Coolant pressure test results

[MTSuby]

After having a coolant system pressure test done, it sounds as though I either have a cracked head, or leaking head gasket. Is the only way to tell to go in and pull it all? I'm ok with replacing the head gasket myself (I hope), but will I be able to tell when I get there if that's the problem, or will I have to just replace it and see if that solves the problem?

 

Also, if I end up doing the gasket, any special tools I need? Other than beer..

Thanks!

 

The shop just told me I need to pull the engine for this.........is that right? Oh boy.

[jeffroid]

You should be able to see if your HG was leaking, and should certainly be able to see cracks.

 

I don't know how you did your presssure test, but I believe you can also get a coolant system pressure leak from an intake manifold gasket failure. That actually happened to me but it was on an EA81. Just be sure that's not your problem before you go yanking your heads off, possibly for no reason.

 

After having a coolant system pressure test done, it sounds as though I either have a cracked head, or leaking head gasket. Is the only way to tell to go in and pull it all? I'm ok with replacing the head gasket myself (I hope), but will I be able to tell when I get there if that's the problem, or will I have to just replace it and see if that solves the problem?

 

Also, if I end up doing the gasket, any special tools I need? Other than beer..

Thanks!

[nipper]

If you suspect a bad HG you need to do a compression test to be sure. Cracked blocks are rare, head is more suspect.

 

Now if you are looking for a coolant leak, a pressure test may not help. it will juyust confirm there is a leak (that may not be visable). There is a die that you put in the coolant that works with a black light. You can trace the leak back to its source. The firs step in that would be to clean the engine.

 

Also check for exhuast gasses in the radiator.

 

nipprt

[MTSuby]

Ok, thanks. The pressure test showed that there were no leaks, or as the mechanic told me, no external leaks, which he said meant either a cracked head or head gasket, and nothing else, I asked a couple times for him to confirm that those were the only things it could be.

Jeffroid- I should be able to see a leaky gasket or cracked head? How? Would I just know it if I saw it or is there something specific to look for?

I suppose a compression test is next...wonder why the garage didn't suggest one. I need to check both my oil and coolant to see if there's something that jumps out in those fluids, but for now all I know is that they found no external leaks, and I'm losing a good bit of coolant.

[nipper]

Lets back up a bit. When was the last time your waterpump was replaced. That may not always show up on a leak down test.

 

On the engine, either a compression test can be done or a leak down test. The former they put compressed air in the cylinder and watch the pressure gauge to see if it leaks down and at what rate. It can tell a little leak from a big leak. Also with a leak down you can watch to see if the coolant is pushed out of the radiator.

 

Now since you passed the ccolling system leak down test i doubt you have a bad HG or cracked head block.

 

It doesnt take alot of burnt coolant to make alot of smoke. What color is your exhaust.

 

This isnt a turbo is it?

 

nipper

 

PS find another shop, something doesnt sound right.

[Gloyale]

I agree with Nipper:eek: lol Get a different shop. Most *general* or non-subaru mechanics are WAAAYYYY!!!! to eager to say "OH it's the heads" or Headgasket in this case. They don't even know you can do that job engine in car, Duh!! They would probably see the little valve cracks after pulling the heads, and tell you you need new ones(BTW, nearly all of these engines get tiny cracks, right between valves in each chamber. They are fine)

 

If this is a turbo, it may be that you've got the other cracks, in the exhaust passage. But on a non-turbo probably not. Are you overheating? Do you have any white smoke? Oil in coolant or vise versa? Any wettness on the t-belt covers under the pump?

[jeffroid]

Sorry, my post was a bit ambiguous. When I said you should be able to see tell if a head gasket was leaking or you had cracks, I meant after you took the heads off.

 

That's why I was wondering about how the coolant system pressure test was performed. On "normal" cars, I believe that if you pressurize the radiator and loose pressure without any coolant leaking externally, that could have a tendancy to indicate a head gasket or cracks.

 

On Subarus (at least EA81's) the intake gasket can leak coolant into the intake and you would have no external visual evidence. I'd have to think about the water pump some more, but it occurs to me that would have to leak externally.

 

If you have no other symptoms of a cylinder failure such as bad compression or leakdown test numbers, smoke, bubbles in the radiator, or milk in the oil or filler tube, I would guess it's not a head gasket or cracks. Please don't misinterpret this statement to mean that any of these symptoms in isolation definitely mean that you DO have a headgasket leak or cracks.

