Page updated on 05-22-2018

IMRC stuck open 1998 3.8

02-07-2009, 05:56 PM
IMRC stuck open on my van. I have narrowed it down to the solenoid that controls the vacuum to the actuators.
My problem is how do I remove the solenoid? I read that it just snaps into place. Not sure if that's accurate.

02-10-2009, 07:15 PM
I figured it out. The solenoid has a integral plastic clip on it's backside that has to be slightly expanded, then push downward on the solenoid and it comes free easily. No more P1537 & P1538. Actuators are working again. I'm ready for the Emissions test finally! :loser:

02-17-2009, 05:40 PM
Hi. I have a 98 Ford Windstar with a 3.8L with the CEL and three codes P1537 P1538 and P0147 (I think)
A friend advised me to change the little plastic pieces and I did. I erased the codes drove about 70 miles and the light came back on this time with just one code, P1537. I did the check where I took the lines from the top of each IMRC one of the vacuum lines has strong suction and the other has none. Also when I cover the one with the strong suction the rod from the opposite moves. Does anyone have any suggestions.

02-17-2009, 07:18 PM
For me it turned out to be the Solenoid that controls the vacuum to the two acuator's.
The acuators rods will move with your engine running somewhere above 3000rpm. If they don't move. Your solenoid is bad. It's a dealer part. Cost about $45.00

02-18-2009, 05:47 AM
Was your problem the same as mine? Would the solenoid allow only vacuum on one side if they both are connected to the same? Also can to tell me exactly where it is and was it hard to get to? I could take it to a shop but I have a feeling they will try to stiff me on this one because one mechanic that pointed me in this direction said around $700 bucks. Also if all else fails, know of any "quick fixes" to get thru emissions?

02-18-2009, 11:08 AM
This is a common part that fails. No quick fix for this . You have to remove the window wipers, then the cowel. ( plastic cover) to have room to get at the solenoid. It's an easy job really. The solenoid is mounted on the engine middle left. Small black plastic part with square top and two blue colored vacuum hoses. It's clipped on to the engine side. You have to put downward pressure on it to come off. I put my digital camera back there and took all sorts of pictures, then downloaded them on my computer so I can see what I was looking for. Total time to do this job is 3 hours for us amatuers. Do you have an e-mail I can send pictures of the part to you.

02-19-2009, 04:36 PM
That would be great! Pictures would definitely help. Thanks

02-19-2009, 06:31 PM
1996 -1998 should use a separate vaccum driven actuator for each bank.
The 1999 and newer uses 1 electrical actuator for BOTH banks.

On the vaccum version.....the 2 actuators share the same vaccum source......and one can leak....robbing both of their vaccum.

From what you are saying.....when you removed 1 line and had NO (or very little) suction....the one still plugged in is most likely your leaker.
I would verify this by....still with the no suction line disconnected....finger over the end.....use your other hand to disconnect the other actuator and put your finger over the end of that line......if this gives you suction in both lines......then what I said above is correct.

If may have a crack or pinch in the vaccum line.

The actuators are pricey....and there was a thread on here a while back about an aftermarket version not being compatible with the electronics of the windstar (still gave CEL and IMRC fault codes).
For this might be best to stick with OEM, even though your wallet will be lighter.

Use care when handling these as there is a diaphram in there that can crack.....which is what causes the leaking.

02-20-2009, 12:17 PM
I have mine wired shut with with aluminium #18 AWG wire.


02-20-2009, 07:25 PM
Wiring shut is OK until you romp on the accellerator.....and they don't open when expected....which will light the CEL.
If you live in an area that does emission testing the CEL (and the code(s) that they get when they connect to the OBDII port) will keep you from passing the emissions test.

Now the electrical version.....might get away with them being disconnected from the actuator....but not with the vaccum actuator....springs hold them open.....and the actuator pulls them closed......the electrical sensor is a part of the actuator(s).

Stuck open will cause more drivability problems than stuck closed.
If only 1 is stuck....then you end up with an unballanced condition between the front and rear banks of cylinders.

02-23-2009, 05:35 PM
Hello Mr. Wiswind, How are you?
let me start by saying thanks for your help. I performed the test....with thumb over one with little to no suction and then doing the same over the other and I did get the suction in both. So it is the one closest to the wipers(that's the right one I think) Now I know exactly which one to replace. Thanks a bunch!:smile:

02-25-2009, 05:47 PM
Ok. I think I've done something so wrong! I replaced the IMRC with a used one and it seems that I have made the problem worst. instantly when I start the engine the rods move up when I rev the engine they move down. I don't no if that's the way they are supposed to move. The van is running rough and acting like it wants to cut off. I did the test again.. taking the vacuum off and again no vacuum on one line.... I'm so confused!

02-26-2009, 06:35 PM
With no vaccum (with motor OFF) springs in the IMRC pull them OPEN....and hold them open.
When you start the engine.....vaccum is applied to the actuators pulling both shafts to the closed position and holds them closed.
At a certain RPM....(around 2900 on my '96....I read someplace that it is different on some other years) the PCM sends a signal to the electrical valve (IMRC solenoid) in the vaccum line to close and interrupt the vaccum to the IMRC actuators.....causing them to OPEN.

I am NOT big on reving the motor to check on this....and there may be other drivability factors involved in the PCM deciding to send the signal other than just RPM.
So.....I would just worry about them moving between the motor OFF to the motor ON at idle.

You might have another problem causing the rough idle.
Verify that the vaccum lines to the actuators are in good condition....not broken.

Could your replacement actuator have a ruptured diaphram?....yes, it is possible.

