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Sorry I haven’t been updating everyone, My Grandpa passed away last week and he’s been in the hospital for awhile so haven’t really been focusing on this, haven’t even read all of the replies yet.
So I took it to someone is s wizard with this stuff and has been the first honest person about this car to me, I had him replace the tailshaft housing for a completely desperate reason and I had him figure out why such low numbers. He said there definitely a vibration in the motor, I thought it was the solid motor mounts but, he said there is a vibration. And he said Cly 8 is making Zero power at all. He’s already tried fuel, spark, and everything else. For some reason 8 cly is making Zero power. So now it’s sitting at home in the driveway. My guy said he’d have to pull the motor out and tear it all apart to find out exactly where the problem is, and he quoted for 4-5 grand. I paid for a working **** short block!!! I called Thompson motorports, they said just have my guy call them so I did, he said they were going to talk to the owner, I called them a week later and at first they played stupid like they were having troubles remember who I was claiming “we deal with a thousand 416s all the time gimme your name” like you deal with thousands of 416s that are fucked up?? So then they said my guy said he was going to try a few things. So I’m getting the ******* run around it seems like. Anyways with everything going on right now, hearing all this news bout sent my over the edge.😐😩 Opinions?? And sorry it has been forever since I got back to you all.
take the valve cover off and look and see if cylinder 8 is missing a push rod, if its there see if you can rotate the engine over by hand and see if the rocker arms move at all for that cylinder.
First of all, pull a valve cover and make sure rocker arm is attached and working. If the valve is not opening it will be a dead cylinder.
Buy a $20 temp gun. Shoot the header with the temperature gun and see for your self that cylinder is not making power. Of temperature is lower than the rest he is correct. Do that first before pulling cover.
if its low temperature and the rockers are actually opening and closing valves correctly the it may be internal but I find it hard to believe its making zero power unless no spark or fuel is reaching that cylinder
take the valve cover off and look and see if cylinder 8 is missing a push rod, if its there see if you can rotate the engine over by hand and see if the rocker arms move at all for that cylinder.
Pics of the block? Pics of entire motor I want to see for sure this doesn't say 5.3 on the block if your really concerned then get your phone pop the hood and take pics for us and this may solve some issues
kind of good to hear #8 is dead. I started reading this and was like holy crap!
But if a cylinder is dead theres going to be a vibration. Seems like #8 needs to start working befor a teardown/engine removal is necessary.
Funny thing when I did headers I completely forgot to plug the #8 spark plug wire back in, that'll cause some problems!
Anyone with some common sense should be able to diagnose why its not working without tearing an engine down.
Stay calm, its just a car and you have no idea the cost yet or if anything needs to be removed more then a valve cover. If a lifter didnt make it in thats like the worst possible case, and highly doubtful. Pushrod maybe but still unlikely. Keep your head up!
I am sorry you did not get the answer you wanted from us. I understand your frustration. It sounds like we spoke with your mechanic and if we can help with anything please do not hesitate to ask. We do in fact work with thousands of builds around the world so please bear with us if we ask who you are when you call so we can get the notes on your build, this prevents us from giving you the same steps every time you call to check. I understand you paid for a "working short block" as stated but I am not sure how you feel you have not gotten one at this point. The short block is a air pump, it is pretty difficult to have it prevent fire, If you do not have fire it is missing something, In any case we are here and happy to help you find your issues with the build. Please keep us updated and let us know if we can help with anything else.
Sorry I haven’t been updating everyone, My Grandpa passed away last week and he’s been in the hospital for awhile so haven’t really been focusing on this, haven’t even read all of the replies yet.
So I took it to someone is s wizard with this stuff and has been the first honest person about this car to me, I had him replace the tailshaft housing for a completely desperate reason and I had him figure out why such low numbers. He said there definitely a vibration in the motor, I thought it was the solid motor mounts but, he said there is a vibration. And he said Cly 8 is making Zero power at all. He’s already tried fuel, spark, and everything else. For some reason 8 cly is making Zero power. So now it’s sitting at home in the driveway. My guy said he’d have to pull the motor out and tear it all apart to find out exactly where the problem is, and he quoted for 4-5 grand. I paid for a working **** short block!!! I called Thompson motorports, they said just have my guy call them so I did, he said they were going to talk to the owner, I called them a week later and at first they played stupid like they were having troubles remember who I was claiming “we deal with a thousand 416s all the time gimme your name” like you deal with thousands of 416s that are fucked up?? So then they said my guy said he was going to try a few things. So I’m getting the ******* run around it seems like. Anyways with everything going on right now, hearing all this news bout sent my over the edge.😐😩 Opinions?? And sorry it has been forever since I got back to you all.
I don't understand how you can blame Thompson at this point, have you pulled the valve covers yet? done a compression test? And why would he have to pull the motor out ?
Pull the spark plug for that cylinder and inspect. I’ve had a coil connector not seat right and the plug never fire. Pretty easy diagnosis before you pull the engine. Check for fuel, spark, compression. Fuel and spark will be an easy fix. Compression, not so much, unless you have a rocker/pushrod/lifter issue, which you can easily see under the valve cover. Don’t pull the engine until you look at these parameters.
I would not pay anyone 5 grand to pull the motor and diagnose it. I think these people smell you from miles away.
It's not that hard to figure out what cylinder is dead and why. Get that fixed before pulling the motor and shitting on the shortblock. The shortblock has nothing to do with fuel or spark.
It will be something stupid like a faulty wire to the injector or loose rocker arm...... As stated do a compression/leak down test and get a temperature gun and get a temperature read out from each primary header tube. Do the temperature read out first as it is the easiest. Could even be a bad spark plug/wire. Happens all the time.
OP dont pay anyone 5000 to tear your engine out if they havent run a compression or leak down test. Get real and have him truly diagnose it. Run a compression test, leak down test and swap plugs, coils, wires and injectors each to a different cylinder and see if the miss follows the parts. This is really basic diag any wizard should be able to do. Thompson motorsports are stand up guys. They will take care of it if it is there problem im sure and i have lots of experience with them. Dont alienate you engine builder by bad mouthing them with out even knowing if they are the cause. Most failure on a shortblock that would cause a single cylinder miss are catastrophic and should be easy to diagnose. Only thing i can think of to really do this is broken rings or bent rod. If its bad rings it will have low compression and leakdown like crazy. Bent rod will have low compression and very little leak down usually. Other then that its going to be head or cam stuff. Pull the valve cover and there your issue will show itself. If the wizard cant give you a pretty damn complete diagnosis before pulling the engine then he maybe more of a smoke and mirrors wizard instead of a true badass.
Update!
i believe I may have found the problem! I finally had time to pull the valve cover, and Found it right off the bat, a broke rocker arm. Ls3 trunion upgraded rockers. They were brand new cnc ported heads with the btr springs n everything already installed from BTR. I still have a little worry though because, What would cause a rocket arm to break?? So now, what should I look at now that I found that??
Thabk you for all of the advice, I really appreciate it. With all I’ve been through with this car I immediately went straight to thinking the absolute worst, something very deep inside being wrong.
Might just have been a faulty casting that finally let go. I think if there was an overall problem ( spring bind, etc.) there would be a lot more breaking going on.
10-10-2018, 08:41 AM
