Glow plugs 101 ***Ver. 2.0***

Your car should have N10591607 or N10591609. If it was updated it should call for the 09. I'd contact VW again and ask again what the part number is. The 07 and the 09 are different voltage units. The 08 is for the BRM.

Well, I said I’d let everyone know how the GP replacement went, so here goes.
I purchased the N10591608 glow plugs that the dealer recommended. More on that later.
Got home, heated up the garage, and popped the hood. Visual inspection: the glow plug harness is shot. It is cracked in several places: each of the “boots” on the glow plugs are cracked, and the insulation between #2 and #3 is also cracked. Pulling the boots off the GPs, all of them shattered in my fingers and I had to use pliers to pull the remaining plastic off of the GPs.
Using an ohm meter, checked resistance and found that #1 GP was dead. The other three all measured 0.7. Using a deep-well 10mm socket and a 6” extension, I had no problem removing the old GPs. New GPs went in fine as well, first by hand then torqued to 15Nm.
It’s late at night, all stores are closed, and I’ve got to get to work in the morning so I repaired the harness as well as possible with electrical tape (just to avoid arcing from the harness to the head). Cleared codes, the car started and ran fine, no CEL.
Two days later CEL lights up again, error code points to #3 GP. Tested resistance on all four GPs, all fine. Wrapped more electric tape around the boot area for #3, cleared codes, and started up no problem, no CEL. Yes, I’ve started looking online for a new harness.

Yea, new harness. There are some threads on building your own harness if you need to save a few bucks.

i have an ALH with 5 speed, so when i went looking for glow plugs, i got a bit confused with what was offered because of how some websites presented them. since i have a manual trans, i have the glow plug coolant heater. some vendors show notation of "for vehicles WITHOUT glow-plug coolant heating" for the fuel related glow plugs. this is silly, because the fuel related glow plugs work in engines with or without coolant heating, and the other larger glow plugs are only used in the coolant heater which is only on the manual trans cars. anyway, here's some info i discovered:

bosch part numbers...

fuel related glow plugs:
0250202002 also has a part number of 80028. has a threaded electrical connector.

0250202022 has smooth electrical connector and is 18mm taller than the other plug on the portion of the part that's outside the engine. (even the bosch website has this part description poorly worded: "Installation Restrictions: For vehicles without glow-plug coolant heating")

that's it. they have the same voltage rating and the same specs for the portion of the plug that's inside the engine.

coolant glow plugs:
0250201036 these are 12mm.

reference:
http://www.bosch.com.ar/ar/autopecas/produtos/catalogos/Catalogo Bujias Incandescencia 08.pdf

Glow plug light on for short time

2012 Golf 74,000 miles on it, wouldn't start and glow light flashed. Waited a few hours, it started with no light, but I had limp mode soon after but for only a few minutes with flashing light. Turned back home and let it sit for a day. No issue since, but decided to take it to dealer to check. They say glow plug module, throttle control module and inner cooler kit all for $1850. I can't swing that right now. Car seems fine. Can I wait? Where should I take it in Detroit metro area?

Sounds like bunch of crap to me. Did they give you any further info? Did you pull any codes yourself? Could be better to get codes before you spend any money. Check on here for related issues after getting the history codes. Make sure to get second opinion as well.

I'm not really a code getter, but I don't trust the dealership and don't know where to go. In reading about intercooler here, it may be my not being able to start was that being iced up (it was a very cold morning, but no warmer this week), and it damaged the glow plug? Is that possible?

A flashing glow plug light is actually an error NOT related to the glowplugs, for reasons known only to the VW engineers.

It's a "there's a serious problem and I need to be looked at ASAP" check light designed to get attention. Could absolutely be a control module... but also a whole bunch of things... so scanning for codes is the right step to take to narrow it down. Otherwise it's all just random internet guessing... and that can get expensive.

and Sarah, if you paid that dealer for the diagnosis, I would ask them for a print-out of the results. That should include all the codes, and anything they may have observed.
I've got this scary picture of you going to the dealer with an issue, they charge you $80 and say, yes, that will be $1850 to repair.

