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It seems there are some air pockets in the coolant system. Make sure to burp them out.
I will add coolant/water and try to burp system. Though I dont understand how this would happen? The system should not need to be burped, unless something else is going on, or fluid is being lost somewhere.
Also, I just got back from an appointment. Put car in park, no revving. So then for shits I put the car through other gears, then back into park, no revving. Again in and out of park, into reverse, into drive, into neutral, drove a few inches, back into park, no revving. So this - changing load and gaskets that get hot and cold and vacuum and this and that......its hard to understand. The sporadic crap leads me to think about the ECU being faulty. But again, I am obviously ignorant and dumb when it comes to this because I have had the problem for years. I go in and out of park/neutral/drive and no revving, but sometimes revving, but not always revving, but once in a while, but not always..........so dumb.
I will add coolant/water and try to burp system. Though I dont understand how this would happen? The system should not need to be burped, unless something else is going on, or fluid is being lost somewhere.
Whenever you detach any coolant line or hose, you're supposed to burp the system. For example, when you clean IAC valve, you need to remove two water lines attached to it, so air can be trapped inside the system when you put it back after you clean it. There's a special vaccum tool that can allow you get rid of all air pockets in the coolant as shown in this vid.
I think the only part I have not replaced is the vacuum control solenoid (Denso part in video). Are these suspect to failure? Maybe I could just buy one and replace.....at this point....why not? (I know I have to check the entire vacuum line, too). But I am thinking of grabbing this part. When the car revs up and down, I hear an off and on clicking or hissing from this part. One of my above videos may pick up the noise....
I think the only part I have not replaced is the vacuum control solenoid (Denso part in video). Are these suspect to failure? Maybe I could just buy one and replace.....at this point....why not? (I know I have to check the entire vacuum line, too). But I am thinking of grabbing this part. When the car revs up and down, I hear an off and on clicking or hissing from this part. One of my above videos may pick up the noise....
The video shows you how to test it. All you need is a 9V battery and multimeter.
I dont have a multimeter, but I guess I can grab one from AutoZone.
Which is more likely....the valve is bad or the rear mount is bad? I was just under the hood and it is hard to see the vacuum line going to rear mount. But now I get it....hose to the intake.......and a hose that splits to each mount. I had the mounts replaced about 1.5 years ago..... from what i can see, all the vacuum lines look good....no cracks....they almost look new.
I hear the clicking sound too, after I rev engine. According to video, that means the valve itself is OK. So I need to get the tools to check vacuum to the mounts. Maybe the rear mount is bad, like in video.
I hear the clicking sound too, after I rev engine. According to video, that means the valve itself is OK. So I need to get the tools to check vacuum to the mounts. Maybe the rear mount is bad, like in video.
If the sensor is good, you don't need to replace it. For installing engine mounts, I don't know how much they charge you for the labor. But you need to get the OEM engine mount. It saves you money in the long run. If you have to buy aftermarket ones, this same guy shows you what you need to do before you install it.
The problem with the surging (up and down) idle started after some jackass pulled up my intake (to the point of where I could look down in the engine and see the valves) in order to do a valve cover replacement. This happened end of 2019.
Middle of 2020, I had my motor mounts replaced (due to noise/thumping/vibration) with aftermarket mounts. After mechanic installed the mounts, the noise/thumping/vibration went away 100%. Also, the engine stopped "moving up and down" when I would test by holding foot on brake and moving from park to reverse or park to drive. I have no motor mount symptoms.
Having said this, my thought is that the mounts are fine and the vacuum is fine. Though I am learning ALOT (thanks to your postings) about the vacuum control valve and how it relates to mounts.
I still believe the issue is within the intake. Jackass mechanic did something. Pinched a gasket or did something to the intake manifold gasket. He clearly didnt know what he was doing, and he routinely dropped things where they should not have been dropped (while intake was open).
Though....the problem occurring and then going away, when changing loud, when going in and out of park/drive/neutral/reverse........that is obviously a CLUE. And yes, that in itself points to vacuum leak, I think.
I guess I need to get car to a highly rated mechanic. In Las Vegas right now.....good luck. If you can get your car into a mechanic.....you have to then worry about how good they are. It is a mess out here right now. Most mechanics cannot get you in for several weeks.
Also, as far as vacuum leaks, I have sprayed water on the suspected areas. I tried this when the car had no issue and I have tried this when the engine revs up and down. I've sprayed water meticulously on one area at a time. I've sprayed water all over. I've sprayed so much water that it looked like a hurricane under the hood. No water....anywhere....on anything....makes the idle change or makes the idle stick.......
Also, as far as vacuum leaks, I have sprayed water on the suspected areas. ....
It's not just vaccum hoses. You need to check all the gaskets and make sure they're good, not broken, and chipped off. There are two paper gaskets, one n the throttle body, and another one between throttle and manifold. Check if there're any cracks/holes on the air intake hose.
Just a thank you note for everyone who has been going back and forth with me today. Appreciated!
Going to head to casino for drinks soon......I'll be driving my BIPOLAR Acura!!!!!
