Hot Start Problem - What exactly is it?

[randywebb]

What exactly happens to cause a hot start "no crank" problem?

Does some metal part in the solenoid or starter swell?


(There is no entry in the FAQ for this and the search engine is not able to pull it up either). My hope is to get some answers that a mod can add to the FAQ.
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1986 2.1L Westy 2wd Auto Trans.

[scottychop]

No idea, but I would guess the solenoid. My hot start problem was actually NOT the starter or battery cable but the ground straps. I replaced battery ground, trans ground, and engine ground and suddenly I had NO more hot start problems...

[MarkWard]

On our race cars, it is very important if you go off track or spin to not stall the engine. The starter is heat soaked as well as the engine. Add the high compression and the engine has swelled with heat and you have a no crank hot situation.

I wonder if you put a ziplock bag of ice on the starter solenoid if yours would start after it cooled some. Lots of heat back there with no way to just get out of there.

[randywebb]

ice is an interesting idea tho I'm not sure how I could accomplish getting it in there

whatever is causing this, it does not happen with a cold engine (at least has never happened with at least 30 starts)

if I stop for gas or some other stop of about 5 minutes in duration, it does not happen (about 12 trials; and I cannot recall it ever happening)

but at least 3 times, if I run the Van for a while (hot engine) and then stop for 20 minutes or longer - it will nto crank (no clicks from solenoid; LEDs light up fine; fuel pump runs[it is new BTW])

then after 2 hours or the next day, it will start and run fine

one time, I decided to measure voltage while trying to start it:
there was a voltage drop while the key was turned to Start (from ~ 12.5V down to ~ 11.5 V; measured at the cig. lighter outlet on the dash)

---> the above symptoms make me think that the heat causes some metal piece to expand and then that locks up the starter - but if so, why does the solenoid not click??
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1986 2.1L Westy 2wd Auto Trans.

[wareiter]

What happens if you use a remote starter switch? Might help isolate the problem. The remote starter that clips to the solenoid for working on the car solo. I had an intermittent no crank and wired a lawn tractor ignition switch to the solenoid and ran it up into the cabin through the battery vent. Still used keyed ignition to "run" but used tractor switch to engage starter when key would not crank.
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1985 weekender
1989 560 SL
1995 RR Classic
http://waterboxer.blogspot.com

[MarkWard]

Like this.

[Vango Conversions]

It's usually the voltage drop increases as the wiring heats up. That's why installing a relay helps.

[BC Westie]

Vango is right. The resistance builds up in the wires when it is hot out. In my case it happened for 2 years, hot sunny days and usually when trying to get on or off a ferry boat. Sucked. The PO had installed a door bell start button. As soon as I removed this, put a new ignition switch it fixed it. The door bell dropped the voltage to much on hot days. I also have the bypass relay which I will install eventually. But restoring my ignition circuit back to stock and making sure the wires were all good fixed it. Next the relay that is in the Samba classifieds.
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1980 Vanagon Cali Import 86,000Miles
1981 Vanagon (Auto) 219,000kms
1981 Westfalia (Auto) Cali Import 169,000Miles
1981 Westfalia 300,000kms
1982 Westfalia Cali Import 193,000Miles
1982 Westfalia (Auto) 205,000Kms
1984 Vanagon 306,000kms
1987 Vanagon GL 300,000Kms

[randywebb]

Yes, resistivity does increase with heat. For Cu wires, resistance per unit length will go up about 30% from 20 oC to 100 oC (boiling water). That is not a lot, but might push a marginal system "over the edge."

But... then the starter should crank slowly, shouldn't it? Mine doesn't and in fact, the solenoid does NOT CLICK

Also, why does the problem NOT occur when I stop for 5 minutes?

I hear people here use terms like "heat soak" of the solenoid or something but I've never been able to get a satisfactory mechanistic explanation of exactly what component (wiring in solenoid?? it is a big relay after all) is getting soaked with heat and what that does to it...
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1986 2.1L Westy 2wd Auto Trans.

[BC Westie]

Mine was all or nothing. No slow crank. New starter as well.
_________________
1980 Vanagon Cali Import 86,000Miles
1981 Vanagon (Auto) 219,000kms
1981 Westfalia (Auto) Cali Import 169,000Miles
1981 Westfalia 300,000kms
1982 Westfalia Cali Import 193,000Miles
1982 Westfalia (Auto) 205,000Kms
1984 Vanagon 306,000kms
1987 Vanagon GL 300,000Kms

[kamzcab86]

[randywebb]

can you change the titles when you add a thread? Temp II sensor could be added to a couple of those

BTW - my own Temp II sensor is new...
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1986 2.1L Westy 2wd Auto Trans.

[Gruppe B]

Hi Randy,
What is the age and condition of the wiring going to the starter?

My old Porsche 924 (don't laugh ) had a seriously corroded positive supply cable that caused the exact same condition. I had thought that it was a starter problem but a friend recommended replacing the ground and positive supply lead with new and the problem completely went away.

Just check the resistance in the cable and if high, replace

[randywebb]

looks fine from what I can see w/o a lift or disassembly

always been an Oregon Van; 195k miles; and I have never found any electrical corrosion on it
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1986 2.1L Westy 2wd Auto Trans.

[Tobias Duncan]

I had the EXACT same symptoms as the OP.
Long road trip and after five hours of driving if I stopped the engine I would get no crank or even click. Blazers recommended new battery and starter.
Turns out it was a loose ground strap between the chassis and the transmission.

Ground issues will give you some odd symptoms and this is often one of them.

[purplepeopleeater]

Sounds like crappy Duralast/Autolite starter problems I have had.


went with a good used starter I knew was a bosch original and problem went away, hmmm

[AdrianC]

I've had an old starter on one car which - when hot - would just refuse to crank. Basically behaved as if the battery was totally flat. There were three ways to get it to go again - wait half an hour, get a jump start, or pour a bottle of cold water over the starter motor. All three were foolproof. Replacing the starter resolved it.

On the van, currently, we occasionally get something a bit similar - if it's hot, then the starter can very slowly churn over once, pause, then spin over OK but a little slowly. I _think_ it's the bush. I've got a replacement ready to go in, just got to get round to it.
_________________
Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
www.WhereverTheRoadGoes.com

[Buick Truck guy]

I also have a hot start problem on my '84 Westfalia with about 90K miles. It is a summer vehicle so it is not all rusted up and we have had it for about 25 years.

This is what happens. When I go out to start the van cold it starts and runs great.

If I drive it for maybe 1/2 hour or more, stop it and then try to start it again in less than 1/2 hour +-, it will slowly turn over a little bit or click like it has a bad battery but will not turn over fast enough to start. Let it get stone cold and it starts with no problems.

I have replaced the battery.

I have replaced the starter.

I have removed the battery and cleaned the ground wire to the body and so it would make a good connection including cleaning the body surface where the cable attaches to the body.

I have replaced the ground wire from the body to the transmission on the drivers side of the vehicle and cleaned the contact points for the cable on the body stud and the transmission. (it is a 4 speed manual)

I can bump start the van to get it going with no problem.

I still have the problem.

Can someone please give me an idea of what to do next?

I would appreciate any help that you can provide.

Thanks

Larry

[tjet]

[mightyart]

This is an aircooled trick that might work on older waterboxers to.
Hot start relay, how it works:
http://www.wolfsburgwest.com/wired/wired_03_01/wired_03_01.htm
Order one here:
http://www.busdepot.com/wr1