Golf IV / Jetta IV :: Different Boost Pressure When Idle And Driving?
May 29, 2014
I bought my GTI used and don't know what software its running but I have some questions about the boost pressure. When I'm in Idle the car will only boost to about 7-10psi when i rev the engine in neutral, But when I'm driving it will boost all the way to about 17-20psi if I really stomp it, 15psi if I'm just giving it a bit of "go". The car takes off and goes really quick, seems like it has a lot of power so I doubt there's a boost leak but I'm wondering does the car boost differently in Idle because it knows its not moving?
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I just got done with a complete engine rebuild on my 02 1.8t jetta, had everything hooked back up and went to start it for the first time and it wouldn't. I went back looking for loose connections, nothing. Worked and banged my head for a day or two, I had fuel and spark but couldn't get it to fire. Finally I "choked" the intake to see if it was getting too much air and it fired right up. I unplugged my map sensor giggles and it starts up perfectly. I then hooked everything back up and what do you know it starts up and runs fine, but if I plug the sensor back in it kills the motor after about 10 seconds of running and won't start until I unplug the map again.
Car runs and drives but wont boost over wg pressure but that's probably because sensor itself is unplugged. I just wanna know what could cause it besides the sensor itself being bad. I ordered a new one waiting for it to get here (hoping it fixes the problem).. And I'm talking map (manifold absolute pressure) not maf (mass air flow), just in case people are confused.
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I have a mk4 1.8t Gti. Recently I have been having issues with idle and boost. I read the codes and multiple random misfires in all 4 cylinders came up, idle control and the crank, knock, and o2 sensor came up. Shows that system is running to lean as well. I changed the spark plugs and wires, check the coil packs they where done about 1k miles so I expect them to be perfectly fine. When I clear the codes it idles below 9-8k rpms. I also noticed the breather hose coming out of the valve cover into the EGT has a hole melted into it, could this cause any of my issues?
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i have a 05 GTI 1.8T and recently started overheating while driving. for a few months it would overheat if i idled too long but now after driving for 5 minutes it overheats and also wont build any boost. i could hear a hissing sound after i shut the car and thats coming from the flange where the coolant temp sensor is, but is hissing where is mounts to the engine.
update- i replaced the o-ring on the flange, that got rid of the hissing. the no boost must have been due to the engine overheating, but it is still overheating i guess im gonna check the thermostat next.
update 2 - checked thermostat and it is good so I'm at a loss here.
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I have a 2003 golf gti 1.8th awp with 160k miles. I was due for a change so I grab castrol edge 0w40 the euro formula like I normally do but the stp filter was on sale with it so i used that. a week later the low oil pressure light comes on when the cars fully warmed up but only at idle I can review it above 1000 and it'll go away. I decided to change the pressure sensor sense it's cheap and easy nothing. I also went to a Bosch filter which I had before same thing light comes on only at idle.
So I decided to drop the pan and clean the pick up there was some crap in it wasn't to over clogged. I did little notice plastic piece surgery in the pan but when I first got the car the dipstick was deteriorating and I know a few little prices fell in there. Also noticing a fairly clean looking motor and oil pump so I don't think sludge is a issue. Anyway I decided to try mobile 1 0w40 euro formula and I read k&ns 3001 filter is a good oversized filter. Anyway light still comes on only at idle, what next?
Addition info the the car it's a stage 2 apr tune with euros ports pcv hoses turbo inlet pipe 42dd's catless exhaust recently had a leak in radiator so replaced that and the fuel pump went out within the last month or two
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I am having a problem with my car today. When I started it today while going home from work I noticed that it's idling a bit rough. Then i noticed that the pressure is going under -0.8 bar. Golf 4 1.8t boost going under 20 hg at idle. While driving it is normal but when i slow down it hesitates like it's gonna turn off and the pressure goes less than -1 bar .. What the problem may be ?
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I have a 2001 Golf 1.8T and while driving the oil pressure light turns on and the meter goes beyond the midpoint. I brought it in to a shop and they told me I need to change the oil pump and will cost $900. They told me it's because I don't frequently change oil and once the new oil is in, it caused the problem and only way to drive the car again is to replace the oil pump.
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I have a mk4 Jetta 1.8t. Problem started last night. After I drive for about 15-20 minutes the oil pressure warning light comes on. It doesn't feel any different and my oil is full. Could my pump be going bad? I hear a slight tick near the bottom of the engine on the passenger side. But the car idles fine and drives fine too.
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Why my 2002 Jetta 1.8t does this?
After I drive for a while I have to [slowly] open the overflow cap and relieve pressure in order to not lose coolant while the car sits. It steams for a bit when I open the cap and then the coolant rises in the reservoir then I close it.
If I don't do this then the car loses coolant but I don't see any leaks visible under the car.
