EGR cleaning and other questions

[avatar28]

Well, I don't know what the heck is going on now. I replaced the thermostat and it seemed to be working fine at first. Got up to normal and stayed there. Then it went back to the exact same behavior. The temp needle will go up if I let it idle but when I drive it drops back to between A and L.

 

[rubydist]

that is not unusual for a SHO motor - the thermostat is not in the most ideal location, and variations in reported engine coolant temperature are very common (a "normal" undocumented enhancement, in Microsoft-speak)

 

[SHOtimer]

Well, I don't know what the heck is going on now. I replaced the thermostat and it seemed to be working fine at first. Got up to normal and stayed there. Then it went back to the exact same behavior. The temp needle will go up if I let it idle but when I drive it drops back to between A and L.

That's perfectly normal - especially in cooler weather.

Doug

 

[avatar28]

good news/bad news

Thought I'd just update everyone. Got a good news/bad news situation.

Today I got the rear cap for the EGR tubes out and removed the TB and proceeded to clean the crap out of it. I used some intake cleaner but it did okay. I was running out so I switched to carb cleaner and holy crap it cleaned the heck out of it. Combined with spraying the intake manifold I could reach, the EGR nostrils and the access port on the rear, I think I got it cleaned pretty well.

The good news is that I seem to have successfully resolved my CEL coming on once the car warmed up. I bought another one from Auto Zone. When I put both thermostats in a *** and brought it to a boil, the one from Pep Boys started opening quite a bit before the Duralast. So I reinstalled the Duralast. Maybe it's also that it's warmer but that seems to have possibly fixed my low temps when driving issue.

Now the bad news. Car didn't want to run at first, it stalled out if I tried to let it go to idle but giving it even the smallest bit of throttle kept it alive. I'm also getting a ton of white smoke, probably more even than when I ran Seafoam through the throttle body. That has cleared up somewhat although I still get some. A bigger concern now is that my idle is super low. It's running about 500 rpm in Park, on the verge of stalling out. The oil pressure light is also flickering. If I give it gas the light goes away. Oil level is exactly where it should be. I've gone over all the connections and I don't SEE anything that didn't get reconnected. I sprayed TB cleaner around the TB gasket and IAC and the idle didn't change any.

So, any ideas what I did and why the idle is so low now? Could I have inadvertently clogged the IAC?

 

[Off Road SHO]

Very possible. Use the same Carb cleaner on the idle nostrils. Also make sure the electrical plug for the IAC is clean and no bent pins.

Tom

 

[avatar28]

Very possible. Use the same Carb cleaner on the idle nostrils. Also make sure the electrical plug for the IAC is clean and no bent pins.

Tom

Do I remove the iac valve to get to them? How do I get that bottom screw out without removing the manifold.

 

[Off Road SHO]

That bottom screw is for cleaning the EGR nostrils, not the idle nostrils. And yes, remove the IAC valve (and while you have it off, slot the bottom hole if it isn't already, makes for easy removal of the IAC in the future) clean and re-**** the shaft of the IAC and flush out the nostrils. Stuff a rag on the back side to catch any crap you dissolve and dislodge.

Tom

 

[avatar28]

That bottom screw is for cleaning the EGR nostrils, not the idle nostrils. And yes, remove the IAC valve (and while you have it off, slot the bottom hole if it isn't already, makes for easy removal of the IAC in the future) clean and re-**** the shaft of the IAC and flush out the nostrils. Stuff a rag on the back side to catch any crap you dissolve and dislodge.

Tom

No, I meant the bottom screw of the IAC valve. It doesn't look like there is an easy way to access it with anything but an Allen wrench.

 

[avatar28]

Got the IAC off. Cleaned the nostrils although they didn't seem very dirty. I suspect I got them cleaned pretty well doing the EGR. There was some carbon buildup in the IAC itself. I sprayed it out a little with carb cleaner and let it dry out a bit. Still no change in the idle.

Is it possible that the IAC is bad and a partial blockage caused it to work until I cleaned it? Or that some of the cleaner got inside the IAC when I was cleaning the EGR and trashed it?

 

[Off Road SHO]

The EGR nostrils are not connected to the idle nostrils. They both have air leaving them and entering the "Y" of the intake where it is sucked into the next open intake valve.

The IAC motor is a stepper motor I believe, so applying 12 volts will only give you a single click, I think.

Like I mentioned before, while the idle air valve is off, you should "slot" the bottom hole, so you don't have to totally remove that bottom screw. Makes get the IAC valve in and out a breeze.

Have you set the idle lately with the computer?

Tom

 

[SHOtimer]

You may have ruined the IAC by cleaning the intake with it still in place. Hopefully cleaning it will resolve the problem.

I used a bent coat hanger to help clean out the nostrils behind the throttle body in the intake.

The oil light is flashing because the idle is too low - the engine isn't producing enough oil pressure.

Tom has a good suggestion on slotting the IAC, but if you don't have the equipment that could be difficult.

You should also reset the idle.

:NOTE 1: The Ford owner's manual directs that the idle program be relearned following any service when the battery has been disconnected. To do this, it states that the engine should be started and allowed to idle for the (approximately) 70 seconds without touching the gas pedal. Adding the accessory loads ensures that the EEC and IAC valve can accommodate the additional air flow requirements and still maintain the programmed idle speed.

