Niaboc67

This is a 03 civic with 150k miles on it. Brand new stat. When I turn the car on it overheats in a matter of about 8 minutes the top hose is hot and lower is cold. No fans are on but not sure when they should kick on. Guess the stat could be faulty it was just installed though. Car heats up under a few minutes if driven. Just seems like the water boils very quickly here and is not circulating. Has anyone experienced this? Could a fault radiatior or heater core also cause this boiling hot water in the top hose and not in the bottom effect? I burped the system, let it sit with the cap off for an hour.

Like this:


​​​​​​thank you

ezone

Was the engine running for that hour?
What do you see that makes you say it's overheating?

Niaboc67

temp gauge rises past mid range. Also if I leave the car running with the rad cap off after a few minutes it will start violently boiling over gushing out coolant like a volcano.

ezone

Wow... sounds like no circulation for some reason.....maybe either a blockage or a pump problem. When did this problem start?

Can you get any heat output from the heater at the time it is overheating?

Remove the thermostat, put it back together with just the gasket installed. Refill system to just below the radiator neck so you can see if the liquid is circulating inside while it runs. Start engine....see if liquid is circulating inside the top of the radiator while it runs. See if overheat issue is gone with stat removed.


Was an aftermarket water pump installed?

Niaboc67

A gates water pumped was installed and a non-OEM stat. I tried this without the stat recently and it drove fine without the stat, no overheat. I don't know if this means that the radiator is good or bad but when I pull the drain plug all the coolant comes running out very quickly. Does this mean that there is perfect flow through the radiator, no blockages? When the car begins to overheat the a/c starts to turn cool when right before that they were blowing hotish/luke warm air.

Colin42

same car as this one you posted about?
the one thats been overheating for 3 years and then you poured sealant goop in it?


https://www.civicforums.com/forums/3...air-price.html

Niaboc67

yes, I took it to a garage who installed a water pump and stat. They said they would try their best to clean all the sealant out. I am figuring that the sealant either clogged the heater core or radiator now. Oddly though they told me they let it run in their garage for an hour and it didn't overheat and they drove it and it didn't overheat. So something is not smelling right.

Colin42

Doesn't it have a blown headgasket? a waterpump and thermostat aren't going to fix a blown headgasket.

Niaboc67

Yes, the head was replaced too. The works were done to it. I had it tested by two master techs who confirmed a blown head gasket. When I asked the garage after the job was over how the gasket looked they said they didn't see anything wrong with it. So I essentially wasted money on it. I had so many people tell me head gasket this or that, even master techs and come to find out that wasn't the problem. But it seems there must be residual sealant in the radiator and heater core too. But why would they say they drove it and it was fine? And let it sit for an hour and it was fine? When I drove it myself it immediately overheated. Nothing changed it was exactly the same as before the work was done.
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NDNV

Is the thermostat installed correctly? Jiggle pin at 12 o'clock, and cylinder part towards the block and gasket installed correctly?

Niaboc67

The mechanic I talked to thought it was also a bad stat. These mechanics have been doing repairs for 20 years. This will be the 5th stat put into this civic. I don't understand why stats never seem to work on this car. The car drives fine without a stat. But when one is put in there it just overheats and starts boiling over coolant very quickly. I put a stat in a few months ago. Did the job perfectly, triple checking the work and the steps in Haynes, it still overheated. Could it possibly need an OEM that is to the exact specs of the 7th gen civic? I know that sounds crazy but that's what people on different message boards keep saying. That non OEM stats just won't do the job right.

mikey1

i agree with that,

at this point you have nothing to lose by trying an oem stat

Niaboc67

The garage tested the electricals because the fans weren't coming on. They rigged it up so that it they would stay on. Anywho that was suspected to be the problem. A short somewhere between the fans and the fuse box. So it looks like that will need to be replaced. Then I took it for a spin and it overheated again despite the fans being on. The mechanic checks it out puts his hands near the fans and tells me hot air isn't being blown off the radiator. So it looks like they will diagnose more tomorrow. Right now it is some electrical work and a radiator replacement. I won't be charged for the diagnostic. How much do you suspect this to cost?

ezone

Oh **** it's THAT car.
What happened to "abandon the car on the side of the road, set it on fire" ??

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If your mechanic doesn't know what to look for, the MLS (steel) head gasket will appear just fine.
The breach is usually where the black coating kinda peeled away around the fire ring (edge of a cylinder) or two or three.

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Disconnect both big hoses from the radiator. Leave the cap on. Stuff a garden hose (no sprayer) into the top hose port (wrap with a rag to form a loose seal) and turn it on full blast.
Is there any flow resistance, does it back up and flow out the top instead of flowing out of the bottom radiator hose fitting?

