1998 Pontiac Grand Prix
3800 (3.8) 6 cyl
160,000 miles

Check engine light began flashing a couple weeks ago, and when it did the car would hesitate to accelerate, happened before a few years ago and had my coil packs replaced. So yesterday I was just putting coolant in the radiator and decided to disconnect the battery to reset the ECM, and check engine light. Went to go start and it only tries once then stops dead. It's not like a low battery where it trys several times but just doesnt have the power. It only tries once then stops. Even tried jumping the battery just to rule that out and it still didn't work. What happened? I really need my car to get to work, someone please tell me my engine is not seized, and this is a simple fix... i'm stumped. and yes there is gas and good oil in the car. Thanks

You don't indicate why you were adding coolant in the first place but the flashing check engine light indicates a solid misfire. The fact that you were adding cooling makes me suspect you had a prior overheating problem and the symptoms point to a possible blown head gasket or cracked head. You cranking problem sounds like it might be hydrolocked on liquid coolant in the cylinder. Remove the spark plugs and then crank the engine. If coolant spits out of any of the cylinders, the our suspicion is confirmed.




78 Corvette Pace Car For Sale-18k mi orig-Florida

I was adding coolant because my low coolant light flashes off and on sometimes, temp gauge never really gets to hot, but I did replace the thermostat a couple weeks ago because my heater would blow out cold air, i figured my thermostat was stuck open. But this is what I don't understand, the car had been sitting there for a few hours, it was cooled off, thats when I decided was a good time to check my water. I filled it up, started the car, it ran fine. Shut the car off and then proceeded to disconnect the battery and re-connect it... thats when it no longer would start. Is it possible that the battery is not supplying enough amps to the starter, or would the starter at least continue to try even if that was the case. But I will test the hydrolock theory when my dad gets here with some tools, thanks for help.

Check your connection at the battery but you still haven't resolved where that coolant went. Heaters usually stop working because they are full of air and not coolant. Another thing that points to a head gasket problem. You need top pressure test your cooling system and get to the bottom of the coolant loss. I suspect it's already too late.
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78 Corvette Pace Car For Sale-18k mi orig-Florida

Here's the deal with the coolant issue. About 3 months ago, water pump locked up. Blew coolant everywhere, my local car guy "apparently fixed it", but im not so sure he filled it up with coolant after it blew half of it out. Also it appears now to have green coolant, and ofcourse this car only takes Dexcool the orange stuff. I'm not so sure if thats a big deal. But since you are leading this to a cooling system issue, I'll lay out what I know. BTW my low coolant light was periodically going off and on long before all of this, I figured it was a loose connection or bad sensor. But first the water pump failure. Everything was fine after that, till about 2 weeks ago when car took a awhile to reach a high temp and heater started blowing out cold air. Also I noticed the coolant was boiling at some points. (but car never really got to hot according to my temp gauge) Literally bubbling out of the backup reservoir. I asked a guy at work about that and he said the thermostat being stuck open can cause coolant to boil. (really didnt make any sense to me) but changing a stat is a cheap fix, so I did. Didnt resolve the issues, and now im stuck with this current issue of it not starting. Oh and one more thing I noticed, the ground post on my battery got so hot last night it began to smoke. What the hell causes that? Could something grounding out cause the car to only try once to start? I know there are alot of issues here, I'm just poking at what one is keeping the car from starting... again thanks for the advice, more is always welcome, I just hope my dad gets here soon so we can test some things out.

The battery post getting hot is your bad connection issue. Take the cable off, clean it with baking soda and water mix and then wire brush it.

You may have 2 different issues here with the starting and the coolant loss but you need to get to the bottom of the coolant problem with a pressure test because all signs point to a head gasket problem there even if it isn't the cranking problem..




78 Corvette Pace Car For Sale-18k mi orig-Florida

Well the battery is now for sure no longer the problem... I just removed it from the car, cleaned everything till I could see nothing but metal and copper. Hooked it up to a smart charger, holding voltage and amps. Re-installed the battery and still same issue. Things are looking grim.... there is no way I can afford a new car.... My wife says one of her friends is bringing a mechanic over, which would be nice, but I won't hold my breath. Thanks for help.

Pull the spark plugs out as I advised so you can find out if it's hydro-locked
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78 Corvette Pace Car For Sale-18k mi orig-Florida




(This post was edited by Hammer Time on Jun 17, 2009, 12:25 PM)

Thats my next step... I was going to head down to my dad's house and grab some more tools that I need, cause he said he has to work late, and well I'm not gonna wait around for this ghost mechanic anylonger. So I guess I'll head on down and grab some tools. BTW, if it's hydrolocked its still gonna be an expensive repair right? Especially fixing whatever caused the water to get in... like head gasket....

Yes, if it's hydro-locked, that means it could be serious but there are a couple other possibilities. That engine has a know problem with the plastic intake manifolds leaking coolant into the valley but that would still require a new manifold and dis assembly to find out if it is.

