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General Information => Troubleshooting => Topic started by: steve6 on January 19, 2009, 03:08:37 pm
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can someone tell me how I can test these, my car wont start in the cold anymore :X
:?
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can someone tell me how I can test these, my car wont start in the cold anymore :X
:?
sure fire way is to take them out and energize them. does it crank fast enough?
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I have been wondering about using an IR thermometer to check each individually.
If you were to keep your IR dot on the end of each plug (Or maybe on the head right where they screw in?)
would you see a temp increase at each plug
(and assume they are working, or not, based on temp rise)?
If the plugs run until the cylinder head coolant temp sensor sees a rise in temp, one would think you could see this rise on the head itself.
Thanks!
-Brad
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can someone tell me how I can test these, my car wont start in the cold anymore :X
:?
sure fire way is to take them out and energize them. does it crank fast enough?
ok, so they have to come out? no resistance test or anything that can be done?
The car starts if I put the block heater on it... its got a brand new energizer battery.... The glow light plug never turns off when turning the key on.... I assume they arnt heating up enough.
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You can check the resistance to see if they are burned out. Unfortunately, to do so you still need to take the bus bar off and that's most of the work anyhow.
Did this happen all of a sudden or gradually? If you have a multimeter, you can start by checking the bus bar to see if it's actually getting voltage. Based on your description of the light never going off, it sounds like you could have a relay problem.
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Here's an overview of one possible troubleshooting procedure fwiw, assuming all you own is a testlight or cheap multimeter:
1) start by confirming that the glow plugs are getting power. Sadly the light on the dash has nothing to do with power to the glowplugs. Multimeter or test light to the wide copper buss bar... turn the key on... you should have power for 5-20 seconds depending on engine temp.
2) if you *don't* have power, go upstream to the glowplug fuse... it's in a small plastic box on the firewall next to the brake booster. It loves to develop hairline cracks, so either test both sides with your multimeter/testlight or remove it and see if it falls apart in your hands.
3) if you still don't have power your next stop is the glowplug relay.... tall relay-looking device mounted on the fuse panel. Not easy to troubleshoot unless it looks physically damaged... swapping out with a good one is the quickest way
If in (1) you determined you are getting power to the glowplugs then they need to be tested individually. Unfortunately as they are wired in parallel the buss bar needs to be removed... not a fun job but it can be done. 8mm wrench and a magnet on a stick are your friends here. With the buss bar removed you can check for continuity at each plug individually... they usually fail open.
If you own a heavy duty current meter you can test the plugs pretty well with the buss bar on... I use a cheap NAPA meter:
(http://i197.photobucket.com/albums/aa85/vwaldon/hi_current_meter.jpg)
Will all 4 plugs in working order you should see 50-60 amps dropping to 35-40 once they warm up a bit (assuming a nice strong battery). Anything less suggests one or more plugs have gone to meet their maker. Note that I'm giving pretty wide current readings... cheap gauges are not that accurate, different plugs draw different currents, and initial battery voltage has an effect as well.
One other suggestion: they are not that expensive *and* seem to go in short succession, so I always replace all 4 at once.... such a pain to get the buss bar off I only want to do the job once any given winter. :wink:
I keep meaning to do a HOW-TO on this one... 'course I'd need to track down a stock engine since mine have been pimped and would not make for good pictures. ;-)
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I've always found the fastest way is to pull the injectors and look down the hole to see if they glow.
The plugs themselves are fiddly to get in and out (especially the one behind the fuel pump) but the injectors are just the lines, four injectors and replace the heat shields for $2. It probably helps that I've got the curved Hazmet injector line wrench from Metalnerd.
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It probably helps that I've got the curved Hazmet injector line wrench from Metalnerd.
Oh sure... thanks for reminding me... Santa did not put that beauty in my stocking this year despite the nice long letter I wrote him. :cry: :wink:
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My dad the VW mechanic was out for a visit and got to use one for about 5 minutes. He looked at me like Old Yeller when I went to put it back in the toolbox so I just handed it to him and bought another one. Just get it.
