I swear my Mom's 94 Z28 is cursed. First I had to send the PCM out for the tune, no biggie. Well when it comes back the Opti is shot, then I had to do head gaskets, then I had to stick Earls header gaskets in cause the fel pro's didn't seal the Hooker shorties. Well now the cooling system is doing something retarded. Its not the typical bleeding where the temp is stable then jumps up and eventually you get it bleed. Oh no it stays around the 200-220 mark, whatever the center of the gauge is. Noticed a large coolant puddle at the last place it stopped at, after driving around. Fans don't seem to be going to high, so I thinking of checking the relays, low speed is on.

Has a tune in it from Ion, according to his sheet the fans should def. be on at the temps I'm seeing. This car didn't run hot at all before I did the head gaskets. I checked today and the thermostat had been gutted, the prior owner had also installed a electric waterpump. You can hear it running when the switch it turned on and can see the coolant level drop in the radiator. Doesn't seem to be leaking from any hoses and I had replaced the upper and lower radiator hose. So I'm thinking if that coolant puddle was hers it leaked out of the overflow. I don't know this car is driving me crazy. If my LT1 gave me this much grief I would have ripped it out for a LS1 by now.

 

I haven't replaced any head gaskets in quite a while, so I'm just taking a stab here....Is there an "up" side to the gaskets, to insure that all the water passage holes are open to the heads?

 

Make sure your radiator cap is good. I had a Stant cap less than 4 months old start allowing air in instead of sucking coolantout of the overflow. Over a months period of time it caused a large enough air-bubble in the radiator to make the low-coolent light go on.

Also, you did reinstall the coolent crossover pipe that goes from the hose at the top of the radiator to the back of each head? If not the system cannot be bled properly. Some retards actually think it is OK to eliminate this pipe like a bunch of dumbasses. It is required for proper coolant circulation and bleeding of air pockets.

Lastely, make sure your coolent temp sender(s) are in good condition. The one that registers to the PCM could be bad and if so you won't get the fans to come on when needed.

 

one other thing to check is the plastic side tank on the rad. My car had the battery rubbing on it and since the plastic gets so hot it wore a hole.

 

Hmm I've checked it for leaks and such both running and not since getting it back to the house yesterday, doesn't seem to be leaking anywhere.

Yes the crossover pipe was reinstalled. I'm thinking of picking up a cap for it as it appears to be the original cap on there. Also for the bleeds, do you just loosen up the screws? On my car I've normally just kept adding coolant til I've had the air out, you know run it, if it has air in the system then the radiator was usually low and I just added more, I probably haven't used the bleed screws on my own in years.

I think only the low speed fans are coming on. I tried swapping relays around like suggested on shoebox's website. I have a multimeter, is there anyway I can read the relays out to see if they are good, like what post to post to read on, should I see some resistance, or just continuity?

I've had the coolant temp sensor go bad on me on my own car, but that popped a code when it went. That does make sense to me though why the gauge would say I'm at a certain temp but the low speed is only coming on, and at that point its looking like 220-230ish.

 

well heres a question for you all... what if your overfill cap won't go on very well could this be a culprit of it not being able to bleed correctly also? if that cap is not sealing right? mine does the same thing his does but my overfill cap wont twist on right? sorry for the thread hijack for a quick second. also camaro0corey where on shbox website did you find to switch the relays at I need to check that out...

 

Turns out in my case it seems like it was just a radiator cap and a quick top off. I'll have my Mom drive her car around for a while and see if it keeps running at 180, where it seems to have leveled off at now.

Hmm on the website it was under How To's then cooling system test and operation or something like that.

 

Update. Car is running around 220-230 again, and also just puked coolant out of the overflow again. Not sure why.

 

Headgaskets again? How quick is it puking out. have you pulled the cap off to make sure the water circulated once it gets warm?

 

Is coolant supposed to continuously flow through the hose from the steam pipe?

If brand new Fel Pro head gaskets are the problem I'm gonna tell her to full coverage then burn the car to the ground, I'm getting pretty frustrated with this thing.

One recommendation I've gotten so far is to pick up a mechanical pump and a thermostat, get rid of the electric pump setup. That still doesn't explain why it didn't overheat before I did head gaskets, but now it does.

