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General Information => Troubleshooting => Topic started by: rubberducky on February 21, 2006, 04:37:25 am
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hi everyone,
i've recently gotten the Jetta (1.6 n/a) back on the road, for no particular reason, just felt like driving it. this has been a problem before, but its now starting to bug me.
i'll start her up, and let her idle, so i can get some warmth reading on the temp guage on the dash, and i go, but within 5 minutes of me going the temp just drops to nil. i guess i'm wondering if there's an correlation between engine operating temp and fuel consumption. anyhow, my question is that is this due to a bad thermo, that's stuck wide open? i know the guage is working properly (as far as i can tell - when i ground one of the wires, it goes 'hot'; take the sensor out and dip it in boiling water, the needle moves), and even after a 2 hour drive, i open the hood and i can put my hand on the valve cover and its not that hot... because of the cold we're having here, it may take a while for me to actually get to replacing the thermo - i just wanted to get an second opinion to see if my keeping her running as is would negatively affect anything other than the fuel consumption.
Many thanks in advance, please excuse my babbling
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sounds a lot like a stuck thermostat. Regarding whether it's good to run the engine like that, not really. It's harder on an engine to run cold than to run at the normal operating temp. The thermostat is located in the water pump, take off the spigot that goes to the bottom of the radiator and you will find it in there. Replace the O-ring, pointy side of thermostat goes inwards.
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chrissev,
thanks, that's kinda what i thought. i guess i'll try to con my way into a garage to do the work. it sure beats working outside in below freezing temps.
Cheers.
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Im having a similar problem to that. Except mine is the inverse of yours. I have a bad radiator and a good thermostat. You have a good radiator and a bad thermostat. A simple solution would be to trade radiators. With my "bad" radiator you could get your engine temp up right away...
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Hi guys,
as an update, it was a crappy thermostat. man, what a pain it was to get it out. by the way, that plastic undercarriage cover thing, is that necessary? its falling apart, and the insulation's sucked up so much coolant and oil over the years, its real heavy and tearing itself apart. i decided to not wait for warm weather or a garage i can con my way into... which is probably a good thing, since i've got a lot of distance to cover this week.
bryanbryan89x, how do you mean a bad radiator? how's it bad? not that i can help, but just curious.
i've managed to not break the two bolts that hold the thermostat housing... go me! if anyone's interested, i'll try to see if this warmed engine affects the mileage at all.
one more thing (i know, i babble) i've noticed, in the few hours that i was working on the car, i unplugged it. the temps were around freezing, and by the time i was done, it didn't want to start at all. is the culprit the 15w-40 Rotella? as i crank it, i see a lot of white smoke, can anyone enlighten me as to what that means? as long as its plugged in, it'll start into the single digits, so i'm assuming its the oil...
anyhow, i'm tired. almost 4 hrs to install a $10 part. not to mention 2 trips to the store. man, i suck at wrenching.
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one more thing (i know, i babble) i've noticed, in the few hours that i was working on the car, i unplugged it. the temps were around freezing, and by the time i was done, it didn't want to start at all. is the culprit the 15w-40 Rotella? as i crank it, i see a lot of white smoke, can anyone enlighten me as to what that means? as long as its plugged in, it'll start into the single digits, so i'm assuming its the oil...
15w-40 is too thick to be used for winter oil. I have 5w-40 in my car right now and it is all right, but still a bit thick when temps dip below -15, but fortunately that is not too often. 15w-40 is like tar when it gets below 0 outside. It is a thick, hot weather oil, to be used in the summer. I worry about your bearings at start up. Some people who live in northern areas where temps are routinely below -20 use 0w-30 or 0w-40 and have great things to say about it. Synthetic is always better than dino oil because it doesn't change viscosity as severely as dino oil does when the temperature changes.
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chrissev,
thanks for the info; as i've suspected. i've got some time to kill this am, before heading down into the big city; so i think i'll get the oil changed to 0w-something, preferably something synthetic. hopefully, eliminating that factor should ease my concerns about the starting cranks and the battery longevity. that would have been the next to go, although i wouldn't want to spend the money, i would have gone for something like a optima red top... i guess its better than getting stuck at somewhere without a plug.
and one more thing... i take it the temps in your post were in *c?
Danke.
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I'd check the glowplugs too... If they're weak, or not all of them are working, it'll cause hard starting. Sometimes if I leave my truck plugged in overnight and it's above 20F, the glow plugs cycle for maybe a second -- so if you've been leaving it plugged in, it's possible that you've not noticed lack of glowplugs. If it's turning over fast enough, and has good glowplugs, it should start even with tar-like oil. Won't be good for the bearings, but if the battery can sustain cranking speed, it should start. I use a 1000CCA battery for a V8 truck engine. $64 at Costco.
I've got 5W40 in mine this winter (since I'm running biodiesel, the fuel gells up below about 20F anyway...).
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chrissev,
thanks for the info; as i've suspected. i've got some time to kill this am, before heading down into the big city; so i think i'll get the oil changed to 0w-something, preferably something synthetic. hopefully, eliminating that factor should ease my concerns about the starting cranks and the battery longevity. that would have been the next to go, although i wouldn't want to spend the money, i would have gone for something like a optima red top... i guess its better than getting stuck at somewhere without a plug.
and one more thing... i take it the temps in your post were in *c?
Danke.
yeah temps were in celcius. The poster who recommended checking glow plugs has a good point. Definately the car won't start at all when it is cold outside if the glow plugs are in poor condition or not working.
bis spaeter
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Thanks fellas for the input.
i've changed the oil this morning, to 0w-40, synthetic. it wasn't exactly cheap, but i figure it'll be worth it if i can avoid having the car not start while i'm away from a plug. as a matter of fact, i'm experimenting tonight by not plugging it in, although i did put a piece of cardboard and a bath towel rag on the engine, under the hood (although its probably meaningless).
the temps are good (i think), the guage reads right about center, and the fan's been kicking on - since the temps never got that high, i've been wondering if that actually worked.
hopefully, without making an ass out of myself, i'm going to assume that if the car starts up without problems, the glow plugs are good, since everything else should be tip-top. i'm feeling a bit better about the battery since it was able to start the car the other day without any assistance, and i've just driven 2 hours straight, so hopefully its charged. although i've got some doubt, since i saw the battery led glow dimly every now and then. i guess i should probably check the brushes or something...
anyhow, thanks everyone for the help; i'm sure it won't end here.
Cheers.
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The thermostat is located in the water pump, take off the spigot that goes to the bottom of the radiator and you will find it in there. Replace the O-ring, pointy side of thermostat goes inwards.
I have to change my thermostat as it is stuck open. I have a 1.6 N/A in a 91 golf and now I'm wondering where the thermostat is. I thought it was at the head where the top pipes connects to the top of the rad. Please someone advise.
Also does a new thermostat come w/new o ring or is this a dealer item. Will I need to use RVT?
Thanks in advance.
Out.
Greg
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BTW I am searching for a bentley :)
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It's at the bottom,in the water pump housing.Remove the two bolts on the lower rad hose inlet,and it's right there.If you don't have power steering,it's easy.If you do,then you need to remove the pump and bracket.
Beware of air locks in the rad when refilling.I usually pop the upper rad hose off and refill the rad there,letting it burp till it's full.Then reconnect and fill the reservoir.
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just to add, i got my thermo from NAPA, it came with a o-ring. and i used some RTV, just for good measure.
looks like i've got back glow plugs, wouldn't start at all this AM, took me forever to get it goin. i guess i'm going to have to come up with plugs today... and a new battery next.
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Thanks for the quick replies. I'll get to it this weekend.
Out.
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yet another update...
i went out and got 4 plugs... got to the first two, ones that aren't obstructed by the fuel injector pump. one was swollen at the tip, and the other wasn't. i'm sure that swollen one certainly didn't help; but i'm assuming that they all should be covered in soot, to a certain degree.
now comes the obvious question:
i've never had to take off the injector pump. i'm about to go spend some quality time with the Bently, but i know he's not all that descriptive at times, so if anyone has any input, i'd really appreciate it.
i get the impression that i don't have to replace all plugs at the same time, but i'd still like to get at them, since i don't know what kind of condition they are in. any and all advise are appreciated. wow, that sentence had the letter 'a' in all of its words....
Thanks
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You might want to take a look at:
http://www.4crawler.com/Diesel/CheapTricks/GlowPlugs.shtml
Gives lots of good info about the glow plug system.
And I would do this:
Or, replace the bus bar with individual 12ga. wires from each glow plug to a common connection with the power feed from the fusilble link. This way, you can isolate each plug for testing easily, without the hassle of removing and installing the tiny nut that attaches the bus bar to the glow plug, which is the trickiest part of the whole process.
I did this to my Vanagon, and it makes checking for bad glow plugs
much easier.
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No need to pull the injection pump.Pulling the injector lines helps,but is also unneccesary if you have patience.Use a magnet and a long flat screwdriver to help get the plugs started in the holes,and putting the little nuts back on.
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hi guys,
me again. thanks for the tips. it turns out the fusible link was dead. many thanks to hoyt for the info there. saved me hours and $$$ for needlessly replacing things i otherwise need not have.
thanks wyldman for the info. i wasn't entirely sure if the plugs would come out / go in with that little space. i'll make sure i have ample patience before i get at the last two glow plugs.
many thanks all.
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I'm thinking this is a fluke, but i've driven about 360-some-odd-miles since i've replaced the thermo; just filled the tank this morning, and i'm at about 46mpg. the tank before, i think i was somewhere around 35mpg... and i've done more than my usual amount of city (Boston) driving, as well as leaving the car idling for quite some time.
my understanding is that in colder temps the fuel efficiency does down somewhat. does that mean i can expect the mpg's to go up with warming temps? that'll be sweet.
at least for the time being, i think all's well with the car. let it sit out for at least 2 hrs in the cold (below freezing), and with the new fusible link, she started right up. i'm still a bit worried, but i guess i'll find out today. took a look at the battery, it's something like 575CCA. geez. i think that's the next thing i'm going to replace.
Thanks again everyone.
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46mpg is closer to what I'd expect for that car and engine...
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yay!
its about -10*c out and she started, no problems! just some rough idling. on a related note, the 15w-40 i drained and left out isn't all that tar-ish. it still slopped in the container when i shook it.
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yay!
its about -10*c out and she started, no problems! just some rough idling. on a related note, the 15w-40 i drained and left out isn't all that tar-ish. it still slopped in the container when i shook it.
try pouring it. you'll see it's pretty thick. The oil needs to be fairly free flowing for easy starts when it's cold, because the battery is cold so it has less amps then when it is warm and it therefore cranks the engine slower.