Steve8091

I'm about two weeks into this mini-me (Y8 on a Y7), and I started it up successfully this morning, though I had a hunting idle. I figured I'd try to solve it by getting the air out of the cooling system, though when I went to do so, I found that there was very little coolant in the radiator. I filled it back up, and the car no longer started.

After cranking it a few times and getting ready to go back inside, I noticed liquid accumulating under the car - always a good sign. I figured out pretty quickly that it was coolant. Whenever I cranked the engine, it spilled out of the exhaust in a steady trickle.

I assume that there are two possibilities at this point - either I have a bad head gasket or I have something connected wrong on my intake manifold. With the sheer quantitiy of coolant coming out, I'm thinking it's a wrong connection. I should be able to get out and post up some pics shortly.

Any ideas?

92lxsleeper

there are coolant lines running through the intake, that you could have mixed up with vacuum lines. for example the coolant line that runs between the lower intake manifold, and the cylinder head, its welded to the pipe that carries the PCV from the cylinder head to the intake.

wannaBjdmca6

what he ^ said.
and dang it can be destructive to ur engine im imagining
like a hydrolock

Steve8091

Yes, I'm a bit scared of essentially dumping water into my intake, if that is what has happened. I'm hoping I can just crank it through. Anyway, here is a diagram of my connections:



The ones I'm most concerned with are the one marked "coolant" and one of the two IACV connections. They are attached underneath the manifold to the following two points:



And I fear I may have them reversed. Even then, aren't they both coolant? Any idea what I've done wrong?

92lxsleeper

your problem is (B) take that off and plug it up. thats for a cold start assist. you are dumping water right into the engine if thats really hooked to the coolant.

before you try cranking the car over again. fix the coolant lines, and pull the spark plugs out and crank it for a second with the spark plugs removed (blows the water out, without hydrolocking., then drain the oil, and put new oil in. then spray some WD40 in each cylinder and continue to crank. let it crank over maybe 20-30 times, then put the spark plugs in and start it up. let it run maybe 5 mins. and do another oil change to assure that there is no more water in the engine.

92lxsleeper

btw hydrolocking will not hurt an engine, unless under a heavy load, where it can possibly bend the rods. just pull the spark plugs and crank it over to spray water out the cylinders. works on every type of gasoline engine, and i've done it multiple times, especially to quads that i've dumped in ponds by accident lol.

Steve8091

Thank you very much for your reply. I had a feeling...that's the one I was most worried about. What do you suggest I do with the extra coolant line? I'm thinking I can tee those two tubes shown in the second photo together, and send the single line into the IACV. Also, why do I have an extra coolant line? What was I cooling on my Y7 that I'm not on my Y8?

92lxsleeper

on teh second picture, the bottom hose is part of the pcv system. it connects between the valve (its currently connected to on the block) and it connects to the underside of the b7/z6 manifold. idk about the y8. and the upper hose goes to the IACV

Steve8091

One last question - this guy (from a guide on another forum) says that the lower connection is the cold start assist and that the upper is the evap purge. With what you're saying, it would be the opposite. I'm thinking, though, that both ports stream directly into the manifold air stream, and that it doesn't really matter which is which. Just looking for confirmation.

92lxsleeper

ya. cap those two off. and the top one will probably go to the pcv (bottom hose on the other pic).

is there any ports on the bottom of the y8 intake?

ive had one, but neve payed any attention to it.

Steve8091

No, there is no port on the bottom. The closest thing is the cruise control vacuum, which is in the lower, rear right-hand corner. I'll probably get to this tomorrow night (have to go buy more oil and coolant, and a tubing tee)...I'll report back. Thanks again.

Steve8091

After re-reading this and several guides, I think that all I did was reverse the two lines shown in the second pic of my first post. I have that coolant line (the top tube) connected to "B" on the manifold, and the PCV line (the bottom tube) connected to the IACV. All I need to do is swap those two lines, so I'll have the coolant line hooked up to the IACV and the PCV line connected to "B" (see pics below from yet another guide). Sound right?

92lxsleeper

ya that sounds right. you should have NO coolant lines going into the intake manifold.

on the firs picture, hook the top hose (b) to your PCV. cap off the bottom, and the cold start assist. (or just run a hose between them, doesn't matter) and hook the bottom hose (on second picture) to the IACV. then do the steps i explained to remove the coolant from the engine.

