BHW glow plugs with mk4 harness?

[tims944]

So im wondering if anyone can explain or help with what im experiencing...

I put new glow plugs in and swapped from the individual connectors to a newer solid 1 piece brm/mk4 style glow plug harness. wired it all properly

about 6 months in i got a glow plug #2 fault, they all test good. even read proper voltage at the connector, my motor is in a porsche so i have tons of space for the harness. Is there a reason no one uses these it seemed the much cleaner approach?

like do i maybe need to cut the tubes a bit shorter because they arent seating properly?

anyone experienced this? i think i have spare individual connectors so worst case i can try swapping back,might remove 1 and make sure it seats fully?

starting to get annoyed with the emissions message and check engine every few starts.

cheers.

this is for a 2.0l PD bhw motor.

 

[oilhammer]

No idea why VAG chose to have the glow plug connectors arranged like that on the BHW from the factory, other than it looks like it would get in the way of the fuel filter/bracket.... but then, they could have just as easily designed that bracket a little differently.

The placement of the glow plugs in relation to one another, and the angle, is the same on the BHW as it is on the BEW or BRM, so it would stand to reason your "bridge" would work. But they can and do fail.

 

[tims944]

it tests perfect though which is what i find odd, ive removed it a few times and checked the others like i pulled it on the weekend, put back than got a code for #3, #4. pushed it back havent scanned again since... wondering if its actually just a poor contact i did a good job sealing soldering etc when id did it though so its kind of annoying...

 

[oilhammer]

Tough to test unless you are able to pull the same current through it as the glow plug. A simple Ohm test won't work. Clearly the Glow Control Module is seeing something to set the DTC.

Also, soldering is not the "approved" method (according to Volkswagen).

 

[tims944]

i mean i wasnt measuring amperage going through but i was reading voltage out of them when triggered, also played with connector scanned it for fun on my run home after work now only #1 and #4 are saying it.. im convinced its like there not seated on glow plugs properly and its setting because high resistence ? ill have to pull them and play with depths maybe need to shorten the mk4 style plugs a bit.. well see !

managed to get my highway temps down was close to 100 C before. was averaging 95.. 96... might try a lower temp rad fan switch, the bigger alu rad is helping though!

 

[oilhammer]

I have no idea what you mean by "mk4 style plugs". The BEW and the BHW left the factory with the same Bosch 7v ceramic plugs, which were then switched to a Bosch 5v steel plug and a software change that wasn't very good, then were changed to an NGK 7v plug and yet another software change. All the same glow plug fiasco is the exact same for the BEW and BHW (and BKW, for that matter.... but that is the early V10).

So if you are using the glow plug bridge from a BEW car, it will clip on to whatever plugs you are using in the BHW, because they are the same plugs.

100C is not overheating. You know you can actually have coolant temps TOO cold, right? Ideally you want it pretty warm. The engine is most efficient then, and assuming you are not running an EGR, that will help better in cold temps.

 

[tims944]

hey sorry maybe wording that wrong, im not using the individual connectors but the bew/brm bridge style 1 piece, but it seems when i move it it clips differently or makes and unmakes contact ill have to pull it, and well thats my engine temp, id have to check fuel temps, i did have a problem at one point with fuel boiling. so i moved the filter off the motor and into an air flow path havent had problem with it since, and i know 100 isnt terrible but keeping intake air temps down and coolant at a moderate level is smart.

 

[oilhammer]

No your wording is correct, I totally understand what you did, and your logic is sound... using the bridge style connector vs. the individual leads the BHW used, I get it. But that has nothing to do with the connection to the plugs themselves. I think, if your plugs are all good, then you have a bad bridge, or a bad connection where you spliced it into the harness.

 

[tims944]

mhm.. ill see if i have another bridge dont really want to tear into the harnes again, it seems like maybe thats the case i just find it so odd that id changes from plug # so easily it used to never pop a CEL. than it was only #2. for the whole winter of moving it in and out of the shop, than this spring 1,2,4. removed it all checked tried to tighten connection now it seems to be popping #1 & #4 only... odd and annoying, it was nice having a clean cluster !

 

[PickleRick]

Im running the "bridge" style glow plug wires supplied by faast forward automotive on the bhw in my 4 runner.

As im sure you've noticed the bridge can be a little hard to seat fully but I did no mods on mine to get it functional other than crimp and heat shrink the new bridge wires in place of my original individual connectors that were falling apart.

 

[tims944]

I will have to try spending extra effort making sure they seat better maybe...
Or trying to tighten the terminals..

Glad to hear from someone who has it working as intended though.

Appreciate the response.

 

[PickleRick]

No problem. Took me a few tries to get mine on right. As I was routing the new coolant hoses I knocked it loose a few times that triggered a cel. You can feel them almost pop when they lock into place, almost like a spark plug boot. Once in place they don't come off super by barely hitting the bridge. I will be ordering another for my bhw Passat, it is also falling apart and will throw a cel every couple weeks. May stay on a day or a week but then goes away. The warning beep is the most annoying part

 

[jac harnett]

Wow what a lot of info here. This may be a foolish question. I have the emission and cel light on. Scan tells me #1 glow plug issue. some where saw someone said number one is at the fire wall? thats not correct is it?
Thanks, Jac

 

[PickleRick]

I can't remember the order of the plugs but VW didn't put them where common sense says they belong. @oilhammer can tell you their order off of the top of his head.

 

[Lotawood]

I had a glow plug fail this winter. It was listed as number 1 glow plug fault with VCDS.
It was in the back nearest the firewall.