LT1 Pacesetter headers problem
10-13-2007, 06:29 PM
#21
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Another thing that can do it besides running lean is getting your cam off one tooth, makes the exhaust valve open while the air and fuel is still on fire.
Also severely retarded timing will do the same thing, and allow ignited fuel to pass through the headers.
The last culprit can be rockers that are way too tight, and holding the exhaust valves open again allowing burning fuel to enter the header.
Running lean in my experience will not cause cherry red headers, it will be more likely to make the engine overheat, and can certainly do damage to the pistons and internals because the gasoline acts as the only direct coolant on the valves and piston crown.
the thing with the lt1 is that the opti is only able to be installed on the cam correctly in one position, and has no adjustability which makes getting the cam in wrong a big flub up. my advice to you is to reset all the valve lash, if that doesnt fix or help it, then i'd verify that the opti was installed correctly, and after that i'd be pulling the timing cover to verify cam timing.
My other advice for you is to run the engine as little as possible with the current problem, you will trash your headers very quickly doing this to them.
Also severely retarded timing will do the same thing, and allow ignited fuel to pass through the headers.
The last culprit can be rockers that are way too tight, and holding the exhaust valves open again allowing burning fuel to enter the header.
Running lean in my experience will not cause cherry red headers, it will be more likely to make the engine overheat, and can certainly do damage to the pistons and internals because the gasoline acts as the only direct coolant on the valves and piston crown.
the thing with the lt1 is that the opti is only able to be installed on the cam correctly in one position, and has no adjustability which makes getting the cam in wrong a big flub up. my advice to you is to reset all the valve lash, if that doesnt fix or help it, then i'd verify that the opti was installed correctly, and after that i'd be pulling the timing cover to verify cam timing.
My other advice for you is to run the engine as little as possible with the current problem, you will trash your headers very quickly doing this to them.
well I know its not a timing issue and I know its not its not the rockers but the cam not to entirely sure about.... im about 98% sure its not off by one tooth... what I think it is is the stock muffler off a camaro that I had put on there for the time being since my old one was bad (waiting to order my borla with 3" tubes so that should help) and a bad MAF... reason being I disconnected the MAF and took of the muffler and they were only slightly red after that... something else im thinking is that the coolant system isn’t bled all the way and the block isn’t cooling down they way its suppose to there for causing the exhaust temp being produced to be extremely way to high.... I have to replace my temp gauge though because its bad so that’s the first thing im going to order to find out what the real temp of the car is running at....
one more problem is that im losing oil pressure after the car has been running for a while (it goes from 30 to 0)... from what I was reading out of my Haynes Repair Manual is that that could be because my coolant has air still in the lines (because remember I said I don’t think I bled them all the way)... I have check the oil filter, oil pressure sensor (as far as it being tight and not leaking), pressure screw above the oil filter and the NOC sensor on the other side of the block, and the oil drain plug.... anybody have any ideas? Is what im reading possible to happen?
10-17-2007, 01:04 AM
#24
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Put a oil pressure gauge on the car and see if you get the same reading as the factory gauge. Sometimes they aren't very accurate. If you have 0 psi, you've got some serious problems.
11-06-2007, 04:11 PM
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So I found out why the headers where glowing cherry red... there was a vacuum leak. The Idle control valve inside the throttle body was broken and there was another leak on the small air hoses going to the AC unit by the computer. Pretty much the connector that had three hoses going to it was broken. Two of the nipples were broken off and it was crumbling to pieces... as far as the oil pressure problem I haven’t figured that one out yet.
11-06-2007, 05:27 PM
#26
I had some oil pressure issues right after i rebuilt mine, mine was different symptoms because i wasnt getting anything to the right side bank. My issue is that my 3 o clock oil gally plug blew out and went threw my timing chain..This is what Ws6terror had to say:
On the oil pressure issue, how is the oiling otherwise is it pretty low even with the hv pump? the first place i would look when you pull the motor is for the "check ball" under the rear main cap, its just a little pressed in ball under there, it blocks a passage that runs straight out the top of the block i believe to the oil pressure sending unit. Without it you will bypass the filter and never have satisfactory oil pressure. If that checks out, knock out all your galley plugs and remove your cam bearings which are likely toast, and scrub the **** out of the galleys with engine cleaning brushes to look for debris. When you reinstall the plugs have them tapped and put in threaded plugs, dont forget the holes on the lifter galley plugs behind the timing chain the two outboard ones at 3 and 9 should have a pinhole drilled in them to lube the chain.
