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car dies if I take oil cap off

C

Corona99GT

New member
So my car makes this loud whine when its on but I didn't think it was the engine it self so I figured, to my opinion it was either the alt or the a/c comp. So I went ahead and took the belt off and started the engine good news it was the a/c comp. bad thing is I don't remember why but I decided to take the oil cap off and the car started to act up and just died. So I replaced the belt and the oil cap and started her back up everything was OK until I took the oil cap back off did the same thing just died, what I did notice it that when the oil cap comes off I hear the engine sucking air thru the oil filler hole is this normal with these engines?
 


Well I just changed it out today and after I changed it I took the oil cap back off and this time the revs went up and then they came back down to a rough idle and then I put the cap back on. I have a friend who works with diesel engines and also owns a GP he told me it could also be the intake manifold gasket is this true? Car has 150k on it and don't know it they have ever been changed.
 
under the throttle body, look at where the lim meets the block and heads, at the V where it turns up to the head, if you see some rtv oozing out its probably been done before, but that don't mean its good still.

could try a coolant pressure test to see if its holding.

and the lim gaskets are a warranty fix at the dealer if its never been done before,(for older models i don't know what year your car is) you could go to a dealer and have them run your vin to see if its been done by a dealer somewhere.
 
There should be an o-ring below your pcv and one on the cap above it plus a spring. If anything is missing..that's the most likely reason. Because air from various areas is getting to the TB and causing a huge vacuum leak.

While these cars are known for LIM gaskets going bad, they typically don't cause the type of issue you are having and the symptoms wouldn't fit at all.

ScottyD... RTV is always in the corners, factory or replaced gaskets. Best way to tell guys about checking them is to look by the thermostat housing where hte LIM meets the head. If you see a black gasket, it's plastic and should be swapped out for longevity. Aluminum...good to go.
 


Ok thanks guys I will check the LIM gaskets see if there plastic or aluminum, and reguarding the pcv valve when changing it I didn't see that spring your talking about I did notice the O-rings but no spring and the PCV valve they sold me just came by its self. cars a 99 gt by the way.
 
go to a GM dealer and get a PCV kit.. it comes with the correct valve, oring, spring, and retainer. Some aftermarket PCV valves flow to much and will cause issues.
 
scottydoggs said:
... the lim gaskets are a warranty fix at the dealer if its never been done before,(for older models i don't know what year your car is) you could go to a dealer and have them run your vin to see if its been done by a dealer somewhere.
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I work at a GM Dealership, given the age and mileage there wouldn't be warranty work of any kind on it. If your meaning the recalls for them for engine fires, that was Valve Cover Gaskets and Spark Plug Retainers ONLY.
You can go by a dealer and see if the recalls were addressed, and if there was any work done regarding the LIM gaskets, but you will have to pay for those to be replaced. You can replace the LIM Gaskets yourself if you have a full weekend and basic tools.

If they have never been done, I would suggest changing them just on principle of how the originals were designed and how much they fail. But its up to you and your wallet to argue that, not me :p
 
i thought there was a recall on the older ones for the lim, i drive a regal , and when i looked up all recalls for my car there were quite a few so i may have thought i saw it there, thanks.
 


Idk why but I assumed that you don't take th oil cap off while the engine is running are you sure thats not your problem... I mean they say you need a tune to run those one things that replace the oil cap idk
 
Taz Magester said:
Idk why but I assumed that you don't take th oil cap off while the engine is running are you sure thats not your problem... I mean they say you need a tune to run those one things that replace the oil cap idk
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I just cleaned my engine this weekend and when the car was running i wanted to take the engine cover off, so i removed the oil cap&neck, i forgot the engine was running, so i took the cover off looked down to see the moving parts inside the hole lol! scared me half to death but then i listen to the way the engine was running it was fine, no sucking noise of any kind thats for sure.. so i put the neck/cap back on shut down the engine and continues cleaning. so he shouldnt have the issue of it stalling, cause i sure dont.
 
BillBoost37 said:
Sheff...a weekend for LIM's, I'm gonna guess you aren't flat rate! :D j/k... a weekend for a first timer is about right.
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HAHA I did mine outside in the rain in 10 hrs with hand tools and umbrellas :p

I was saying a whole weekend for those that haven't dove into an engine before.
 


Perfection knows no bounds or time limitations :p

It was actually suppose to be clean and clear. We got the engine apart and thunder rolled in then it got bad lol. Buds garage was cluttered and we couldn't roll the car up hill and into the garage so we just made due and took our time
 
Well who would of though that a simple spring and the little o-ring on the bottom of the PCV could cause all that trouble. I put them in and now it works just fine no more loud whine and no more engine stalling or air sucking when I took the cap off (just to make sure it was that :p). Heck even the SES light came off after a couple of minutes. I miss that little light LOL.

Thanks for the advice guys it really helped out.

Now for the LIM gaskets it would be the first time I change those but once I buy them its just a matter of taking the time to change them out. Well it it means just unscrewing and taking the old ones out and putting the new ones it and screw every thing back together i see no problem in that.
 
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