Date: Sun, 8 Jul 2007 16:40:42 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: 87 Westy Engine Running Warm---At Wits End
In-Reply-To: <IDEPLDGAOJLNOHOKJNPFMEECDAAA.JParkins@RTHcorp.com>
Content-Type: text/plain; charset="us-ascii"
I am really not sure what your problem really is. Do you even have a
problem? If the coolant in the pressure bottle is around 200F than that is
normal. Whether the coolant is 185 or 195 or even 205 is not cause for
concern. What matters is that it reaches some limit, and stays there
except in unusual conditions. Waiting for the fan to come on, it will
raise, and it should fall once the fan is on. Fan should cycle. Does the
temperature go up on the highway? It should fall slightly after running at
steady speed. Hill climbs, high outside temps, AC will also raise it.
Maybe the gauge needs to calibrated or you have a bad voltage regulator
for it. If high temps are speed or load related you may have a bad
radiator. Clogging and cracked internal baffles are the common failures.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
John W. Parkins
Sent: Thursday, July 05, 2007 6:14 PM
To: vanagon@GERRY.VANAGON.COM
Subject: 87 Westy Engine Running Warm---At Wits End
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!