Steve8091

Got it...I'm back up and running again. Now back to the problem I had before - hunting / oscillating idle. It oscillates once or twice a second by about 200 rpm. I took it for a quick spin around the block, and it also seems to all but die when I let off of the clutch and the gas. In other words, if I shift into second gear, release the clutch, and then let off the gas, it decelerates suddenly.

I bled the cooling system to eliminate bubbles in the lines. I suspect the IACV...I'm going to run through the idle troubleshooting procedure starting on 11-192 of the Helm's manual.

As before, tips are appreciated...thanks for the help so far.

Edit: My other strong suspicion is a vacuum leak at the intake manifold. I'm not able to get the rear center nut back on, at least not without removing the entire head.

92lxsleeper

for the vacuum leak, use an unlit propane torch and put it around the intake, if there is a leak, then the engine rpms will increase.

as for the idle, check the IACV,then the FITV. you may also need to adjust the throttle body. are you using the one for your d15 or the y8?

how is the mechanical, and ignition timing?

is there a Check engine light (CEL)?

Steve8091

I checked the IACV...the screen was a bit clogged, so I cleaned it out. That had no effect on the hunting idle. I've tried the ECU relearn as well, and it is definitely something beyond that. I ran to the auto parts store and had my codes read. I'm missing an O2 sensor, so that one popped up as usual, but I also got a 1509, which is an idle issue (REALLY?? THANKS!).

My strongest suspects right now are the missing nut on the back of the intake manifold causing a vacuum leak or possibly the IACV splice not being 100% (although the engine does react when I remove the connector).

I'm using the Y8 throttle body and because my RPM's are so high, I'm thinking that I'll need to adjust the idle screw at some point. I'm hesitant to do that until I get the hunting issue resolved, as that'll just be another variable to deal with (unless an excessive RPM could be the source of the hunting).

j.packsb

i would definately check for the vacuum leak as most of the time, with idling problems, its sumthing very simple like that. or at least in my experience. if u have a bolt that you can't get on the IM and it has anuything to do with idling, thats probably the problem. i would plug that hole and see if it helps.also, let the car sit at idle and stick your head around in the bay and see if u can ear any leaks. sometimes theyre to small to hear but who knows? maybe ul get lucky.. keep us posted

fastrxu

I would recommend starter spray over propane but i guess they both work.
Your idle should rev up when you spray the starter fluid all around suspected vacuum leaks IF you have a vacuum leak

Steve8091

I thought it only fair to post my final solution. My mini me had several problems, all of which are now corrected.

1. I had coolant in the exhaust, caused by hooking up two hoses backward. I followed the procedure described herein to eliminate the hydrolock, reattached the hoses, mopped up the garage floor, and solved that problem.

2. My timing slipped. After about a week with the swap, my car died when going from reverse to first gear. I checked and had both spark and fuel...crap. I pulled off all of my belts and TB cover, and found that my TB had slipped. It was still on all of the pulleys, it just slipped a few teeth (TDC was not TDC). I have a few ideas as to why. I think it was either caused by the auto-parts-store belt I used having a slightly different tooth profile, or the fact that I had a hunting idle constantly stressing the belt and teeth, or some combination of the two. I'm hoping that with a changed TB and the hunting idle fixed, this doesn't reoccur.

3. Hunting idle. After cleaning the IACV, checking for vacuum leaks, and confirming my timing, I actually discovered the problem when the car died. As I was trying to restart, I noticed a loud humming coming from the engine bay. I felt around, and noticed that it was coming from the IACV. I bought it used as a part of the "fully functional" manifold I purchased. I bought a replacement (used), put it on, and the idle settled right back to normal.

At this point, I think I'm good to go. I haven't wired VTEC yet, as I didn't want to introduce any more variables, but that'll come soon. Thank you all for your help.

b18cKoupe

If your missing a nut on the intake manifold thats a pretty big deal. Id loosen all of the intake manifold nuts and retorque in the proper order(inside out) while replacing that nut. If you remove the oil filter and possibly the i.m bracket if your running one you might be able to get it from underneath.