Ok... so my idleing problems just got a whole lot worse

[lochenjons]

So today I went to pick up a roll bar for my truck and on my way back my truck would not idle at all and was leaking a lot of oil. It would stall at every light (had to rev it in neutral and then go down to drive when the light changed before it would die). Awhile ago it had problems idleing after I went wheelin' but never this bad it would just be rough and barely not stalling. The next day it ran fine, did it again after I went wheelin again and the same thing happened, the next day or so it was fine. But I havent even gone wheelin for awhile beyond some intense mall krawling and now its worse than ever. I assume it has somehting to do with the carb. Maybe vacuum hoses or whatever it is? I dont know anything at all about that but I know a lot of other people have had similar problems and that was the solution. But then why would it leak oil? I cant find where its leaking from either, it all gets blown back to the tcase and driveshaft. BTW its a 350/350/203. Not the original engine but I have no idea when it was put in (PO). Carb was rebuilt when the PO had it however long ago.

 

[lochenjons]

Also I tried geting it to work just now and notice the voltmeter goes way up and down when I rev it. Is the alternator involved in this whole mess too?

 

[k204dr]

is your oil pressure sending unit leaking? its on teh back of the motor.

 

[lochenjons]

is your oil pressure sending unit leaking? its on teh back of the motor.

Ill check that today but I'm not so much worried about the leak at this point and I doubt that would cause it to not idle. Oil pressure is down but only to like 45 while driving and like 20 at idle (normally at just under 60 and just over 30)

 

[diesel4me]

check the PCV valve..

If the PCV valve gets no vacuum due to a clogged hose or passage in the intake,or the hose is damaged or dissconnected,it will let pressure build up in the crankcase,and force oil out of any opening like the dipstick tube,seals,etc--also it will go past the rings, and possibly foul the plugs..

Any vacuum leak will cause a rough or poor idle,or even stalling if its a big enough leak,like the hose to the power brake booster or PCV valve..time to get some carb cleaner and spray it on suspected leaky hoses and gaskets,and see if idle speed changes--AFTER you make sure the PCV valve is getting vacuum and working..I've seen them stick open too,sludge can build up in one pretty easy..

 

[lochenjons]

If the PCV valve gets no vacuum due to a clogged hose or passage in the intake,or the hose is damaged or dissconnected,it will let pressure build up in the crankcase,and force oil out of any opening like the dipstick tube,seals,etc--also it will go past the rings, and possibly foul the plugs..

Any vacuum leak will cause a rough or poor idle,or even stalling if its a big enough leak,like the hose to the power brake booster or PCV valve..time to get some carb cleaner and spray it on suspected leaky hoses and gaskets,and see if idle speed changes--AFTER you make sure the PCV valve is getting vacuum and working..I've seen them stick open too,sludge can build up in one pretty easy..

Ok you gotta be on to something because theres oil stains covering the valve cover where the pcv valve is. So should I get a new pcv valve or what should I do? I dont really know anything about pcv valves, never had a problem until now. Ill try the carb cleaner too

 

[Brodie]

If in doubt just change the pcv valve. They are only like 8 bucks.

 

[diesel4me]

pull it..

You can do a quick test of the PCV valve by pulling it out of the valve cover,and putting your thumb over the open end--it should have good vacuum present there,if not,the hose is clogged,the valve itself is clogged,or the passage in the intake is blocked with carbon..

You should have a breather of some sort on the opposite valve cover too,if you dont, the PCV valve sucks air in anyway it can,like past the rings or any other way possible--crankcase needs to be vented,NOT sealed!..you should feel a slight suction if you hold your hand over the hole the breather goes in on the valve cover,if the PCV system is working right...

If you used fuel line on the PCV valve,it sometimes collapses under vacuum,and wont let the PCV valve work..use hose made for PCV systems,that has much thicker and stiffer walls,to avoid this problem..

 

[lochenjons]

You can do a quick test of the PCV valve by pulling it out of the valve cover,and putting your thumb over the open end--it should have good vacuum present there,if not,the hose is clogged,the valve itself is clogged,or the passage in the intake is blocked with carbon..

You should have a breather of some sort on the opposite valve cover too,if you dont, the PCV valve sucks air in anyway it can,like past the rings or any other way possible--crankcase needs to be vented,NOT sealed!..you should feel a slight suction if you hold your hand over the hole the breather goes in on the valve cover,if the PCV system is working right...

If you used fuel line on the PCV valve,it sometimes collapses under vacuum,and wont let the PCV valve work..use hose made for PCV systems,that has much thicker and stiffer walls,to avoid this problem..

Ok actually I was wrong now that I really look at it the oil stains are coming from what I assume is the breather that goes up to the air cleaner. There's also some stains where the oil cap is that wasn't there before. The pcv valve doesnt have stains around it but this would make sense with what you said I think. What does the pcv valve actaully do anyway? And the open end I have my thumb over is the hose comng from the throttle body I think or the valve covers? Like I said I dont really know a whole lot about this

 

[lochenjons]

Ok I replaced the pcv valve and it seems to be working perfect now, Ill have to wait to after I drive it around to make sure (Im blocked in where im parked ) but just sitting there in park it idles perfect. The hose to the throttle body wasnt clogged I checked. thanks guys for the help