Engine over heating

[jynxtrix]

yup, the title says it. Engine overheating, I don't get it either. it idles fine, but when I start to boost it starts to overheat. I also don't get ANY hot air from my heater. Now obviously that means there is an air pocket, but for the life of me I cannot get it out if it is there. at first I was worried about a possible bad head gasket, but there's no oil in the coolant, no coolant in the oil, and no sign on any of my spark plugs that coolant is in any cylinder. everything registers normal, the car doesn't act like it's over heating at all, even though my gauge says it is. If I rev it a little in neutral it cools off for a second, but then starts heating up again.

Also, I replaced my fuel filter with a more free flowing one today, it runs better than it did, but I am still running lean at just about the 7 psi range. I know my fpr is working, and from what I read in the ca18 fsm, and compared to the s14 fsm, my s14 fuel pump actually pumps higher pressure than a ca18det fuel pump would I guess all i can do is replace it anyway and see. Even though my fuel pump seems fine. 38 psi at idle. I'm so damn frustrated with this thing.

[mbmbmb23]

Take it to a shop that can pressurize the coolant system and see where its leaking from. You might have exhaust gasses leaking from the combustion chamber into a coolant passage (bad HG) or you might have a thermostat not opening.

[zero_gripS13]

thermostat most likely.

and is that 38 psi at idle with vacuu disconnected or connected?

[A2V]

Temperature gauge that reads high has four reasons why it happens, the lack of engine coolant, collapse radiator hose, faulty water pump or thermostat.

[jynxtrix]

38 psi with the vaccum disconnected. it goes as high as 44 or so when boost comes on.

I pulled my thermostat when all this started, threw it in water, it opened, but not until the water was already beginning to boil. I'm running without a thermostat at the moment.

I don't really wanna do a head gasket already, but it's looking like that's the way this may go. I'm gonna try to refill and flush the air out one more time when I get home today. we will see how that goes before i tear it all apart.

[sjbsuperman1425]

do you have the stock fan w/ shroud of electric fan? replace the thermostat just in case, put coolant in, and "burp" the system. if your coolant is boiling to quickly, you could also have a bad rad-cap.

and set the fuel pressure for 36psi no vacuum, 28psi at idle.

[jynxtrix]

right, I don't have an adjustable FPR. I'm still running the stock one that came on the engine. and shouldn't that make me run rich if anything? I'll try the cooling system again in a few min. on my fans? I'm running the stock electric fans for an s-14 on the stock radiator wired to turn on with the key, which again shouldn't be an issue because an s-14 radiator is the same same as a jdm s13 ca18 radiator.

[sjbsuperman1425]

how do you know you're running lean? the S14 fuel pump may have more pressure than the stock CA fuel pump, but might not flow enough volume.

[jynxtrix]

narrow band a/f gauge says so. and I think it is the fuel pump. My walbro will be here in a couple of days though.

[sjbsuperman1425]

narrow-bands = s***. my friend and i have the same one, his reads lean to the max and gets black smoke, mine changes with voltage..

get a walbro and adjustable FPR and you'll be good.

[jynxtrix]

yeah, like I said, the fuel pump will be here soon. I still can't stop overheating though. I don't get it. I can't drive the car anywhere either. I live within hearing range of 3 sheriff's officers and it's 4 miles into town, if I so much as rev in my neighborhood they cite me for it. The only reason i can drive it is because they work all day and i get off at 2 so i can work on it till they get off at 5 or 6.

~Here the the things I know to look for to recognize a bad HG.~Oil in coolant~coolant in oil (milky crap on oil cap)~steam in exhaust~coolant smell in exhaust~over heating (obviously)~no heat from heater (also a sign of low coolant)~orange tinted build up on spark plugs (not to be confused with red tint caused by fuel additives) Am I missing anything? I've only got the no heater symptom, but for the life of me can't seem to get this bastard bled out.

How much is a CA18 worth a bullet in the block? cause we are getting there fast.

Sorry, I'm just ranting now. So, tomorrow. Anti freezeradiator capand try again.

Also, is it better to have my AFM before or after my turbo? silly question I'm sure, but I have it before the turbo. That's fine right? but how does the engine know the air temp AFTER it gets run thru the big hair drier? I havn't slept in days. I'm rambling. damn. good night.

