Here is the story so far. For about 6 weeks I had a check engine light on When I pulled the codes it was telling me there was a large vacuum leak that I tracked down to the purge valve was leaking. Car ran fine the entire time. When it got warm out I put a new purge valve on it and after 4 engine starts the check engine light went out and the car has been fine for 2 weeks driving it every day.


Now yesterday I started the car and drove it 3 miles to walmart. Did my shopping in 15 min and came back out and now the problem. Car starts, runs for 5 seconds then shuts off. I tried several times to get it to run and finally if I kept my foot on the gas and held it at 2000-2500 rpm it would run. Soon as I took my foot off the gas it would die. Tried to start it a few more times and now can't even get it to start for 5 seconds. Called the tow truck and an hour later he comes and can't hook to the car with all the cars parked around me so I figure lets see if I can start it and move it. Car starts right up I put it in gear pull out and move the car to the top of the parking lost where it's clear. I put it back in park and it's just sitting there idling happy as can be. I get out of the car to tell the driver that maybe I don't need a tow (as I'm only 3 miles from my house) and while walking back from his truck the car died.


Skip ahead to today after the car has been sitting in the drive way for 18 hours. Went out looked under the hood and don't see anything. Try to start it and it fires right up no problem. I let it sit and run for about 5 min then I hear what sounds like a spark plug wire arcing to ground. I went and found it's the purge valve that I replaced pulsing on off a couple times a second. I unplugged it to verify and the noised stopped. The entire time the car is just running fine. I turned the car off and plugged the purge valve back in and started it back up. It's no longer purging and the car is running fine.


It's at this point I rev the motor a couple times and the wife notices a lot of white smoke coming out the tail pipes. Looks about the same as when the headgaskets went on her Ford 3.8. I checked the coolant and it was very low in the overflow. I added some water but I don't see any bubbles coming out in the overflow tank like I did when her ford blew the head gaskets.


Now I've read on there that these cars are prone to have problems with the lower intake manifold gasket. Could that be the source of all of these problems? I have no problem replacing that gasket if it's the source of the problem but I don't know that it would cause the car not to start.


The car is a 2004 SS NA3.8 and has 136,000 miles on it. I use it to drive 160 miles round trip to work 3 days a week and I really don't want to be stranded 80 miles from home after work one day. During all of this no message came up on the message center and no check engine light came on.


Any ideas on more trouble shooting I can do? First thought was to check fuel pressure but I don't see any valve on the fuel rail that I can connect me gauge to.

 

A leaking LIM gasket would explain white smoke. Replace the OEM gasket with a Felpro aluminum one. You might as well replace the faulty designed OEM UIM with a reinforced Dorman, and plastic coolant elbows with aluminum ones while your at it. Makes me wonder if steam or water may have gotten into the purge valve or solenoid causing it to arc. There is a Schrader valve on the front side of the fuel rail you can check pressure at, but you probably would have a check engine light and codes if fuel pressure got low enough for it to die.

 

Most likely water in the combustion chamber &/or O2 sensor is causing the no run condition, but I'm surprised there is no check engine light.

 

Thanks for the feedback. Yesterday I ordered the better Fel-pro gaskets for the lower and also the dorman for the upper. Figured while I was in there I didn't want to reuse the old upper gasket. Good Idea on the elbows. I think I can pick those up cheap at autozone. Same felpro gaskets from Rock auto were 50 bucks opposed to 75-80 bucks if I got them locally.


Seems like a straight forward job to replace. I've replaced Head gaskets on a SC 3.8 ford plenty of times and even replaced an intake manifold on my wife's 4.6 mustang so unless Chevy built in some new surprises that I'm not aware of I hope to get this done on a Saturday afternoon.


Now if the car still stalls after I do all this I guess I'll have to go hunting for another problem but I can't imagine I'm unlucky enough to have 2 major problem strike at the same time. When the car started acting up I too was really surprised it didn't throw a check engine light. I was hoping it would so I could pull a code a have a place to start checking.

 

I think once you change the upper and lower intake gaskets it should run just fine...
I would change the spark plugs..(while you have it apart).

Be sure to change the oil/filter a cpl times to be sure the the oil isn't also contaminated... after the repair.....

I would also recommend using the aluminum elbows... VS ... the plastic ones as they still have a tendancy to fail...

Don't use the orings that come with them... as they don't seal really well and have a tendancy to leak and or pop out...
I would use aftermarket o rings that are 1 size larger than what they come with and that will solve the oring issue.

 

Thanks for chiming in Stumpi. I didn't know about the elbow O-rings. I replaced mine about 2 years/25k miles ago with the ones they came with. Think they were Dorman. Haven't had a problem yet, but guess I'll need to keep an eye on them now. MrJaySC, you may want to deal with the fuel injectors also since you'll be removing them. I was able to get a set of six new OEM (either AC Delco or Delphi) ones on ebay for about $90. I checked recently and the same deal is still available. I questioned the low price and contacted the seller and they said the reason was that they were overstock. Whether that was the truth or not, I don't know, but haven't had a problem yet. Regardless, you're gonna want to at least replace the fuel injector O-rings since you'll be removing them and should not take the chance of having them leak. You may also want to replace the fuel regulator while you're at it. They've been known to be a problem too. Saw a UIM explode once because of it.

 

Well I spent Easter Sunday replacing the LIM gaskets. To my surprise the gaskets that were already there were the metal with black and green rubber. I think they were the improved GM gaskets. I went ahead and replaced them with my Fel Pro gaskets.


Problem is the car still won't start. If I push the throttle half way down while cranking it will come to life but is spitting and sputtering and soon as you let go of the gas it dies. It's almost like a big vacume leak. The only lines I unhooked was to the break booster and the one coming off the throttle body. I've double checked that everything is connected that I can think of. I feel like I'm back to square one.

 

Played with the car some more today and If I hold throttle down part way I can get the car to start sometimes. It will miss fire at around 2500 rpm then after a few seconds it clears up and is running smooth at 3000rpm. Then as I slowly let my foot off the gas it seems ok then just when I take my foot off the gas it dies.


I did get it running once where I took my foot off the gas and it sat and idle right at 900 rpm. Seemed off but if I touched the gas to rev it up it would sputter. Tried a couple of times then it died.


At one point while I was trying to keep it running in park the trac assist light turned on and the message center said to service the traction system??? After a few more tries to start it that message went away.


This seems to be the same problem I had before I did the intake gaskets so I wonder what other problem I have. I checked fuel pressure and it seems good. Key on 55psi. Cranking 50 psi. Running for 2 seconds 58psi.


Could it be that one of the 3 spark plug coils is going bad so I have a misfire on 2 cylinders? Is there a good way to test the idle air bypass valve in the throttle body? When the car would shut off I can hear it making a kind of creeking/popping noise for 2-3 seconds.

 

New mass air sensor fixed the problem.

 

Congrats!