 

Ok, thanks. The pressure test showed that there were no leaks, or as the mechanic told me, no external leaks, which he said meant either a cracked head or head gasket, and nothing else, I asked a couple times for him to confirm that those were the only things it could be.

Jeffroid- I should be able to see a leaky gasket or cracked head? How? Would I just know it if I saw it or is there something specific to look for?

I suppose a compression test is next...wonder why the garage didn't suggest one. I need to check both my oil and coolant to see if there's something that jumps out in those fluids, but for now all I know is that they found no external leaks, and I'm losing a good bit of coolant.

[mikeshoup]

No way to get a definitive answer with just a coolant pressure test.

 

Need to do a compression test or leak down test.

[daeron]

I assume you are "losing" coolant? and this is what is making you run the cooling system pressure test in the first place? Coolant can get into your air intake at the intake manifold, it can get into your exhaust directly and cause steam, it can leak into the oil passages, it can blow between the combustion chamber and the coolant passage (this would cause a constant bubbling into the radiator, eventually OVER pressurizing it, and bubbling all the time into the overflow.)

 

Now, in the case of oil and coolant mixing, there are two checks. For one thing, your coolant should start looking nasty foul brown, like a bad melted milkshake. You might also want to fill the radiator up with some full strength antifreeze, and run around for a while.. let it "lose" the antifreeze and after adding say, an additional gallon or water drain the oil into an open pan. Look and see if you can find any indication of the neon colored antifreeze in the oil.

 

I agree highly with others, the people in this shop you are going to dont seem to have their heads up their taillights. If you don't want to figure this problem out, it would probably be wise to take it elsewhere. a coolant pressure test is NOT, by itself, a barometer by which to decide it is time for a new headgasket.

[MTSuby]

Alright, thanks a lot everyone. I have a shop that specializes in Subarus, but it's all the way across town. The shop I brought it to is just a little shop and tire place that's a 5 minute walk from work and I figured they'd be fine to figure out where a leak is coming from.

 

My car is not a turbo. 87 GL wagon, carbeurated. (EA82). I replaced the oil and water pump...that could be part of the problem since I'm a bit new to this...I have been smelling some coolant when I drive, but I've learned there could be a million reasons for that. There are no puddles of coolant under the car. I'll check today to see if I notice oil in the coolant or coolant in the oil, but it sounds like I should take it to the better mechanic. I am losing coolant.

[Gloyale]

Alright, thanks a lot everyone. I have a shop that specializes in Subarus, but it's all the way across town. The shop I brought it to is just a little shop and tire place that's a 5 minute walk from work and I figured they'd be fine to figure out where a leak is coming from.

 

My car is not a turbo. 87 GL wagon, carbeurated. (EA82). I replaced the oil and water pump...that could be part of the problem since I'm a bit new to this...I have been smelling some coolant when I drive, but I've learned there could be a million reasons for that. There are no puddles of coolant under the car. I'll check today to see if I notice oil in the coolant or coolant in the oil, but it sounds like I should take it to the better mechanic. I am losing coolant.

 

Check all the hoses espescially the heater hoses. The ones that run from the back of the engine into the cab. You have to remove the spare tire to see them. Check them out really well, when they leak it is ussually steam or it just hits the exhaust an disipates. And it is the high point of the system so it won't leak at all when sitting, only after it pressurizes. Cost is about 5 bucks to replace with 5/8 heater hose If you replace those hoses, and you're car is a manual, just be sure you make them long enough to bow away from the clutch fork/cable assembly. I even looped a zip tie around mine

 

There is also a small hose running from the carb base in front, over the manifold, and T's into another tube. And the *hose to you know where* from under the Tstat onto the block under manifold. You can change it if you need to since you have a carb manifold(turbos it's almost imposible). But it is way easier to do with the manifold off, say if you ever need headgaskets:burnout:

[daeron]

handy way to check for steam or mist from a pinhole leak in the cooling system:

 

park in a darkened garage, or wait till night time... get the engine good and warm/hot.. and get a laser pointer and point all through the engine bay. that should show up any cloud of water vapor, whether mist or steam.

 

good luck

[MTSuby]

Ok and these leaks would not have shown on a pressure test?

[daeron]

well, you know...

 

i went and got two threads confused, I THOUGHT i had already mentioned that in the one where it was actually apropriate... no, youre right. My foot is in my mouth

 

Sometimes I brainstorm and try coming up with "more" ideas without re reading the whole thread. my bad. the positive pressure test should have eliminated that kind of stuff.. BUT was it done with the engine warm?