The surging in the video doesn't appear to be the revving I've observed when a mount (or the vacuum hose to that mount, or the solenoid in between fail). You can remove this variable from the equation by clamping the line that comes from the back of the intake manifold to the mount control solenoid.
what kind of behavior did you experience when covering the IACV intake hole with two fingers? does the surging persist or does the engine speed drop very low and stabilize?
The surging in the video doesn't appear to be the revving I've observed when a mount (or the vacuum hose to that mount, or the solenoid in between fail). You can remove this variable from the equation by clamping the line that comes from the back of the intake manifold to the mount control solenoid. Should I do the idle is normal or when the issue occurs? Good news: I know of the line you are referencing. Thin little line......
what kind of behavior did you experience when covering the IACV intake hole with two fingers? does the surging persist or does the engine speed drop very low and stabilize?
I know Acura did this exact test....the tech explained it to me. And he said (I cant remember everything) that what he did proved that its a vacuum leak and not the IACV.
However, I can try this myself and report back. For this test, I should do this when the issue occurs. I place my fingers over the hole at the bottom of the throttle body mouth. But what I am worried about is....won't the car stall when I pull the tube away from the throttle body?
If I follow the instructions, I dont understand Step 5. Do I have to disconnect a TCS valve? And if I start the car and the issue isn't occurring, do I perform the test. Actually, when I start the car, the issue NEVER EVER happens. The issue ONLY happens when I go from Drive to Park or Drive to Neutral.
Car won't stall if you remove the intake tubing in front of the throttle (between the air filter housing and the throttle). this is also why the comment earlier about the tubing not being inserted wouldn't matter much...you're interested in what's happening behind the throttle where there is a vacuum because the engine is trying to suck air in and the only place it's able to get it is either a) the main throttle plate or b) the IACV passageway.
Plug the hole and surging stops; bad IACV.
so...where ever this vacuum is...it's oscillating open/close to let more air in (engine revs up) and closed to let less air in and the engine revs down? doesn't sound likely...not with the video you sent.
also...ECU failures are pretty consistent; won't be flipping back and forth in terms of failure and more importantly without CEL or DTC's being triggered.
Car won't stall if you remove the intake tubing in front of the throttle (between the air filter housing and the throttle). this is also why the comment earlier about the tubing not being inserted wouldn't matter much...you're interested in what's happening behind the throttle where there is a vacuum because the engine is trying to suck air in and the only place it's able to get it is either a) the main throttle plate or b) the IACV passageway.
Plug the hole and surging stops; bad IACV.
so...where ever this vacuum is...it's oscillating open/close to let more air in (engine revs up) and closed to let less air in and the engine revs down? doesn't sound likely...not with the video you sent.
also...ECU failures are pretty consistent; won't be flipping back and forth in terms of failure and more importantly without CEL or DTC's being triggered.
Sorry for the horrible video.........did I do this right?
Also, the IACV is new. Like 4 weeks old. Intermotor IACV.
I guess I have to do the test when the idle is revving up and down. I just tried to get it to duplicate but it won't do it at the moment. Will try again. Will get problem to occur then plug the hole and see how it reacts.
I had trouble getting problem to replicate. Had to drive car out of driveway and finally when I went back in park.......
Engine decreases when I cover hole and revving stops. Then revving issue does not return when I stop covering the hole. If this means the IACV is bad then something else is making it go bad. I just replaced it with a new brand name iacv.
Also, the IACV is new. Like 4 weeks old. Intermotor IACV.
I guess I have to do the test when the idle is revving up and down. I just tried to get it to duplicate but it won't do it at the moment. Will try again. Will get problem to occur then plug the hole and see how it reacts.
yes, get it to surge then cover that port.
I bought a new IGNITION coil made by denso (whom I consider very reputable) and it was bad from the start; though not consistently which led me on a wild goose chase.
If the IACV is bad.......it was perfect for 3 weeks.....then bought the farm? Is there anything that could be making the iacv go bad? Like the pigtail? A ground? Something weird? This is literally the 6th or 7th new IACV. most of the new iacvs I installed had the problem reappear the first time I started the car after iacv replacement. This time, it was fine for weeks......
Yes I saw the video. To me it looks like you have found the problem? When the IACV is blocked the surging stops and idle smooths out; albeit too low for normal operation?
Perhaps the ECU needs to learn the response characteristics of the IACV, which is why I mentioned idle relearn.
or perhaps the brand is just not very good? I typically go Honda on such things…
Yes idle relearn as per the books instructions; unplug battery, then Run engine to get the coolant temp is 194, radiator fan has come on once and all electrical stuff is off. Idle for 5 min.
If the IACV is bad.......it was perfect for 3 weeks.....then bought the farm? Is there anything that could be making the iacv go bad? Like the pigtail? A ground? Something weird? This is literally the 6th or 7th new IACV. most of the new iacvs I installed had the problem reappear the first time I started the car after iacv replacement. This time, it was fine for weeks......
You can remove the IAC valve and test it. You can use a 9V battery to power it instead.
