NOT blown headgasket-now with correct comp #s

[hatchsub]

Some of the East coasters already know about this but this saturday i roasted a headgasket or two on my EA81 sedan. It was 95 out and i drove 3 hours to the cape. Not a good idea. Anyways i figured i was imune to this seeing as how it only had 76,000 on it and its an EA81. Bubbles in my coolant told otherwise as well as my temp creaping up and the fact that i was half a gallon low on coolant when i checked the next day.

 

Ive been told Rockauto is the best place to buy stuff cheap. I figure im going to buy the headgaskets and valve cover kit. The intake gaskets area already ordered from the dealership. The exhaust gaskets arnt leaking so I think ill reuse them.

 

Just informing everyone and just seeing if im thinking about this right. Im going to pull the motor entirely since its not that much more work to do and i get to check out the motor mounts.

[Andy FitzGibbon]

Rockauto prices seem OK and I was impressed with their service when I ordered from them. Shipping was fast.

Andy

[GeneralDisorder]

Make sure you don't have a leaky coolant hose or manifold gasket first. EA81's rarely blow head gaskets and I'll wager your's are fine.

 

GD

[hatchsub]

Hmm i figured for sure that they were gone though. I saw the bubbling in the radiator. I checked around for leaks and found none.

[hatchsub]

Just had a thought..i wonder if i just let it run too low and sucked some air into my lines and that is what i saw. Im going to pop the cap and check again later tonight with the car running. With any luck im in the clear.

[samneric]

Rockauto prices seem OK and I was impressed with their service when I ordered from them. Shipping was fast.

Andy

 

I 2nd that notion. Parts arrive in a day or two.

 

I've bought bunch of stuff from them lately and been pleased.

 

...and check out this deal - even if you get it for spares, nows the time to buy...

 

BECK/ARNLEY Part # 0322580

Head Set, 1 Per CarChoose: [Wholesaler Closeout -- 30 Day Warranty (Only 5 Remaining)] ($28.79)[Regular Inventory -- Full Mfr. Warranty] ($63.99)

$28.79$0.00$28.79

 

 

I just paid $85 for the Felpro set from Napa (although there seems to be more pieces in it)

 

Steve

[TheSubaruJunkie]

If you want to know for sure, perform a compression test on the motor.

 

Hope its just something simple and stupid.

[hatchsub]

Just went out and double checked. Its fairly cool outside now. First of all i was low on coolant again after having driven from the cape back. So i topped it off and went for a spin to warm stuff up. Then i pulled back into my parking lot and popped the radiator cap and revved it up. Everytime i revved it little bubbles could be seen coming up from the bottom of the radiator. This leads me back to headgaskets.

[subaru360]

If anything turns out to be bad with your engine, I have a complete EA81 here with a new factory gasket set to go with it. It's a leftover from the superoo project.

[hatchsub]

I saw that in another post. Thats good to know. Thanks. Mine is still running really well though so i should be fine.

[GeneralDisorder]

Everytime i revved it little bubbles could be seen coming up from the bottom of the radiator. This leads me back to headgaskets.

 

First EA81's don't have overflow's. The engine warms up, coolant expands, and any extra is allowed to dump out on the ground. For this reason there will always be an airspace at the top of the radiator to allow for expansion when warm.

 

I advise this because it is important to notice that there is air in the coolant at all times. Air dissolves into the coolant at the top of the radiator, and can form bubbles as it is churned up by the water pump.

 

Now - there are several places you can be losing coolant.

 

1. Leaks. Upper and lower radiator hoses, thermostat housing gasket, carb base gaskets, manifold gaskets, heater core hoses, carb base heater hose (from heater core supply tube), heater core, heat control valve, and head gaskets (external). It's important to note that a leak of the size you are experiencing will usually NOT show up on the ground if it's near the engine. They will often evaporate due to engine temperatures before they hit the ground. The best way to look for leaks is with coolant dye and a black light - both are cheap. It's also helpful to use a hand pump system pressurizer so you don't have to run the engine. It is far, far more likely that you have a leak than a bad head gasket.

 

2. Internal leakage. Head gasket, manifold and carb base gaskets (burning it), and freeze plugs (into the oil). Head gaskets will often pressurize the cooling system resulting in VERY bad things - like splitting a radiator seam or blowing the tank off the end of the heater core - or blowing old hoses. You can do a compression test, but it may not show you anything useful if the leak is small. The best course of action is to do a hydrocarbon test of the coolant. That will tell you if cylinder compression is entering the cooling system. The cylinders have a LOT more pressure in them than does the 13 psi cooling system so exhaust gasses will always enter the cooling system if you have a compression leak into it...... If you had a leaking freeze plug you would probably know it already as the oil would be milkshake.