__________________________________________________ ________________________
Heres the rest of that post if you want it, might not be helpful.
https://ls1tech.com/forums/showthrea...sh#post7931679
On the oil pressure issue, how is the oiling otherwise is it pretty low even with the hv pump? the first place i would look when you pull the motor is for the "check ball" under the rear main cap, its just a little pressed in ball under there, it blocks a passage that runs straight out the top of the block i believe to the oil pressure sending unit. Without it you will bypass the filter and never have satisfactory oil pressure. If that checks out, knock out all your galley plugs and remove your cam bearings which are likely toast, and scrub the **** out of the galleys with engine cleaning brushes to look for debris. When you reinstall the plugs have them tapped and put in threaded plugs, dont forget the holes on the lifter galley plugs behind the timing chain the two outboard ones at 3 and 9 should have a pinhole drilled in them to lube the chain.
__________________________________________________ ________________________
Heres the rest of that post if you want it, might not be helpful.
https://ls1tech.com/forums/showthrea...sh#post7931679
11-06-2007, 06:11 PM
#27
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you said that when the maf was disconnected it ran better?
try and see if when u disconnect the maf while the car is running the motor should stall. if not than u definitely need a new maf. if the car does stall though there is still no gurantee that it is good
also, you may not want to do this but, take a meter to one of your front o2 sensors and make a splice in one of the wires, the haynes manual will tell u how to do this, from the voltage reading even though it is not entirely accurate it can give u a general idea if you are really running lean or if the 02 sensor is throwing everything off.
try and see if when u disconnect the maf while the car is running the motor should stall. if not than u definitely need a new maf. if the car does stall though there is still no gurantee that it is good
also, you may not want to do this but, take a meter to one of your front o2 sensors and make a splice in one of the wires, the haynes manual will tell u how to do this, from the voltage reading even though it is not entirely accurate it can give u a general idea if you are really running lean or if the 02 sensor is throwing everything off.
11-07-2007, 01:54 AM
#28
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If you're worried about the O2s being bad, unplug their harnesses and see if the problem remains. If they're bad, this would cause the car to stay in open loop, and it should run rich.
11-07-2007, 08:49 PM
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nah the main thing was the headers were red hot but now that’s fixed and I know that when the maf is removed the computer goes into a default mode to make the car run so unplugging the maf while its running would just turn it into the default mode... and I just rebuilt the motor so I aint taking it out again... Ill just take it to a shop here by me that works solely on LT1's to do that but I appreciate the help 355z28.. I posted the oil problem up in another post here’s the link to that thread if anybody wants to help with the oil pressure problem:
https://ls1tech.com/forums/lt1-lt4-modifications/810735-oil-pressure-droping-0-when-lower-then-2500-rmp-s.html
https://ls1tech.com/forums/lt1-lt4-modifications/810735-oil-pressure-droping-0-when-lower-then-2500-rmp-s.html
11-20-2007, 10:06 PM
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Pull your oil filter off ,take your oil cooler off and clean it. Then take off the oil piece under that, twwo bolts and clean it out. If that doesnt help,your oil pump is bad, or your pick up tube is lose. My car had the same problem;but my pick up tube came off and my oiler parts were stopped up with plastic parts from my low oil senser.
11-21-2007, 04:26 PM
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nah found out it was the worst case serineo... there was too much clearence in the bairings or something like that and there were little metal shavings all over the enfinve from the bearings... now im just going to have it professionally rebuild and put a bigger cam in it now...
This is a sad mistake to see happen.
11-21-2007, 05:01 PM
#33
Dont do that! if youve already done it once just do it again, you know what to look for now!
lol i had to take mine out right after i rebuilt it and go through it again because my bearing wore funny all because a stupid problem but anyways.
Just because you have a set back doesnt mean you cant do it unless you have the money to just go pay some one then i guess do it.
personally id give it another shot, that will save you money to buy other goodies for the car later. Just pay close attention, THREAD your oil galley plugs, plast guage everything and give it another shot.
lol i had to take mine out right after i rebuilt it and go through it again because my bearing wore funny all because a stupid problem but anyways.
Just because you have a set back doesnt mean you cant do it unless you have the money to just go pay some one then i guess do it.
personally id give it another shot, that will save you money to buy other goodies for the car later. Just pay close attention, THREAD your oil galley plugs, plast guage everything and give it another shot.