[float_6969]

My guess is that some crap has plugged up your heater core and you're not getting the air bled out properly. Also, you are leaving the temp slider on full hot right? There is a valve that closes off the heater core if you turn it on cold and you'll never get the air out of it.

It's also possible that you have a leaking coolant line. I don't think the car is actually overheating, but due to the air in the system, it looks like it's overheating.

Also, as has been stated, it's possible for the HG to leak in such a way as to pressurize the cooling system, but never draw any coolant into the combustion chamber.

As for the MAFS, before the turbo, as FAR from the turbo as you can get it, but don't put any elbows right before the MAFS. Also, the temp if the air doesn't matter. MAFS stands for Mass Air Flow Sensor. Mass being the important word. If you know the mass of the air entering the engine, the temperature and pressure don't matter.

[jynxtrix]

right, i know it can pressurize my cooling system, but there would be air bubbles and it would push out coolant when I started it wouldn't it? It doesn't do that.

My temp slider isn't even installed. I have it disconnected at the moment because i have no ac, and because it wasn't moving anyway (not sure what the deal with that is)

no coolant leaks either, till i shut it off, then it pushes some out, but not much, I don't have a coolant bottle anymore, somewhere between then last three states and two years this project has spanned I lost that. hmm.

I think I'll put my own temp gauge in it tomorrow just for the hell of it, I trust those more...

again, a possible stupid question, but how does it estimate the density of the air if it doesn't read air temp? I'm confused, I think some of my old dsm info might be causing me to get confused as to how this thing runs.

And as you can see, I'm still not sleeping, lol.

probably should have mentioned this earlier, but thanks for the patience guys.
Modified by jynxtrix at 2:31 PM 8/7/2009

[jynxtrix]

so apparently there is some difference between the ca sending unit an the s14 gauge, cause my oem gauge reads thru the roof, but my brand new aftermarket water temp gauge goes nice and steady between 185 and 195. Haven't got it all sorted out yet, but my heater blows a little warmer too. I had to drill a hole in my head where the thermostat housing is, and that made me a little nervous, but it all worked out, so I'm happy. Still waiting on my fuel pump, and need to buy an adjustable FPR.Also, it ran really good today, but at about 7-8 psi it just cut out like i turned they key off, i got worried for a sec, and the when I hit the gas again it seemed fine, but I didn't push it either. it's done it a couple of times in the last few weeks, but this is the first time that it has done it when the engine seemed fine.also my afr gauge is reading alot leaner than before, but idling and running better than before. any ideas?

[sjbsuperman1425]

dont believe your narrow band at idle or at all..if you use it at all, its only good at WOT. As for your water temps, as long as your coolant is staying within the range you specified, im guess you are good with that issue.

get the walbro in, get the adjustable FPR installed and set to 36psi (no vacuum), you should be ok.

[ca18detgabby]

u sure that T-stat is in the right way and fuctioning properly?

[jynxtrix]

<<<<is a noob to the forum, and to the ca18det, Not cars and engines as a whole. Eeeesh... I must wreak of rookie.Anyway, yes the direction is right, and I heard alotta static about bad batches of t-stats, so i boiled it with a turkey thermo to check it before I ever installed it. it opened at 185-190 this time.

Took car out for a run yesterday, a little light play on some back roads. Not too much cause I'm still waiting on my fuel pump. so I kept it to 3-4 psi, (i actually had to get gas, so I really wasn't driving it just to blow it up). Runs good, but i think i'm hitting some kind of limiter (not rpm). went to 7ish psi a couple of times, when I shift, boost bumps up to 8-9ish psi. occassionally it just cuts out. like everything just stops... for a second or so, I left off the gas, give it gas again and it drives like nothing happened. Gonna get my fuel pump done before I drive any more. Temperature is great, still waiting to work the air bubble out of my heater though.My aftermarket temp sensor is installed right next to my oem one, and stays steady at 190. But i still don't get hot air from the heater, maybe warm, but definitly not as hot as i remember (i lived in north dakota and it worked awesome). oh and I need to find a window amp. mine went out, and now that I don't have it, the lack of AC on my engine is terribly noticable.