NOTE 2: It is preferable that the car be driven immediately after setting the idle programming. While driving, allow the coolant temperature to rise to the normal range and run the car through its entire performance range.

Idle Speed Program Reset Procedure
-----------------------------------------
1) Disconnect the negative battery terminal.
....Optionally, disconnect the keep alive memory (KAM) connector in the small
....wire also landed to the negative battery terminal.
2) Wait at least 30 seconds.
4) Reconnect the KAM connector or negative battery terminal.
5) Start engine normally (never press the gas pedal).
6) Allow the idle speed to settle for at least 30 seconds.
7) Within 70 seconds of starting the engine, concurrently apply all accessory loads.
....a) Climate control to MAX A/C.
....b) Headlight switch ON, brights ON.
....c) Turn steering wheel slowly ~1/4 turn side to side.
....d) Press brake pedal.
....e) ATX SHOs only: shifter to DRIVE.
8) Do not turn off engine for at least 5 minutes.
__________________

Doug

 

[avatar28]

The EGR nostrils are not connected to the idle nostrils. They both have air leaving them and entering the "Y" of the intake where it is sucked into the next open intake valve.

The IAC motor is a stepper motor I believe, so applying 12 volts will only give you a single click, I think.

Like I mentioned before, while the idle air valve is off, you should "slot" the bottom hole, so you don't have to totally remove that bottom screw. Makes get the IAC valve in and out a breeze.

Have you set the idle lately with the computer?

Tom

Well I've reset the computer by leaving the battery disconnected overnight. And now the check engine light is coming on again today. Haven't pulled the codes yet but I'd be surprised if they weren't EGR related again. Hard to let it relearn the idle because if I don't give it gas at first it will stall out.

You may have ruined the IAC by cleaning the intake with it still in place. Hopefully cleaning it will resolve the problem.

I used a bent coat hanger to help clean out the nostrils behind the throttle body in the intake.

The oil light is flashing because the idle is too low - the engine isn't producing enough oil pressure.

Tom has a good suggestion on slotting the IAC, but if you don't have the equipment that could be difficult.

You should also reset the idle.

I also used a coat hanger and copious amounts of carb cleaner spray for clearing the EGR passages. How deep are the nostrils anyways, how far down does the coat hanger need to dig? And let me make sure I'm poking around in the right spots.

The two circled upper ones go to the IAC and the two lower ones to the EGR? Where, exactly, do the two holes on the back side going to the IAC run to?

None of the discussions of cleaning the EGR seemed to mention the need to take the IAC off so I didn't. Hopefully it's not that and is just a vac leak. Just hope I didn't jank up the throttle body gasket. It doesn't seem to be a part anyone stocks any more.

 

[Off Road SHO]

The EGR passageway goes out the bottom of the "Y" and makes an immediate right turn towards the firewall. I had to take out both plugs (with the intake off to thoroughly clean everything. From the firewall side, the coathanger will need to be about 12" long. From the bottom, only about 2-3".

You need to test your EGR diaphram and make sure it is opening the EGR valve in the first place. You can apply enough vacuum with your mouth to open the EGR valve. You'll be able to hear and feel the clicking diaphram as you alternately apply vacuum, and no vacuum.

Have you checked for vacuum leaks?

Tom

 

[avatar28]

The EGR passageway goes out the bottom of the "Y" and makes an immediate right turn towards the firewall. I had to take out both plugs (with the intake off to thoroughly clean everything. From the firewall side, the coathanger will need to be about 12" long. From the bottom, only about 2-3".

You need to test your EGR diaphram and make sure it is opening the EGR valve in the first place. You can apply enough vacuum with your mouth to open the EGR valve. You'll be able to hear and feel the clicking diaphram as you alternately apply vacuum, and no vacuum.

Have you checked for vacuum leaks?

Tom

I've tried to. Spraying carb cleaner around doesn't seem to affect anything. Haven't tried it with the throttle sensor unplugged to force it into open loop mode so going to do that. The egr gasket is pretty suspect looking. Going to replace it too since I had the egr off.

 

[Off Road SHO]

The EGR gasket as well as the throttle body gasket are not critical rocket science. Re-use the old gaskets with some hightemp silicone sealer or permatex gasket maker and squish it till it oozes.

A small little tank of propane with an unlit plumber's torch on it works great for finding vacuum leaks if you can get the car to stay running long enough. When the propane gets sucked in at the vacuum leak, the engine will speed up.

Tom

 

[avatar28]

Looks like propane is my next step then. Carb cleaner is doing nothing for it. I can't even hear the whistle at the base idle (around 500 rpm right now). If I speed it up to normal idle speeds there's definitely a whistle but I can't place it. The EGR gasket was pretty wrecked but I got the new one on and everything tightened down and still nothing. Going to run up and see if I can get some hose and a new propane tank. Will report back shortly.

 

[Off Road SHO]

Just crack open the propane valve, just enough so you can hear it coming out of the hose.

 

[avatar28]

*sigh* I'm about ready to give up. Even with the propane I can't find ANY leak but I can still hear it a little, just not well enough to pinpoint it. It's clearly tiny though. All I can think to do is to take the TB back off and redo everything I might possibly have left off with it and for the thermostat and/or start just replacing vacuum hose. I kind of feel like it's that or pay a shop to smoke it for me and I'd rather spend the $100 on something useful like, say, the valve cover seals or new plugs and wires.