Could the vapor canister purge valve cause severe rough ilding??

[93explorereb]

Greetings:

I am considering a 94 explorer with 160,000 miles, all of which is in fair condition. However, it has a nasty rough idle!! Might it be this purge valve? I know that some models have this valve in addition to a EGR sensor valve or DPFE sensor. All else reads normal, even though the owner has an extra whopping 5-6 extra quarts of motor oil in the crankcase!! The motor goes from a slight lifter tick to a quiet no lifter tick every 10-15 seconds. Plus the engine check light is on. Ironically, despite 50 million quarts of oil in the crankcase, the pressure reads normal? Oh and one of the spark plug wires got slightly damaged (heat/burned), on a small on a small area (slight gash). What say you? Overall the motor runs smooth (auction lot). Thanks in advance!!!!

 

[boggs1227]

well the pressure will always read normal because the oil guage is fake ,it's either going to be normal or not ( when pressure drops below 5 or 10 psi thats when it goes below the normal reading) despite how much oil is in it .there is another sensor on the oil pan that trips when you have to low of oil in the case .

if your going to buy the truck ...did i read this right it's at a car auction ?? ....
see if you can't remove the extra oil in the crank case and the plug wire replaced to see if that clears up the rough idle.i fear there may be a reason they put so much oil in the engine ...don't know .but if the check engine light is on you really need to see what codes are being sent by the computer ...that alone may tell you if this is a good purchase for you .

a bad evap/purge solinoid may casue you to smell gas fumes under the hood seeing how they are not being pumped back to the gas tank , but as to the rough idle idk..... more likelly a egr problem .....like when my dpfe went bad ,the truck would start up and goto 400 rpm's then once warmed up it would surge at idle ( from normal rpms to about 1200-1300 rpm's then back to normal) also driveing it would do the same thing ,power would be off and on while driveing ( pretty dam irritating ) .

 

[mikeinri]

Vaccuum problems DEFINITELY cause idle problems. Not saying that's the only possible cause, but it is the first thing I'd fix.

As for the oil level vs. oil pressure. I can't imagine how, on any vehicle, a high oil level would correlate to high pressure. The pressure can only be as high as the pump can deliver. So, unless there's a problem with the pump or something else, I wouldn't expect to see a high oil pressure just because there's too much oil in the pan. Does that make sense to you guys?

Agree with boggs, read the codes to know what else you're going to have to deal with.

Mike

 

[MrShorty]

A couple of additional thoughts (definitely pull codes, check for vacuum leaks, and the other things that have been suggested):

I don't why anyone would intentionally add that much extra oil. An engine that is running really rich or misfiring badly, can get gasoline into the oil. Gasoline is a terrible lubricant, and, if you get that much gas in the oil, you may be burning up bearings and stuff (if they aren't dead already). Does the oil smell like gasoline or seem extra thin? If coolant is getting into the oil, that's just as bad. Any sign of water in the oil? Lifter tick, especially where it comes and goes, suggests the possibility of lubrication problems. Couple these two things together, and I personally would be worried that this engine might be in trouble, at least until I'd done enough testing to convince myself otherwise.

Spark plug wires operate under very high voltages, so any bad spot in the insulation can become a place for spark to "leak" out, causing a misfire. Because spark plug wires are easy/cheap to change, this isn't near as big a deal to me as the previous concern. If they weren't willing to change wires as a condition of sale, I'd almost certainly change the wires as soon as I got it home.

 

[93explorereb]