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Here's an overview of one possible troubleshooting procedure fwiw, assuming all you own is a testlight or cheap multimeter:
1) start by confirming that the glow plugs are getting power. Sadly the light on the dash has nothing to do with power to the glowplugs. Multimeter or test light to the wide copper buss bar... turn the key on... you should have power for 5-20 seconds depending on engine temp.
2) if you *don't* have power, go upstream to the glowplug fuse... it's in a small plastic box on the firewall next to the brake booster. It loves to develop hairline cracks, so either test both sides with your multimeter/testlight or remove it and see if it falls apart in your hands.
3) if you still don't have power your next stop is the glowplug relay.... tall relay-looking device mounted on the fuse panel. Not easy to troubleshoot unless it looks physically damaged... swapping out with a good one is the quickest way
If in (1) you determined you are getting power to the glowplugs then they need to be tested individually. Unfortunately as they are wired in parallel the buss bar needs to be removed... not a fun job but it can be done. 8mm wrench and a magnet on a stick are your friends here. With the buss bar removed you can check for continuity at each plug individually... they usually fail open.
If you own a heavy duty current meter you can test the plugs pretty well with the buss bar on... I use a cheap NAPA meter:
(http://i197.photobucket.com/albums/aa85/vwaldon/hi_current_meter.jpg)
Will all 4 plugs in working order you should see 50-60 amps dropping to 35-40 once they warm up a bit (assuming a nice strong battery). Anything less suggests one or more plugs have gone to meet their maker. Note that I'm giving pretty wide current readings... cheap gauges are not that accurate, different plugs draw different currents, and initial battery voltage has an effect as well.
One other suggestion: they are not that expensive *and* seem to go in short succession, so I always replace all 4 at once.... such a pain to get the buss bar off I only want to do the job once any given winter. :wink:
I keep meaning to do a HOW-TO on this one... 'course I'd need to track down a stock engine since mine have been pimped and would not make for good pictures. ;-)
I've often read that you can test them all in the car with an OHM meter. Unhook the bus-bar and check the reading on the easiest one you can get to and if it is good, hook the bar back up and take a reading of them all in series and if they are all good the number will be in the neighorhood of 4 times higher than the individual one read, or in multiples of the known good one telling you how many are bad. If any are bad then you have to test them individualy. If they are all the same brand plug and type they should all read equal or pretty close. :)
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Well, they are about an ohm each, so the 4 in parallel is 1/4 of an ohm... a sensitive ohmmeter could probably pick that up, although at that end of the scale the leads and fuse of the ohmmeter probably enter into it as well. Mine reads about 8/10 of an ohm with the leads shorted. Temperature of the plugs would also enter into it... there's a whole school of diesel tuning based on that.
Always many ways to skin the proverbial feline, heh?! :wink:
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Did this happen all of a sudden or gradually? If you have a multimeter, you can start by checking the bus bar to see if it's actually getting voltage. Based on your description of the light never going off, it sounds like you could have a relay problem.
I was always parking it in my garage with the block heater since the beginning of winter, and at work it was underground parking, one day I parked it outside and wouldn't start, I had to get it towed home, block heater on it the next day and it started. I have a feeling a couple glow plugs are working. The glowplug light.. it used to shut off after about 60 seconds, but in this extreme cold snap we've been having, I havn't seen it turn off yet..
I knew about this long ago, just addressing now... aint no worries the other jetta starts in -30c without issue. but it has a ***ty transmission :cry:
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stupid double post
and I have a brand new Energizer battery from walmart.. less than 2 months old.
I was getting lots of cranking.. lots of smoke, just no fire :lol:
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All that stuff about ohms and such is making my head hurt. I "want" that stuff, but you "need" a battery charger and a compression tester. Always know your compression values and the battery charger will test the glowplugs. They will get red hot if they are good, toss them if they don't.
