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Overheated and now won't start

N

NayGP

New member
I have a 2000 Grand Prix GT and the other day when my sister was driving my car the thermostat went out and it overheated going down the highway. Blew the radiator cap off and spewed anti-freeze everywhere. After we got a new radiator cap for it and more antifreeze it would we let it cool down and it would not start. Have been told it could possible be one of two things. Either some of the antifreeze got the coil packs wet and shorted them out or possibly it jumped time. What would be the easiest way to find out what the problem is? Any insight into this is greatly appreciated.
 


If it fires on starting fluid then its a fuel / computer problem. It it does not fire at all its a spark problem. Fun fact our ignition control modual controls spark during cranking.

Any CELs? (Check engine light)
 
Okay so it did not start with the starting fluid. It acts like its trying to start, but it wont. so we're at a spark problem.... could it be that the coil packs got shorted out? or maybe the plugs and wires??
 
check engine light is not on, and it did not start with the starting fluid. Its just me and my brother in law figuring this out, and I have limited knowledge of cars.
 


Let's start off easy. The chain jumping time would be the first I've ever heard of, and I've heard/seem millions of these cars on forums etc. Secondly, the coils and all under hood connections are weather packed, this means when you drive through rain and puddles, they won't cause issues.

1. Does the engine turn? (If no, search on my name and L36 failure for what happened)
2. Is there fuel at the rail?
 
As Bill mentioned, everything under the hood is pretty much water sealed and water safe. Possibly your motor seized up, maybe you loss compression do to fried piston rings, im not sure if any coolant entered the block or was able to exscape but maybe it hydro locked. A lot of possibilities but if your car just overheated I dont see that affecting your fuel or much of anything else unless the coolant did affect electrical components.

Depending on how long the car was driven after the car started to overheat, ima bet it a mechanical problem(like the water pump seizing, etc.) possibly preventing the motor to turn over. Also, this over heating issue may have revealed any other problems the motor may have had if any, contributing to the problem.

Im not sure what the issue is but I hope you figure it out. Im not sure if my thoughts are right or wrong but they may help you.
Oh and if or when you correct the problem, make sure the ECT(engine coolant temp sensor), Thermostat,fan,coolant flow and mixture etc. are all functioning properly to prevent future issues. The ECT is one of the most important bc it controls most of your engine cooling components(or at least does most of the leg work providing the engine temp so the other components no when to turn on/off and or to work properly
 
He says it is trying to turn over.

So that means it is not hydrolocked.

Something else is the issue and I do believe it still has to do with the uim failure. The problem is, he has a massive vacuum leak at this point causing the car not to start.
 
Okay so here's where we are at... We replaced all plugs and wires... Cleared our all cylinders and we did find a vacuum leak.. Got that fixed, replaced thermostat and found out I had a crack in the radiator. Replaced that and the top hose. Now my fans aren't coming on... Fuse and relays ate good and we can here the relays kicking in... I'm about ready to give up.. Love my car but starting to wonder of this is all worth it..
 


did you ever get it running?
ever do a compression test? what about a coolant pressure test? how about any testing other then replacing parts?
 
yes it is running... taking it to get tested tomorrow morning. and the only replacing we've done is what was needed.
 
As the all exhalted guru and telepathic visionary able to read minds through the internet, I have a few questions still.

You said clear out the cylinders. Cleared out of what?

I have a direct area I'm aiming with my questions, don't want to scare you by listing things out w/o getting more direction.

FWIW I've never found a compression test to tell me much on these engines. The one time it did tell me something, it simply confirmed that a piston was missing.
 
When we pulled spark plug out of number 2 there was antifreeze on it...this happened to my brothers grand prix a few years ago when it got flooded out... So we got that compressed out and after that is when out actually started... Now today it wouldn't start again...
 


i hope you weren't trying to crank the engine over like that to much with coolant in the cylinder, thats what would cause the rod knock your gonna have in a thousand miles or less after you do the lim gaskets.

id park the car asap, and then do the lim gaskets and check the upper intake for all the regular warping or cracking. clear that cylinder after you dump the coolant from the engine, ,then do the lim gasket job.
 
Something has failed which is letting coolant in. Either upper plastic intake, upper intake gasket, or lower intake gasket. I doubt its a headgasket but its possible.
 
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