Man am I glad I found this forum. I just bought a 2005 V last week. I was reading about sat nav update firmware. I noticed this thread but payed little attention to it because I wasn't experiencing the sensor problem. Yesterday the oil temp alarm went off. And panic ensued. Then I remembered this thread and started watching temp go from 300 to 270 then 250 then back to 300 and realized it must be the ground issue. so this morning I cleaned up the chassis ground and installed star washer. Temps now staying under 220 and not fluctuating so bad. When I have more time I will attack the other ground wires. Thanks for saving me a bunch of stress. If I hadn't read this thread I would still be stressing out thinking I just bought a broken car.
I know this battery ground to the chasis seems simple but after having this problem for two years, nothing has been simple for me. Can someone explain hot to connect this 8" hotwire kit (Racetronix) with the battery terminal lugs that are provided? I do not see any 10mm bolts near the battery or strut tower that would be a quick connect. In addition, doesn't the battery ground go directly to the strut tower now? I have replaced the oil temp sensor, cleaned grounds on the back of both heads & main strut ground, added the star washers, added a ground wire from the black lead on the sensor pigtail to the lower part of the chasis and still have this jump in the oil temp from 220 to 300 in seconds while driving. I am at a loss and would really appreciate any help to finally resolve this issue...
I have added this ground wire from the negative battery terminal to the chassis ground, and this still does not fix the problem. It is a large battery cable. Is there any reason why a large gauge wire would be any less beneifical in solving this issue?
Where exactly is the sensor? I think I would like to try grounding it.
Sensor is on the passenger side of the oil pan. To the inside of the wheel. It has three wires.
Knowing I can't trust the sensor, I cut the wire for the temp, I think it was green and white (look back several pages). Now I get --- in my display but the oil level sensor still works. FYI same sensor for oil and temp.
OK guys, I have a question, and I'm sorry if this has been covered but bear with me. I am looking at buying a V and when I went to test drive it it was having the oil temp gauge issues. However, the coolant level was staying nice and steady and didn't show any issue. In your opinions, would I still be safe buying this car? The price is pretty damn right! Thanks
The probability that the indicated high oil temp is anything other than a gauge/grounding issue is quite small. You could, presumably, attempt cover the issue is the sales agreement.
I would think your safe. You WILL be annoyed, but safe.
Just wanted to say thanks for this thread. 1.00 worth of washers and no more oil temp warnings. My bad ground was at the passenger side fender. 5 mins and done. Thanks again
Well I added the star washer and it worked until I drove in the rain and then it started again. The next fix is
to ground the sending unit from the oil pan to a chassis ground anyone else do this yet? Where did they attach the ground?
I have to put the car up to install my new Revshift trans mount and will take car of the ground at the same time.
The two "main" grounds are:
1. Under the hood support. This one is the WORST and you have to wire brush the surface, both sides of the terminal, everything else on the bolt and use contact cleaner on the threads. Install the star washer between the bolt and cable terminal, not between the cable and surface.
2. Right above the starter motor. Engine ground
3. Behind the heads, two.
4. Driver side near radiator bottom.
5. Dash board instrumentation, buried in the dash
A couple of guys (I think it was a couple) found a bad crimp for the ground connection on the sensor plug in.