Hey Guys,

I am having some issues with my 91 Civic Si. I bought it with the stock motor, and the head gasket went last month. Since doing the head gasket, I have been having issues with coolant still. I noticed that after driving it, the coolant overflow reservoir is full when hot and when I come back to check it cold it is still full. When I open the radiator at the cap, it seems that there is suction on the cap (negative pressure, opposite of the normal pressure you experience with the cooling system when hot). So I thought it was a bubble, but I have bled it, driven it, bled it again, driven it and I just bled it again tonight. I have also noticed that once the major bubbles stop, I have a lot of fine bubbles. I do not know if this constitutes the "fizzy" coolant symptom of a head/ head gasket problem? I did have it overheat on Friday, so I turned the heat on (which kept the temperature down), took it home, added coolant and bled it again. I am not losing coolant on the outside, and I do not see white smoke coming from the tailpipe. So I am stumped here. So far I have been driving it for work and filling it back up in the evening once it is cold. I'd like this thing to run 100% Anybody have some ideas here to help me get this thing back there?

A quick recap: I completed the head gasket last week and these are the symptoms I am seeing:

1) Overflow bottle completely full when I finish driving (car hot)
2) Overflow bottle does not empty as motor cools down
3) I am putting small amounts of coolant in the car
4) Overheated on Friday, turning the heat on kept the temperature down
5) Lots of tiny bubbles coming from the radiator when I burp it

Thanks for any help you can provide.

Brian

 

Brian,
did you check the radiator? have found that with a lot of miles they become plugged. I don't care how often the coolant is changed, it just happens. sounds like the head gasket replacement didn't completely seal, hence the bubbles. perform a pressure test of the cooling system(requires special tools) and report back to us.
Dave
in the rva (east henrico)

 

Yea you definately have a head gasket problem. Sorry seems you have to redo the job.

 

Did you put the HG on upside down? It is marked "UP" and it is very easy to put on upside down. I've done it.

Did you re-use the head bolts? Head bolts stretch over time and will bottom out in the block, causing head lift, which seems like what you're experiencing. Even with head-studs, people have observed head lift. Re-torquing the studs will help with this.

So you could try re-torquing your head bolts and see if that helps. Be happy you just have to take the valve cover off. If it was B series you'd have to remove the cams too.

 

Hey Dave. I ended up putting the old stock radiator from my CRX in it prior to the head gasket change. So I know the radiator is good, unless something happened to it after taking it out of my CRX.


Yeah this is what I am worried about. I just moved to an apartment away from home, so I have a small amount to work with here. I can always drive it back to my mom's place and do the work on a weekend, but damn.

I do not think I put it on upside down. When I put it on, I did take several moments to make sure it lined up with the oiling ports properly. It almost did go on upside down, and at the last minute I corrected it. I ordered ARP head studs and installed them according to the instructions (three steps to the factory recommended 60 ft/lbs). According to ARP, you are NOT supposed to re-torque the head studs; however, I looked that up a few years back when doing a mini-me in my CRX so I will look into this again.

I am going to drop the car off with my local mechanic tomorrow. I asked that he perform a cooling system pressure test, compression test and leak down test if so necessary. He said if I drop it off in the early am he will check it out and get back to me before close of business. I hope to have some news tomorrow. I rented a cooling system pressure test kit from Advance Auto, but the pump is bad and cannot hold any pressure over 10 psi.

 

You should do a leak down test, or have the mechanic do a leak down test. When you apply the air pressure you will see it drop where the head gasket problem is.

 

When doing your HG job did you machine the head? If not it is possibly warped. Aluminum heads tend to warp faster then say cast blocks/heads like a 4G63.

 

Yes I had the head machined. I spoke to my machinist yesterday, he also confirmed that he pressure tested the head and there no cracks. I checked the block with a straight edge. That was all I had. It looked good to the naked eye, but I guess that could have been off.

Also, I don't know if this changes anything. I ordered a metal head gasket for my motor this time. I know they come stock with the composite head gasket, but they are such a pain in the ***. I paid more for the metal head gasket, but could that be part of my problem?

I am thinking I may order my next head gasket from Honda directly.

I am going to drop the car off tomorrow. I was going to today, but my mom was supposed to pick me up and she forgot so I had to reschedule.

 

when you check it with a straight edge you are suppose to use feeler gauages and see what the thickness differences are across the head. Did you do that?

 

No, I did not use feeler gauges. However, I took it to the shop yesterday. They called me back in the afternoon and said that the civic passed the head gasket test. He did not tell me what the head gasket test was, but I am assuming he performed a leak down test, because when I dropped the car off insinuated that he would when he told me he would be able to tell me what exactly was wrong. He told me that he had ordered a deeper cap with a higher pressure rating than the OE one I purchased the other day. He replaced my overflow tank with a Deer Park bottle and his technicians were taking it up and down 95 to see if that had any effect. Have not hear back from them today.

 

Replacing the overflow bottle will not change anything, unless the hose inside of it was damaged and not reaching the fluid at the bottom.

Otherwise, I am suspecting a replacement cap will start helping the situation since I am blaming the cap on the reason why you are not bringing the fluid back into the radiator when cool.

 

I agree with the cap being a good start. Maybe pressure test the radiator too.

Also, try and 'bleed' the radiator system. Not sure if that is what you consider burping it. But there should be a bleeder valve on the thermostat housing or near it at least. Fill the radiator and crack the bleeder valve. Wait till it's not pushing any more air out and add fluid as you do this. Then close the valve.

Hopefully you just had a bad cap and some air got in the radiator system.

 

OK UPDATE!

They replaced the cap and drove it up and down 95. Guy said he could not get it to fill up like I was seeing. When it did fill up, the coolant went back in once the motor cooled off. The mechanic also answered my question about the small bubbles I was seeing. It was not the "fizz" scenario I was reading about, just negligible amounts of air getting trapped in the coolant as it passed the cap opening while I had the cap off.

The deer park bottle was only so they could see the coolant flow better. It is kind of hard to see into the coolant flow bottle, as it is opaque to begin with and 23 years old.

I will update after a longer drive to see if the cap did in fact fix the problem... The radiator said Denso on the top so I assumed it was OE.

Answers to the last few questions: I did use the bleeder valve

 

Cap did not do the trick. It seems the motor is still pushing coolant to the reservoir and not pulling it back... I am going to let it cool down and double check.

The shop did a head gasket and block test. They said it passed. Could something still be wrong with the head gasket though?

 

Your radiator sounds clogged then, are you positive it is in known working condition?

 

Have not had any problems with it. I took it back to the shop today. The guy said they were going to check the radiator. He said they did not see any issues with it last time though.