Bad head gaskets???

[dhopper340]

Hello all, I want to start by saying that I am new to subaru and working on their engines.  I have a 1979 Brat EA71.  When I bought it it had a bad cylinder.  The EA71 engine was rebuilt by a local Subaru shop.

My Dad and I installed the engine with a new weber carb. First we checked all 4 cylinder compression and each was exactly 120.  So we decide to try to run it with the radiator out still so no water in the engine.  It basically starts right up and idles for about 10 seconds before we killed it.  Didn't want it too get too hot.  It sounded great actually.  So now we are excited and we hook everything else up and fill it with coolant etc. 

We turn it over and it turns over twice and immediately locks up and won't even turn by hand. We pull the plugs and turn it over again and coolant shoots out of the cylinders on the passenger side (nothing on the drivers side). The cylinders were completely full of water.  What the heck? This can't be just a leaking head gasket can it? Could this be a crack in the head?  It sucked in so much water in 2 turns of the engine it seems like something bad...

If it is sucking water that bad through the head gaskets it wouldn't read 120 psi on those cylinders (1 and 3) would it? Any help would be appreciated we are struggling.

 

[moosens]

If that’s the case I have a set of new old stock headgaskets for only $20 on eBay right now. 
 

I’m kind of beat right now but I’ll give this some thought. 

[dhopper340]

Thanks, I have some extra head gaskets included in a gasket kit i bought. When we have a 120 psi I assumed the head gaskets were good but maybe not...  Also I didn't mention we pulled the intake and put new intake gaskets on to see if that was the problem but we put more water in the radiator and still sucked water into cylinder 1 and 3.

[el_freddo]

I’m not overly familiar with the EA71, but with the Weber carb did you block off the throttle heater coolant passage at the base of the carb? 

This could possibly be an issue, I don’t know for sure. Only thought as to why it’s the passenger’s side is the car is parked on a lean towards that side of the vehicle, allowing the coolant to flow only that way. Long shot. 

Worst case scenario, you need a new head due to corrosion or cracking somewhere that fills both cylinders (I assume) very quickly. 

Sorry I can’t be of more help. My initial thought was the intake manifold gaskets leaking. Did you check that are out thoroughly when you replace the gaskets? No signs of leaking or deformity on the mating surfaces. 

For a rebuilt engine I would’ve expected a much higher compression. Running it for that short period of time without coolant would not cause any damage. I’ve seen (and cringed) people run them for up to a minute without coolant! Not cool. 

Hopefully you get this sorted and it’s a simple issue to fix. 

Cheers 

Bennie

[dhopper340]

4 hours ago, el_freddo said:

I’m not overly familiar with the EA71, but with the Weber carb did you block off the throttle heater coolant passage at the base of the carb? 

This could possibly be an issue, I don’t know for sure. Only thought as to why it’s the passenger’s side is the car is parked on a lean towards that side of the vehicle, allowing the coolant to flow only that way. Long shot. 

Worst case scenario, you need a new head due to corrosion or cracking somewhere that fills both cylinders (I assume) very quickly. 

Sorry I can’t be of more help. My initial thought was the intake manifold gaskets leaking. Did you check that are out thoroughly when you replace the gaskets? No signs of leaking or deformity on the mating surfaces. 

For a rebuilt engine I would’ve expected a much higher compression. Running it for that short period of time without coolant would not cause any damage. I’ve seen (and cringed) people run them for up to a minute without coolant! Not cool. 

Hopefully you get this sorted and it’s a simple issue to fix. 

Cheers 

Bennie

Hey Bennie thanks for your quick response! we didn't think about water getting in at the carb thats interesting.  My dad is going to pull the carb off later today and let me know what he sees. The car is over an hour away in my dad's shop...

We initially thought it was water getting into the intake through the gasket so we replaced the intake gaskets.  The old ones looked fine no tears or anything obvious and the mating surfaces look good from what we can tell.  Next time I'm over there I'll pull the intake off and give it a better look.  Any slick way we can test if there is a crack in the intake manifold? Maybe somehow pressurize it with water...

For the compression I read that an EA71 can read up to 160 psi I think?  I couldn't find a lot of references to that.  When they rebuilt the engine they had to bore 40 over and used ea81 pistons (I could not find ea71 pistons).  So I was thinking the ea81 pistons probably lowered the compression overall but each cylinder was exactly 120 so I figured that was pretty good and it seemed to run well and idle briefly even without adjusting the carb or timing.  if I had a leaky head gasket on the passenger side at least that side would be significantly lower you'd think but it isn't.

Thanks, Dustin.

[dhopper340]

So my Dad pulled the carb off and the coolant passage was blocked off by the gasket.  He also took off the intake manifokd and said he plugged all the ports in the manifold filled it with water through the heater hose.  He then saw water dripping out of the intake side.  So in summary we are pretty sure the water is leaking into the intake somewhere in the manifold.

Has anyone had an intake manifold leak and suck in water like that? Is there a common place where a crack could form between the water and air passages? We will do some more testing and hopefully we can find exactly where it is leaking if it is and hopefully it is repairable. 

[moosens]

There are two ports in your intake. One for air/fuel mixture and one for coolant/antifreeze. 
 

Sometimes that gasket under the intake goes and even sometimes just a bad moment as you’re installing etc. 

 

There’s no crack in the gasket your dad put on previous? 
 

Left bank only I’d be thinking head gasket. Maybe the shop messed up somehow. 
 

Let us know what you find. 

[dhopper340]

1 hour ago, moosens said:

There are two ports in your intake. One for air/fuel mixture and one for coolant/antifreeze. 
 

Sometimes that gasket under the intake goes and even sometimes just a bad moment as you’re installing etc. 

 

There’s no crack in the gasket your dad put on previous? 
 

Left bank only I’d be thinking head gasket. Maybe the shop messed up somehow. 
 

Let us know what you find. 

I replaced the intake gaskets when I was there. The one I replaced looked perfect and water got into the cylinders after the new one so I don't think it's the gaskets but maybe it's the mating surfaces.

We were thinking head gasket as well and we might get to that point but I'm trying to eliminate anything else before we pull the engine out.  Couple things make me think it's not the head gaskets. 1. the cylinders on that side have good compression and the exact same compression as the other side and 2. I would think if a head gasket was leaking it would be a slow leak. This basically filled the entire cylinder with water in like 2 or 3 rotations... that seems like a pretty severe leak like water is just dumping into the cylinders. 

Anyway I'm going to pick up the intake manifold tomorrow so I run my bore scope through it to inspect it for cracks or anything. I'll post and update after that.  

Thank you guys for your help!