 

Anyhow, if you are smelling coolant when you drive, and coolant is disappearing from your radiator, you may have a leaky heater core. One way to test this would be to bypass the thing entirely for a little while, IF that is an option.. just splice the two hoses entering the firewall between the center of the car and the brake master, together. One is supply and one return from the heater core. If your smell goes away, and you keep your coolant where it belongs, then you've ruled that out, too.

[subie_newbie]

Or, just see if your pass. side floor is wet. When you turn on the defrost does your windshield get worse?

[MTSuby]

Ok, first of all, no problem, I forget to read and listen all the time.

NO oil in coolant, NO coolant in oil (that I can tell so far, it's a little harder to tell). The DRIVERS side rug is wet.........hmmm

[nipper]

Ok, first of all, no problem, I forget to read and listen all the time.

NO oil in coolant, NO coolant in oil (that I can tell so far, it's a little harder to tell). The DRIVERS side rug is wet.........hmmm

 

YAY! trust me thats a good thing, the lesser of two evils

 

nipper

[subie_newbie]

YAY! trust me thats a good thing, the lesser of two evils

 

nipper

 

 

So does that mean heater core in this car? Usually it's passenger side...

[daeron]

it IS on the passenger's side... but the lines enter the cabin on the driver's side. Pull your spare tire, and look for two parallel hoses, about 5/8" diameter, running roughly just above the DS head gasket.. i forget how far forward they go and I am not looking at my engine bay right now, but they both go into the firewall between the transmission tunnel and the brake master cylinder. if your floorboards are wet on the driver's side, I would inspect that area thoroughly.. and pressure test or no, check it when its running and hot, with a laser pointer to see if you see any stem or mist. the water is coming from somewhere, if their pressure test missed it then thats just one more reason not to go back to that place

[MTSuby]

Alright, thanks! I know the hoses you're talking about. I'll take a closer look and hopefully get the thing figured out by the weekend..

[MTSuby]

Ok, thanks for all the help so far. Whether or not I've got a cracked head or head gasket, I am getting a lot of coolant in the car, so I have a question on using a bypass to connect the heater hoses. Do they only have coolant in them after the engine is warm & the thermostat has opened? So can I pull them from the firewall & connect them without draining the coolant?

[Gloyale]

Ok, thanks for all the help so far. Whether or not I've got a cracked head or head gasket, I am getting a lot of coolant in the car, so I have a question on using a bypass to connect the heater hoses. Do they only have coolant in them after the engine is warm & the thermostat has opened? So can I pull them from the firewall & connect them without draining the coolant?

 

 

If you've got coolant in the car. Your heater core is trashed. It can leak from the core itself(pass floor wet) or from the brass tubes leading through the firewall(drivers floor wet). Either way it needs replaced(remove dash, don't be scared it's not too hard). For now you can by pass it by looping the suppply hose right back to the return hose.

 

Those hoses have coolant in them all the time. t-stat open or not. You will lose some when you disconnect them. But not all of it, no need to drain the whole sysem. Just be ready for some coolant.

[subie_newbie]

If you get a pipe joint in the right diameter (5/8"?) you can just cut the hoses inside the engine bay with a razor blade and lift them quickly, insert the splice into one, then push them together, clamp. At most, you'll spill a cup or two, plus whatever comes out of the heater core side (minimal). This way, you don't have to dig under your dash right now, it will be easier to just pull the heater core into the passenger compartment without needing to worry about the hoses being too short and messing with hose clamps while on your back, and it'll force you to get new hoses, which you should do anyway.

[Gloyale]

This way, you don't have to dig under your dash right now, it will be easier to just pull the heater core into the passenger compartment without needing to worry about the hoses being too short and messing with hose clamps while on your back, and it'll force you to get new hoses, which you should do anyway.

 

This doesn't make sense to me. The heater core cannot simply be pulled into the pasenger compartment. The whole dash must be removed. Then the air distribution box has to be removed, the heater core is mounted inside of it. Hoses too short? Messing with clamps on your back? There are no hoses to be disconnected in the passenger compartment. The hoses end at the firewall.

 

 

Cutting and splicing will work for the bypass. but isn't nessecary. One hose can be removed, the the other looped around, they are the same diameter(unlike old GM setups) Then he doesn't have to by new hoses later unless these ones are toast.

[MTSuby]

Alright, thanks a lot. I'll wait until the first chill is in the air this fall to worry about the core, for now I just want to bypass it. I think all my hoses could use replacement, so it's not a bad idea to cut them, but I'd like to use their hose clamps, so I think I'll just take them off. If that ends the leaking and I don't have a cracked head or gasket...