Date: Thu, 14 Aug 2008 09:21:22 -0500
Reply-To: Jim Felder <jim.felder@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jim Felder <jim.felder@GMAIL.COM>
Subject: Re: Overheating at idle
In-Reply-To: <4cb8e63b0808140659v34db92dci45fc7ee3dfdaf1a6@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
No, from what you say, I don't think it's the fan. And the "suddenly"
could be thermostat failure (it was on my wife's Acura, but that one
would randomly overheat going fast or slow... the brass cage cracked).
I'd definitely check the thermostat, like just remove it and try that,
just to get that variable out of the way. Plus, it isn't difficult to
do. If you pinch off the hoses, you won't lose coolant.
Jim
On Thu, Aug 14, 2008 at 8:59 AM, Tom Rowsell <86westy@geoexploits.org> wrote:
> I'd have to say "suddenly". You didn't mention the thermostat as a
> possibility? Could it be partially opening or something like that?
> Several people have mentioned the fan, but I don't see how that can be
> a factor when the rad is not even hot...
> Tom
>
> On 8/14/08, Jim Felder <jim.felder@gmail.com> wrote:
>> Did this problem appear suddenly, or did it slowly get worse over time?
>>
>> I can think of two things. One, you have something in your radiator
>> that is slowing down the flow of coolant through it. Moving at highway
>> speeds could overcome this. You might try a radiator flush for that,
>> but it won't be conclusive if that doesn't work because of how
>> difficult these radiators seem to be to clean. Some on the list have
>> taken their radiators out and had them professionally cleaned, but the
>> general consensus seems to be that new radiators are cheap enough that
>> it doesn't make much sense to do anything but replace them.
>>
>> The other thing that occurs to me is, and this is more likely in my
>> opinion, that you have a failing water pump that isn't efficient
>> enough to move water at low speeds but when the engine is turning
>> faster it does the job.
>>
>> One final thing that probably doesn't apply to your situation is
>> something that happened to me last summer when I had a cracked head.
>> The engine did seem to overheat at low speeds and run OK above 35.
>> Something I never figured out, I guess having to do with the dynamics
>> of the crack and the compression.
>>
>> Jim
>>
>> On Thu, Aug 14, 2008 at 8:23 AM, Tom Rowsell <86westy@geoexploits.org>
>> wrote:
>>> The fan is working fine. At first I suspected it, so I wired a switch
>>> to it to turn it on manually. Running it on high does not help because
>>> the rad is not hot anyway.
>>> Both the front and rear heaters are producing lots of heat. If I reach
>>> under the van, the 2 heater lines are scalding hot, but the 2 big rad
>>> hoses are hardly warm.
>>>
>>> Thanks
>>> Tom
>>>
>>> On 8/14/08, Ryan <easywind1975@hotmail.com> wrote:
>>>> Tom,
>>>>
>>>> Confirm your radiator fan status using Ken Wilford's write up on his web
>>>> site http://www.vanagain.com/How2fan.htm. The 86 and up should self
>>>> bleed
>>>> after a few cycles (I think). Does your heater blow heat?
>>>>
>>>> Ryan
>>>>
>>>> ----- Original Message -----
>>>> From: "Tom Rowsell" <86westy@GEOEXPLOITS.ORG>
>>>> To: <vanagon@GERRY.VANAGON.COM>
>>>> Sent: Wednesday, August 13, 2008 11:37 PM
>>>> Subject: Overheating at idle
>>>>
>>>>
>>>>> My '86 recently began overheating but only at idle...drive all day on
>>>>> the
>>>>> highway and it's fine, but stop and idle for a few minutes, and the
>>>>> temperature climbs. Rev the engine and the temp returns to normal. Even
>>>>> after a 15 minute drive: stop and idle, and it'll get hot.
>>>>> I recently had a leak, so it might be an air lock problem ? I'm thinking
>>>>> the
>>>>> water pump or the thermostat. It's not the fan since the radiator never
>>>>> seems to get hot enough to kick that on. I guess tomorrow's job is pull
>>>>> the
>>>>> thermostat and check it? There are no unusual noises from the water
>>>>> pump...
>>>>> As usual, all advice and critiques appreciated :)
>>>>>
>>>>> Thanks
>>>>> Tom
>>>>>
>>>>
>>>>
>>>
>>
>
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