I just did an engine swap on a 93 civic with a d15b7 engine and everything is running fine, with the exception of the coolant.

The first time I cranked the engine, I had the coolant system filled and had a funnel on the rad filled half way to allow air to escape, and the coolant blew out of the funnel like a volcano. Once the initial burst of coolant, I can fill it back up and it acts fine. The occasional bubble comes up, but for the most part it acts normal with no bubbles.

I am thinking that it is a head gasket, but compression is as follows:
cyl 1- 110psi
cyl 2- 105psi
cyl 3- 103psi
cyl 4- 124psi

the engine has 140k miles on it.

I was able to successfully start the vehicle a couple of times and it was fine, but then it decided to do it again...and I assume it was because the engine was still a little warm.

The only thing I can think it would be is the intake manifold. I had to swap the intake from the new engine and use the old one, and I did reuse the gasket.

Is it possible that the gasket is leaking between the 4th cylinder and the coolant jacket on the intake mani? And would that cause it to have massive pressure on cranking, but not during the time the engine is running???


PLEASE HELP!!!!

 

if you put cold coolant in a burning hot engine and started it circulating, then i could cause it to burst out of the radiator, otherwise if it is spitting coolant all the time out of the top excessively then its possibly a head gasket, those compression reading are a little low from what im used to seeing, 140+

 

Nope, it was room temp coolant in a room temp engine. And I want to see if there could be anything other than a head gasket first.

I am seriously leaning towards the intake manifold gasket as the culprit but I have never heard of this problem before.

 

I am not clear on the funnel in the radiator arrangement. Can you give more details?

Do what again? Give more details.
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Have you driven the car to see whether it overheats or blows white smoke from the exhaust?

Regarding the compression numbers, how did you do the test? Have you tried a cylinder leak down test?

 

The funnel is a cv boot that fis perfectly in the radiator cap spot and it will hold a little extra coolant.

The couple times I started the engine and nothing happened was when the car was sitting for hours between startups and the rad cap was on. The time it blew, the rad cap was on and the overflow hose flew off and it shot out of the nossle.

I did drive the car an it acted fine. No smoke, gauge stayed in the norm, and no smells or anything unusual...in fact for doing an engine swap, I was half expecting the car wouldn't work! Lol

The compression test I performed was done with the tester from the auto parts store. One spark plug hole at a time.

 

Maybe the radiator cap is bad and not holding proper pressure?

Click the compression link in my signature. Did you do the test as described there?

 

No i didn't do that...I will have to rent it again and try all over again