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Jason Vance (Jason)
| | Posted on Monday, June 24, 2002 - 10:32 pm: | 
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...afterwards I threw a bucket of mud over the hood; not it starts right up...
just kidding...
On a lighter note, I've had some weird stuff happen with regard to my cooling system.
A couple of weeks ago, the expansion tank blew, probably due to a faulty pressure release cap. Still waiting for parts, but I recently had an episode of chronic coolant boiling off, usually after shutting the rig down. Saturday, I boiled off 2 of the 3 gallons of coolant while trying to drive up a mountain road and luckily found a grocery store to get more coolant and water to make the trip home. Pulled the thermostat yesterday and have been driving without it (still percolating the coolant after shutting it down). Checked the thermostat and it doesn't open. Yippee!
Here's the kicker, for the most part, the temp guage stays in the lower quarter of the guage. I know the guage and sender is working because it has read temps spanning from low to high in the past 3 days...however, I'm still perplexed as to how I can possibly manage to drive my Disco, with the A/C blasting in the 100+ degree Las Vegas heat with a shut thermostat and still keep it in the lower end of the temp range.
Somebody throw me a bone...hopefully the new hoses, thermostat, cap and expansion tank should clear things up. |
B.Bailey
| | Posted on Tuesday, June 25, 2002 - 01:38 am: |
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I'm not 100% clear on what you are describing, but I had a coolant leak last summer that was very hard to detect. Usually you can see the crusty white stuff all over the place when there is a leak, well this time it was dripping directly onto the top of the engine, right were there is a "valley" on the outside edge of the rocker cover. Anyway, it was dripping directly onto that point and instantly running away onto the ground or instantly evaporating without a trace on the hot engine. The leak was coming from the heater hose thermostat valve or something like that. It is a small cylinder with two hoses coming out one end and one going out the other, it has a small metal arm attached to a cable coming out of it. Anyway, it is right on top of the engine compartment, slightly to the left and rear as you are standing in front.
The thing is, I knew I had a slow leak somewhere, but couldn't find it. It was coming out of the valve, but only when my thermostat in the cabin was turned all the way to cool. Therefore, while we were driving around during the cool Oregon winter, it rarely leaked. But when we went for a 2000 mile trip around the back roads of Montana, I started getting hot under the hood. You may have the same problem (other than the faulty overflow lid) only in reverse, yours leaks when it is set anywhere above "cool", therefore you're not leaking whenever it is hot out and you are using the A/C, but if it is cool enough out to turn the heat up, even just one click, it begins leaking coolant.
Just a theory.
http://landrover.mrbaileyshistory.net |
Jason Vance (Jason)
| | Posted on Tuesday, June 25, 2002 - 04:08 am: |
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Naw, I don't think it's that...coolant leak is obviously coming from the expansion tank. Failure of the cap to release pressure allowed the seam in the tank to rupture. Pretty easy to see where it's coming from because it is gushing out with some vigor...like old folks rushing for the buffets around here.
When I lost those 2 gallons on Saturday (and the way I am usually losing coolant), it was after parking and shutting the engine down after the temp started to drastically rise...I sat there and watched the expansion tank puke out 2/3's of the coolant.
Why does it percolate after shutting the engine off? Easy, the fans are no longer operating to cool the coolant in the radiator, and the gigantic heat-pump of an engine continues to transfer heat to the coolant without the coolant moving throughout the system (e.g. via water pump). After the pressure builds up, the coolant pisses out of the expansion tank because the tank is ruptured.
The leak isn't a mystery...the mystery was how in hell...er, Las Vegas, was I able to keep the engine running as cool as it was with a stuck (closed) thermostat. Thank goodness for 2nd Day Air; may I be whistling a different tune tomorrow. |
Anonymous
| | Posted on Tuesday, June 25, 2002 - 05:03 am: |
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YOU HAVE A LEAK IN YOUR SYSTEM..DO A PRESSURE TEST. AFTER ALL IS PARTS ARE FIXED...JUST A SUGESTION . |
Dean Brown (Deanbrown3d)
| | Posted on Tuesday, June 25, 2002 - 09:54 am: |
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Yet more words of wisdom from ANON.
Jason, how do you know the thermostat is not opening? I presume you boiled you one and watched it not open right, but the coolant gets much hotter than that.
Dean |
Anonymous
| | Posted on Tuesday, June 25, 2002 - 11:47 am: |
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Dean, any easy way to check the Tstat is hold the upper rad. hose, Do this after engine is to temp, if its hot and you can feel some movement / flow in the hose the Tstat is working somewhat. If fairly cold and no real feeling of movement tstat is closed. or blocked... |
p m
| | Posted on Tuesday, June 25, 2002 - 01:08 pm: |
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Dean, Jason,
another way of testing it is to crank your heater to the max. if the temperature goes down, you either have a stuck t-stat or clogged radiator or both. an IR non-contact thermometer gun from NAPA or other parts' store will let you measure the temperature difference between the radiator tanks. On my very clogged rangie's radiator, the temp difference was about 2-3F. After it has been recored, the difference increased to 12F. BTW, the same device could be used to diagnose the t-stat - I know that my rangie's t-stat is okay, and the thermometer shows readings within 1-2F for area near the thermostat housing, upper rad hose, and intake tank of the radiator.
peter |
Jason Vance (Jason)
| | Posted on Tuesday, June 25, 2002 - 01:39 pm: |
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Anon is correct...I need to wait until I replace the expansion tank because the system doesn't hold pressure. The T-stat IS toast...if it doesn't open within +/- 10 degrees C of it's designated range, then why would I trust it to open, let alone fully open, at higher temps? Heck, at 90 degrees C I couldn't even persuade it to open with a spoon. FWIW, the radiator is fine; before Saturday's incident and after pulling the T-stat, it stays in the lower quarter of the temp guage. |
Jason Vance (Jason)
| | Posted on Tuesday, June 25, 2002 - 07:20 pm: |
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Woohoo! Parts came and I just finished replacing the hoses, expansion tank, Tstat and cap. We'll see in a week if this solved the problem... |
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