94 Engine problem
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
94 Engine problem
I posted before, but I'm starting a fresh thread...
I pinned #4 & #12, and I got no codes, so everything seems to be OK in the ECM.
Engine feels like it's missing. If a certain cylinder is misfiring, should that throw a code?
Heavy vibration still coming from engine compartment, feels sluggish, lower exhaust note, engine noise seems to be coming from under passenger side valve covers, less noise from driver side, and gas mileage is pretty horrific. Car bucks a bit from a dead stop putting it into first or reverse (have to give it quite a bit of gas to not stall it).
One more week until my mechanic has an opening... any ideas until then? Was thinking I'll pull a plug and see what the condition is. No sparking/arcing at night visible, so I don't think it's wires...
I pinned #4 & #12, and I got no codes, so everything seems to be OK in the ECM.
Engine feels like it's missing. If a certain cylinder is misfiring, should that throw a code?
Heavy vibration still coming from engine compartment, feels sluggish, lower exhaust note, engine noise seems to be coming from under passenger side valve covers, less noise from driver side, and gas mileage is pretty horrific. Car bucks a bit from a dead stop putting it into first or reverse (have to give it quite a bit of gas to not stall it).
One more week until my mechanic has an opening... any ideas until then? Was thinking I'll pull a plug and see what the condition is. No sparking/arcing at night visible, so I don't think it's wires...
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by zr1fred
With LT-1's the number one problem for missing, hard starting, lack of power is the opti spark. (Cap carbon arced from moisture, etc), and no, it usually won't throw any codes
...and also have your catalytics checked out. Could be your passenger cat is clogged causing excessive backpressure to that bank....just a thought...
Racer
Joined: Jun 2006
Posts: 408
Likes: 0
From: Elkton MD
Missing and vibration
Sounds like a burnt plug wire. Take a close look while cool and during the day with good light. Make sure no wires are 'glued' to the exhaust, etc. and look for toasted spots. Then take another look in the dark (unplug the hood lamps) and look for sparks from the wires to 'ground' (any part of the engine). There shouldn't be any lightening under the hood.
The EGR valve can cause missing and will change the exaust note very noticably. Diagnose it by making sure it moves with vacuum and goes fully closed at idle, especially when cold.
Hope you find it.
The EGR valve can cause missing and will change the exaust note very noticably. Diagnose it by making sure it moves with vacuum and goes fully closed at idle, especially when cold.
Hope you find it.
Last edited by IRAraid; Jul 17, 2006 at 08:04 PM.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Although opti is always a consideration, it does not strike me in this case as the problem. I like the cat theory and checking the EGR might be a good thing to check anyway. I would just check the fuel pressure just to make sure the simple things are OK. The O2 sensors come to mind but I would think if it was that defective it would throw a code. One bad plug wire I would not think would make the engine run as bad as you indicated. Good Luck. 
Pro
Joined: May 2006
Posts: 549
Likes: 2
From: Bardstown ( Bourbon capitol of the world ) KY ( The Bluegrass state )
You to
I'am currently having the same problem as pr1mu5 
My car is acting the same way, tell me did your car just do it all at once. It was running good the night before and I had just charged my a/c. Please let me know if your machanic/you finds the problem. I'll keep you posted on mine and let you know what my machanic says
Thanks
My car is acting the same way, tell me did your car just do it all at once. It was running good the night before and I had just charged my a/c. Please let me know if your machanic/you finds the problem. I'll keep you posted on mine and let you know what my machanic says Thanks
Pro
Joined: Nov 2000
Posts: 703
Likes: 2
From: Cypress Texas
My '94 has went through several sets of O2 sensors since I have owned it and only one time did it throw a code for it. It may be worth looking into. I read on another post that you should only go back with Delco's as the Bosch's tend to go out sooner.
Large Impressive Member
Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
If you have a plug or wire defective, it won't throw a code. It almost sounds as if it is in 'limp home' mode. But this should be obvious in such ways as excessive oil temperature and/or pressure, coolant temperatures, etc. Do you know that all of the vitals are good? The noise you mentioned concerns me too, details?
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Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
The coolant spiked once to 216, but hasn't done it since. Other than that, just the heavy vibration and noise.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by pr1mu5
The coolant spiked once to 216, but hasn't done it since. Other than that, just the heavy vibration and noise.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
Originally Posted by Corvette Kid
216 is not a problem and well within the safe range. How about oil temps and pressures under all conditions?
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Well while you're waiting to have your tech look at it, and since you think there's a noise coming from under the RH valve cover, you might as well pull it off and have a look. It's the 'easy' one on an LT1. If nothing's askew, pull your plugs and look at them, they could very well provide a clue, too.
Pro
Joined: May 2006
Posts: 549
Likes: 2
From: Bardstown ( Bourbon capitol of the world ) KY ( The Bluegrass state )
Found it
The 95bluebomber and i broke my engine down on saturday and found the problem.
It had droped a valve 
and the piston hit.
So if i were you I would leave it untouched untill a machanic could take a look at it. Good luck
It had droped a valve and the piston hit. So if i were you I would leave it untouched untill a machanic could take a look at it. Good luck
Le Mans Master
Joined: May 2005
Posts: 7,301
Likes: 2,222
From: Central Maryland
I'd yank that valve cover before running that engine again. I'm guessing broken valve spring, bent pushrod, or dropped valve. But let's hope it's nothing too serious.
Be well,
SJW
Be well,
SJW
Burning Brakes
Joined: Nov 2005
Posts: 1,211
Likes: 2
From: Dumas Arkansas
Originally Posted by pr1mu5
The coolant spiked once to 216, but hasn't done it since. Other than that, just the heavy vibration and noise.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
The noise is odd, hard to explain, but it sounds clear on the passenger side of the motor, not on the driver side. Kinda like a 'whoomp whoomp whoomp' noise, it might even be the exhaust... I know I inherited a problem with the exhaust, someone tried to jack up the car using the exhaust, so the pipe has a 'flat' spot on it (pre cat, I believe)...
My mechanic will be taking a look at it on the 31st, I'll keep you all posted.
Pro
Joined: May 2006
Posts: 549
Likes: 2
From: Bardstown ( Bourbon capitol of the world ) KY ( The Bluegrass state )
I dropped my engine off at a machine shop yesterday(on my b-day) and I'm looking at a bill between 800 and 1200. I'll find out more about the price next week when he breakes into it. I have asked several people how this could have happend? I don't understand since the engine had just been modified about 6 months ago. I guess, unlucky me!!
I'll find out more about the price next week when he breakes into it. I have asked several people how this could have happend? I don't understand since the engine had just been modified about 6 months ago. I guess, unlucky me!!
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
Plugs and wires. Dur.
One of the wires was almost completely burnt through (I guess it was on/near exhaust?) and the plugs were heavily 'used'.
I'll let you know if that's it, or if there's more, tomorrow. (Gotta do this first, and then see if the problem goes away).
One of the wires was almost completely burnt through (I guess it was on/near exhaust?) and the plugs were heavily 'used'.
I'll let you know if that's it, or if there's more, tomorrow. (Gotta do this first, and then see if the problem goes away).