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New to LS1T and have a few questions for you guy's.
I bought a 2001 Z06 off CL and i was told the engine had some problems.
I knew this before I bought the car. But the car had been sitting for over a year and was in pretty crappy shape. I hate to see cars in this shape. I had to rescue it. So I trailered the car home and straight into the garage.
So here are the problems.
I charged the battery over night and went out to try to start it.
The battery seemed to have a good charge I checked it with a MM and it read 12.6 Volts.
Went to hit the key and it was just barley turning over, so I jumped it off with the battery jumper and it was still slugish but it started right up.
But the car would barley stay at idle. It sounded like it had a knock of some sort on the top end over the RHS head. Bent Valve?
It was also backfiring what sounded like throught the throttle body.
Here is what the PO told me about what happened.
He said he was going down the hiway at about 80mph. and the car just started loosing power. He said he limped to the next exit a couple miles up and pulled into a gas station and the car just died. He said he could not get the car to crank back up so he called a wrecker and had it towed to a friends house. That is where the car has sat outside under a bunch of trees for over a year.
I'm thinking the engine may have jumpped time and possibly bent some valves.
What are your thoughts?
I have not checked to see if the car has any codes or not but the check engine light is on in the dash.
What are your thoughts?
What are the best options?
Complete rebuild? the bottom end only has 55K miles
Just pull the heads and have them worked and replace the timing set?
Complete rebuild with a stroker 383? and have heads worked.
I pulled the valve cover and pulled the push rods out and nothing looked out of order and nothing bent.
But I started the car inside the garage and noticed that the car is burning really rich. filling the garage up with gas smelling smoke.
Joe
I will have to go to the parts store and buy a compression tester.
I will get back to you on that but I also wanted to mention that the car has an after market cam, Headers and computer tune with no tuner.
Is it possible that the cam could be bad giving these symptoms?
Or does it sound like the car has jumped time?
I did not see any broken springs or bent valves and after I pulled the valve cover on the right side I started the car up to see if anything looked out while running and to see if I could tell where the noise was coming from and now it sounds like the noise is coming from more of the center of the engine under the intake.
Thanks, Joe
I've not had an LS1 jump time on me, but I have had a Nissan do it and a BMW do it. Both times the motor would not run, but here is the other kicker. You know how the starter sort of makes a chugging noise from the compression while turning the motor over? It sounded more like a hair dryer due to every valve being bent. It spun freely. Since the LS1 is a tight interference engine I would think it would be the same.
One thing I did see one time. My sister in law drove a car poorly and forced it into reverse while rolling forward at 30 mph. The camshaft pin ended up bent. The end result was the cam timing was off enough to run like ***, but close enough to actually run. If the problem is cam related, could be something in the timing set.
Compression test is your next step. Look for 165 to 180 psi. If your down around 120, and a shot of oil into the cylinder doesn't raise it, time to start the tear down.
All of the plugs were black and wet and smelled like gas.
The #6 plug was difficult to get out. I could not get a socket on it.
I don't know if this is normal or not (my first LS engine)
but the plug almost seemed like it was not in at the right angle.
The block interfered with getting a socket on it.
I got a pair of needle nose vise grips and turned the plug out with them until it was finger loose. It did not seem like it was cross threaded, it turned ok and went back in ok. But it also seemed like it was not in as far as the rest of the plugs.
Like it was only 5 or so threads in and then it was tight.
So what are the thoughts?
Complete rebuild?
I did not do the oil in the cylinder because I was unsure of how much to put in it.
But it was the only cylinder that was low.
Thanks for all of the help to this point guys. Please help me out here. I would really like to figure this out.
Thanks, Joe
Good deal. A squirt of oil out of a can or say a tablespoon. If that compression comes up, it's most likely a ring. If not, it's typically a bent or eroded/pitted valve. Then, the higher likelihood is the exhaust valve
That plug being in at a wrong-ish angle could possible indicate something hit it.