With an inexpensive product warantee, Pull-a-part gives me an endless supply of glowplugs. It sounds like you need at least 2 if not 3. Goodluck-warren :mrgreen:
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All that stuff about ohms and such is making my head hurt. I "want" that stuff, but you "need" a battery charger and a compression tester. Always know your compression values and the battery charger will test the glowplugs. They will get red hot if they are good, toss them if they don't.
With an inexpensive product warantee, Pull-a-part gives me an endless supply of glowplugs. It sounds like you need at least 2 if not 3. Goodluck-warren :mrgreen:
Diesel blocks from the vw's never make it to the wreckings yards around here... engines always get pulled first. :x
Ill just order a few and change atleast the easy 3.. lol.. $20 a piece :shock:
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Easiest way I have found to test the glow plugs, is turn on the interior light, and click on the key.. if the interior light "dims", your glowplugs (or some of them at least) are working.
I had the fuse go the other day, and knew right away, cause the int light wasn't dimming.
After that, yeah, pull off the bus bar, and check them in the car (ohmmeter) . If they are bad, you gotta pull the bus bar to replace them anyway.
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All that stuff about ohms and such is making my head hurt. I "want" that stuff, but you "need" a battery charger and a compression tester. Always know your compression values and the battery charger will test the glowplugs. They will get red hot if they are good, toss them if they don't.
With an inexpensive product warantee, Pull-a-part gives me an endless supply of glowplugs. It sounds like you need at least 2 if not 3. Goodluck-warren :mrgreen:
Diesel blocks from the vw's never make it to the wreckings yards around here... engines always get pulled first. :x
Ill just order a few and change atleast the easy 3.. lol.. $20 a piece :shock:
They should make a short one for cyl. #1 :cry:
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I wish IDI GPs were as easy to take out as the TDI's.
I just tested my TDI's GPs and they were all fine. But this morning it had a rough time starting...
for the first time EVER my 1990 IDI starts twice as fast as my (parent's) 2000 TDI. Why could this be?
To not jack this thread anyone with know-how please pm me? the coldest it gets at night was -2C, -5C is the low for tonight.
(I HATE HOW EXPENSIVE GP'S ARE! :evil: )
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Hmm.... My car would not start this morning (First day below 50F in a month), which brings me back to this thread...
Since I have not been there before,
Can all 4 glow plugs be removed with the IP in place,
or must you remove the IP to get the #1 GP?
Ill try the infrared pyrometer trick and see if I can shed some light on this.
Also will be tring to pull off Vince's patented pimping of said wiring at the same time....
looking like a bit of work for me this evening..
Thanks,
BRAD
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You can remove the #1 glow plug without moving the I.P. or the injector lines. I did it by loosening the nut and then using a small magnet on the end of a screwdriver to turn the nut and eventually pull it off. Same for the glow plug itself. Reverse to install. Slow but doesn't affect your timing.
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*Edit: I did not read the above post.... sorry!*
Ahh, so only #1 is accessible without removing the pump and lines?
That sucks.
I am hoping for a problem common to all 4,
It used to take 2-3 cycles to get it started in the cold
(according to most here, that may indicate a bad plug or 2)
and this morning, I got nothing!
(started the car for like 5 or 10 minutes, in 30-45 second intervals)
Does the light still come on without GP's functioning,
or is it a smart light?
Thanks,
BRAD
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Ahh, so only #1 is accessible without removing the pump and lines?
That sucks.
Actually I think he means the opposite, as in "*even* #1 is accessible without removing the pump and lines".
Having said that, for the minute or two it takes to remove the hard lines I always pull them... there's only so much busting up my fat knuckles can take.
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Yes to Vince's reply. I was trying to address your worst case scenario. While it might not be the most efficient way to do it, when I was doing this I just didn't want to touch anything that might cause other issues (read: that I could break).
Oh, and it's not a smart light.
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a tool like this one (http://www.canadiantire.ca/browse/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524443249619&FOLDER%3C%3Efolder_id=1408474396672955&bmUID=1236039951522&deptid=1408474396672839&ctgrid=1408474396672853&subctgrid=1408474396672955) might help in those tight spots :wink:
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**I really hope I am not bugging you guys yet.... Thanks GTD!!!!
