Head Gasket Leak?

Hi:

Probably a repetition of earlier (and frequent) questions, but here
goes:

1990 3.3L Grand Voyager - lots of miles. When it gets hot, lots and
lots of gas bubbles start appearing in the coolant overflow container.
I've seen this before in other vehicles - I gather there can't be any
other cause than a leaky head gasket, right? Is there any need to
confirm this cause with any reliable test?

Obviously when this happens (usually during some hill climbing), the
cooling system doesn't really do its job very well and things start to
overheat.

Dave

 

It probably is a head gasket leak. One reliable test you could perform
that is also inexpensive is a compression check. It sounds like the
leak is between one of the cylinders and a water jacket; a compression
check would reveal one cylinder with low compression, or possibly two
next to each other with low compression.

I believe you can get a compression tester for under $50.

--Geoff

 

His car has already flunked a pretty reliable test of head gasket
integrity....

I once had a car with a blown head gasket that flunked the bubble test
but had compression within specs on all cylinders.

 

Really? Did you find the source of the leak?

I agree, the overheating and bubbling into the coolant reservoir is
probably enough to condemn a headgasket in this case. I understand there are also kits you
can get that will detect the presence of exhaust gasses in the coolant; these can be used
to confirm a head gasket diagnosis when the problem is less obvious.

But a bubbler that passed a compression check, eh? Wow. I didn't know
that could happen. Did one of the cylinders have lower compression than
the others, but still read nominally within spec?

--Geoff

 

Other thing to ask the OP is if he is using proper mix of coolant or just
water, as water will boil over and cause similar symptoms to headgasket
failure. Also check cooling system performance, perhaps the radiator is not
performing properly and/or the cooling fan is inoperative.

 

Have you tried a pressure test of the system and the cap? There is also a
test that's run that detects the presence of CO in the radiator. Have these
things done first it may be a simple fix. The engine might also be running a
little hot due to a bad stat, or partly clogged radiator a bad hose etc.
Either way don't start yanking it apart until you run some simple
inexpensive tests.
Larry

 

When the headgasket blew on my Dodge Spirit with a 2.5, all of the
coolant would get pushed into the recovery resevoir causing the engine
to overheat. Right before having it fixed, I would have to empty the
resevoir into the radiator once or twice a day. The spark plugs also
showed evidence of anti-freeze getting into the cylinder.

-Kirk Matheson

 

sure you can verify this with a test, pull the coil connector and connect
shop air to each cyl one at a time with the radiator cap off, crank the
engine and you will see the coolant blow back thru the radiator, this will
indicate a blown gasket/cracked head, normally cyl 3 and 4 are the faulty
ones if the head is warped, but check all cyl's the coolant passages may be
blown into the combustion sytem

Glenn Beasley
Chrysler Tech

 

consider also that this could be caused by a cracked cyl head..

Really? Did you find the source of the leak?

I agree, the overheating and bubbling into the coolant reservoir is
probably enough to condemn a headgasket in this case. I understand there
are also kits you
can get that will detect the presence of exhaust gasses in the coolant;
these can be used
to confirm a head gasket diagnosis when the problem is less obvious.

But a bubbler that passed a compression check, eh? Wow. I didn't know
that could happen. Did one of the cylinders have lower compression than
the others, but still read nominally within spec?

--Geoff

 

It was a cracked cylinder head (note your suggestion above!).
Mitsubishi 2.6, with the famed intake-valve-too-close-to-exhaust-valve
head crack.

I don't remember that much detail on it, sorry.