Well here is the issue with the puking out. She can drive it like well over a half hour to various stores or whatever, and then it randomly spills it out once she is parked, comes out and finds pools of coolant. It isn't leaking a drop while its running.

Also the hi speed fans were on today.

 

Well if you have an electric water pump turn it on with the car off and see if its working. You can even pull the thermostat to make sure water flows like it should and even bleed the system that way to make sure no bubbles are in the system. That would be the first thing I tried.

Also what made the headgaskets pop in the first place? Did you get the heads resurfaced? So many possibilities for it to over heat LOL


Also get a coolant pressure cap and make sure it holds pressure and is not leaking into the cylinders or anything.

 

If it were getting coolant into the cylinders wouldn't I have white smoke? Yep heads were cleaned, pressure tested and surfaced. I have coolant flowing, I checked with the cap off out of curiosity today. You can hear the water pump working if you have it on and the car off. She is talking about going back to a mechanical. She wants it done as cheaply as possible though, and I'm not sure I trust the $68 one, the valucraft. Anyone know if for $68 its the whole waterpump, or just the center section? I'd be more comfortable at $141 for the Duralast or a factory one, but now we are talking over $200 at gmpartsdirect.

 

you said you never used the bleeder screws on your car. try bleeding it on hers and see if it helps.

 

Tried, the screw on the hose nothing comes out, one by the thermostat housing spits coolant out, never in a steady stream though. How long do you typically bleed it? I sat there for about 5 minutes today.

 

Ok, first off do some reading. You OBVIOUSLY don't know how to bleed the system.

Sorry, go do some searches on bleeding the system. Really frustrating helping and then seeing someone doesn't want to help themselves by using the resources available first.

First off, you do NOT bleed the system (ie, open the bleeder screws) with the car/waterpump running. ie, you don't run the pump or the engine with the bleeders open, EVER!

If you open the bleeder on the heater hose it will suck air INTO the system and create an air pocket. It will displace water in the system with air and you will have an even bigger issue.

You open the two bleeders with the engine/coolent cold, everything off, open the radiator cap and start filling the radiator until water starts to come out the bleeder on the thermostat housing. Once coolent starts coming out there, close that one off. Leave the bleeder on the heater hose open. Now fill the radiator as much as possible until it stops going down. Then close off the heater hose bleeder. Since you have an electric waterpump the rest gets easy. Jump the pump to run with the engine off and keep topping up the radiator until it stops dropping off. Once that is done put the radiator cap on, disconnect the waterpump and hook it back up normal and you are done. DO NOT open the bleeders with the engine or waterpump running.

After that your system is bled and if you puke coolent after that then you have either a) a warped deck on the block or heads and it isn't sealing, b) improperly cleaned the block/heads upon reassembly and they are not sealed, c) installed a burnealed/defective head gasket, or d) didn't torque the heads to spec or have a bolt(s) not holding torque thus the head is lifting on the power stroke. All of those cases can cause a headgasket leak where you get exhaust gas into the cooling system but not really sucking of coolent into the combustion chamber (you probably do get some coolent sucked in, but it is so minimal it doesn't cause any smoking).

Also, if after bleeding it like I explained, when you run the car it should cause pressure in the radiator hoses. It should do it rigth away, but give it one heat/cool/heat cycle to determine if there is pressure or not. If not then the radiator cap is bad or the system is bleeding pressure off somewhere else, and that much pressure should cause some white smoke if the headgasket is blown.

 

Alright here is the new issue. She wanted a mechanical pump and thermostat, so I stuck them in. Now the fans aren't running? Could the prior owner had used the fan circuit to power the electric pump or something? Fans aren't running, car isn't running any cooler. I'm about to bleed the system the was 95 TA the beast has instructed.

 

Alright guys I bled it as directed above, seems to have done the trick. Car runs around 195 while cruising around, when sitting still in the driveway fans kick on around 235.

It says on the sheet from Ion that the fans should come on low/high 205/215, so maybe the gauge is off from the actual temp or does the heads get that much hotter than the temp at the waterpump?