Hi Guys. I also posted in the Golf MK VI section but here I think is more appropriate.

I've been having cold start problems with my 2009 MK VI 2.0 TDI(CBDC), no errors when scanned. After loads of investigation I found out that regardless the outside temperature, my glow plugs are not getting any current. I've zeroed in on the G62 sensor. I made a read with VCDS with the sensor connected and it gave me a +9 degree Celsius value. Then I disconnected the sensor and was expecting to get the default value(from my understanding, with G62 disconnected ECU gets the default value which is -40 degree Celsius). But surprisingly I got the same +9 degree Celsius value.

I concluded that it might be the ECU. So I decided to replace it. Before buying a new one I tried testing with 3 ECUs from similar 2.0 TDI engines(a Passat CC, and 2 Golfs 6 2.0, identical to mine). And this came actually as a surprise: all 3 ECUs(plus mine) indicate +9 degrees with the G62 disconnected. Wasn't it supposed to -40? Has anyone come across this before because I can't quite get to the bottom of it?

SarahR said:

Where should I take it in Detroit metro area?

Click to expand...

When I lived in Ann Arbor, the only person who touch our cars was Martin Bergel. He's in Fowlerville:
http://www.martinbergelllc.com/

hmm, only getting about 4.8 v to my glow plug harness in each socket... I guess I should try the spray before replacing it.

I recall reading something about the BEW only having about 5v is normal to the Glow Plugs? Is this right can I get a confirmation?

Depends if you've had the "upgrade"... VW changed their minds a few times on the PD engines... I'd first call a dealer with your VIN to find out what they have on record...

Yuri

Hello I was wondering if someone could help me on some trouble shooting with my 01 beetle. I recently had the cel come on after putting a front driver's side wheel bearing caliper and brake hose ( about 100 Miles later) I was taking a drive and it popped on no problem at time drove home and parked for evening . was going to make a quick run to my uncle's house next day. I started it started harder than in 6 degree weather which I felt very odd ( almost hot out) cel was still on and I thought I will just see here in drive if it does ok. Killed it when letting clutch out. So have a bit of throttle to coax it into going done ok then but obviously something up. I could not turn over like 1100 rpm . and it was white smoke city. put obd reader on said the po380 code . cleared code while plugged in. Then seen it was glow plug related. I cracked the throttle hit 2200 ran like a champ thought maybe a fluke or the relay zipped over to his house home no trouble. Drove my truck a week knowing I may have to address this as soon as possible 6 days with 4 12 hour shifts would allow. So my Sunday off I went to inquire if it was doing g anything. I started let set a couple minutes to see if cel was staying off. It popped on. I shut off cleared and now it won't start. And as I cleared the code its not throwing a code either. It turns over like it will start then like a computer or something has it killed. I work souch I have little time I ordered a 180 relay going to try it before more exploring and trying to research. To me this seems very odd .has anyone else heard or had this or similar issue or can steer me in a direction. I would be so grateful. Its like I lost my best friend. Any input would be appreciated thanks so much and sorry for the rambling g and punctuation and grammar errors.

Bigo, unless you've trouble shot the issue down to the glow plugs or related, you might get lots more views (and help) by starting a thread in the Mk IV section. G/L!

Very good thread! Thanks for the help

My hack/"fix"

Son's car was triggering a GP CEL even after replacing a bad GP. We did the basic troubleshooting and determined that it was a bad connection from the harness connector to the GP. Cleaning didn't help/fix. I figured that there was just too much of a gap with the connector so I stuffed some aluminum foil on top of the GP connector and then shoved the harness down on it. It's been several weeks now and no CEL. Sometime down the road a more permanent repair will be made.

Glow plugs

Excellent info on diagnosing / replacing glow plugs. that was my problem. I have two Mercedes diesels and would never ever thought a plug reading a couple ohms of resistance would be a failed plug. Wow ! thanks so much.
Mike W.