Another thing to remember is that the PCM will hold a failure code for a certain number of drive cycles without any failure before clearing the failure code and turning the CEL OFF.
So....the CEL and stored failure code will normally remain AFTER you have solved the problem until the PCM sees that it is not there for a while of driving.

03-02-2009, 04:40 PM
Wiring shut is OK until you romp on the accellerator.....and they don't open when expected....which will light the CEL.
If you live in an area that does emission testing the CEL (and the code(s) that they get when they connect to the OBDII port) will keep you from passing the emissions test.

That's my problem, I think both are bad. I keep getting a lean code with them wired open, can't remember the exact number.

I ordered them from Rockauto along with enough other parts to qualify for the waiver if I don't pass... so I've got that going for me. But hopefully it will pass now.

03-02-2009, 05:03 PM
You don't want to wire them you will have drivability problems at the lower RPMs (as you are having).
If you wire them CLOSED, all you loose is the high RPM boost.

Again..... on the 1996 through 1998, the springs hold them OPEN......vaccum pulls and holds them CLOSED.
If only 1 side is closed, then you have a unballanced situation between the 2 banks of cylinders, and the PCM will not be happy with that.

03-04-2009, 11:14 AM
The old ones are in the garbage now (garage floor). I had them wired opposite of what their "failsafe, ha-ha-ha" no-vacuum state is, I guess that's closed.

So when I put it all back together I'll have to hold both of them closed while I start it?

Right now I've got it stripped down to the rear cylinder head (had to, something fell in it), putting new gaskets on everything, new PCV and hose. The IAC, TPS, MAF, EGR, O2 sensors and a bunch of other anagrams I can't remember are all new. Hopefully I'll pass emissions now, if not I made sure I spent enough on parts for the waiver.

How the hell do you get those back exhaust manifold bolts off? I'm thinking a flexible ratchet? Going to go get one and try that.

Rockauto sent me the green upper intake manifold isolator bolts for my '98, will those work? I thought they were for later models.

Keeping my fingers crossed...

If that works it's on to getting the damned AC to work right!

07-22-2011, 03:17 PM
I'm not sure how long its been since anybody has posted on this thread but if it would be possible, can someone show me a picture of what im trying to fix. I'm having the same problem as well. I'm a total rookie when it comes to cars, pictures help a lot so i know what im looking for.

07-22-2011, 09:24 PM
Getting a good picture of this on the vehicle is not easy.
The IMRC actuators are on the passenger side of the for each bank of cylinders.
This is a close up of one.... (

The grey tube is the vaccum connection to it.....the black rubber connection on the top of the actuator body.
The vaccum supply to both IMRC acutators comes from the IMRC Solenoid, which is located on the back side of the upper intake manifold.
The PCM (computer) sends a signal to the IMRC Solenoid to control if the vaccum is applied to the IMRC actuators to CLOSE the IMRC.
The vaccum supply is common to both actuators, so if one leaks, it will cause both actuators to not have vaccum.

The IMRC actuator has a bellows inside (very easy to damage) that connects to the curved metal shaft that comes out the left side in the picture.
The shaft connects to the IMRC shaft, which has the plates on it....1 plate for eacy cyinder in the bank.

The grey electrical connector on the side of the actuator body connects the PCM to it.
There is a variable resistor inside the actuator that indicates the position of the IMRC shaft to the PCM.

07-25-2011, 10:56 AM
Wiswind, thank you for the picture. Sorry if im asking for too much but would it possible for you to tell me what I'm trying to replace or would it be possible for you to label the parts that you would think i need replacing on the picture? Thanks in advance. Because i talked to a worker at my near by autozone and he told me that it might be an eletrical problem or i might have to replace the whole Intake Manifold. For some werid reason, what he said didn't make any sense to me.

07-25-2011, 07:54 PM
The IMRC shafts are held in the OPEN position by springs.....they are pretty strong.
You should be able to manualy move them to the closed position.
The direction to move them would be the direction that the IMRC actuator pin would be going INTO the actuator.
If you can move the IMRC shafts manualy, and they do not bind, then the problem is most likely the actuator.

Often only 1 actuator goes bad......the diaphram inside cracks and leaks......and since they both share the same vaccum source, vaccum to both IMRC actuators is lost.
To figure out which actuator is defective, with the motor running at idle, pull the vaccum line off of 1 of the actuators and put your finger over the end of the vaccum line.
Does the other actuator move...and close the other IMRC?.....if so, then the one you unplugged is defective and the other side is still good.
If the other side does not move......plug the vaccum line in and do the same with the vaccum line on the other actuator.
If this still does not get one of the actuators to work......try checking to see if you have vaccum going to can do this by unplugging both of them and holding a finger over each vaccum line......there should be a good bit of vaccum present.
If you do not have vaccum, you will need to troubleshoot why.
I would start by checking to see if there is vaccum INTO the IMRC actuator solenoid.....which is what the other end of vaccum line that goes to the actuators connects to.......There will be a vaccum line going into that solenoid from the back side of the upper intake manifold.
The IMRC solenoid is mounted on the back side of the upper intake manifold as well.
It can happen where one of the vaccum lines becomes defective......maybe got hot or crushed, or broken/disconnected.

If you end up replacing one or both of the IMRC actuators, I would buy a Motorcraft one.....I don't know if they solved the issues that folks reported with the Dorman brand or not.
It is best to see if only 1 is defective because they are you don't want to replace both unless both are truely bad.

08-11-2011, 05:43 PM
Thank you wisewind for the help. One of the vaccum lines was damaged. I replaced it and the service light went away.

Add your comment to this topic!