Thanks guys! Actually its a lot for auto,boat, etc donations. I am thinking that part of the problem maybe the DPFE Egr pressure sensor. Also I don't believe that the oil smelled like gas, and coolant is definetely out as a mixture. I just think that ignorance was a common practice and they just kept adding oil instead of changing it, for starters? Sometimes gas does mix in, via small and or large increments (heavy city stop and go), and if driving tons of hwy miles, as I do, well then, you will burn it all off. It appears that they tried to condition old muddy oil with new fresh oil, rather than just change it? I can't imagine what the inside of the oil filter looks like?Who knows? The oil isn't runny and it isn't too thick, it looks like your average dirty oil. What I mean't interms of the pressure being high, was that the crankcase being so full, that the oil has now forced its way up and out via the valve cover gaskets! However, I didn't detect any visible current and or active seepage? The lot is going to drain the oil down to the normal level for me. I will bring another spare spark plug wire, and replace the defective one. Also, I have an extra DFPE sensor from a donor explorer (junkyard) in new like condition. I don't have immediate access to a code scanner! However, should it be the DFPE sensor, then it will almost clear itself up within several minutes of idling time. Other than that it just needs a good cleaning and some leaf spring bushing/shackles. She doesn't sag or anything. They are asking $600.00. Thanks in advance!

 

[boggs1227]

good idea on the junk yard dpfe ,but like with any high wear sensors ( like the dpfe cause it's subject to hot exhaust gas's ) the chances are kinda low if you got it out of the yard ...maybe you got a good one since you said it looked newish.....i went out and bought 3 iacs from a yard ,2 look somewhat worn ..not to bad ...the other looked like it was just boxed up and in really good condition. they all tested ok ( withen 1-2 ohms of each other) but only one really worked well ( the newer looking one) .but like mike mentioned before ...look for vac line leaks ,may be your problem as well ...i would also pull the fpr line off and smell or see if any gas is in the line ,if it is then the fpr is shot ( fuel pressure regulator) .

code scanners ....

if you do buy one from advance auto if you can part with $30 then this is a great scanner for the money : http://shop.advanceautoparts.com/ProductDetail.aspx?MfrCode=EQU&MfrPartNumber=3145&CategoryCode=3389

better than actron that only has a led and a chime to let you read the codes
this one has a lcd display that gives you the codes with out dought....much better .

 

[93explorereb]

Cool! Thanks!! Now as for that scanner, does one have to plug it directly into the vehicle's system from the top of the actual unit? Otherwise I just may pick up this one today, thanks again. What say you?

good idea on the junk yard dpfe ,but like with any high wear sensors ( like the dpfe cause it's subject to hot exhaust gas's ) the chances are kinda low if you got it out of the yard ...maybe you got a good one since you said it looked newish.....i went out and bought 3 iacs from a yard ,2 look somewhat worn ..not to bad ...the other looked like it was just boxed up and in really good condition. they all tested ok ( withen 1-2 ohms of each other) but only one really worked well ( the newer looking one) .but like mike mentioned before ...look for vac line leaks ,may be your problem as well ...i would also pull the fpr line off and smell or see if any gas is in the line ,if it is then the fpr is shot ( fuel pressure regulator) .

code scanners ....

if you do buy one from advance auto if you can part with $30 then this is a great scanner for the money : http://shop.advanceautoparts.com/ProductDetail.aspx?MfrCode=EQU&MfrPartNumber=3145&CategoryCode=3389

better than actron that only has a led and a chime to let you read the codes
this one has a lcd display that gives you the codes with out dought....much better .

 

[93explorereb]

Where exactly is the connecting computer? Is it underneath the dashboard? Thanks again!

 

[boggs1227]

(under the hood) the test connector is on the left side of the engine ( passenger side) ,it's between the fuse / relay box and the fire wall .it will have a black plastic cover over it and with 2 sets of connectors inside the cover ( a single and multiple connector) .to connect the wires to the scanner is a no brainer....they only connect one way .

one thing you may want to try when you get the scanner and use it is to of course read the codes stored in the computer . this will tell you all that is currently wrong with the truck but it will also have stored codes as well .write down the codes then i'm sure the scanner will have some function that will let you wipe clear any " stored" codes .....once you did that take the scanner off the truck ...disconnect the batt and wait 20 minutes then re-connect the batt and then start the truck.

what your doing is you read any current and stored codes before then wiped the system clean then you started and ran the engine for a while ....this may give you the same codes and or new ones to compare to the ones you wrote down the first time ...sometimes stored codes will give you a cel and clearing them out will help you figure out if you get any returning codes and help narrow down any engine problems quicker.

hope that was not hard for you to understand