You will get false knock detects and the crank sensor might lose sync at odd times. It's more likely to be noticeable with the crank sensor during fast accelerations where decoding is more critical.
The foil shield should be tied to the drain conductor (braided wire). Odd yours were not grounded, it could just have been age taking its toll. I have a few harnesses here that I can check and see if they are the same way.
My sensors are all grounded, just not shielded. I'm a mechanical guy so really I just reverse-engineered the OEM wiring, I saw that the "shield" in my car was not grounded on either side. Because the OEM "shield" wasn't actually a shield, I didn't shield my knock and crank sensors. I don't have a scan tool at all right now, can I view live data with a VAGCOM? It's an early OBD1 car without the true OBD plug.
Worst case scenario, I will build a knock sensor/crank position sensor harness. I can use one plug for all 6 wires + 2 shields through the bottom of the firewall near the shift linkage. I have the harness drawn up, I just would rather not spend the $200 if the car runs without the true shields. This is the conclusion need_a_vr6 and I came to when we talked over PM; try it as-is and build a new harness if I need to.
Yeah I remeber us talkinh about it now. One of those things where its a fine line between totally fine and potential problems, especially intermittent ones.
Remember me asking about anyone getting false knock, and experimenting with knock spacers?
Then about the car shutting off randomly at WOT for a split second.
Yeah, it was from the harness I made. Added the shielding from a stock harness, and its gone.
Also, the way I had the rear knock sensor wiring hidden, it was very close to the plugwires. After the wiring, it all but went away. New plug wires, and its now all gone.
Water/coolant expands when hot. If the system is a closed system, you will blow the weakest joint, when the pressure gets high enough, hence the need for a pressure relief (AKA: Rad cap.)
This happens all the time while driving. On a show car, trailer queen, its not that big of a deal.
But on a daily, everytime the system gets hot enough, and pressure builds, coolant has to be displaced from the system, so it leaves through the over flow spout on the radcap adapter.
If there is no overflow, it will just leave coolant all over your bay.
A GOOD overflow setup, will recirculate the coolant. It will have the coolant source connected to the bottom, so that if the cooling system is low, the rad cap is open, and there is enough coolant in the overflow to provide enough force, gravity/weight of the coolant in the overflow will push coolant back into the system, self burping it of air.
With out a overflow, you need to constantly check/worry about where your coolant level is/how much you have lost, and you have no good way to check.
Are the systems with pressure correct caps on built in end-tanks (ie, Scirocco rads) insufficient for using as an overflow/pressure release system then?
I have never seen one.
But if it is like most VW cooling systems, it isn't an overflow. Most VW's use an expansion tank from the factory. Much better setup then a overflow, but ALOT harder to hide/plumb in a shaved bay then a simple overflow.
Also, not saying you HAVE to have an overflow on a daily, but I like to do everything right the first time, and not have to mess with it later. If constantly checking/hoping/cleaning is your thing, go ahead and don't run one. On a car I put 30k on a year, and rely on to get me to work everyday, that is not possible.
And if you EVER plan on going to the track, you better have one.
You can run a 'cap only' system (like the stock early mk1) as long as it's the high point.
On a side note, i want to talk more about hiding, moving, and modifying charchol canisters. Where do most people move them to? Maybe give an option for emissions required and non emission required area. Ive always wandered about this modification.
Last edited by rollinslow95; 09-28-2011 at 11:44 PM.
There are some good examples out there of custom coolant overflow tanks though, I snapped a few pics at waterfest this year. I could post them if anyone is interested.
Also can someone show me exactly this 'shielding' you speak of? I am wondering if I have this issue as well.
Here is a picture of shielded wire. The wires carrying the signal are wrapped in a conductive sleeve, either foil as shown here or a woven braid. The shield is grounded, which reduces electrical noise and makes for a cleaner signal. Other things in the bay create "noise," like ignition coils and plug wires.
The OBD2 style are a little harder because they're above the tire, they can hit if you're really low. In some ways that helps because they're already hidden, but you have to relocate the plumbing.
You can buy shielding braid separately, this can be used if you're building a harness with your own heat shrink.
Or you can buy shielded wire, this is much easier.
These guys sell milspec stuff
I have not used either of those products specifically, but similar types. The other guys in here might be able to get you a more specific product recommendation for shielded wire.
Coby good seeing you too! Stop out sometime and check it out
im interested in redoing my whole bays wiring.
its already 90% tucked when i swapped in my 9a 16v and converted to megasquirt
id like to use one of the fancy mil-spec connectors you have afazz
where could i acquire one of those?
ive got a cool idea i would like to try
MK3 16v Club
Making power, 4 valves at a time
Buy my MK3!!
I have used braid in the past but unless you need to use it for a specific reason, the shielded, twisted pair cables are better. It can be tough to find in the right temp rating and chem resistance shielded cable. So keep an eye on that when choosing.
This threads the best. Anyone have some input on using 2.0l wiring? I have almost everything to build a 16v abf clone. It seems most people only talk about shaving the bay on a VR6. Thanks for making this thread, I plan to use it alot this winter!
On the VR6, part of the wiring harness is on the firewall at the top. It just goes across the engine bay from right to left. I am thinking of disconnecting that harness and rerouting it into the rain tray. Will I need to wrap all that wiring in additional cover because of the water that gets in the rain tray?
Engine pic that is going to get half-shaved.....
vr6 turbo, pt6262, MS standalone, water/meth, APTuning gearset, CAE shifter, recaro, bagged, ccws
Built not bought