OK,
So here's what I know after a cursory glance just after work:
Glow plugs (at least #3 and 4) have power (via test light on the buss bar),
They cycle for about 15-25 seconds (50F air temp)
and then shut off.
They turn on when I turn the ignition to start,
and stay on for the duration I am cranking (thought the dash GP indicator does not come on then)
The GPs have power for about 3-5 seconds after the light goes out, and I can audibly hear the relay clicking closed.
Also, I checked the stop solenoid, and it has power with the ignition on position.
It is just a test light, so I dont know if I have 12.7v or 10.7...
I can smell fuel coming from the exhaust, approximately as much as before... you know, when the car started!
Am I thinking straight to be focusing my efforts on the Glow Plugs?
It just seems like the obvious thing, since it was cold this morning (30F)
and this is the only time the car has not started.
Previously on our 10 other nights below 40F, I usually had to start it 3-4 times before it would run.
THanks so much!
-Brad
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well, damn!
I just got the best worst news ever...
Glow Plugs are fine...
Removed all 4 (injector lines intact)
With an 8 & 12mm gear wrench, two long screwdrivers and a bit of magnet trickery.
All 4 gave me between 1.3-1.7 ohms and looked very good:
Black tips, with a bit of buildup that scrapes off with a dental pick.
However, before we took them out,
we were seeing a 20-40F rise in surface temperature in the head (right above glow plug) on cylinder #4 that diminished to a 3-5F rise by the time you got to cylinder #1 on each cycle of the plugs.
That is what made us sure that at least one (on the #1 side) glow was not working.
There was a bit of corrosion on the buss bar and nuts particularly on cylinders 1 and 2.
Could it be just resistance? The mating surfaces of buss bar and glow plug look pretty clean... the corrosion looked much worse on initial inspection, before we realized the buss bar is copper...
Now is a good time to pimp my GP wiring....
Advice appreciated!
-Brad
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Do you still have the injectors out? Really no better way to see if the plugs are working than to power them up while you can physically SEE them. They'll glow bright cherry red in a few seconds if they're any good.
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The injectors are not out, but all of the glow plugs are
and they all glow when hit with 12v.
Now I am buying new Bosch Duraterm's, and putting together the parts to pimp my wiring ala Vince! Hope to get that done tomorrow after work.
My sincere hope is that it was a glow plug / wiring issue. I keep going back to the temperature difference across the head during glow plug cycling.
Still looking for the issue, though!
thanks
-Brad
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If you have four glowing GP's, save your money on the Duratherms. If you know the timing is even close, check your compressiion, you might need that money for rings. Just my 1 cents worth-warren
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Too late, and not my style...
While I appreciate your sentiment,
I cant spend three hours removing a $10 part (of unknown age) to re-install it (cause I know it will fail within days as a matter of principle). I am also going to do Vince's wiring upgrade, while I am there.
(I am big on the "while we are here")
I have already bought the new Duraterms, relay and fused distribution block,
and if I need rings, I will get them.
I will have the new plugs installed and the wiring upgrade done tonight (hopefully) and we will see what I have got then.
I suppose the next logical step may be a compression test,
(which requires new heat shields, after removing the injectors, i think...)
though given how well it ran and started, I am hoping it is not a catastrophic mechanical failure.
I had really wanted to do other stuff before I took the motor apart,
but perhaps the Gods have other ideas for me!
More to follow!
-Brad
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OK, Now I have 4 new Duraterm's in and 90% pimped wiring.
It only took about a half hour to install the plugs (lines still on)
but that was largely magnet trickery, and gear wrenches.
I was unhappy with the fused distribution blocks available from the auto parts stores,
so I will find a nice one tomorrow,
and finish the "everything glow plug related is brand new" job.
At that point if the damn thing dont run, I am down to fuel or compression, right? Damn I hope these plugs do the trick...
