[RESOLVED] Coolant System help!

[KnightHawk434th]

Ok as in one of my other posts (can't remember if it was here, dsmtalk or 2gnt but anyways), I 'm having a coolant system problem that i've ran out of posiblities for. Now unlike the other overheating posts, my car isn't reaching post-boiling temperature, but it is starting to scare me. My coolant level has been dropping over the last couple weeks. It used to be, about 1/2 gallon every 2 or 3 weeks, but last time I drove it (just last week) I put some more coolant in it and topped it off and it was all peachy.

Well I got in my car today so I could go to the local Autozone and get all my parts I need for my spring break problem-fixing marathon (head/oil pan/valve cover gaskets, head bolts, thermostat, coolant temp sensor, coolant system flush, oil change, new plugs/wires) and I get halfway down the first road and my stock in-dash temp gauge start to climb towards the H. I also have a triple-gauge pillar pod, for my oil pressure, volts, water temp gauges. The temp sender on the mechanical one was too short to run around to my thermostat, so I found the coolant plug around the middle back of the block and install the sender for the mechanical one there instead of at the thermostat.

While the stocker is climbing to the H, the mechanical temp gauge in my pillar is reading around 170-185 and not moving anywhere. I stop off at the Jiffy Lube just up thde street to see if I can pick up a bottle of coolant to pour in, but the guy wanted 20 bucks! So I said to hell with that, and I'll just use what I have left in my 1 gallon jug (about half-gallon, or a little less). And since one of my hood bolt is sheared off, I asked him if he could lend me a hand to get my hood open so I could tend to my coolant system. So we did that, then we poured the jug directly into the overflow to the point it was almost full, and I went ahead and primed the system by squeezing the upper radiator hose and put some coolant in my system.

Well I'm like ok, this should fix it...and get halfway down the road again and my stocker starts to climb once more (but yet mechanical one stays the same like before) so I suck it up and limp it to Autozone on the other side of town and the whole time my stocker would climb, touch the H and hang for a few seconds then go back down to normal and hang for a few minutes then repeat. My mechanical gauge is still staying the same, so I'm not thinking I have a problem here, but I'm not for sure.

I have to drive back to Autozone to pick up head bolts tomorrow and didn't think of replacing my radiator cap, so I'll get a new one there too, and then drive to the airport next Saturday morning (airport is like 5 mins away) to drop off a buddy here on campus who is headed to Korea for spring break and then head on my way for my 90 mile drive back home. So I guess the question is, should I follow my mechanical gauge for the drive home (making sure it doesn't get above 215...and if it does call AAA and get towed home) and ignore my stocker or should I watch both? I wanna say watch my mechanical gauge incase my coolant temp sensor (still the stock one) is in fact going out...but doesn't the stock sensor control what opens/closes the thermostat? If so, wouldn't that cause my thermostat to open up too much thus causing my levels to go down a bit? Or would that not be an issue? Just any bit of advice on what I should do would be great, thanks.

 

[spoonman]

Is your mechanical gauge hooked up right? Maybe your stock gauge is bad, and the coolant system is fine. If the mechanical gauge does not increase in temp but the stock one does then the coolant temp sensor could be bad, if it is the start ups will be very hard starts.

 

[KnightHawk434th]

Yea it's hooked up right. The way I did did it was place teflon tape over the threads nad thread the sensor into the back of the block. Everything else came pre-assembled . Anyhow, I THINK I may have fixed it, but only time will tell. I had to go back to autozone because I lost my reciept with my claim ticket and all warrenty information on it, so I had to get another. Well, while I was there I bought a new radiator cap with the locking pressure releave valve on the top and put it on. I poured a little coolant into my thermostat housing and replaced the cap. I then presurized my system, relieved pressure and pressurized it again and started it up. Stock gauge reading fine, pressurized the system while car was running and then went about my way. The stocker jumped maybe 2 time on the way back, but did not go above 2/3 way to the H. Drove around a bit more, and temp read normal on both gauges. So What I'm thinking, is that radiator cap was bad and ended up leaking pressure out of the system at the same time as letting in air pockets to mess with the thermostat. I'm also thinking my coolant loss might still be a HG, but also could be the pressure that was relieved. I'll find out on my way home next weekend, if not sooner...but I think I might have solved at least that problem. Still going to replace everything that I bought since I skimped out on those during my last build. Just more as a preventative practice I guess.

