Hey guys,

My car overheated and blew the head gasket. I got the head machined from a local shop, bought felpro mls head gasket along with water pump and timing belt. Put everything together and it starts up fine with no leak. Then I bleed the coolant with heater on max; 20mins in and its spitting out coolant from the radiator. Upper radiator hose hot, lower hose cold. The front of the car is raised up on the jack stands.

https://streamable.com/rdirn

I compression test and 185psi on all 4 cylinders.

Any idea?

Thanks in advance.

 

check your thermostat. It sounds like it's stuck closed.

 

Was engine also overheated in the video?

Is the cooling system filled with water?

 

The lower radiator hose never got hot so the thermostat never have a chance to open.

Radiator is filled with antifreeze with water already mixed.

 

The temperature is about 1/3 on the needle.

Radiator is filled with premixed antifreeze + water.

 

Forgot to mention.

I went to autozone and got another thermostat and replaced the original Honda one. It still does the same thing, the lower hose still cold causing the thermostat not to open. I ran without thermostat and the coolant move normally and no geyser after 20mins. Both hoses hot and temperature about 1/3 on the needle.

I threw both thermostats in a heated pot and they both opens around 173 - 175 degree.

Not sure what's going on here. First time I ran into a problem like this.

 

Assuming that the B20 engine requires 50:50 coolant, does this^ mean that you are further diluting 50:50 coolant with water?

The B20 engine does not come from a Civic. Have you looked up the proper B20 bleed procedure?

Have you rented a block tester kit to see whether exhaust gas is spewing from the radiator?

 

Premixed meaning you don't have to add water like this https://www.autozone.com/antifreeze-...gal/391379_0_0

I bleed my civic d16z6 the same as my d15b7 and my integra b18b1. YouTube videos confirm my procedure is fine as I've been doing for over 10 years.

Went and borrowed block tester with the fluid from autozone along with radiator compression tester. Block tested is good as the fluid doesn't change color, squeezing this for a about 20mins. Radiator compression test holds 16psi for 20mins.

I drove the car without thermostats for about 30mins with no problem on the temperature and coolant is still full. No milky substances.

Still at a lost.

 

The only thing I didn't reused was the Honda head bolts. I threw those out and use ARP head studs instead following ARP torque sequences. I'm still racking my brain and wondering if I should removed the head to check the block and the head for any hairline crack at this point.

 

You sure that you have your heater hoses hooked up correctly?

 

Pretty sure. I took each hose off and put the new one back on before moving to the next hose. The only hose that doesn't fit is the upper hose which is too short so I bought a dayco hose from AutoZone and use that instead.

 

I'd get an FSM for the engine and look at the coolant hose routing diagram.

I put one hose on incorrectly and the thermostat didn't open nor did coolant route correctly. End result car started to overheat and the coolant began boiling during the burp procedure causing a geyser.

Was a simple hose misplacement problem. I even tested the thermostat which checked out fine. Once the hoses got put into the proper spots, all coolant related problems went away.

 

I'll recheck it tomorrow. Lets hope this is it.

 

Yeah I believe the bypass hose which is a u shape off of the thermostat elbow

 

I checked the coolant lines and seem right.

Here's a video of the coolant lines.

https://streamable.com/zhx4z

Tell me if any of them is out of place.

Thanks

 

Did not found why but I drilled a hole in my thermostat and that seems to fix the problem with the car running cool and both upper and lower hose getting hot.

I'll leave it as is for now.

Thanks for the help guys.

 

Still don't see them all. You have one capped on the distributor side while you have the long small one from the timing belt side of the water pipe running to the throttle body. Can't see where that one continues to or ends. Can't see the IACV and it's hoses.

Drilling a hole through the thermostat isn't the proper fix and shows something is still amiss.

 

Thanks for the help. Here is the coolant line from the water neck and throttle body.

https://streamable.com/1al39