*cliff notes at the bottom for those who don't need all the details*

I finished my B18B swap last month, and it's been running fine since then. After starting it for the first time, I bled the cooling system by idling the car with the heater blowing full-hot until I stopped seeing bubbles, and the coolant level stopped going down. Since it's been consistently warm, I haven't used my heater since then. Last night I was coming home and it was a little cool outside, so I moved my climate control temp lever(I think intermix control is the technical name for it) to about the middle position without turning the fan on to warm up a bit. The engine was warmed up at the time(about 80-90 deg C, which is where it normally runs), yet after about 5 minutes of driving, I still felt no heat coming from my vents. So, I turned the fan on, and waited a couple more minutes - still nothing. Finally, while waiting to turn left at a light(still with no heat), my oh-so-wonderful CEL pops on and my car starts idling and driving like crap. So I limp the rest of the way home(about 2mi or so) and go to retrieve the code(s). It's a 14 - IACV, which I'm pretty familiar with since I dealt with that same code a couple years back with my old engine(kept throwing a 14, and I swapped several IACV's and bled the cooling system numerous times trying to fix what turned out to be a loose vac hose ). So I went over the obvious things - checked for loose vac lines and any vac leaks, checked to make sure the IACV plug was still connected and that the wires were OK, checked for coolant leaks and loose hoses - I found that I'd forgotten to secure the clamp that goes on the heater hose running to the heater valve on the firewall. Apparently it's been like that for nearly a month, but I couldn't detect any leak from that connection, and the clamp seems to be too small to fit over the end of the hose, so I just left it kinda sitting in the middle of the hose and put a pipe clamp on the end since I didn't want to deal with hot coolant all over the place. Since air in the cooling system can cause the IACV to go nuts, I figured there must have been some air trapped in my heater core, and when I tried to use my heater, it got into the rest of my cooling system and tripped the IACV code. However, since my coolant was still very hot, and it was late(past 1am, I had to get up at 6 for a class the next morning) I didn't try bleeding the cooling system, but I did reset the ECU and tried running the heater again. This time it didn't throw a 14, but it also didn't produce any heat. Happy that at least the code was gone, I called it a night and hit the sack. Then this morning when I was driving to school, I decided to try the heater again. About halfway to campus(it's about a 10min drive thru city streets and morning traffic) my CEL turns on again, and the car behaves like it did the night before, and there is still no heat. When I got home from school, I let the car cool down, then I proceeded to bleed the air from the cooling system by idling the engine with the radiator cap off and the heater blowing full-hot like I usually do. The strange thing is that I didn't see any bubbles come up, but the coolant rose steadilly as it warmed up and expanded, and I had to keep syphoning the coolant out of the filler neck by stuffing paper towels in there to keep it from running over. I let it idle for a good 10-15 minutes and saw no bubbles, nor did the CEL come on, and the heat was still nonexistant. While I was messing with the radiator and looking in the reservoir, I noticed a small amount of what looked like oil floating at the top of the reservoir. Thinking it was the headgasket, I ran a compression test and got 205 200 205 205, which are roughly the same numbers I got when I had just finished the swap. So, I figured it was just the leftover gunk that had been in my cooling system before the swap(old engine died a gruesome death, and I didn't flush the system prior to the swap). That brings me to where I am now - still trying to figure out what's wrong with my heater/cooling system.

Sorry about the long post, here are some cliff notes:

*swap done a month ago and running fine since then
*tried to use my heater for the first time since then and it doesn't work
*moving temp/intermix lever torward hot eventually throws a code 14-IACV
*tried bleeding the system - no bubbles came out

Any help or insights are greatly appreciated.

 

Wow, big *** post. Very great explination, however, please try to make it more organized to read next time

It's strange that the IACV code comes on when you turn on your heater. Does the IACV code ONLY come on when you turn on the heater??

I would check your coolant lines for the heater inlet hose, and the outlet hose. Make sure the flow of coolant is proper, if you have a hose backwards, that could be the problem...

What I would also do is tighten the Fast Idle valve diaphram. That is located underneath the TB, there is a plate over it on the back part. Remove that, and you will see the white spring loaded diaphram. Simply turn the white part in the clock wise position until it's all the way tight.

I would suggest also re-bleeding the whole system, make sure the coolant flow is all good.

Keep us posted.

 

Thanks for the reply Yeah, I tend to be long winded, sorry about that.

Yup, the IACV code only comes on when I turn on the heater, or if I move the temp control lever toward the hot side(I keep it on the cold side for obvious reasons - summer).

I just picked up some cooling sytem flush, and I'll be giving that a whirl this weekend. While I have the system drained, I'll check out the heater hoses. I never had any heater problems before, and I think I reused one of my stock hoses and one that came with the swap, so maybe the one that came with the swap is clogged up with gunk or something.

I'm not sure if I have a fast idle valve. From what I remember, that's an OBD-0/OBD-I thing. My TB just has the coolant lines running thru it for the TB heater like the rest of the OBD-II ones I've seen.

Once I get the system flushed, I'll definitely be rebleeding the system. What confuses me is the fact that I didn't see any bubbles at all when I was bleeding it today, yet the way the IACV and heater are acting up means there must be some air somewhere in the system. Is there a better way to bleed the cooling system other than what I've been doing(idling with the radiator cap off, heater going full blast)? I know some B series blockes have built-in cooling system bleeder valves, but I don't remember seeing one on mine.

Thanks again for all your suggestions, I definitely need to get this squaed away before winter. I guess I could always carry a blanket in the car

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by inspyral &raquo;</TD></TR><TR><TD CLASS="quote">... *tried bleeding the system - no bubbles came out...</TD></TR></TABLE>Yeah, but it sure sounds like you still have air in there somewhere. Keep trying - make sure your temperature control is all the way to hot when you bleed. Sometimes I have to squeeze the radiator hoses to push air bubbles over to the radiator or to the bleeder.

With a swap, there may be a high point in the system somewhere where air collects. You may have to loosen a hose to let air out. Maybe a heater hose at the firewall happens to be the high point in YOUR cooling system? I suppose when the factory put a particular engine in a car, they gotta figure out where the air collects so that's where they put the bleeder...

 

Thanks for the suggestion. The temp control is all the way hot whenever I bleed my cooling system. However, I read somewhere that the cable can sometimes go off its track or somehting like that preventing it from opening the valve all the way, so I'll check for that when I flush the system. Yah, I usually squeeze my hoses as well to try and work the bubbles out, but I'll go over them again.

 

Well, I just spent the last couple hours flushing and bleeding my cooling system, and I'm glad to say things are as they should be again . After I got it drained, I pulled off the heater hose going to the intermix valve to the heater core, and I found that it was bulgingabout an inch in from the end. I took a gander in there and found one of those little red plugs that IAS likes to use stuck in there . I guess they shoved it in so far that I didn't notice it when I was dropping the swap in. Anyway, long story short, after flushing and bleeding the system several times and readjusting my idle(it was set around 1100-1200 or so), every thing is back to normal. w00h00, I get to have heat for the winter
Thanks again for your insights and suggestions.