need help really bad !

[newsome93]

okay so my ranger has always burned a lil oil its a 94 3.0 liter 2 wheel drive but when i went to put a quart of oil in i pulled the oil cap off and engine quits i understand this is an internal vacuum leak but is there a certain valve that could be stuck or gasket please nhelp if you can

 

[Big Jim M]

Yeah the PCV is prolly not shutting as it should..
Big JIm

 

[newsome93]

not it donetried the pvc

 

[oachs83]

Things like the EGR or IAC could be stuck wide open. Otherwise you may need to do a compression test and find if you have a low cylinder. You might have a busted head gasket or warped head.

 

[Big Jim M]

Things like the EGR or IAC could be stuck wide open. Otherwise you may need to do a compression test and find if you have a low cylinder. You might have a busted head gasket or warped head.

Please elaborate! I'd like to know how any of those would shut the engine down simply by taking the oil cap off???
Big JIm

Newsome I think the PCV should be looked at once more.

 

[newsome93]

went and bought brand new one today i was thinking intake gasket but if this helps yals suggestions its using more oil too

 

[Big Jim M]

went and bought brand new one today i was thinking intake gasket but if this helps yals suggestions its using more oil too

If the pcv works then you can start looking at the oil use.
First off is it leaking the oil? Is the bottom of the engine really dry?
If so and the pcv is now working then the oil use is the valve guides and seals.
To repair them one needs to take the heads off and see how much "play" the valves have inside their respective guides. If little or no play then the problem is the seals. New seals are cheap and easy to install.
If there is abnormal play in the valves then a machine shop can install new guides... And there goes your oil use.
Big JIm

 

[oachs83]

Please elaborate! I'd like to know how any of those would shut the engine down simply by taking the oil cap off???
Big JIm

Newsome I think the PCV should be looked at once more.

Because I have personally seen all these besides the EGR valve cause this very problem. If you bust through the gasket on the internal engine side in the right place you can create extra vacuum inside your motor if the rest of your engine is sealed tight. Then when you take the cap off you bacically allow a big vacuum leak killing the motor. In my case it was a warped cylinder head. With the IAC you need the proper VAF (volume air flow) in a engine and in some cases a faulty IAC will disrupt the VAF. I have never actually seen the EGR cause this problem but I have seen it cause poor idle and cold start problems so I just threw it out there as a suggestion. Also there are just some engines built this way and is actually normal for the engine to stall if the oil cap or even dipstick is removed (a 2.5L Mazda for example). 9 out of 10 cases the PCV valve is the culprit but he stated he replaced his and unless the one he bought was faulty you need to think outside the box.


Here is a good way to check for faulty PCV. When the engine is running and warmed up take a pliers and squeeze the hose going to the PCV shut ( be careful not to break or slice the hose). Now listen, if you hear a clicking sound that means your PCV is working and if you hear nothing get a new one. Also check your hose going to the PCV carefully.

 

[Big Jim M]

I'm sorry!

Because I have personally seen all these besides the EGR valve cause this very problem. If you bust through the gasket on the internal engine side in the right place you can create extra vacuum inside your motor if the rest of your engine is sealed tight. Then when you take the cap off you bacically allow a big vacuum leak killing the motor. In my case it was a warped cylinder head. With the IAC you need the proper VAF (volume air flow) in a engine and in some cases a faulty IAC will disrupt the VAF. I have never actually seen the EGR cause this problem but I have seen it cause poor idle and cold start problems so I just threw it out there as a suggestion. Also there are just some engines built this way and is actually normal for the engine to stall if the oil cap or even dipstick is removed (a 2.5L Mazda for example). 9 out of 10 cases the PCV valve is the culprit but he stated he replaced his and unless the one he bought was faulty you need to think outside the box.


Here is a good way to check for faulty PCV. When the engine is running and warmed up take a pliers and squeeze the hose going to the PCV shut ( be careful not to break or slice the hose). Now listen, if you hear a clicking sound that means your PCV is working and if you hear nothing get a new one. Also check your hose going to the PCV carefully.

I just spit my beer all over my keyboard. I'm laughing so hard I can hardly type.

You wrote "If you bust through the gasket on the internal engine side in the right place you can create extra vacuum inside your motor if the rest of your engine is sealed tight."

Please elaborate! I never have been able to find that "just the right place" in my engine.

Big Jim

 

[oachs83]

You know you have second guessed me before about 10lbs of compression in my one cylinder how you swore you have never seen and couldn't believe it. It end up to be my exhaust valve was out of round not holding any compression. That I even showed you a picture of it I might add. In that case I have seen over a dozen dead cylinders with 20 or less lbs of compression but yet you claim to have never heard of it. Also I have seen a few of your comments on here and I have to say that you do indeed steer people in the wrong direction sometimes and you seem to be very arogant with your posts. I do this everyday and have been for over 15 years now. Most of this stuff I have personally seen and others very reputable mechanics have shared there experience with me. For example... customer comes in with a rough running engine, we find that it stalls badly when the oil cap is taken off. I do a compression test and find the #2 cylinder to be around 85 lbs. Now that is getting low but should still run the car at a better level. The other cylinders are all around 110lbs so I think to myself what if I remove the oil cap and do the test over. Sure enough that #2 cylinder drops to 45lbs. Find it to be a warped head, replace head problem fixed= happy customer. So why could the same not happen with a head gasket, you act as if you have never seen it, it doesn't happen. Believe me stranger things in the car world happen. So get off your high horse and get some facts before you start yapping on this forum giving people bad advice.