Finding coolant will confirm the engine has to come apart.




78 Corvette Pace Car For Sale-18k mi orig-Florida

Well alot has been done and some of it to my detriment, but thats how things work i guess. The ghost mechanic showed up with my wifes friend, he seems to know alot about tools, engines, and parts, just lacks the diagnostic skill. After letting him run his own tests, after tapping on the starter with a hammer... we did get the car to try more than once, it actually seemed to try twice... We removed the starter (though I was sure this wasnt the problem, since you can actually hear it engaging the flywheel) and I took it to be tested. It passed the first test, then we ran 4 more tests and it failed each time. We put a brand new starter in the test machine and it sounded much healthier, and more rpm's.
I spent $180 on the new starter. Installed it, and.... same thing. Nothing. One try thats it. Rather mad at the loss, we began to remove the spark plugs. No one had a 24mm socket so we called it a night. Brought home a 24mm today to see if we could turn the crank pulley. The crank only turns about 2 inches forward and then able to turn it about 2 inches back, but thats it. No signs of water coming from plug holes.... Aslo I had one of the guys try to start it so I could watch the crank pulley, it does jump a little when the flywheel is engage, but not much. Well, today the mech guy called some freinds and they said only other thing it could be other than seized, is the time chain bound up/broke or whatever. Do you think thats a possibility? Well I went to my 2 hour class, came back, and half my engine is tore apart. I figured what the heck, it wasnt gonna run the way it was, let these guys do what they want, its free... Only thing left to get to the timing is the crank pulley/damper, in which we need to get a puller, which I plan to get tomarrow, so we called it a night. I remember pulling the harmonic balancer of an old buick, it wasnt fun. Let me know what you think, I just dont see how the engine could sieze with oil, and a deisent amount of water, but like I said that crank pulley dosnt want to budge past two inches.... Thanks

Did you try doing that with all the plugs removed?
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78 Corvette Pace Car For Sale-18k mi orig-Florida

Well... end of story. The car is running, and no one has a single idea how. I was sure the motor was seized. We finally got to the timing chain, and everything looked good. The wierd part part is, somewhere between the inital breakdown and tearing half the engine apart, the crank pulley was able to be turned by hand, and kept turning, didnt stop 2 inches later. I have know idea what happened, but I never saw any signs of water coming from plug holes, I checked probably 8 times when we would turn the crank. All I know, is that with the help of a ghost mechanic, we fixed a ghost problem. Hopefully it doesnt happen again.... Thanks for all your advice....

Ok well it's not end of story. The car ran great for 2 weeks, no misfires, no check engine light, no overheating. Then at the end of that two weeks, I got the misfire, and the engine light again, car began running hotter also. As much as I didnt want to, I put water in the radiator, and sure as heck, the car bogged down, shut off, and seized up the crank again. After turning the pulley several times by hand, apparenty unseizing my crank, I was able to get the car started, it bogged and bellowed a thick white smoke for 20 minutes, then began running normal. It is apparent I'm getting a crap load of water into my chambers. If it were a head gasket wouldnt it be a slow seepage of water and not just shooting everything I put it my radiator into the chambers. Today I had to run some errands, took it on the highway, and my temp gauge got hotter than ever, almost redline, it got up to about 245 or 250. I know im low on water, but if I put any in it locks the engine. I need to know what the heck is putting all that water into my combustion chambers. Unfortunatly I barely have a dime too my name to spend on it, but if its a stuck valve or whatever, point me in the direction, cause I'm at a loss what to do.... (oh and still no signs of water coming from the front plug holes) I can't get to the back ones without tilting the engine, and I can't do it by myself. And while I was turning the pulley I could here what sounded like a hissing releasing from somewhere....

This engine has a known problem with bad intake manifolds. They are plastic and deteriorate right at a water port and they fill the valley with coolant. You won't know for sure until you pull the manifold off but it will be obvious then.

Here is a TSB on the subject







78 Corvette Pace Car For Sale-18k mi orig-Florida

This helps alot... I'll look at my Haynes Repair manual for detailed instruction. I'm optimistic at this point, and hope its not a head gasket, cracked head or block... thanks for the info. I'll keep posted on progress.

Good news indeed. I ordered an entire intake manifold with gaskets, for only $60 online (auto stores around here wanted $130) spent 4 hours yesterday with my dad replacing the unit. Sure as heck, not only was the gasket in terrible shape, the actual manifold itself was cracked and broken right next to the coolant passage, there was alot of water sitting in there.... Car runs great, and its not consuming a liter of water ever time it runs... Much thanks to you for your diagnostic help and advice. Cheers!

Glad I could help




78 Corvette Pace Car For Sale-18k mi orig-Florida

Good job, HT. Just don't try to 'spend' these.
Loren
SW Washington

You mean those 2 squares that say "Image not available"?




78 Corvette Pace Car For Sale-18k mi orig-Florida

Well, those were supposed to be stars. Hmmmm. Must be this new monitor?
Loren
SW Washington