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Discussion Starter #1
I have a 1987 VW Golf, with a rebuilt engine
(I was told it's a GT with 5,000 miles on it at the time of purchase, 3 years ago.)

One of my problems for three years now is that after driving for a while (=until the engine gets hot) my oil pressure light comes on flickering and even starts buzzing. I was advised by some mechanic three years ago, that the oil in the car was probably of the wrong kind, and that I should get 20w50 type oil. Many oilchanges later the problem still persists. Could it be that I keep using the wrong kind of oil, or could it be that my oil pressure sensor is wrong? What is the correct oil grade for a VW Golf GT?

Thanks in advance, Gabor

PS. I am not good with fixing my car myself, so I will probably have to ask a mechanic to check whatever I am advised to check.
 

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To me it sounds like that the oil sending unit is bad. But not bad enough to fully fail. If I were you I would just change it or have it changed. When you first start it after a full cold soak (Overnight outside) is the light on?? After the car has been running for about 5 min does the light go out? I think the oil you use is 10w30. But if that was me i would use 20w50 in summer and 0w30 or 5w30 in the winter.

Just my .02!

[ March 11, 2003: Message edited by: A3VeeWee ]
 

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Replace the oil pressure switch and maybe the oil pump too.But change the switch first.
 

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Discussion Starter #5
When you say "oil sending unit", do you mean
"oil pump"?

When the engine is cold, the light is not on. I need to drive around for couple of minutes before the problem starts. When I drive on the highway, it may take longer, since the problem tends to go away at 3200 rpm.

I have not noticed any decline in the gas mileage of my car in the past 3 years (cca 27 miles per gallon), so I was thinking that
nothing bad may be happening, maybe it is the oil pressure sensor that is bad. But I will definitely want the "oil sending unit" checked.
 

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So I went yesterday to the nearest AutoMark (AAA recommended) center. When I was talking to the guy on the phone, he agreed that I may need a new oil sending unit and perhaps and oilpump.But once I was there his colleague said that actually they do not have means to test those units and they don't want to make unnecessary changes. They would rather put in a thicker oil. After the oil change I had to remind them that they (halfharteadly) promised to look into this oil lamp issue. They came back saying that my oil level was low, and that I may want to come back some other day for a test that would look for
oil leaks in my engine. (Should not leave the car there because yesterday they were overwhelmed with work.)
I am sort of sceptical, since whether my oil level was low now or not, I remember that for a year I kept a close I on it, I saw no problem with that and yet my oil lamp was flickering.
And for sure, the oil lamp was flickering on the way home, as before, although I don't think all the oil they put in could have evaporated before me leaving their lot.

It was only at home that I noticed on the bill that I was given a 5w30 grade Halvoline oil, which I suspect is not of the thicker kind. So I am a bit frustrated about them, and this is the AAA recommended place in the Charlotte area!

Anyway I will try to find another place where someone is willing to replace my oil sensor. And probably I need an oil change for a thicker oil don't I?
 

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I spoke with my local vw speed shop,and he told me to replace the sending unit.They will always set off the buzzer.Unless you are real low on oil.Then that could be your problem.
 

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As for the 5w30. that is thin oil. They should have put 15w40 ot higher, if they wanted to put heavier oil in it. As far as my memory serves me. All you have to do to the oil sending unit is unplug it and ground the unit. the light should stay lit or flash. Thats how i do it all the time at work. Maybe it is differant on VW but i doubt it. Hope this helps. Also if i were you i would just change the sending unit. Its only about 5 bucks.

My .02
 

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yeah i would say your best bet is to start out withe teh pressure sensor. and chekc your oil.i bet you have, but i gotta say that cuz my car is in teh shop right nwo cuz i didnt.
 

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Discussion Starter #12
It seems that only the VW dealer has oil pressure switches in this town. I got for myself an appointment for this coming Thursday.

When I talked to the dealer's parts department they asked me WHICH oil sending unit do I want to replace. Apparently there are two of them on this model. (87 VW Golf.)

Could you give me any advice on this (before Thursday)?

Thanks in advance, Gabor
 

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Discussion Starter #14
Actually this may help a lot. I have noticed a long time ago that I can make the buzz go away by shifting to lower gear --and thus increasing the rpm over 3000. As my engine
gets warmer, the threshold may climb up a bit, but my oil light would never buzz above 3,300 rpm.

Could this mean that it would be my low rpm pressure sensor is the culprit?

Gabor
 

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Discussion Starter #16
I was at the dealer's place today. They replace the low pressure oil switch, and the problem seems to be gone! I wish to thank everyone for the great advice.

Best regards, Gabor
 

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Discussion Starter #17
Actually, it seems that the problem is not completely gone (although the situation got much better).

After a really long ride on the highway (water temp goes up to 3/4 on the scale), when I leave and slow down, the oil lamp does come on again. But it seems to have a tendency to "heal itself": without me doing anything (like pushing the gas to increase the rpm), the filckering would go off (then come on again).

So it seems that replacing the "low pressure oil switch" resulted in a behavior that "tries to fix itself". (This was not like this before). But the oil lamp still does come on when the engine gets really warmed up.

I got also an oil change today (the dealer gave me 20w50 Castrol oil) so it can not be an oil grade issue (nor an oil loss, since I could not see any oil leak, and the oil change just happened today).

So I am a bit puzzled but hopeful.

Should I wait a bit or get also the other switch replaced. (The dealer said they did not replace it, because they tested my car after replacing the first switch and found it in order.)

Best regards, Gabor
 

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Discussion Starter #19
To tell the truth, the phenomenon became a little harder for me to understand.

It seems that (as before) the problem starts once my cooling water temperature indicator reaches about 3/4 of the scale (this seems to be the highest point that my thermosthat would normally allow). If I am driving on the highway at this moment (60 mph, over 3000 rpm) then the flickering/buzzing will not start until I leave the highway (and let the rpm "fall").

Before replacing the low pressure oil switch
there was only one way to make the problem go away: I had to switch to lower gear, and
make sure that the engine is turning at at least 3000 rpm. (3200 once I have been driving for a really long time never more.)

Ever since I got the low pressure oil switch
replaced there is also another way to "help". If I take my foot off the pedal, and let the rpm fall to 1000, in most cases the buzzing would stop, in some cases even the flickering would go away. As before I am able to make the problem go away also by giving more gas, and it seems that now the highest trehshold of 3200 rpm went down
to 2900 rpm. So there is definitely a positive change, although it would take a 10 page study to explore all the subtle differences. ;-)

As before, if I give a big kick to the gas pedal while waiting for grean light, the buzzing would stop (flickering might stay), and the buzzing would not restart until I
restart going. So it seems that what my engine "hates" most is turning anywhere between 1100 and 2900 rpm, while pulling weight. Before I defiitely got a buzzing in this situation, now changing the rpm in either direction seems to help a bit.
(Even changing my speed by giving less gas
seems to trigger momentary "self-healing" since the switch got replaced.)

By the way I spent Saturday afternoon
in front of a friend's garage, who made some unrelated repairs (fixed my door handle).
The car was standing on a very clean spot, and after I left, there was no drip of oil visible, so I do not believe that I would have any oil leak problems. (Neither did my friend, who seems to know much more about cars than I do.)

I guess this car just has a soul.

Best regards, Gabor
 

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As for the coolant gauge issue, Maybe your Coolant temp sensor is bad also??

All the flickering of the light and the on and off buzzing sounds like you might have a wire rubbing ( Grounding out) somewhere? in the oil wireinr circuit..

Just a thought. might want to check wires also

I feel you pain. Try figuring this stuff out all day long, six days a week.

I want to kill myself.
 
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