Hi. Been reading this thread in detail and using the techniques described. I'm not sure, but it appears that my harness is broken at the "boot" for each glow plug. I'm guessing somebody (hopefully not me) tweaked it. I ohm'd my plugs and they all read about 5 ohms on my 2005 Golf TDI.
It has been throwing codes P0674, P0673 and P0101.
I've included some photos for people to check out the harness. Can anybody confirm that this harness isn't right? It really looks like the "boots" are snapped.
https://goo.gl/photos/GB6WBwL1kJcNjw6V8

Digital Corpus said:

I've always wanted to do this, but I also couldn't stand putting US threads on a metric car. However, by fluke, I was browsing through a manufacturers catalogs and noted they sold glow plugs.



Though it's off by 1 mm for the length of the tip, and the body is 10mm shorter, I confirmed that the thread placement, pitch, and body length are all proper for the B4' and ALH's. One can thread their own plugs, or buy some shorter ones with M4 threads manufactured onto them. Anyhow they belong to the 1998/1999-2000 Land Rover Freelander. For barely over a 20, I might as well order a set...

Click to expand...

I felt the same, threaded the glow plug with a M5 thread. Took a grand total of 30 minutes to thread all 4 new GPs, pull the old GPS and make my own harness. Even fixed the wonky cylinder designation for the GPs so that when the cyl 1 GP is dead it will throw the correct code.


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Do we have a diagram for the glow plug relay and how to test it outside the car?


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MIL light revealed a P0380 mechanical fault in glow plug system. My tech clear the code and recommended running the car. I did exactly that for a year. Off upon startup, and MIL after 30 seconds. I replaced the harness and plugs. Two were very black. I am confused about the way the light is off for each startup and comes on in 30 seconds. When this happens, the tone of the engine always changes.

All advise appreciated.

That's the ECU adjusting. Some of the glow plug codes need to be cleared (I've read). Some will go away after x starts with no fault.

Also, the glowplugs represent a substantial load to the engine, and they run for a short period of time AFTER the engine starts. When they finally shut off the engine will change tone slightly as the load eases up.

Just bought a 01 tdi last fall. Iddly enough, it was hard to start now that its 10 degrees outside. Discovered the glow plug relay was missing from the relay panel under the dash. Genius mechanics......

Great write up! I tested my glow plugs today and they're okay. Just need to do the other checks now!

Glow plug error code

I have a 2009 Jetta tdi sportwagen with 220,000 miles. Today it started a bit roughly but drove fine for the first few minutes. Then the flashing glow plug light came on and the car lost all pick up. Not quite limp mode, more like an old diesel without a turbo.
Turned around, went back home, read "Glow Plugs 101". I pulled the harness, checked the glow plugs with an ohm meter, each read 1.6.
Replaced the harness, car started like normal, drove it for a few miles, all seems ok.
So now what to do?

Limp mode is kinda like an old diesel with no turbo.
I'd say, you need to get it scanned and see why the glow plug light was flashing. There should be some error codes stored.

I pulled the glow plug harness today, sprayed the connectors with contact cleaner, added some dielectric grease and drove to the mechanic. About 10 miles each way, car is performing as normal.

The mechanic scanned the car and here are the codes he pulled:

01025 - EGR System Insufficient Flow P0401 - Intermittent
01674 - ECM Power Relay Load Circuit: (J271): De-Energized Too Early P068A
01378 - System Voltage Too Low P0562 - Intermittent
00665 - Boost Pressure Regulation Control Range Not Reached P0299 - Intermittent

The car needs a DPF, this I know. The housing is cracked. Mileage has been consistent and performance hasn't dropped (until yesterday when the glow plug code was thrown).

Lights were left on last week by my significant other and the battery was dead when I went out to drive to work. Got a jump from AAA an all seemed good.

So the question is: what's going on? Maybe it was a loose connection between the harness and the glow plugs?

Anyone know what these codes mean?

BTW - I love this site. I've kept my car alive by the few things I've gleaned here. 220,000 miles on a "09 VW TDI Sportwagen. Car has been very reliable.

I hope everyone has a safe and wonderful holiday

Thanks
David