Date: Thu, 10 Aug 2000 14:52:58 -0400
Reply-To: "R. Hotchkiss" <hotch@hotstrings-inc.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "R. Hotchkiss" <hotch@hotstrings-inc.com>
Subject: Re: Coolant temp warning light won't stop flashing - is my
diagnosis correct?
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Doug,
Another reason the light might continue to blink is if your anti-freeze/water ratio is wrong. The level sensor also measures resistance (I'm no engineer) and bringing the ratio to where it should be, will make a difference. I know you didn't mention any changes, but might you have added straight
coolant to top it off?
Just another thing to contemplate.
Hotch
86 Vanagon GL
89 Jetta GL
Philly
http://www.hotstrings-inc.com
>
> Date: Thu, 10 Aug 2000 12:26:54 -0400
> From: "Fitz-Randolph, Douglas" <Doug@beaconmarketing.net>
> Subject: Coolant temp warning light won't stop flashing - is my diagnosis
> correct?
>
> Hello fellow list members - I am in need of some technical support for
> my '90 Syncro 2.1. I just finished replacing my exhaust system (long
> story, for another time) and now my coolant temp gauge warning light
> begins flashing about 10 seconds after I start the engine and does not
> stop. The engine can be hot or cold, same result. The coolant and
> overflow reservoirs are both full. Any flashing I refer to is not the
> self-test flashing when you start the engine - that occurs normally.
>
> I performed the following troubleshooting steps with a cold engine:
> 1) Disconnected coolant reservoir sensor lead - no effect on flashing.
> 2) Disconnected coolant reservoir sensor lead and bridged contacts - light
> flashed constantly - no 10-second delay after starting engine.
> 3) Disconnected single-wire temp sensor lead (bottom of thermostat housing)
> - no effect on flashing, temp gauge does not register.
> 4) Disconnected sensor lead (side of thermostat housing) - flashing stops,
> engine idle increases.
> 5) Disconnected sensor lead (side of thermostat housing) and bridged
> contacts - no effect on flashing, engine idle decreases.
>
> Based on that I'd conclude that the sensor in the side of the thermostat
> housing is bad. I don't think it's a wiring issue because bridging the
> contacts did have an effect. What do you all think? There aren't any other
> things that could make that light flash - are there?
>
> I did have to use a torch to loosen the exhaust bolts, and I was very
> careful to shield everything nearby with pieces of sheet metal, but perhaps
> the sensor is a little bit fragile and didn't like the heat? Just a guess.
>
> Assuming my conclusions to be correct, my next question would be... if I
> unscrew that sensor, how much coolant is going to come pouring out? And
> will I have to spend all day trying to get air out of the system?
>
> Thanks very much in advance.
>
> Doug Fitz-Randolph
> Freeport, ME
> '90 Syncro
>
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