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Discussion Starter · #1 ·
Extra info:

I have a single Sony Explode amp and one 15" HX2 Fosgate speaker installed. I don't usually listen to my music 'too' loud, since it seems there may be an electrical issue. Anytime I crank up music with heavy bass, the lights dim considerably. I've even had my radar detector beep at me and display "low voltage" (this, again, was only when I was playing bass loudly). Because of this, I rarely crank it too much.

Issue:

Three times now, the oil pressure light has beeped at me and started blinking. If I shut the car off and back on, it will go away.

First time it happened:

I was sitting in a parking lot on break at work, listening to some music (car is idling). A killer song comes on and I crank that ****. About a minute later the oil pressure light starts blinking and the car beeps at me.

I check the oil, level is fine, however, when I pulled out the dipstick, the plastic funnel came out about a half inch with it... I shoved it back down into the hole and replaced the dipstick. When I cranked the car back up, no oil light.

Second time it happened:

Same thing, bumping music, about 30 seconds later, oil light. I turn off the car, turn it back on, and no more oil pressure light.

Third time it happened:

This morning, I crank the car (it's about 55 degrees out), let it warm up and drop back to normal idle, and as I'm driving down the exit to my apartment complex the oil light comes on again. This is the first time it's come on when I wasn't playing music (radio was off). I shut the car off, back on, it goes away and I carry on towards work.

At the next light, idling, the oil light comes on AGAIN!! Now I start to worry and I pull over, kill the car, check the oil level, reset the stupid plastic dipstick funnel, crank the car back up and no more oil light, as usual. Slightly worried, I keep heading to work.

It hasn't happened again so far, however, that was just today.

What I've done so far:

At lunch I took the car to AutoZone for a battery/starter/alternator check. The battery checked out bad, so I will replace that as soon as I can (that may explain the dimming lights issue with heavy bass, as well as the oil light--if the low voltage situation is causing the oil pressure sensor to act up). We checked the starter and alternator next. The starter tested bad as well but the alternator was OK.

Not sure why the starter would show as bad. I've never had a problem starting the car.

So that's where I'm at with this. Anyone have any insight on what these symptoms could mean? I'll know more once I replace the battery... it's just gonna be a few days as I'm in between paydays, at the moment.

Thanks! (and sorry for the long post, I like to be thorough when it comes to this kinda stuff)
 

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For 1, you are probably over drawing the battery. The alternator cant keep up with the power draw either. That will probably fail next. Is your amp underated for the speakers you are using? Try turning the gain down on the amp. If you are underpowering your speakers and have the gain up too high you will also fry the voice coils on the woofers, and then they wont work either. You may need a more powerful alternator and battery
 

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If the battery isn't at fault for the low oil pressure light then maybe the sensor itself is beginning to fail and this is it's way of showing it. Do you have vag or anyone local to you have it? May be worth scanning it just as a reassurance.

On a side note, what guage power wire are you using?
 

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Also get yourself a capacitor for your amp power lead. Takes a lot of the strain off of the battery/alternator...
 

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Discussion Starter · #5 ·
For 1, you are probably over drawing the battery. The alternator cant keep up with the power draw either. That will probably fail next. Is your amp underated for the speakers you are using? Try turning the gain down on the amp. If you are underpowering your speakers and have the gain up too high you will also fry the voice coils on the woofers, and then they wont work either. You may need a more powerful alternator and battery
The amp is a bit underrated for the speaker, however, I have the gain on the amp turned almost all the way down. I don't always listen to loud music, which is why I still have the 'budget' amp/speaker setup, it's just to give a little more low end and fill out the sound overall.

(this amp/speaker combo came out of my last car, which I had for 4+ years... didn't cause any issues there, and that was a POS 92' tercel, lol--I cranked the **** out of it in that car--I'm using the same power/ground wires in the GTI)

If the battery isn't at fault for the low oil pressure light then maybe the sensor itself is beginning to fail and this is it's way of showing it. Do you have vag or anyone local to you have it? May be worth scanning it just as a reassurance.

On a side note, what guage power wire are you using?
I called the dealer earlier today to see what they had to say. The guy I talked to mentioned the sensor could be going out, but he was puzzled that it only started while bumping the system. He said that the low voltage could possibly be causing the sensor to foul up. Would vag-com show something about the sensor? I didn't know it was that detailed.

I had the amp kit professionally installed at CarToys, using a 4 guage I believe (I got the amp kit a long time ago and IIRC it was for a 1000watt system). I know the power/ground cables are adequate for my current amp.

