cooling system reservoir

[albsure]

hey guys, a lot of you said that the reservior is not vented , and i got no takers on my blowout plug theory. should i plug the hole where water is spitting out of when it gets hot. it stands to reason that if water ( coolant )can spit out then air can get sucked in. also what does the sensor / switch ?? in the upper rad. hose control. and if there is no water in the oil and vice versa does that conclusively rule out a bad head gasket ? i am truly grateful for all thoughts and input.

albsure

[chrissev]

hey guys, a lot of you said that the reservior is not vented , and i got no takers on my blowout plug theory. should i plug the hole where water is spitting out of when it gets hot. it stands to reason that if water ( coolant )can spit out then air can get sucked in. also what does the sensor / switch ?? in the upper rad. hose control. and if there is no water in the oil and vice versa does that conclusively rule out a bad head gasket ? i am truly grateful for all thoughts and input.

albsure

The reservoir is vented through the cap.  It is a pressure cap and releases at a certain amount of PSI.  If your reservoir is venting coolant anywhere else it is either broken, or something attached to it is broken.  

Re:  the sensor in the upper rad hose:  that is for the glow plugs.

Re:  bad head gasket:  you should see some oil in the coolant or coolant in the oil.  If the gasket is bad around the pistons then your cooling system will pressurize because of the compression leaking into it.

[albsure]

thank you chrissev, will a compression test reveal this problem if i'm getting pressure in the cooling system from a piston to water jacket defect in a head gasket?

[fspGTD]

A compression test might work, but I wouldn't recommend that approach because if the leak is only very slight as (it often seems they are), it might not be large enough to effect engine performance/compression.  I've also experienced head gasket leaks that only happen when the engine gets warmed up.

A pretty telltale sign of gasses from the combustion chamber leaking into the cooling system is removing the expansion cap and smelling the coolant inside.  If there is no head gasket leak it should smell nice and sweet, like new coolant.  Combustion-chamber gas polluted coolant smells foul.

There are also chemical testers that can test for the presence of exhaust gasses in the cooling system, basically a glass jar you put over your expansion chamber and let the gasses bubble up through it to see if the special liquid inside changes color.  If it does it indicates exhaust gasses are present.  I have tried those before though and found with the diesel that they are a bit hard to use.  Since the diesel has such diluted air/fuel ratios, the exhaust gasses are also diluted, and so it takes longer than expected for the liquid to change color.

The test I mentioned in your other thread, to start it up when cold and with your hand replacing the pressure cap, feeling for an immediate rise in pressure test I mentioned in your other thread is a good way to go.

[vwmike]

If there is another place which coolant is coming out on your reservoir then it is probably best to replace it rather than attempting to fix it. A new reservoir isn't all that costly.

[chrissev]

thank you chrissev, will a compression test reveal this problem if i'm getting pressure in the cooling system from a piston to water jacket defect in a head gasket?

Compression test won't tell much.  You could have 200psi in the cylinders and say, well, looks like my head gasket is leaking, but it could just be worn rings.  I like the idea that Jake Russel was talking about, putting your hand over the coolant reservoir top and feeling for pressure changes.  That might just work.  If you feel a rythmic pulsing that increases in tempo with increase in engine rpm, that would indicate that one or more cylinders is leaking compression.

[albsure]

most of you guys have BENEVOLENTLY shared your experience in all of my threads.

THANK YOU.

i will report back asap

al b sure

[fatmobile]

I was just helping a guy with a bad head gasket.
 The stream of coolant heading into the resevoir was intermittant.
 It should be a steady stream of coolant but there were bursts of air entering the resevoir.
 When we pulled the head, there was a bad spot from cylinder to water jacket, near the #1 cylinder.

[albsure]

hi guys, i was about to give a report when i saw fatmobiles post. if you are talking the small diameter line going to the top of the res. , at the suggestion of a few of you of you guys i started removing the restrictor from that line. under the weight of my smooth jawed rounded edge needle nosed pliers ( used a grinding wheel to make them non evasive ) i used to work the restristor out of the end of the hose. i felt and heard a definative crunch. i thought i broke it in the line. it seemed to be about an 1" long. it was only about 7/16". the rest was hardened krud that had built up behind it. had to be completely blocked. cleared the line, started the engine, let warm up observed the new found flow, topped off the reservoir and no more blinking light. i took about a 10 mile trip and still no blinking light. thanks to you ALL i think that we are at the end of this saga. now all i have to do is drain some water and add some coolant.and i think that the head gasket ( my great fear in all of this ) is just fine. THANKYOU ALL FOR YOUR RELENTLESS HELP AND SUPPORT.

al b sure.  ps whats wrong with a radiator with a top and bottom tank and a CAP.