 

[Big Jim M]

Oh crap!

You know you have second guessed me before about 10lbs of compression in my one cylinder how you swore you have never seen and couldn't believe it. It end up to be my exhaust valve was out of round not holding any compression. That I even showed you a picture of it I might add. In that case I have seen over a dozen dead cylinders with 20 or less lbs of compression but yet you claim to have never heard of it. Also I have seen a few of your comments on here and I have to say that you do indeed steer people in the wrong direction sometimes and you seem to be very arogant with your posts. I do this everyday and have been for over 15 years now. Most of this stuff I have personally seen and others very reputable mechanics have shared there experience with me. For example... customer comes in with a rough running engine, we find that it stalls badly when the oil cap is taken off. I do a compression test and find the #2 cylinder to be around 85 lbs. Now that is getting low but should still run the car at a better level. The other cylinders are all around 110lbs so I think to myself what if I remove the oil cap and do the test over. Sure enough that #2 cylinder drops to 45lbs. Find it to be a warped head, replace head problem fixed= happy customer. So why could the same not happen with a head gasket, you act as if you have never seen it, it doesn't happen. Believe me stranger things in the car world happen. So get off your high horse and get some facts before you start yapping on this forum giving people bad advice.

Now I've went and spilled my coffee on the damn keyboard.. Your posts are humorus to say the least.

You wrote: Sure enough that #2 cylinder drops to 45lbs. Find it to be a warped head, replace head problem fixed= happy customer.

And I'm still laughing! I just didn't wish to tell you at the time it simply don't happen! But now you have went and posted crap again so I'm calling you out.

You haven't elaborated about "If you bust through the gasket on the internal engine side in the right place you can create extra vacuum inside your motor if the rest of your engine is sealed tight."
and cannot...for sure! And now you bring the "warped head" back into the mix. At the time I didn't call you out but you have went too far this time.

Just so you will KNOW! If vac can escape the head or the gasket so does COMPRESSION.. the compression causes far more problems than any vac does from the same problem.

You obviously don't have a clue about the workings of an internal combustion engine. Try not to give advice unless you have seen a post from someone else that knows something and has posted so you can copy and paste the answer.

You know owch83 this isn't a chat site where one tries to impress the girls! Dudes come on here with real problems.. Problems they have no idea how to solve. When others give answers that are impossible to CURE their problems bad things just pile up for the dudes..

It's a good thing that you would like to help! But try to limit your help to problems that you at least have some idea about.

Big Jim

 

[SMTGREG]

Let's get to diagnosing the problem and not another pissing match.............. I have never seen an engine stall when removing the oil cap but s--t happens. First remove the spark plugs for inspection and oil fouling, also check the VENT tube from the oil filler pipe to the intake tube for bolckage or restriction. If you have one plug that shows fouling then thats the cylinder to concentrate on. Looking at shop manuals you could have an intake gasket leaking on the bottom of one of the runners. That would suck oil into that runner causing excessive oil useage and high vacume in the crank case. In other words IMHO I belive you have a leaking intake manifold gasket.

 

[oachs83]

Big Jim, Seriously like really seriously. Like I said I have seen a few of your posts before and they are quite laughable to say the least. You sound like one of those guys that either works in a "Rapid oil change" or behind a parts desk. I run into a lot of your kind that seem to think they know it all just because they listen all day to others or change oil on 20 cars a day. Your kind gets very annoying to deal with at times and can never admit when they are wrong. Now you may be right or you may be wrong about the head gasket as I have never seen a head gasket be the culprit but I have personally seen a warped head do this so who is to say a gasket can't do the same? Now I am very sorry we all can't be lil Henry Ford and I bow down to you and your knowledge. I must get back to work as lunch is over for me I have to do some actual mechanic work. It is a shame that you and I whored this guys thread up and for that I am sorry and I hope you find your solution.


P.S. As far as why or how this works I can't actually explain it, as well to me it just does not seem to be possible if you think the way that a engine is to work. But for some reason I was losing either compression or vacuum when I took the oil cap off while doing the compression test. I took the head off to further inspect and the head was warped. The head was replaced and it fixed the problem. I can see where one would not think this is possible as I can't 100% explain it either but it is what it is and I got the problem solved at the end of the day. Stranger things have happened.

 

[newsome93]

well im seriously thinkin intake gasket cuz i just put new heads on cuz i used o have a warped head and it did fine except for miss and lil water loss i drove it year like that so s**t does happen but im trying intake gasket and for the BIG kid on hear nobody knows it all so get over yourself dude but i thank everybody for their sugestions thanks if any body has any more please post but as for creticism you can keep that to yourself thanks

 

[Big Jim M]

Newsome you must have other problems that you haven't posted. Nothing in your posts points to a head gasket.
Now you say that the heads are new. Does that mean NEW or does it mean new to you?
When you put the heads on did the oil use start or change in any amount?
If the heads come off of the engine I would advise checking the guides for execssive wear and installing new valve seals.
But as I wrote... nothing you have said leads one to think a head gasket.
Big JIm