Either way, you've got an almost dead cylinder, probably costing you 40-50 horsepower.
If shooting oil in doesn't bring compression up, you'll need to pull that passenger side cylinder head to figure it out and fix it. I'm betting on an exhaust valve or seat issue.
I will have to go to the parts store and buy a compression tester.
I will get back to you on that but I also wanted to mention that the car has an after market cam, Headers and computer tune with no tuner.
Is it possible that the cam could be bad giving these symptoms?
Or does it sound like the car has jumped time?
I did not see any broken springs or bent valves and after I pulled the valve cover on the right side I started the car up to see if anything looked out while running and to see if I could tell where the noise was coming from and now it sounds like the noise is coming from more of the center of the engine under the intake.
Thanks, Joe
First "jumping timing" is a problem with belts or the old nylon gear timing sets, not really applicable here. I could see it possibly happening in engines with a LONG chain but this isn't one.
What do you mean by "no tuner"? Improper tuning can destroy an engine.
I asked the guy what after market parts the car has on it and he said it has an aftermarket cam, headers and a tune. There is also a wire that looks like it goes to possibly a tuner or something in the glovebox. But there is no tuner to plug into it.
So if it is a bent valve, would that cause it to back fire through the intake?
And the car spits and sputters and pops ( backfire) I'm afraid to try to drive the car down the road to see what kind of " power" it has.
And possibly messing something up worse.
So I'm trying not to run it any more than I have to until I can narrow the culprit down.
Thanks guys.
Joe
I'm calling cam lobe/lifter failure on that six hole. Most likely the exhaust side. It should just be stripped down to the short block to inspect and have the heads freshened with a new cam. Something like the Titan IV. .040" Cometics and trunion upgraded rockers
I'm calling cam lobe/lifter failure on that six hole. Most likely the exhaust side.
What he said..
sure sounds like it.. a knock with popping back through the intake
Have you tired disconnecting injector plug and plug wire on each cylinder one at a time to see if the pop stops, it will stop on the cylinder that is messed up and if not wanting to go all into removing the engine right just yet..
You could go around on each cylinder one at a time, remove one rocker and push rod, remove injector plug and plug wire for said cylinder until the knock goes away, replace everything for said cylinder if knock doesn't go away and move to the next, the idea is to find out if its a cam lobe and lifter problem... just make sure you test both intake and exhaust for each cylinder.. before moving to the next.. hope this makes sense ...
Or just remove the rockers and take the cam out and have a look at it..
guess it depends how much work your into doing .. i would just do the cam removal first..
But really i have no idea, really doesn't make much sense as to what the seller told you happen.. less he was driving it with crazy knock.. well i guess the lifer could have cracked the roller in half all at once.. but idk ... Just trying to help ya out man peace
Edit: I worked on a 2001 TA once that had the MAF go out which caused it to pop and sputter and lose power...
Was also thinking the knocking noises could be simply because it had been sitting for so long and the lifters bleed down, that could even cause some miss too..
On top of it being sitting for so long, the valves that were open could have built up lots of rust and what not.. causing compression problems .. yeah maybe ..
What he said.. sure sounds like it.. a knock with popping back through the intake Have you tired disconnecting injectors and plug wires on each cylinder one at a time to see if the pop stops, and if not wanting to go all into removing the engine right just yet.. You could go around on each cylinder one at a time, remove one rocker and push rod, remove injector and plug wire for said cylinder until the knock goes away, replace everything for said cylinder if knock doesn't go away and move to the next, the idea is to find out if its a cam lobe and lifter problem... just make sure you test both intake and exhaust for each cylinder.. before moving to the next.. hope this makes sense ... Or just remove the rockers and take the cam out and have a look at it.. guess it depends how much work your into doing .. i would just do the cam removal first.. But really i have no idea, really doesn't make much sense as to what the seller told you happen.. less he was driving it with crazy knock.. well i guess the lifer could have cracked the roller in half all at once.. but idk ... Just trying to help ya out man peace Edit: I worked on a 2001 TA once that had the MAF go out which caused it to pop and sputter and lose power... Was also thinking the knocking noises could be simply because it had been sitting for so long and the lifters bleed down, that could even cause some miss too.. On top of it being sitting for so long, the valves that were open could have built up lots of rust and what not.. causing compression problems .. yeah maybe ..
