i saw a built c5 on craigslist for sale i was considering buying. the owner said its a 416 ls3. he showed me reciepts for everything. has tsp heads, callies bottom end, good amount of money spent. but he tells me that if you shut it down after driving, it won't start back up until it cools down. he says the starter just turns very slowly and groans. but when it cools down it starts right up. i say this to my buddy who has never built a motor, but been around mack diesels, powerstrokes and a variety of other motors and says dont touch it. its having cooling issues and running hot. he wants me to verify oil pressure and coolant temp before buying. he actually doesn't want me to get it at all but its right up my alley......he said he guesses its possible the starter is weak and the heat from the headers is making the starter hot and not want to crank fully, but still advises me to stay away........thoughts? the car has 11.7 compression on an ls1 starter

 

Really really common for C5's (hell big block 454 stock gm trucks had the same problem )
to overheat the starter, their airflow to the starter is weak,
Headers make it worse.

All the full track vett's I worked on it was one of the first upgrades was to add a air vent tube to get air behind the headers and or cut the fenderwell.
It also helped the radiator..

You should also be running at least a 5/8" positive lead and the same for the ground back to the
neg post on the battery, direct from the starter base. I get the cables made at a welding shop,
yep they cost some,, fine stand flex copper.. Like a welding stinger uses..

Also stokers increase the required torque to just turn over even if the compression is low.
IIRC the starter of the non turbo 6.2 diesel was the ticket for more starting torque...

 

im also considering buying it just for the motor and putting it in an fbody. would an fbody have a similar problem as well? where i would need to do some mods for airflow? ive never had an issue with my 450 hp ls1 and headers. maybe that 10.6 to 1 compression is much much easier than the 11.7 to 1? and thats the difference?

 

is there anyway to confirm it is a heat to the starter problem and not an engine problem? if coolant temp is good and fully warmed up oil pressure is good, is it pretty safe to rule out th motor?

 

I seriously doubt its the starter. Until you dig into it plan on it being something in the tune etc.

 

I had the same problem with my turbo fbody, i replaced the starter and the problem went away 100%. I think the heat on the old factory starter was just to much. With my new starter it cranks over fast hot or cold. No problems in the last 18months of use.

 

I have a 454ci in my 97 3/4 ton pick up. I can tell you it's go need a starter soon.

 

 

 

I'm thinking about trying some heat shield wrap.....

 

If you have forged pistons and they are clearanced wrong they will expand into the block wall too much and increase friction till they cool

 

 

 

Generally oil pressure is lower at warm idle. The only good way to check these clearances is tear down and re check every thing, Sorry

 

I've seen this on many many makes and models over the years and when a starter will hardly turn with the engine hot, a new starter was always the fix.

One way to see if it's an internal engine issue is to turn the motor by hand with a ratchet cold, and turn it by hand with a ratchet hot and see if it's harder to turn. It's not likely it's an internal engine issue because usually when things expand too far they end up going metal to metal and **** ends there.

 

I upgraded to MSD high torque starter. Loud but effective.

 

Excellent choice, it could be anything from the starter to the pistons BUT I know if it were my car I would have tried a starter before selling it.....just saying hard to believe they didn't try it already. Another possibility is running hot and too much timing. Offer to replace the starter before you buy it? Cheap enough to try.

 

No he said he lost interest in the project. I lied about the car and motor because I didn't want anyone else to see it and potentially try to take the car away from me. Nor did i wan him to see this snd think im bashing or anything. But he agreed to hold until next week for me. I'm on my phone so can not post a link. The car is actually a 99 Camaro with a 441 ls7. It''s in the classifieds here. The cam was specd with torque in mind. It's a hydraulic 23x 25x comp grind with roughly 660 lift. That's what he told me. He sent me a dyno and it made 650 580 on an engine dyno. I'd imagine if the rings were to tight it wouldn't have dyno that right? Peaked around 6600 that's when they killed the pull

 

While it is likely the starter or its main wire, I had a 2JZ that did the same exact thing for a while after being accidentally ran low on oil. Car fired right up when cold and ran strong as hell, but if you got home and shut down it wouldn't want to turn right back on for a few minutes. After about a month or two of it doing that (but running GREAT once it started) it eventually spun a bearing.

Just something to keep in mind...it could be something minor like the starter but it could also be bad news in the rotating assy. Would be worth swapping a cheap rebuilt starter to test before.

 

Hope it works out for you. I learned the hard way over the years not to believe anything you are told about a used car. Its just too easy to hide things. I never bought a used LS car that didn't have issues, even low low mileage ones and the dealers are the worst to lie about sheet. I bought this WS6 I have from Bonner Chev in Kingston pa, figured it would be safe from a new car dealer. 28k miles on it. They put something like graphite in the oil to quiet the engine and Lucas in power steering to hide the worn out power steering pump. They also hid the fact the car was a lease car. Car also had a bad axle. Don't trust anyone! The owner of Bonner Chev is a real **** HEAD.