Oil pressure lamp and temperature lamp

[STB]

Hi guys!

I have the following problem with my beetle:

After some time of heavy driving (highway, stop and go in rushhour), engine should be quite warm, but suddenly the temperature lamp turns on blue, no flashing. A little bit later the oil pressure lamp starts blinking with warning noise when I stop the car or I drive with low engine speed. The oil lamp disappears when I drive with higher engine speed.

Oil pressure was checked and is ok. No error is reported in black box.

Any proposals?

Greetings
Stephan

[hestersu]

The temperature light for a cold engine is the blue light. If this same light turns red and flashes, this is probably a low coolant problem and not an oil problem. While the engine is cold, open the coolant reservoir (passenger side of the car up near the fire wall - big round thing - can't miss it). Check the level of the coolant. If you are low (there are 2 lines - one for low coolant and one to denote max fill), add distilled water if you do not have the prescribed coolant for the car readily available. Do not add just any old coolant to the car - it must be the proper coolant for a VW.

I had a similar issue on my 2001. When I first checked the coolant level, it looked correct. After a 2nd look and almost standing on my head, I realized I was, in fact, low on coolant. I added water and my problem was solved.

The other possibility is the coolant sensor has gone bad and needs to be replaced. The sensor is just inside the reservoir. This is easily replaced.

Check this out and see if this may be your problem.

[STB]

I think you misunderstood me .
The temperature light suddenly appears again with blue light, no flashing, despite of a warm engine. A few moments later, especially when I stop or drive with low engine speed, the red oil lamp appears with beep noise and only dissappears at a speed of 40 km/h or 25 mph.

I'll look for the coolant, after work.

[hestersu]

I'm not going to argue with you, but I don't believe I misunderstood you. I had the same problem with my 2001 NB - after normal driving, blue light came on, the red light came on later, flashing and I think I had some kind of alarm. I was at idle at the time. I actually turned on the heater to force air through the radiator to cool the engine down until I could pull over and check everything. The light went out after getting the car up to speed (30mph perhaps). Again, I was forcing air through the radiator which cooled the car down.

My problem was low coolant. After adding water, I never had the problem again. This same problem has shown up as a coolant sensor problem. It could be either situation.

If its something completely different, please post back here with the solution so we can all learn another possible solution to this type of problem.

Good luck.

[STB]

No need to argue .

Your actual description matches my problem.

Hopefully just adding water will fix it.

I will check it after work and will give feedback!

Thanks
Stephan

[STB]

I checked the coolant level and unfortunately it is ok.

So I will have to check the coolant sensor at my garage.

At this trip home from my office the temperature light started flashing blue instead of just staying on. The red oil light starts flashing when stopping or driving slowly, just the same as before.

Any more ideas?

Btw: I use Long Life Oil!

[kcfoxie]

If it's flashing blue it could be the coolant tempature sensor (about $6USD).

[rcy]

For the blue light when engine is hot it's most likely the ocolant temp sensor located on the coolant flange in the engine bay. This is a cheap and easy fix. DO NOT let a stealership jack you for this repair, as the part is like $6 and the labour is about 5 mins. No tools are even needed. Make sure you get a new o-ring for the sensor too.

Now, are you sure the red light you are seeing is the oil pressure light and not the blue coolant light turning red. You seem confident in your post that it is the oil pressure light - I just want to make sure as the coolant light can be either red or blue depending on what it's trying to tell you (or, more commonly, how it's malfunctioning).

If you are sure it's the oil pressure light, it might be the pressure sending switch (miraculously, this is one part that I'm not aware of there being major problems with). However, the fact that the light goes out when the revs go up might be more indicitave of a failing oil pump or some other internal problem restricting the flow of oil.

Best thing to do is have someone (you might have to bend over at the stealership for this) hook up an oil pressure gauge in place of the switch and see if your pressure at idle is within specs. If it is, the switch is bad, if it's not you have some bigger problem to deal with (like oil pump etc.)


*edit* Whoops...I see you say the pressure was checked and was OK. Is your oil level OK? Last time oil was changed? What kind of filter are you using? What grade oil are you using? Just for peace of mind, maybe change the oil using the recommended 5w40 and an OE filter. Maybe your filter is plugged or the media/center tube is collapsed or the bypass valve in the filter is defective all of which could affect your oil pressure.

[STB]

Oil was changed 6 month ago. I used the original long life oil!

I'm wondering about the relationship of the two lamps. The blue coolant light comes first and the oil pressure lamp follows at low speed or stop.

This morning I delivered the car at my garage. But no light appears
Outside temperature is a little bit lower this morning...

Hope they find an error ...

[STB]

New week - new information.

My garage cleaned some contacts because they did not really know what to do , but it did not help.

Tomorrow the temperature sensor will be changed, hope that this will work...

If this fails, I have a problem. Exchanging the black box willl cost about 500 Euro ...