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Engine dies out when oil cap is pulled off ++

Posted: November 3rd, 2001, 5:51 am
by OverDrive
Hi folks. The car is a 94 GS Auto with 80,000 kls. Recent work includes new alternator/belt, spark plugs, rotor, distributor cap, Engine flush, replaced tranny oil.<P>Is this normal? If I have the car running and pull off the oil cap the engine just dies.<P>Also, I'm noticing a couple noises lately. One sounds almost like low grrrrr noise that seems to come from the area around the vincinity of the alternator belt pulley(could it be the timing belt? Does it make any noise when its going?). I just replaced the alternator and the belt about a month ago though. There is also a slight tapping/knocking noise from the top/front of the engine(valves?).<P>Sorry for all the questions, I'm not very mechanically gifted. :)

Re: Engine dies out when oil cap is pulled off ++

Posted: November 4th, 2001, 1:15 am
by white fish
they all die when you remove the oil cap<BR>the noise [img]shrug.gif"%20border="0[/img] maybe you put the belt on too tight <BR>the tapping could be HLA's (use 5w30 oil) or it could be the cam friction gear

Re: Engine dies out when oil cap is pulled off ++

Posted: November 4th, 2001, 2:18 am
by mitmaks
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by white fish:<BR><STRONG>they all die when you remove the oil cap<BR>the noise [img]shrug.gif"%20border="0[/img] maybe you put the belt on too tight <BR>the tapping could be HLA's (use 5w30 oil) or it could be the cam friction gear</STRONG><HR></BLOCKQUOTE><BR>You saying that all cars would die if u pull off engine cap?????? if so my cars dont

Re: Engine dies out when oil cap is pulled off ++

Posted: November 4th, 2001, 2:43 am
by OverDrive
Whew! I was worried there. Thanks for the information.

Re: Engine dies out when oil cap is pulled off ++

Posted: November 4th, 2001, 1:14 pm
by Bri94GS
Mine doesn't die when the cap is off either

Re: Engine dies out when oil cap is pulled off ++

Posted: November 4th, 2001, 3:53 pm
by OverDrive
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Bri94GS:<BR><STRONG>Mine doesn't die when the cap is off either</STRONG><HR></BLOCKQUOTE><P>Hmmmmm, varying opinions :) Whitefish have you tried it with yours? <P>Also, what are HLA's? And if its a cam friction gear how is it fixed? :o Thanks.<P>*edit* I think I got the answer to the "friction gear" thing <A HREF="http://www.geocities.com/MotorCity/Downs/8175/cams.htm" TARGET=_blank>here</A><p>[ November 04, 2001: Message edited by: OverDrive ]

Re: Engine dies out when oil cap is pulled off ++

Posted: November 5th, 2001, 5:40 am
by codyhoover
mine doesnt die but it really doesnt like it. same with the dipstick. i dunno why

Re: Engine dies out when oil cap is pulled off ++

Posted: November 5th, 2001, 1:56 pm
by Custommx3
These that the motors are having issues.. <BR>Are the high mileage engines?

Re: Engine dies out when oil cap is pulled off ++

Posted: November 5th, 2001, 3:57 pm
by GMGQ
Cuz your engine is pressurized. If you pull the cap or something, then it can't maintain that pressure to pump the fluids around. That's one of the things a mechanic can check for. They take off the oil cap, and replace it with the pressure gauge thing, to check for leaks or anything.<p>[ November 06, 2001: Message edited by: GMGQ ]

Re: Engine dies out when oil cap is pulled off ++

Posted: February 9th, 2004, 10:07 am
by superslacker
my k8 with 90k miles on it won't like it if i pull off the oil cap, and my older 120k mile K8 would crap out completley if it was taken off. i also think maybe it has to do with the atmospheric pressure of where you're as to whether this happens or not.

Re: Engine dies out when oil cap is pulled off ++

Posted: February 9th, 2004, 11:54 am
by IanL
Its the Positive Crankcase Ventilation (PCV) System. For explanation, see this thread

Taking the cap off, or removing the dipstick, puts the crankcase to atmospheric pressure. From the above explanation, this is equivalent to putting a large hole in the intake pipe downstream of the TB. So a whole lot of air gets sucked into the engine which hasn't been measured by the VAF. So the mixture is far too weak, and the engine dies.

If your engine doesn't do this, my guess is that your PCV Valve is stuck shut.

Re: Engine dies out when oil cap is pulled off ++

Posted: February 9th, 2004, 7:30 pm
by nos92mx3
mine dosent die when i have to oil cap off and mine has 198,xxx miles.

Re: Engine dies out when oil cap is pulled off ++

Posted: February 9th, 2004, 9:20 pm
by lakersfan1
Mine dies.