One odd note, my retarded Narrow band AF gauge has been reading crazy lean, but i ripped my exhaust off by accident, and it immediately stared reading normal. Any idea what that is about?

[float_6969]

Yes, the S14 sender is different.

The slider controls a valve on the heater core. via the air mix door. Are you sure you have it set to full hot? If not, it's gonna take FOREVER to get the air out of the heater core.

Also, you NEED an overflow bottle. That can also be a source of air in the system. Here is why;The system works like this. As the coolant heats up, it expands. This creates pressure. This pressure is used to increase the boiling point of the coolant mixture. The system pressure is controlled by the radiator cap. When the system pressure exceeds the radiator caps's capacity, the extra coolant is routed to the overflow bottle. When the engine is shut off and starts to cool down, that extra coolant that was run over to the overflow bottle, is drawn back into the cooling system past the radiator cap. If the hose is just left open to the air, every time you turn the car off and it cools down, air is sucked into the system.

In anticipation of this, anytime I allow air to enter the cooling system, I purge the air from the overflow line by overfilling the overflow tank, and then blowing air into the tank with a hose sealed over the lid until I get nothing but a solid stream of coolant into the radiator neck.

[jynxtrix]

note noted, you wouldn't by chance know if the s14 ka sender uses the same 12x1.50 fine metric thread pattern as the ca would you? oh well, I suppose i could just take it to autozone and find out too.

I just added an overflow bottle this weekend, i forgot to mention that. at this point, i've replaced everything but the heater core and the radiator. as far as the slider goes, the cable ran out to a valve under my hood, i just took that valve out and piped them straight together, though so far this has yet to make any difference in my air temp in the cabin, it dispelled any questions I had about the valve being in the way. When I ran my wiring through the firewall, i did disconnect a couple of bolt that held the heater. I'll go in soon and double check that nothing was disconnected by accident under the dash.

[float_6969]

IIRC, they do have the same threads. Just pick up an S14 sending unit and thread it in and the gauge should read correctly.

Oh, I forgot you have an S14. Then yes, in the case of the S14, the valve is external and if you've eliminated the valve, then all of the air from the heater core should easily purge from the heater core.

[jynxtrix]

if my FPR is functioning properly (from everything I can tell by adding boost and vacuum to it while the fuel pump is on), and I'm planning on running stock pressure off my turbo for a while, Do I really need to worry about an adjustable FPR? Will the walbro 255 still be okay with the oem fpr? Also, when I boost, I go to 7-8ish psi, but then I get nervous. I've seen it spike as high as 10 psi when I shift, and it seems like it want to climb to 7/8/9/10 psi as I accelerate anyways, but like I said, I get nervous and let off the gas by then. My wastegate actuator is run off my vacuum, I have boost controller, but i haven't hooked it up, and I'm not gonna until I get the oem setup right. a little advice please? Also, that "who turned the key off" feeling I keep getting, is that boost cut? I'm running a virtually stock setup, I shouldn't be hitting that should I?and no, my walbro isn't in yet. I'm still waiting for it. This is just me pondering what I've discovered over the last few days up until I decided to stop driving it until I got my new fuel pump in.would it help if I put down a list of what mods I do have?

[sjbsuperman1425]

you could be hitting fuel cut possibly if your stock pump is tired and what not?

Also, the walbro usually overruns the stock FPR, so an adjustable one is usually recommended.

[jynxtrix]

still running the oem fpr. walbro installed, with 444cc injectors and she runs like a dream. pulls hard as hell, I love it. for some reason the wastegate seems to be set to 10psi instead of 7, and the fuel pressure is at 45 (no vacuum) but it doesn't seem to bother the engine in the least. You could almost believe the car came with this engine it's so smooth. After two years of trial and error (mostly error) it is good to go. Now I can start the path to upgrading parts gradually. My girl will be thrilled (she drove it earlier and loved it, aside from being scared of the sound of my bov), now we can go back to being a regular couple (as opposed to her wondering if she's in love with a obsessed mad man, lol). Ahh, soo happy. now i just gotta reinstall my my stereo and such and register it. Thank god there are no emissions here. I'd be scared other wise...

Thank you all for your help. I'm sure it's not over. Maybe I'll post pics up soon if there's any interest. Good night folks!