how to differentiate leak of intake gasket or HG?

[idosubaru]

i have two vehicles that leak significant coolant into the combustion chambers, EA82 and ER27.

 

what's a good way to determine whether it's head gaskets or intake manifold gaskets? both seem to leak ALOT, like it's pumping right into the cylinders. where the head gasket leaks i've seen before have all started small and increased over time. i know that probably doesn't make sense, probably just in my head. and of course there's a certain amount of wishful thinking, hoping at least one is only intake manifold!

 

anyway - any hints/tips on verifying either way for sure?

[nipper]

A vacume gauge will show if its a head leak (it will affect compression) as opposed to an intake. A comporession gauge may not show a typical subaru leak, as the cylinder head is not under stress when its just cranking. A vac gauge will have a vibrating needle as the engine is running, and the head is under the stress of combustion.

 

nipper

[idosubaru]

A vacume gauge

crack! don't have one or know how to use it.

 

if you buy one do they typically come with instructions? where to hook up, how to use/read?

 

how would it physically make a difference? intake leak wouldn't affect vaccuum, and HG would?

[nipper]

19.00 at an autparts store, dont over spend on this. A cheap one is as good as an expensive one.

 

http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm

 

nipper

 

PS if your leaking water into the manifold, yes the vacume will pull it in, but the water is technically sealing up the leak (as long as there is more water behind it).

 

nipper

[Petersubaru]

certainly not scientific here...over the years I have had several headgasket leaks, but none that pumped water into the cylinder..Also I have had one intake gasket with a small hole in it which did as you described...a lot more volume of water can be sucked in through intake

[idosubaru]

certainly not scientific here...over the years I have had several headgasket leaks, but none that pumped water into the cylinder..Also I have had one intake gasket with a small hole in it which did as you described...a lot more volume of water can be sucked in through intake

great - thanks a lot! that's kind of what i'm thinking about both of these, i've never seen any head gasket consume this much internally either...so i couldn't decide if i was just being optimistic or theirs a hint of possibility.

[Petersubaru]

great - thanks a lot! that's kind of what i'm thinking about both of these, i've never seen any head gasket consume this much internally either...so i couldn't decide if i was just being optimistic or theirs a hint of possibility.

I think it would be easier to change the intake gasket first especially if they have not been done for a long time (maintenance item)..also hopefully the stud(s) won't break as you are trying to undo them

[idosubaru]

hopefully the stud(s) won't break as you are trying to undo them

i've had to deal with that a number of times. totally annoying no doubt.

[Frank B]

well, on either engine it's easier to remove the intake then the heads. So I would say try the intake gaskets first. They really aren't that expensive. Of the ones I've replaced, you can tell by looking at them that they were leaking. They also looked like mush oozing out between the heads and the intake.