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I have question about power steering pressure switch in golf 4 1.8t
Idle go high to 2000 rpm .. when i plug-off the Power Steering Pressure Switch its go fine .. i want know is this " Power Steering Pressure Switch " effect stability in high ?
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To start I drive a mliv 1.8t jetta. The car has a stage II custom tune, a turbo back exhaust straight piped, and a splitter valve. The valve cover gasket, spark plugs and coil packs, rear o2 sensor (with a 42dd spacer as well) were all changed recently to try and stop my problems from reoccurring. Also the MAF sensor was cleaned too, but was not very dirty. The problem tends to cease when I delete the codes and it has to relearn the fuel mapping. When the check engine light comes back on, the problems re occur. The code thrown is catalytic converter below threshold, but i have no cats. What happens with my car is, when the car is fully warmed, the car has a rough idle, to where it sounds like a heavy duty diesel truck when idling, the car will shake from the vibrations, when i go to start moving, the car bogs down to where it feels like it will stall, but it will buck and shoot off. Also when driving the car randomly bogs down, but then will shoot off will power! Sometimes at idle when its bad, if i tap the gas, the car will back fire very loudly.
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I drive a 2005 Jetta IV 1.8T R-line. The engine shakes/vibrates at Idle and when I drive.
Also when if I drive at high speeds when I stopped the engine just switches off when idling.
What could be the cause?
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I'm having a strange issue with my R. My idle seems to get bouncy/seek RPM after i boost and come to a stop. No codes present on VCDS
Mods are Unitronic stage 1+, VWR intake and R8 ignition coils
~54K miles and pulls hard.
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my car into VAG COM and since then it hasn't boosted past 4 lbs. it has Revo stg 2, K04, aftermarket side mount, full exhaust and a couple other bolt ons. Before the car was spiking at around 23/24 lbs. after pressure testing the system I found that the turbo inlet pipe was lose, so I tightened it. Still no change. I tried holding the battery terminals together for 10 minutes to reset the ecu and I also tried clearing the codes through a handheld code reader. No codes even come up anyways for this. The car is a 1.8T.
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So my 2001 1.8t Golf is having some issues holding boost. I have a Gonzo stage 2 tune, CTS FMIC, Forge 008 Diverter, Silicone inlet and MagnaFlow Exhaust. I've also done the whole Evap, SAI delete and installed a catch can.
Starting in 2nd or 3rd at WOT the car spikes up to 18psi and then progressively loses boost throughout the rev range. Close to redline the boost drops to 5 psi or so. It seems to be dependent on the revs. In fifth gear the car holds 18 psi much longer as the revs don't increase as fast.
There are no CELs. I've done multiple leak tests starting at the air box and plugging the pcv/catch can system as well as at the compressor side of the turbo. None of the tests revealed a leak anywhere in the intake system. However, when I stuck my ear very close to the valve cover I could hear what sounded like a very small air leak coming from inside the valve cover. I took a look at the wastegate actuator and it seemed fine, no play in the rod, no loose bolts and to move it just requires enough force to compress the spring and it returned to its original position.
My thoughts are that it could be a fueling issue or turbo in the process of dying maybe.
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Just noticed today that I have a slight drop in boost. Normal boost is 1.5 bar but today it is running slightly lower boost and does not have the same pull through all the gears.
2001 mk4 1.9 tdi golf
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I just recently notice a whistling noise when I hit boost. I'm not sure but it sounds like it is coming from my gauge. I'm not losing boost pressure. I do have a glow shift gauge. The most recent install was the TIP which I clamped on to the turbo but I'm wondering if it isn't on tight enough.
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I was riding along today everything running fine then I came to a stop sign and when I pulled off my car wouldn't run 10 psi of boost it was only running 5 psi so I when to a buddys checked everything over and all my piping looked fine so I went up the road and everything was fine so when I started going home it did the same thing pulled of shut the car off pulled off and it was fine again.
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I think my stock DV is going bad, my car makes a weird noise under boost?
1. Only happens when first starting the car after it has been sitting for an hour or a few. (not overnight)
2. Does NOT happen when first start in morning.
3. Goes away after like 5 minutes every time and the normal WHIIISHH sound comes back like it should when I step on the gas.
4. It does not make the sound at idle.
This recording I made was of my car being revved up after it sat for one hour.
[URL] ...
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Car started to do some weird stuff today. Misfiring under high load, as I get into boost.
Idle is around 1000-1100 RPMs. Cold start is fine, idle is normal in terms of going higher a bit, but then it sits at 1kish. This started last night after the car sat for a couple hours. Totally normal running and driving prior to this.
I've seen all the MKV threads about it that suggest everything from battery, to alternator, to grounds, to vacuum leaks, to intake leaks, to MAF.
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I have a 98 chevy 2500 5.7l.Im not getting oil to my heads. My oil pressure is 50 drivin 30 @ idle. so pumps workin at least half workin. do they go like that? or they work or they don't? Any trick or a test to run b4 i pull the pan.
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