Hard Plastic fuel return hose/pipe over transmission

[AndyBees]

Thought I'd share what I recently found when doing maintenance on my Van.

The TDI engine vibes and aftermarket oil Pressure Sending Units don't do well together. After several of the Senders going bad, I decided to set-up the Sender remotely using a grease gun hose for extension purposes. So, an 18 inch hose put the Sender about center over the transmission. I supported it up high above the transmission with a metal spring, attached a Sensor Wire and a Ground Wire.

So, apparently the Ground Wire lost contact and the metal spring completed the circuit. During the winter and early spring, I did not drive the Van much at all, however, seems each time I was out and about, I smelled diesel fuel. I just assumed the odor was coming from a vent hose leak on the tank which I knew existed. But, from the accumulated road debris, it appears to have been in the making for quite some time. Maybe my fuel economy will improve ....

Anyway, below is what I found...

In the pic below, you can see a segment of the plastic return fuel pipe melted into the apparently hot spring. The ground spade can barely be seen pointing down in the area of the T near the hole where the spring is connected.

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'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003.

[Vanagon Nut]

Nice catch!

I think details like that can really apply to an engine swap. Especially a DIY type. Whats rubbing on what, how things are routed and positioned etc.

Those black hoses look and feel otherwise quite robust.

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[DanHoug]

wow. some things bother me.... sensor circuits just don't draw that much current to heat up a steel spring to the point of that degree of melting. we're talking milliamps, not amps of current to drive the meter. if the spring was indeed that hot to melt the return hose, we are talking AMPS of current.

so, just conjecturing here, something else is going on. a possible poor engine to body ground, with alternator current or maybe the brief starter current seeking additional ground paths thru any metal contact including the spring. that's my first guess.

then i'd go to transaxle heat but this is a very long shot, it just doesn't make sense with the airspace available. i'm staying with a ground issue.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[AndyBees]

DanHoug, I had the same thoughts as well, something pulling lots of current.

That sending unit works just fine. And, the gauge has never shown any sign of not working properly, that I've noticed.

Besides the ground cable on the front end of the transmission (nice and clean, no rust or corrosion), I installed another cable from the engine block to the body two or three years ago.

I'll take a look at the other end of the Ground wire to see where it is attached. I'm pretty sure I ran it all the way to the front near the gauge. The "heat up" could have been a one time thing. There could have been current accidently sent down the ground wire then if followed up the spring for a second or two. Like I said, I did not drive the Van very much at all from early winter until late Spring, and then not much. So, I'm thinking this is something recent even though it has road debris on it.
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'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003.