Date: Thu, 5 Jul 2007 17:59:08 -0500
Reply-To: Larry Alofs <lalofs@RCN.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Larry Alofs <lalofs@RCN.COM>
Subject: Re: 87 Westy Engine Running Warm---At Wits End
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You need to be sure that it really is overheating.
An IR type thermometer is a very useful tool in cases like this. You
can quickly check the temp of hoses on both sides of the thermostat, the
radiator input and output, the heads, etc.
(2.) What is the resistance of the ECU temp sensor after full warm up.
Compare it to the resistance vs. temp chart in the Bentley
(7.) What do you mean the switch looks fine? Did you check its
continuity in hot water at various temps?
Yes, it's worth checking ground and other connections for sensors and
gauges.
Good luck,
Larry A.
John W. Parkins wrote:
>My 87 Westy has been running warm, so I haven't been driving it. Symptoms:
>
>1. Temp needle halfway between LED and max temp
>2. ECU temp sensor voltage (ECU pin 10) reads .3 vdc after full warm-up
>time. (I have a connector wired in parallel with the ECU connector so I can
>read voltages, much like a DigiTool.) Doesn't this indicate a reasonable
>temp?
>3. Temp gauge sensor is at 75 Ohms. (I have tried 3 different temp gauge
>sensors with the same results.)
>4. Coolant temp in reservoir is at 200 deg F. (I placed a thermocouple in
>the reservoir. The thermocouple wire was sealed so that the coolant system
>was sealed and operating at pressure.)
>5. Coolant system has been pressure checked and maintains proper pressure.
>6. Radiator is hot, or at least very warm. When I turn on the heat, hot air
>blows up through dash.
>7. Radiator fan does NOT come on. (I checked the switch, and it looks fine.)
>8. I replaced the thermostat and housing top prior to having problems.
>(Could the thermostat be in backwards? Would I still have some coolant flow
>anyways? Remember that the radiator is hot/warm.)
>9. I tried a different temp gauge with same results.
>10. When I put a 90 Ohm resistor in place of the temp sensor, the gauge
>needle is on the LED.
>11. When I heat coolant to 185 deg and place a sensor in it the resistance
>is 90 Ohms. (This would indicate that for the needle to be in the center of
>the LED, the coolant would be 185 deg. However, this seems low considering
>the thermostat starts to open at 185 deg and is fully open at 221 deg
>according to the Hayes manual. Hence, the temperature of the coolant must
>be at least 185 deg and possibly close to 200 deg.)
>12. I have properly bled the cooling system a couple of times and have done
>this procedure successfully in the past.
>
>What is the temperature of coolant at the gauge sensor when the gauge needle
>is at LED center? Anyone know?
>
>The radiator fan first speed is supposed to cut in at 192 to 201 deg and cut
>out at 178 deg. The second speed kicks in at 202 to 211 deg. However, the
>coolant at the engine is hotter, I would think, because the coolant flows a
>bit of distance up to the radiator and its temperature would be reduced.
>Significantly? I don't know.
>
>Could my problem be poor flow up to the radiator? If the thermostat were in
>backwards, could this cause my problems? (I think I was pretty carful to
>put it in correctly, but there is always the chance.) Anyone ever install a
>thermostat backwards? What happend? Could this cause the ECU temp sensor
>to read cool and the gauge sensor to read hot?
>
>Could I have a clogged hose? Could the radiator be clogged?
>
>Could there be a problem with a ground messing up the gauge reading?
>
>I think the van has about 170-175k miles on it. The engine runs pretty
>smoothly.
>
>Boy would I appreciate help on this one! Thanks!
>
>
>
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