A good radiator core should be able to easily handle the flow of a garden hose without backing up.

BUT if it doesn't overheat with the stat removed, then the radiator is probably flowing good enough.


Were all of the stats aftermarket?

Is the ECT sensor reporting accurately to the computer?

5.0Thunder

I think the rad is probably fine. I'd replace that stat with oem. I had good luck with a cheapo i've always read that they don't work most of the time.

5.0Thunder

Isn't this the mechanic that wouldn't use OEM gaskets?

Niaboc67

....

Niaboc67

The mechanic says the rad might be gummed up because some gasket sealant was tossed in. I could see this because after the sealant was tossed in there was white chunks floating in the rad. The mechanic at first took a temp gun to the stat, said it was 94deg and hoses and said the stat may have gone bad. But then he said it was opening up fine. So I don't know what that was all about. He says that the electricals are fried somewhere between the fuse box and the fans. Because even when this car hits a high temp the fans still don't come on. And when the fans are forced on through shorting the electricals, if you feel the temp from the fans it's like warm/cool air. So the mechanic says it is an indication that the rad has gone bad.

mikey1

if the car is fine without the stat in, then the rad should be fine

Wankenstein

Sounds like the clowns that did the supposed head gasket repair just dumped in a bottle of head gasket sealant and stole your money. How long ago was the headgasket replaced? What test did they do to confirm it was a HG breech at the time?

Niaboc67

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They are a reputable business. Pretty sure they did the full job because they gave me all my old parts inside the respective boxes of the new parts. I am the one that put in the blue devil. I had it tested by two different repair shop master techs who told me it was a small blown head gasket. So going off that it seemed like the logical thing to have replaced. How the master techs determined it was through some software and equipment. It however failed the chemical test. It may have been a faulty water pump. But now since there is sealant in the rad there may be serious flow restriction. When pulling the stat put it seemed to run fine. And went the I pulled the coolant screw out all the coolant freely flowed out. Not sure if that indicates good flow.

mikey1

i think its time to fire your mechanic and hire a new one



.

Niaboc67

Why? What have they done wrong here?

Wankenstein

Oh..don't recall reading that. Well, my apologies to them. I'd like to point a finger your way but, with my latest RTV screw up I can't. Lesson learned the hard way. Wouldn't be surprised at all if the radiator core is clogged as result of that sealant..the heater core may be blocked too.

Follow what Ezone recommends. New aftermarket radiators are inexpensive if needed.

Niaboc67

yes I made the mistake. And yes many lessons learned here. I'll suggest anyone considering that option to run not walk away from those quick fix in a bottle type products. I don't know if the heater core is clogged because hot air does come out of it when it is overheating.

ezone

Sounds like heater core is okay enough to give heat. Not a core problem.
Sounds like radiator is okay enough to keep the engine cool while stat is removed. Not a radiator problem.

Now I'm gonna say to let the engine run without the thermostat and let it run until the radiator fans turn on.....note the position of the temp gauge on the dash. IS it in still in the middle normal position?

Got an infrared temp gun? Got a scanner? Let it idle and Verify the ECT temp shows about 200-210 when the radiator fans turn on. They probably turn off when the temp drops about 5 degrees F.
NOte the ECT and the fan temp switch are far away from each other in the sense of liquid flow. Temp of liquid exiting the cylinder head can be much hotter than the liquid coming out of the bottom of the radiator (the fan switch senses water temp from the bottom hose, not the top hose)


Where's the new thermostat from Honda?

ezone

I'm still waiting for this to happen:
"abandon the car on the side of the road, set it on fire"

Post evidence.....I mean pics if you do.

Niaboc67

I will consider the this option of setting the car ablaze. But in the meantime I'll hear out what my mechanics diagnosis is tomorrow. They were testing it today but never called back, I called them and they said they'd call back, nothing. I guess they are just as perplexed as to why it continues to overheat. I told them about the stat before but I'll reinforce it tomorrow.

The car overheats and no fans will come on. There is an electrical problem. Also seems like a rad problem too. Why dont you think the rad is clogged with the devils blue jizz? I have myself and mechanics in total put in 5 stats in this car. Albeit not OEM, I cannot believe that out of those 5 not a single one would work right despite being aftermarket. The electricals for sure need replacing, so might as well have them do that for sure at this point.

ezone

If you jumper (paper clip) the switch connector on the thermostat housing do the fans turn on?

Niaboc67

yes, I tried this not too long ago and they did. They stayed on. But it seems there is a short in the fuse box. The big gold one, the ports are screwed up or something.