Date: Fri, 6 Jul 2007 00:24:11 +0000
Reply-To: kenwilfy@COMCAST.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Kenneth Wilford <kenwilfy@COMCAST.NET>
Subject: Re: 87 Westy Engine Running Warm---At Wits End
John,
It really sounds like a poor flowing radiator to me. You can check it if you have an infrared heat gun. There are two hoses that you need to test to see if the radiator is flowing properly. One of them is the hose that goes over the top of the transmission between the coolant distributor and the thermostat housing. This hose bypasses the radiator before the thermostat opens to help the engine warm up faster. However if the radiator is plugged then this hose will short circuit the coolant system, bypassing the radiator and letting the coolant temp to continue to rise. When the van is warm check the temperature of this hose. The other hose you want to check is the fat hose that makes a 90 degree bend from the thermostat housing top to the black metal coolant pipe on the driver's side of the engine. This hose should be at least 10 degrees cooler than the other hose. That is showing that the coolant is going to the front of the van, being cooled by the radiator, and then comin
g back to the engine cooler than when it went forward. If this hose is the same temperature as the first one then the radiator is plugged and is being bypassed.
Test your low fan speed on your radiator as well. It should come on when you turn on your A/C (if you have it). If it does not then your radiator fan resistor is toast and needs to be replaced as well. However even if this is bad the higher speed tornado fan should still be coming on around 3/4 of the gauge to bail you out. Since neither fan speeds are coming on, that is telling me that probably your radiator is not getting hot enough for them to come on because it is clogged and being bypassed as we have already discussed. I have brand new VW radiators for sale, also new radiator fan resistors if you need one (these are usually bad if they have never been replaced). I hope this helps you.
Sincerely,
Ken Wilford
John 3:16
www.vanagain.com
-------------- Original message --------------
From: "John W. Parkins" <JParkins@RTHCORP.COM>
> 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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