Didn't think of a cam lobe. A leak down test would help diagnose that. If it holds pressure, a cam lobe would make sense. If not, it would be something not dealing the cylinder.
Didn't think of a cam lobe. A leak down test would help diagnose that. If it holds pressure, a cam lobe would make sense. If not, it would be something not dealing the cylinder.
Yeah huh.. i mean the sellers answer as to what happen is vague, did he mean it wouldn't start back up cause the engine wouldn't turn over or what..
Could have been the loss of power was do to the bearing seizing up, thus the OP said, hard to crank even with charger on, but just because a battery tests at a good Voltage doesn't mean its good..
And the popping and knocking do to ruffed up pitted valves and the lifters not being pumped up because sitting so long.. and then the flooding rich condition do to after market cam and tune.. ya know..
Lots of different scenarios to look at, too many to diagnose 100%
All we can do is offer the best likely scenario as to the problem..
We don't even know if the engine even has oil pressure.. is the gauge broken or what ya know ..
But yeah idk for sure.. not enough info in this setting to go on and be 100%..
peace
Edit: haha Darth_V8r i totally read what you said wrong the first time lol i thought you said " don't think of a cam lobe" and thought you were saying something dealing with the bearings, by "If not, it would be something not dealing the cylinder" hahaha sorry, but yeah either way ..
Ok so I pulled the intake and cylinder head on the right side.
I will try to post pictures also, but the #6 plug was definatley in at a wrong angle.
I pulled the head and the #6 was "cleaner" than the rest of them. Is this car supposed to have double springs? It does.
The number # 6 cylinder also has a divit on the top that looks like possibly a valve has hit the top of the piston. But it also looks like it only hit one time.
It did seem like the pressure was slightly going down on that cylinder when I was doing the compression test. I probably should have left it sit there for a few minutes to see what happened but I din't.
What should I do from here?
Thanks for all the help guys.
Also when I had the car running the oil pressure was good. And the oil is also very clean. No matalic residue, at least not on the dipstick anyway.
You can see the plug at an angle here.
Plug is completely centered.
#6 is the second from the left.
#6 is alot cleaner than the others.<br/>
#6 piston You can see the digit in the upper right.
I meant sealing not dealing. Damn spell check. Something not dealing in the cylinder head.
OP, it only hit once because after that one hit it got "clearanced". Remove that valve, put the stem in a drill and spin it. If it wobbles, it's bent. It can be bent and look straight. Rotation will expose it immediately. Check your pushrods also.
Dual springs are not factory but should be there IMO with a performance cam.
My theory is the PO reused undersized pushrods, got some flexing from the higher resistance in the valve train, high RPMs, the flexed pushrod lofts the valve, and voila - valve float. Consider getting a set of 11/32 pushrods to replace what you've got. Good news is you don't need to pull other head to replace them.
It did seem like the pressure was slightly going down on that cylinder when I was doing the compression test. I probably should have left it sit there for a few minutes to see what happened but I din't.
that wouldn't tell you anything.
cylinders do not hold compression. it pushes air into the hose on your compression tester and the valve/core at the end of the hose holds pressure in the hose and the gauge shows you the maximum amount it was able to capture during the compression strokes.
now a leak down tester would have given you the leakage rate and if it was excessive it would give you a way to listen to hear where the leakage was going.
01-02-2016, 04:17 PM
2001 Z06 Engine Jumped Time? 
peace 
