Not a bad idea... the heat shield that is. Most of my experience is with
Chevrolets, Corvettes mostly, but the same starter solenoid on the GMC.
Later model Chevs had a shield around the starter and solenoid, but I doubt
it would have prevented the problem as he described it...the shield will
delay the heat transfer, but with a sustained high load pulling a motor home
up a long grade, I suspect heat soak is inevitable. Had he continued driving
for a few miles on the level, chances are the air flow over the solenoid
would have cooled it down pretty rapidly to a level that would have
permitted a quick restart. That's why I don't see it as a particularly bad
problem, just an occasional annoyance. A real pain in the drain if you're
wanting to get back on the road though. My current daily driver is a
Chevrolet 454SS pickup; it does this once in a while on a very hot day if
I've been in slow traffic with the air on or idling with the air on for a
good while. What th heck, I need a coke break (diet in my case) too.
Travis
- -----Original Message-----
From: Heinz Wittenbecher
To: gmcmotorhome
Date: Saturday, July 10, 1999 11:08 PM
Subject: Re: GMC: No Hot Start
>I'd suggest the coke route
(the liquid kind of course)
>The other alternative is to put a heatshield around the starter. That's
what
>I did some time back. I think I got it from GM.
>
>Heinz
>
>
>> Which suggestion did you like, Gary...the relay or the coke?
>>
>> Travis
>>
>>
>> -----Original Message-----
>> From: Gary Miller
>> To: gmcmotorhome
>> Date: Saturday, July 10, 1999 10:39 PM
>> Subject: Re: GMC: No Hot Start
>>
>>
>> >Travis,
>> >Many thanks for your very reasonable analysis of my problem and I
>> particularly
>> >like your suggested solution.
>> >Gary
>> >North Bend, Oregon Coast
>> >
>> >
>> >
>> >> This is what GM refers to as "hot soak" and is not unusual under the
>> >> circumstances you described. The solenoid gets extremely hot...it is
>very
>> >> near the exhaust manifold on one side and the engine on the other
(talk
>> >> about a rock and a hard place!) and the resistance of the wire goes
way
>> up.
>> >> It doesn't generate enough magnetic force to pull the plunger in and
>> start
>> >> the engine. As soon as it cools off a bit, it works normally.
>> >>
>> >> This doesn't indicate that the engine is overheating in the usual
>sense,
>> >> just that the starter solenoid got hot. In the situation you describe,
>it
>> is
>> >> quite understandable, pulling a long hill your manifolds were probably
>> >> glowing!
>> >>
>> >> There was a campaign at one time on some of the Chevrolets, mostly big
>> >> blocks as I recall, to install a relay near the starter. It was wired
>> such
>> >> that the normal start circuit only had to pull in the relay, then the
>> >> contacts on the relay supplied battery voltage to the solenoid. This
>way
>> the
>> >> circuit path to the solenoid could be very short. In the standard
>> >> configuration, the 12 volts takes a very long path up to the
instrument
>> >> panel, through the start switch, then through the neutral safety
switch
>> and
>> >> back down through connectors to the solenoid. As far as I know this
>fixes
>> >> the problem. But I think also that the more recently manufactured GM
>> >> solenoids were constructed with more margin so that this is not the
>> problem
>> >> that it was in the 70's. If it is a regular occurrence, you may want
to
>> put
>> >> a newer solenoid on, not because yours is defective per se, but
because
>> the
>> >> newer ones are not as prone to this...I think.
>> >>
>> >> On the other hand, if it isn't happening often, I'd just ignore it. It
>> >> doesn't indicate anything defective, and is only annoying. You need to
>> slow
>> >> down and drink a coke now and then any way.
>> >>
>> >> BTW, a method I've used over the years that you may find useful for
>> >> diagnosing a "no start" problem is to turn on the dome lamp, courtesy
>> lamp,
>> >> or head lamps...any lamp that you can see from the driver's seat that
>> runs
>> >> off of the engine start battery...and watch it when you hit the
starter
>> >> switch. If it dims when you hit the switch, you don't have a problem
>with
>> >> the switch, the neutral safety switch, or the wiring to the starter.
>One
>> of
>> >> the few things you can diagnose withour leaving the seat!
>> >>
>> >> Travis
>> >>
>> >> -----Original Message-----
>> >> From: Gary Miller
>> >> To: gmcmotorhome
>> >> Date: Saturday, July 10, 1999 9:48 PM
>> >> Subject: GMC: No Hot Start
>> >>
>> >> >Tell me, Oh Wizards of GMC Lore, what is going on???
>> >> >
>> >> >I'd been running all day and just finished a climb from
>> >> >SL to 5000' in 20 miles. Engine did not overheat but
>> >> >was plenty warm. After idling for 5 minutes I shut it
>> >> >down. When I came back in about 10 minutes and hit the
>> >> >switch the starter solenoid did not even click. Hit
>> >> >the boost -- same thing. Fiddled with the ignition
>> >> >switch, still dead. Growled at the dog and blamed the
>> >> >whole thing on my wife, sat down and had a Coke while
>> >> >trying to decide what to do. Just on the outside
>> >> >chance I hit the switch again and she fired right up.
>> >> >No more problems for the rest of the trip but I did
>> >> >make where that I cooled down a long time.
>> >> >
>> >> >Now the question for you Wizards ---- Is the starter
>> >> >solenoid giving me notice that it is intending to move
>> >> >on or is this just a normal "hot engine compartment"
>> >> >syndrome? If the solnoid should be replaced should I
>> >> >also replace the starter just to be safe? 120,000K.
>> >> >
>> >> >Gary
>> >> >'77 Kingsley
>> >> >North Bend, Oregon Coast
>> >> >70 degrees, clear skies, gentle breeze.
>> >> >
>> >
>> >
>> >
>>
>>
>
wner-gmcmotorhome]On Behalf Of Dave Lowry