Reminder: per the instructions (step 8 on page 11-148 of the service manual) When you covered the port of the IACV and the idle went really low: that means you are getting only a tiny amount of air into the engine. A vacuum leak would not produce this result. Vacuum leak would show the car idling higher after covering.
The instructions state to adjust the idle speed with the adjuster screw on the throttle body; normally this would be a last resort time (and it appears that way in the book as you have to go through several steps to get to that point).
But since you replaced the throttle body for one from another car, I suppose there’s a strong possibility that the different throttle body needs to be adjusted to fit your engines idle air/fuel needs.
Take a look at the manual and let me know if you land at that same result…
Could I also test the IACV by removing the power to it when the issue occurs? If pulling the power yields no changes, that means the IACV is dead? If there is a change when pulling power, it means IACV is good?
Could I also test the IACV by removing the power to it when the issue occurs? If pulling the power yields no changes, that means the IACV is dead? If there is a change when pulling power, it means IACV is good?
Yes, you can do that as well, assuming you have no issues with the cable.
Reminder: per the instructions (step 8 on page 11-148 of the service manual) When you covered the port of the IACV and the idle went really low: that means you are getting only a tiny amount of air into the engine. A vacuum leak would not produce this result. Vacuum leak would show the car idling higher after covering.
The instructions state to adjust the idle speed with the adjuster screw on the throttle body; normally this would be a last resort time (and it appears that way in the book as you have to go through several steps to get to that point).
But since you replaced the throttle body for one from another car, I suppose there’s a strong possibility that the different throttle body needs to be adjusted to fit your engines idle air/fuel needs.
Take a look at the manual and let me know if you land at that same result…
When I replaced throttle body and IACV, I did perform idle relearn. Car was PERFECT for 3 weeks. (It never ran perfect after replacing IACVs multiple times in past; problem always came back same day).
I have no idea how to adjust idle speed. Maybe there is a video?
I understand the throttle body may need to be adjusted,, but this problem was gone for 3 weeks after I replaced with new iacv and different (and heavily cleaned) throttle body.
Also, a honda IACV is about $220. I purchased the Intermotor IACV as recommended by a previous poster. I was thinking of getting the Denso brand but landed on Intermotor.
Stupid Question: since the problem is happening with multiple IACVs, could there be a clog or problem with the coolant lines that go into the IACV??????
And I still wonder.....due to problems with multiple IACVs, could this be ECU???? ($30 for used, $150 for Adura to program).
Also....what about some type of short or electrical issue with IACV power supply????
The purpose of coolant to IAC valve is to prevent it from being frozen in winter. You live in the Sin City so that wouldn't be a problem right now. If it's not the IAC valve, then there must be some vaccum leaks. On the Service Manual, they show you a diagram of the entire vacuum route. If you have replaced all other gaskets, then you may need to replace the two lower intake manifold gaskets too. They're inexpensive, under $40 for two, but to replace them, you'll need to take out fuel injectors so you can gain access.
The IACV that was connected to the junkyard throttle body is a Denso brand. I could clean it up and 8nstall it, but I'm honestly tired of swapping IACVs. It would be the 6th or 7th I've tried. I swore this would be the last time. Lol.
The purpose of coolant to IAC valve is to prevent it from being frozen in winter. You live in the Sin City so that wouldn't be a problem right now. If it's not the IAC valve, then there must be some vaccum leaks. On the Service Manual, they show you a diagram of the entire vacuum route. If you have replaced all other gaskets, then you may need to replace the two lower intake manifold gaskets too. They're inexpensive, under $40 for two, but to replace them, you'll need to take out fuel injectors so you can gain access.
Yep - I still think the issue could be in the intake because the problem started immediately after the mechanic pulled up the intake to replace the valve cover gaskets. He could have f'd something up. To me, he pulled intake up for really no reason, he should also replace the gaskets (they could be original) while there. All upper plenum gaskets and the manifold gaskets (the gaskets pictured in one of the posts above) should have been replaced. But he was an idiot so.........
1. I wouldn't change coils unless I suspected a problem with the coil.
2. I would change all the gaskets.(use the one throttle body gasket that fits, there are 2 use the correct one that matches. They include 2 since there are 2 configurations).
3. This set does NOT include valve cover gaskets. You will need to buy those separately. As mentioned before you will need to remove the whole upper intake assembly to get to a couple of the valve cover bolts, The air chambers cover them on both the front and the back. Replace the gaskets at the same time.
Concerning the other two posts you made:
I would try to recreate the idle changes made by touching the electrical connectors. I would also disconnect them and use electrical connection cleaner to clean both halves of the connector(s). I would do this before touching the upper manifold. I would also check the IAC gasket by spraying cleaner around the area when the idle is varying and see if it stops. If it does then the IAC valve needs a new gasket.
The alternator pulley is a pain to replace. This is due to the limited amount of space that is available to work. Look at the space and see if you have the tools and the confidence to do the job. Nothing worse then getting half way and discovering you not comfortable and don't have the tools to complete the job.
This intake manifold in photo, does not include the lower intake manifold gaskets? So I need to get lower set and set in photo?
11-04-2022, 12:48 PM