Also get yourself a capacitor for your amp power lead. Takes a lot of the strain off of the battery/alternator...
You know, I considered this, however, I've also read quite a few posts where it sounds like these are not really worth it. There's some debate as to who it helps more, the manufacturers or you... About 10 years ago I had a decent system in one of my old cars where I had lights dimming on heavy bass. I added a cap and it didn't do **** for me. The lights still dimmed JUST as much.... So either it wasn't big enough or they really are a rip-off. (it was a rockford half farred)

Sigh.. well, on the way home from work (after I started the thread) the oil light came on again. I pulled over to check the oil, just in case, and the ****ing dip stick funnel shattered... There are now pieces of plastic sitting just inside the metal oil feed tube. I'm so worried that some pieces fell into the engine and I'm not quite sure what to do. I'm about to go clean up what I can and install a new funnel (have the new one already). Is there anything I should be aware of? How much of a pain in the ass is it to change the funnel? It's not in the easiest of places to really get to.

And if pieces did fall into the engine, what kind of risk does that pose and what should I do?? [help]
 

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Get the new battery and see how it goes. Just because it worked in your other car doesnt really mean anything to me.

Capacitor evens out the power and prevents surging.

If the pieces are in the motor they will melt. Its plastic and made from oil. I dont see that being a huge problem
 

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Discussion Starter · #7 ·
Yea, I understand what a capacitor does. I studied electronics a little when I was younger. Built a few simple circuits before I got bored, so I have the basics down. What size do you think would help? The .5 farred didn't do squat in my previous system. I was pushing two amps then though: 800x2 and 600x4 fosgates.

I only mentioned that the system worked fine in my other car in response to your statements about the potential for failure with the amp/speaker. I understand that it's a different car, different beast, in regards to the other possible electrical issues.

The only thing I'm worried about with the plastic in the motor is that it may clog one of the oil lines before it has a chance to melt.. plus the melted plastic in the bearings can't be a great thing. :-\

Update on this: I changed out the dipstick funnel (that was a little bit of a pain, but not too bad) and took her for a spin... no oil light yet. I suspect it may come on in the morning. I'll keep you guys updated.

Again, thanks for the suggestions and help!
 

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Small plastic pieces will melt into basically the form they started, which is petroleum based. I would just change the oil soon. If your battery wasnt holding a charge your whole system is compromised. Running amps and woofers just makes it considerably worse. As they said your sensor may be on its way out, or just the lack of power to it may cause failure as well, along with the ecu. Car cant function correctly with low power.
 

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If you are building a powerful system you need powerful components. check the battery voltage via meter or with vag-com if you have access to it, meter is easy, check while car is normally running and check with system bumping. replace oil pressure sensor, If the problem continues or you don't want to replace the sensor check the oil pressure with a mechanical gauge to determine if it is accurate. If it is low via mechanical gauge you could be causing problems, when did you change the oil last? filter? could be the pump going bad or screen partially clogged. First step is always to check the voltage.
 

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Vag com can tell you anything and everything you'd want to know about your car. If you force the light to come on, just run the scan and see what it tells you. If the sensor is on the outs it should still be able to tell you
 

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For your current setup, a 1 farad cap should do just fine. For the 2 amps you had before, a .5 was nowhere near enough.
 

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Discussion Starter · #12 · (Edited)
Awesome, great info guys! I doubt it's related, but still no oil light today after the funnel change (can't see the funnel being broken causing the oil light to come on). I will get a 2nd opinion on the battery/starter/alternator from O'reilly's today and replace the battery if it's showing bad there too. I may go with one of those badass Yellow Top deep cycle batts, they're just so damn expensive...

For a cheap vag-com solution, what do you guys recommend? At $250 on ross-tech.com, there's gotta be a cheaper alternative.
 

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A new Optima battery would have been cheaper than buying an OEM styled battery for my benz. Just keep that in mind...
 

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Discussion Starter · #14 ·
Update: While getting the second opinion on my battery, I noticed another cracked hose coming off the valve cover (looks like the PCV lower hose), so I took it up to EuropeanLegacy here in Houston and ordered a new one. The guy there seemed to think that could be related to the oil sensor issue. Once I get it replaced tomorrow, I'll keep you guys posted.

In case anyone else is interested in knowing what I'm referring to, the following DIY covers replacing both the upper Y and lower PCV hoses (it's the EuroJet brand hoses in this guide, which are better than stock, but same DIY either way):

http://forums.motivemag.com/showthread.php?3747836/page1

PS: oh, and the battery checked out bad at O'Reilly's too, so I'll be replacing that as soon as I have the funds.
 

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I would consider getting a cap if your keeping your stereo setup. Spikes of power consumption will put some wear and tear on a batter/alternator... Just a thought. Glad you got your oil issue possibly resolved. Keep us posted 8)
 
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