-Brad
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Update:
I keep hearing "cranking speed" in the discussion of a no start.
I got a new battery and starter today, and will install tonight and we shall see what happens!
I also bought 8 new heat shields in case I do need a compression test.
($1.22 ea, 4 for now, 4 for next time!)
Wish me luck!
-Brad
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NOW,
I have effectively ruled out both the starter and battery. That should take care of the slow cranking speed theory.
The battery tested bad, and was replaced under warranty.
The starter did not engage and disengage smoothly, so it too was replaced.
After installing both, the car cranks more smoothly,
but still does not start.
Next stop:
Compression test?
(I wonder if this devolved from a troubleshooting thread to an inner monologue and nobody let me know?)
-Brad
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Are you sure you are getting fuel? Power to fuel shut-off solenoid? Can you hear it activating?
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Thanks for the reply!
I am not sure I am getting fuel,
though I can smell lots of it coming out from the exhaust during cranking.
I do have 12v at the fuel solenoid,
and can feel it clicking when activated.
I just bought a diesel compression tester, and the line wrench from VW usa.
I may wait for the wrench to show up, or I may give it a go with a 17 open end.
Any specific things to be careful of when removing injectors and lines for the first time? The Bentley really glosses over this subject.
Wont I need to reprime the lines and injectors after I re-install?
Thanks,
Brad
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I totally jascked that thread...
sorry.
I will now start a new one.
Thanks!
-Brad
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Removing injectors:
YES there are things to worry about! The problem is the injector is a steel body into an aluminum casting that is VERY thin along the front of the head.
If they've been in there for a long time they're probably somewhat stuck. Hit them with some PB Blaster or another GOOD penetrating oil ASAP and give it some soak time. The more soaks the better!
Ideally you want to remove the injectors while the engine is warm - this will be a bit of a problem given your situation so you'll have to be careful. The issue is they tend to carbon up around the threads. When the engine is warm it increases the clearances in there a tad.
You'll probably have to use a breaker bar. The key is to AVOID putting pressure on the thin part of the head casting at the front of the engine at all costs. NEVER pull the breaker bar towards you, ALWAYS push it towards the head so the lateral force is going away from the thin bit of the boss. If you search around for "cracked injector boss" you'll find more than a few tales of woe...
More than likely you'll find they don't want to just unscrew - they'll move a bit and get stuck again. Treat them like a tap - loosen a half turn, tighten a quarter turn, loosen a half turn, tighten a quarter turn, repeat. The idea is to try and avoid galling up the threads because the set that will get wrecked is the soft aluminum head, not the hard steel injector.
If one gets really stuck, tighten it back up a bit and give it a GOOD soaking with PB Blaster and then walk away for an hour or so. If you're lucky you'll come back and find it much improved. The key thing is not to get carried away and try to force them - a broken head ends up turning a simple job into something MUCH more complicated.
Once they're out you need to remove the heat shields. I've personally had quite good luck here and mine have always come out somewhat easily. The best tool I've used is a strong magnet - since the head is aluminum which isn't magnetic the heat shield is pretty easy to grab. For the ones that are a bit more stuck I use an old bicycle spoke - the head of the spoke grabs the inside of the heat shield quite well. Other people have suggested using a large wood screw or cranking the motor over and having the compression blow it out. With any luck though they're not particularly stuck.
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Wow, I've really been lucky-I'll be more carefull next time I pull injectors.
I didn't see mention of the special injector socket that makes the job much easier-Hasnet (sp?) for about $100-cheap if you appreciate the all-around beauty of these little motors. I prefer a 17mm Snap-on Flank Drive to remove the spider. Loosen #2 at the IP last-duh-and tighten the same first before attempting to attach any other unions. There seems to be a world of difference between starting compression and running compression, but knowing your compression values for each cylinder can save you a lot of the trouble I've gone through, avoiding the inevitable. It's worth it though-as much as I despise mechanicing, oil, grease, diesel and especially gasoline-I can't imagine driving any other vehicle than my caddy, until I go electric-good luck-warren :wink: