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Engine Specific Info and Questions => IDI Engine => Topic started by: insdtanoodles on December 12, 2005, 10:25:08 pm
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Ok so I have a 96 jetta with a 1.9TD and on this tank I will be getting around 500 -550km, thats 10L per 100k :cry: I think I will have the engine out of the car next week and I need some things to check, I am going to try and clean out my intake but thats all I can really think of. There is alot of play in the turbo spool but I can definetly tell that there is still boost in the car but I dont know how much. I dont really have to tools the time the pump, I made a special adapter so I could use my dial indicator to time it but mine only has .085 play, the manual says I need more to time it. I have new snow tires on the car and they are bigger then stock tires, would that make it worse? The front alingment is out but I cant do anything about it untill I replace the front strut mounts. cant think of anything else but this fuel mileage is killing me, I hit 230km at half tank :cry: :cry: :cry:
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Could possibly be the way you drive it as well. The 1.9TD is a low rpm beast, meaning you should probably shift before hitting 2k rpm. My guess would be possibly injectors, and timing. Does your car burn any oil?
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Snow tires will definitely affect it. They are generally softer rubber, and bigger tires give more rolling resistance and more inertia to get turning which will hurt you. However, bigger tires also give lower rpms, which cna help you.
If you have an EGT guage, you can try advancing the timing more than factory, which is supposed to increase mileage, but it's a little risky without an EGT. I don't have one, so I haven't done that to mine yet. You can also turn down the fuel screw, but then you get less power too. Are you getting alot of black smoke? If so, that's fuel that wasn't completely burned, and your thermodynamic efficiency is dropping through the floor when it's making smoke.
Use the highest temp thermostat you can get for it. New air filter. Make sure the exhaust isn't plugged. Synthetic oil in the tranny.
That's about all I can think of.
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as a fellow 1.9 idi owner....
check the obvious too
- tire pressure (i keep mine at 38 rear, 36 front)
- fuel filter
- air filter
- driving habits
- remove roof rack, excess weight in trunk, etc.
- no air bubbles in fuel lines
injectors/timing may be a problem as well, but try the other stuff first
remember that with winter diesel, you generally get sligthly less kms too
- try using additives if you dont already.
- use quality diesel, dont always get the cheapest, no name crap
i get about 850-900 in the summer, about 50-100 less in the winter. i generally shift around 2000 rpm.
- all the other comments posted before me!
hope it helps.
rico
ps let us know what you did and if it made a difference!
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Three most important things to check when fuel economy is poor, timing, timing and timing! On a 1.9TD slightly advanced from stock is best for economy and power, 0.95-1mm.
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Well I dont think my car burns oil, its hard to tell because its also leaks oil so every now and then I have to top it up. AFAIK the car doesnt smoke all the much, I cant really see any smoke when I look at my mirrors and set on the gas pedal but when I start my car it usually leave and nice black mark on the ground so I cant tell if it is burning oil. I usually shift around 2.5k-3k maybe I should tone it down abit but I dont drive all that aggressively in the city. I do drive very short distances, shut the car off. I usually drive to school and its 5km away, then back home, then to the gym which is 3km away and back home again, on a cold morning when everyone is driving slow the engine never does reach its normal operating tempature. Tire pressure I am going to check this weekend, fuel and air filter have about 5k on them, I only have bubbles in my fuel lines when my fuel tank is getting pretty low. I use fleen flow diesel additives and I usually get the cheap stuff but today I went and filled up on good diesel so I will see how that goes. I dont have to tools to time my injection pump or advance it but I have been looking around for someone in the gta that can do it but now luck. Well I got a full tank and I will see where that gets me but this last tank I got 525 with about 2L left in the tank.
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thats pretty low kms... I get that much when I drive the living crap out of my car. :(
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my 93 td with 270,000km gets about 750 per tank in the summer, 650-700 in the winter now, i drive it pretty soft, but occasionally have some fun. mods are tdi intercooler, fueling turned up, boost at 20psi, k&n panel filter.
i dont' burn a drop of oil, i run amsoil 5-40 europeon car formula synthetic
i should be getting better milage, i'm going to have the pump timing checked soon
check in your airbox, there is some extra pipes in there for quieting the sound etc, take the pipe off the front of the air box, it restricts flow, and take the one out of the top half of the air box too.
if you have bubbles in your fuel line, replace the plastic 1 way valve on the top of the fuel filter in the engine bay, easy to change, and about a $10-$20 part, i had bubbles in mine, this fixed that.
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my coolant temp stays about 70 on my guage (canadian cluster) is this a low temp thermostat? would it REALLY make a big difference in milage? i figure the lower temp coolant is better for more power.
Use the highest temp thermostat you can get for it. .
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my coolant temp stays about 70 on my guage (canadian cluster) is this a low temp thermostat? would it REALLY make a big difference in milage? i figure the lower temp coolant is better for more power.
That's only a 160F. I thought that 180 or 190 was more common. I've seen other posts on here with more direct experience with different temp thermostats than I have. Hopefully someone will chime in.
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Hmmm. I would think warmer would be for more power too. My truck has more power when it's nice and warm, compared to when I first start it. But that's comparing a 190F engine to a 30F engine, not a 160F engine. It definitely has more power when it's really cold outside, but I figure that is due to higher charge density from cold air.
Funny thing is that when it's first started cold, it still has decent torque, but the power drops out complete at higher RPM -- like 2,000 rpm. Is this something to do with compression ignition engines? On old gas engines, I'm used to having to rev them more to keep from stalling until they warm up.
Sorry, this thread is sort of going off topic.....
i figure the lower temp coolant is better for more power.
I don't get that. Please explain. I would think the reverse. I would think that having the engine cooler would cause more heat to trasfer to the engine rather than turning the crank due to the greater temp differential. It also makes your cooling system less efficient at removing heat from the radiator. I would also think that the lower temp would cause the oil to be thicker and not burn off contaminants from the oil properly causing excess wear, yad, yada... Overheating is the worst. Overcooling is next to worst IMO.
Andrew
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as a fellow 1.9 idi owner....
check the obvious too
- tire pressure (i keep mine at 38 rear, 36 front)
- fuel filter
- air filter
- driving habits
- remove roof rack, excess weight in trunk, etc.
- no air bubbles in fuel lines
injectors/timing may be a problem as well, but try the other stuff first
remember that with winter diesel, you generally get sligthly less kms too
- try using additives if you dont already.
- use quality diesel, dont always get the cheapest, no name crap
i get about 850-900 in the summer, about 50-100 less in the winter. i generally shift around 2000 rpm.
- all the other comments posted before me!
hope it helps.
rico
ps let us know what you did and if it made a difference!
re tire pressure: 38psi? wow, that is like pretty high. I usually stop at 32, often a bit lower. You must have a real stiff ride with that sort of pressure.
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38 psi sounds about right... i put mine at 40 psi. less grip, less friction, more mpg :D
when its really cold I wont put 40 psi, since when it warms up the tires might blow etc.
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Hmmm, some good info here.
I guess I'm doing pretty good with >380,000km on the clock. Since I've only gone through a few tanks of fuel I'll get about 750/tank. That's with winter diesel, 2000-2400rpm shifts(3000 occ.) and snow tires running 35-38psi. Something I'll have to do this spring, althought it wil not affect milage, is spring/struts. :cry:
Oh, btw the coolant temp needle barely moves if it does at all. Kind of woundering if the car would benifit with a winter front cover like the dmax does.
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Hmmm, some good info here.
I guess I'm doing pretty good with >380,000km on the clock. Since I've only gone through a few tanks of fuel I'll get about 750/tank. That's with winter diesel, 2000-2400rpm shifts(3000 occ.) and snow tires running 35-38psi. Something I'll have to do this spring, althought it wil not affect milage, is spring/struts. :cry:
Oh, btw the coolant temp needle barely moves if it does at all. Kind of woundering if the car would benifit with a winter front cover like the dmax does.
hmmm i would only put a winter cover on temps around -10c the car could possibly overheat if there wasn't enough cold wind and if it was stationary. maybe your temp gauge is broken?
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Hmmm, some good info here.
I guess I'm doing pretty good with >380,000km on the clock. Since I've only gone through a few tanks of fuel I'll get about 750/tank. That's with winter diesel, 2000-2400rpm shifts(3000 occ.) and snow tires running 35-38psi. Something I'll have to do this spring, althought it wil not affect milage, is spring/struts. :cry:
Oh, btw the coolant temp needle barely moves if it does at all. Kind of woundering if the car would benifit with a winter front cover like the dmax does.
hmmm i would only put a winter cover on temps around -10c the car could possibly overheat if there wasn't enough cold wind and if it was stationary. maybe your temp gauge is broken?
Are you sure your thermostat isn't stuck open? If I see the temp guage barely moving, that's what I'd suspect. And it would get lousy mileage if that's the case.
Off topic, but is the dmax one of the new ones? I want one, but they won't sell them in the US.
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probably is the thermostat. hotter thermostat the better :)
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probably is the thermostat. hotter thermostat the better :)
In the winter perhaps, but I've blown too many head gaskets and warped two many heads from overheating, so I run a cooler t-stat and radiator thermo switch to save my head from an early death. :(
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I agree with Andrew. Any time raising the thermostat rating causes overheating it is almost certainly due to water or air flow problems through the radiator. Check water flow...pump, internal crud build-up and hose condition. Check air flow through the rad. Any blockage can tip a marginal cooling system over the edge.
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Hmmm, some good info here.
I guess I'm doing pretty good with >380,000km on the clock. Since I've only gone through a few tanks of fuel I'll get about 750/tank. That's with winter diesel, 2000-2400rpm shifts(3000 occ.) and snow tires running 35-38psi. Something I'll have to do this spring, althought it wil not affect milage, is spring/struts. :cry:
Oh, btw the coolant temp needle barely moves if it does at all. Kind of woundering if the car would benifit with a winter front cover like the dmax does.
hmmm i would only put a winter cover on temps around -10c the car could possibly overheat if there wasn't enough cold wind and if it was stationary. maybe your temp gauge is broken?
Are you sure your thermostat isn't stuck open? If I see the temp guage barely moving, that's what I'd suspect. And it would get lousy mileage if that's the case.
Off topic, but is the dmax one of the new ones? I want one, but they won't sell them in the US.
I am getting heat in the car, but it has been kind of warm as on late, 0C. Plus my mileage is good.....634.5km/44.21L which works out to 789km/55L tank. So I doubt the thermostat is stuck, must be the gauge cluster although it does move a little bit. I live in the country so I'll usually be going 80-110km/h.
zyewdall
My dmax is an 02 with only about 75000km on it, and the winter front came with the truck. A friend of mine just picked-up an 02, with 325000km on it, and he did not have a winter front. However he did get an aftermarket one for xmas.
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I've blown too many head gaskets and warped two many heads from overheating, so I run a cooler t-stat and radiator thermo switch to save my head from an early death. :(
Are you saying that you have overheated solely due to a higher temp thermostat? There weren't any other cooling system problems?
There were other problems, including a leaking water pump and radiator stop leak blocking some of the coolant passages. However I feel the cooler t-stat and fan switch will give me more time to notice the impending doom and pull over before it's too late.
I'm tempted to rig a relay that cuts off the "ignition" when the temp goes too high, but that could be dangerous (unexpected loss of power could lead to an accident). Maybe set it up to buzz a seatbelt relay.... hmmm....
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zyewdall
My dmax is an 02 with only about 75000km on it, and the winter front came with the truck. A friend of mine just picked-up an 02, with 325000km on it, and he did not have a winter front. However he did get an aftermarket one for xmas.
Ahh, from your signature, it looks like yours is the full size dmax anyway. The one I want is the '05 compact pickup with the 2.5 liter engine. They've been getting nearly 40mpg (US gallons) in some trials in thailand.