 

[KnightHawk434th]

Ok so, I get back on the road and everything is all peachy for a few mins...well, it start to climb again. I think nothing of is because the thermostat keeps opening and the temps come down and all. Well, today on my way to walmart, it happens again and this time...the temps don't go down! Stocker is pegged as high as i can go, and when i shut my car off, my mechanical pilalr guage was readyin 218 and climbing! So I looks for problems and found it while i was pressuring the line. One of my heater hoses had gotten ripped from th hose clamps on there. I have my car towed home, and I come back with it and get a section of of 3/4" hose as well as a 1" section of 1" hose to act as a rubber insert around the 3/4 hose between it and the clamp so it won't tear. Get everything installed and find outthe hose isn't all the way seated on the posts at the firewall. Well, I quit for tonight, and I'm going to pick up tomorrow on that fix, so I did a compression test to see if I have bad rings or even if my headgasket is shot. Here are my numbers:

NOTE: They were run on a cold start, havn't had the time to warm it up yet since my coolant is still leaking. Don't know how much of a differnce it would make to run the test on a warm engine, but here they are anyways. Will probably run a warm test tomorrow.
Cylinder 1 = 220
Cylinder 2 = 230
Cylinder 3 = 215
Cylinder 4 = 240

Now this tells me that my headgasket is fine, and i don't have any problems with my rings correct? But I did a stock engine build with parts from parts dinosaur back in August, and from what I'm reading...my numbers are higher than a lot of stock or lightly modded cars (unless I read wrong). So is it due to the fact it's just a cold test, or did I get a small compression bump during my rebuild? Also, the numbers look good? I read they shouldn't be more than 25% off, which by looking at them, they aren't (except for cylinder 3 to cylinder 4 (i think that is like a 10.x% jump, but the others are below 10%).


EDIT: New results on a hot test that I just got done with:

Cylinder 1 = 215
Cylinder 2 = 230
Cylinder 3 = 210
Cylinder 4 = 235

 

[4UH8ERS]

Wow, First off simplify your problem by eliminating some variables. If your having to add coolant your either burning it (faulty headgasket) or leaking it somewhere (like that heater hose) so fix that.

Once thats taken care of you you must realize that theres 2 possibilities with your stock temp sending gauge. 1. its faulty (most likely) or 2. Your coolant is low so its not continuously receiving readings from the coolant itself. I personally would go to autozone and replace you $8 temp sender on the t-stat housing (its the little tiny sensor).

Next, your CTS is the larger of the 2 sensors and it is what sends the signal to the ECU in order for it to make needed adjustments as the enginge temp changes. The CTS does not send the signal to the cluster itself.

The thermostat is not opened by the sensor readings its a mechanical unit that opens on its own when it reaches its specified temperature.

Once you have fixed all leaks in the system as well as verified the sensors are working correctly then you can make educated decisions on whether or not its actually overheating in the first place. You have replaced the cap so the system has good pressure and its a self burping system so move past that. Make sure your fans our coming on and that you are using a 50/50 mixture. Thermostats are also mega cheap so swapping that cant hurt at $4. anyways i had more for ya but im clocking out now. cya tommorrow

 

[KnightHawk434th]

My bad, I should have posted I got it fixed, but I forgot. It was the pressurized hose from the steel piping (going to thermostate) to the firewall. I replace that hose and used the 1" hose to act as an outside coupler (as stated) as well as reseated my hose on the firewall post and viola, fixed. Also replaced my larger coolant temp sensor (one that signals ECU) and the thermostat while I had it apart. So head gasket wasn't my problem, instead it was my heater hose. The adjustable clamps on there had torn into the old hose in two different places.

Everything else checked out fine including the fans. And I managed to make it 90 miles back to campus with no problems and no puddles. Thanks for the help, it got my mind spinning haha.