idle + oil issue

[vanpook]

evening fellas,

I just joined up the other day and wow there is wealth of great information here.

So, I'm here looking for some guidance on my 91' 2.3. She has been in the family since we got her new from the dealer some time ago and has since then completed 221K with us. Now I know she has been leaking some oil from the area near the oil plug, I have never really paid too much mind to that aside from adding a dash or a dab here and there but the other day she started to act kind of funny. the check engine light lit up and for about 30-40 mins anytime i came to a light or got held up in traffic she started to idle around 500 but after that period of time everything went back to normal. about two days later at a light she idled funny again but this time died and took almost 4 cranks to get her up and running. Only to fail again a 1/4m down the road. I popped the hood and nothing smelled funny, I then proceeded to remove the air intake pipe where i found a bunch of oil in the tube and some in the throttle body. Also i noticed the breather inlet rubber hose that connects to the throttle body was completely loose/worn and was leaking a bit. upon examining the valve cover/head seam i noticed some dried oil and coolant stains. I cleaned what i could, closed her up and got her home. i took the air bypass valve out and cleaned it up, the piston seemed to move without a prob. i fired her back up but this time the highest she would idle was 500 with the bypass valve plugged in and the idle adjustment screw all the way in. i started to do a compression test and only got to do the passenger side the one closest to the front of the car was @ a 150 and the one closest to the firewall was about 110ish the others were closer to the 140 mark. i tried to do the other side but only got as far as shifting the alt so i can get to the plug before the rain started. Now i plan on replacing the valve cover gasket as well as the intakes, replace breather inlet hose, change spark plugs (which look find ) and spark wire plugs.

Should I be looking out for something else? any suggestions

 

[clash69]

I would have it scanned since it threw a code {check engine light} that will give a better idea whats going on

 

[realtripp]

Okay it sounds like you have your compression test done. Each spark plug pair goes to the same cylinder so no need to do it again.

Now you add the figures together (110+140+140+150=540) and divide by 4 (540/4=135) now you multiply to get 15% of 135. (135x0.15=20.25).

Your compression numbers should be within 15% of each other. Averaging the cylinder numbers should give you your baseline (135 in your case). Multiplying the baseline by 15% should give your your acceptable range (20 psi). So if any of them are less than 115 or more than 170 they are out of the range which indicates a compression problem.

Running codes first is probably the best indicator for looking for your problem.

As for the oil problem in the intake, a little is expected. The PCV system is far from perfect. Vaporized oil will always make its way in there to some degree.

Check the air intake elbow that you mentioned, if it leaks tighten it up or replace it. If it is leaking, your engine is letting in unmetered air that will throw off the fuel/air ratio.

 

[Delray Dude]

evening fellas,
i took the air bypass valve out and cleaned it up, the piston seemed to move without a prob.

I vote for the IAC (Idle air Control) valve being bad. Have seen some that even clean and moved freely, the motor was shot and produced symptoms. If you have not replaced it in a long time (or ever) you may be due.

Other things that are common to fail would be the coil packs and the DIS. The DIS failing usually results in funny tach readings (like 3000 RPM at idle).

Simple test to see if coil packs are bad is to unplug one at a time and see if it runs. if you unplug one pack and it runs the same, then you know that pack is good - or making spark - then if you plug the other one in and unplug the 1st one, and it doesn't run or runs roughly, then you know one or more coils in the pack are bad. I have had a coil pack work fine, then not work, then work... But I think I'd try the IAC first. also unplug the battery and let the computer reset itself. It will idle rough for the 1st day as it relearns itself.

 

[vanpook]

first i'd like to thank you all for your input here are the findings of the pony:

replaced the valve cover gasket, as it was leaking and i dont think it was ever changed. inspected all belts and timing agreement between the top and bottom. replaced bent out of shape hoses. degreased a good portion of the engine bay. tune-up and oil change, replaced pcv ( it was all gunked up) i think for the 1.99 it cost that should be a no-brainer with every oil change.

compression test checked out ok, though cylinder 4 was a bit lower then the rest but still within range. IAC looks good, gets the right amount of voltage, and when unplugged car's idle dropped and the opposite happens when replugged. ran KOEO test and it spit out 172, 223, 224 in C mem. one of the coils has a crack along side the connector port so will be replacing that. Now the DIS seems like the culprit, car runs strong when cool but after 150F idle drops to ~500 from the 9xx, the check engine light turns on, after about 5 or 10mins, it jumps back up to 9xx and the light goes off. so right now im just waiting for the replacement DIS and O2 to come in before calling this case official closed.