums/pp152/QB93Z/WazooLogofornewsletter.jpg

[secondchance]

AWESOME!!! THANK YOU!,...Although I will have to ride the Ducati there,..I am not sure I will be let in driving up in a Mach 1....

:jawdrop:[-X
Saturday show is open to all American Muscle! I wanna see your Mach1.

[secondchance]

You are welcome at the Westminster Maintenance Day (WMD) on Sunday in what ever you drive. We appreciate ALL fine machinery.

Jim

http://i407.photobucket.com/albums/pp152/QB93Z/WazooLogofornewsletter.jpg

I thought it was "horsepower through frienship"!

[oricale]

Just a Bump to say thank you to all the folks who I have been in contact with....the knowledge and kindness is unmatched....I want to call out Frank up in NY...he is a sharp guy who I know I can go to anytime..

I was also told there are other Military members in WAZOO land as well:USFlag:.

I will be shipping the car down here this week and going through it for a bit.

As I have you all here looking. Where can I get the best deals on:

Coils
Wires(Actual LT5)
Stainless injectors

Again, thanks to all of you.

Dempsey

[FU]

Coils
Wires(Actual LT5)
Stainless injectors


Coil's , wire's and the gasket's. Call Jerry http://jerrysgaskets.com/store2/root/
Stainless injectors . Call http://fuelinjectorconnection.com/shop/

Your in good hands Dempsey.

[oricale]

OK FOLKS!!!!!,...Found the issue!!!,....Broken TIMING CHAIN Drivers side!!!!
:censored:


Question is....what now??????:confused:

[HAWAIIZR-1]

OK FOLKS!!!!!,...Found the issue!!!,....Broken TIMING CHAIN Drivers side!!!!
:censored:


Question is....what now??????:confused:

Wow, sorry to hear this bad news. It really depends on all the details and funds you have available, mileage, etc. on what you want to do while you're at it. Fortunately you have the expertise of the WAZOO at your disposable unlike me having to figure out and build my motor myself in Hawaii. Best wishes in addressing this issue.

[bdw18_123]

OK FOLKS!!!!!,...Found the issue!!!,....Broken TIMING CHAIN Drivers side!!!!
:censored:


Question is....what now??????:confused:

That is the same chain that was broken on my ZR-1 when I bought it. Do you know any of the car's history on when the running issues started and possible causes? If not, you might want to try to contact the previous owner and ask for details about when he started having problems with the car. That way we could get more of an idea of maybe why the timing chain broke.

Oricale, go to this link to read through what it takes to tackle this project on your own, it is a thread I did to document the repair/restoration process I went through to bring my Z back from the dead.

http://www.zr1.net/forum/showthread.php?t=9693

[oricale]

That is the same chain that was broken on my ZR-1 when I bought it. Do you know any of the car's history on when the running issues started and possible causes? If not, you might want to try to contact the previous owner and ask for details about when he started having problems with the car. That way we could get more of an idea of maybe why the timing chain broke.

Oricale, go to this link to read through what it takes to tackle this project on your own, it is a thread I did to document the repair/restoration process I went through to bring my Z back from the dead.

http://www.zr1.net/forum/showthread.php?t=9693

Hey,..Yeah the previous owner didn't even drive it,..I think Im stuck on that, but there is no noticeable damage from the break.


I am well versed in your thread,..Great work!

[LGAFF]

Rebuilding is not that bad, especially if you do the stock timing. I am not sure I understand, is the car not running at all...it would have to be in order to have a broken chain. Are you sure its just not a tensioner?

[oricale]

Yeah pretty sure,..chain is laying on the table:(,...but apparently it was at idle and died,...then i fired it up for about 1-2 sec as well...

questions;

can pull the engine without removing the hood??

[Paul Workman]

Yeah pretty sure,..chain is laying on the table:(,...but apparently it was at idle and died,...then i fired it up for about 1-2 sec as well...

questions;

can pull the engine without removing the hood??

Yes, far as removing the hood goes, no need to. (Not even on the hottest day of the year!)

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/ZR-1012.jpg

Dayam sorry 'bout the chain tho. Have to wonder what those monkeys did to the motor (if anything) to result in breaking the chain.:confused:

P.

[XfireZ51]

Didn't Marc say that there was a problem w replacement chains and the links? I believe that before he replaces the chains he makes certain the link bars are "peened" so they don't slide out.