LT1 runs in reverse :-(
Thread Starter
Teching In
Joined: Apr 2014
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LT1 runs in reverse :-( Ok, so my car has a few issues, but has anyone had their engine run in reverse on startup? Mine seems to try to do this on every startup, making it seem like the starter is bad, but really it is just constantly fighting with an engine that wants to run backwards! It kicks back and makes all kinds of funny noises, then after trying it a few times, it starts normal. And after a restart when it's warm, it is usually pretty ok as well.
It really shouldn't be possible, but I have shifted into first before and went backwards after letting the clutch out! It doesn't run for long and sounds funny, but it does do it...
I'm far from a motorhead, but my mechanic has never heard of it either... and also didn't fix it last time he had it...
Thanks,
Tim
It really shouldn't be possible, but I have shifted into first before and went backwards after letting the clutch out! It doesn't run for long and sounds funny, but it does do it...
I'm far from a motorhead, but my mechanic has never heard of it either... and also didn't fix it last time he had it...
Thanks,
Tim
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Im not sure how to address ur issue but this is impossible.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Like the folks above said, the engine cannot actually "run" backwards.
But kicking back against the starter could suggest some type of hydrolock. Probably not water related if it happens on every start attempt unless the car is always sitting in rain storms or a car wash, but it could be from a leaking injector(s) that fills the cylinder when cold. That would also explain why it's not much of an issue when warm. It could also be from coolant filling the cylinders, but if a head gasket was bad enough to be doing this on every startup I would think you would have noticed other issues by now (disappearing coolant, overheating, etc.). A couple of tests you could do here - hook up a fuel pressure gauge, run the engine for a bit and shut it off. See how long it takes for pressure to bleed down. Another thing you can do is pull the spark plugs when the engine is cold and see if there is liquid in any of the cylinders.
But kicking back against the starter could suggest some type of hydrolock. Probably not water related if it happens on every start attempt unless the car is always sitting in rain storms or a car wash, but it could be from a leaking injector(s) that fills the cylinder when cold. That would also explain why it's not much of an issue when warm. It could also be from coolant filling the cylinders, but if a head gasket was bad enough to be doing this on every startup I would think you would have noticed other issues by now (disappearing coolant, overheating, etc.). A couple of tests you could do here - hook up a fuel pressure gauge, run the engine for a bit and shut it off. See how long it takes for pressure to bleed down. Another thing you can do is pull the spark plugs when the engine is cold and see if there is liquid in any of the cylinders.
Timing WAY too advanced can cause kickback on startup too. Dieseling might also last for a couple of reverse rotations, if that. The only way out for coolant is either into the oil, onto the ground, or out the tailpipe as a cloud of white smoke. Spinning it a few seconds with the plugs out should remove most of any liquid.
Cam timing dictates running rotation. An old friend had a late '50s Correct Craft with a reverse rotation 283 SBC in it. Not only was the cam ground to rotate in reverse, all the bearings were flipped around to resist spinning. What a nice running boat, plowed through wakes like a hot knife through butter. So sad when some neighbor's kids accidently shot a bottle-rocket under the tarp one July 4th and burned it to the waterline.
Cam timing dictates running rotation. An old friend had a late '50s Correct Craft with a reverse rotation 283 SBC in it. Not only was the cam ground to rotate in reverse, all the bearings were flipped around to resist spinning. What a nice running boat, plowed through wakes like a hot knife through butter. So sad when some neighbor's kids accidently shot a bottle-rocket under the tarp one July 4th and burned it to the waterline.
Last edited by JohnnyBs98WS6Rag; Feb 11, 2026 at 03:20 PM.
Thread Starter
Teching In
Joined: Apr 2014
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Gotya yeah, dieseling sounds most likely even though it is sometimes more than a few rotations. I can’t rule out coolant or fuel getting into the cylinders as it is at 200K miles now. And has also recently had injector issues and coolant clogs like crazy. That dex seems
to be the worst…
to be the worst…
Joined: Nov 2001
Posts: 34,647
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From: Schiller Park, ILL Member: #317
Nothing wrong with Dexcool in this application as long as you follow a proper maintenance routine. There are a few engines that had inherent gasket issues with Dexcool, but LT1s and LS1s are not on that list. FWIW, my Z28 has seen nothing but Dexcool since it left the factory in March of '98 - not a single problem yet, but I keep it properly changed. You should see what happens to cooling systems that were neglected with the old green stuff, it's just as bad if not worse. My '74 had only 42k miles when I bought it, but every part of the cooling system was shot; tons of sludge in the overflow too - all from the old green stuff.
"Dieseling" shouldn't be a problem on an ice cold engine that hasn't even been running yet, so if this is a cold start problem then that's probably not it. Check the cylinders for liquid intrusion (coolant OR fuel). Only other thing that could make sense would be massively advanced timing, as JohnnyB mentioned above.
"Dieseling" shouldn't be a problem on an ice cold engine that hasn't even been running yet, so if this is a cold start problem then that's probably not it. Check the cylinders for liquid intrusion (coolant OR fuel). Only other thing that could make sense would be massively advanced timing, as JohnnyB mentioned above.