 

GD

[Frank B]

If you end up pulling the engine, it's a good time to replace the oil pan gasket too. Clean up the pick-up screen while the pans off too.

 

Oh, and don't rule out the radiator, it could have a small leak and the heat is evaporating the coolant before it drips on the ground. Look for stains. I just replaced a rad in our chevy sedan and this was the case. The only way I found the crack was by squeezing the upper hose which pushed the coolant out. It only leaked when it was hot.

[hatchsub]

Ok just got done doing a compression check of the cylinders. Here are the #'s

 

140

155

160

160

 

Im assuming that these numbers arnt all that bad for a 25 year old engine with 76,000?

[GeneralDisorder]

Those are fine. All plugs removed, fuel pump unplugged and throttle plates wide open?

 

GD

[hatchsub]

oops no. One cylinder at a time (as in the other three had plugs in them), throttle wide open, coil unhooked.

[GeneralDisorder]

You should have all the plugs out so it turns over faster.

 

Unplug the fuel pump and start the engine - run it till it dies. You don't want fuel washing down the cylinder walls while you are testing.

 

GD

[hatchsub]

How far off are my numbers because of this? I realized its probably time for plugs anyways while i was in there so ill buy some new plugs and retest as well.

[GeneralDisorder]

How far off are my numbers because of this?

 

Hard to say for sure. If there was a solid correction factor then there would be no need to test in this manner.

 

Each cylinder will get sucessively worse as you test because the unburned fuel washes the oil off the cylinder walls.

 

GD

[subaru360]

Hard to say for sure. If there was a solid correction factor then there would be no need to test in this manner.

 

Each cylinder will get sucessively worse as you test because the unburned fuel washes the oil off the cylinder walls.

 

GD

 

He has a carb, with the throttle held open no fuel will go into the engine.

 

The numbers aren't bad, they will go up slightly with all the plugs out and it spinning faster. Usually you don't want to see more than 10% difference between highest and lowest cylinder.

[hatchsub]

Hard to say for sure. If there was a solid correction factor then there would be no need to test in this manner.

 

Each cylinder will get sucessively worse as you test because the unburned fuel washes the oil off the cylinder walls.

 

GD

 

Not in my case. The numbers got better as I went along. The 140 was the first, followed by the 155.

[GeneralDisorder]

He has a carb, with the throttle held open no fuel will go into the engine.

 

That just isn't true. If it were, carbed engines would not start at WOT. Plus the accelerator pump is still working so every time he actuates the throttle fuel is being dumped in.

 

The safe bet is to eliminate the fuel from the equation in any case.

 

One cannot compare their numbers to anyone else's if there isn't a standardized testing method that virtually gaurantees the tests are done the same.

 

GD

[daeron]

I agree with GD;

 

unplug the fuel pump, start the car, let it die, pull all four spark plugs, and test again.

 

Your previous results, while they may well wind up being very similar to what you find, may just as well be complete hogwash. You could have 140 in the first cylinder tested, and 170 on the final one tested, if they are all dry.. and thats 30 PSI difference, out of 170.. thats well over 10 percent.

 

My P/S head gasket was blown, and my numbers were 180/185, 150/155 (driver front/rear, passenger front/rear) The differential between the numbers is the important part, not "all four cylinder reading above X." I have heard people on this board claim to have running engines that were perfectly smooth, with not loss of power, when testing a little over 100 PSI on all four cylinders... but that figure was even for all four cylinders.

 

 

For the record, any time I run a compression check, I check each cylinder three or four times before going on to the next one, and I record EACH measurement. I average my measurements from each cylinder to get a "number" and I also discard any figure out of line from the others on each individual cylinder test.

 

 

IE, i test #1 cyl.. 160 PSI, 163 PSI, 120 PSI.. I ignore that 120 and test one fourth time, get 165 psi, average out to about 163.

[hatchsub]

Ok took everyones advice and did it the correct way..as in throttle wide open, fuel pump unplugged, all spark plugs out. Here are the correct #s that are averaged from 4 readings.

 

160

166

166

172

 

They look better than the other ones did. As for my coolant lose, im not losing any that i know of anymore since i replaced the radiator cap. No overheating either. Crossing fingers that that was all it was. Looks like my luck has been passed on to Connie though Sorry Connie.