Hi all,

 

Could someone flick me a link to help me find where the oil sensors are on the 1.9tdi? I know one is under the sump (not sure what that does; is it a level sensor?) but apparently there are 3? One is referred to as a 'brown' one, correct? Where are the other two and is there any special methods for changing them?

 

Many thanks.

Sump thing is level and temperature. 

Brown pressure switch looks to be sticking out of the oil filter housing just near the bottom of the yellow plastic bit on the dipstick tube (zoom in on the first picture here). Not sure if there's a second pressure switch, if there is it'll probably be sticking out of the engine head somewhere, with a single wire connection, and look similar to the brown one, but probably a different body colour.

The brown one looks to be in a location where you'll lose some oil if you change it without first draining the oil.

 

I can only find reference to one oil pressure switch on the ASV, rated at 0.9 bar, described as 'grey' which is confusing. (That's from an erWin doc about the ASV engine)

Parts catalogue says brown 0.55-0.85 bar (top line)

 

 

Edited 29 June, 20178 yr by Wino

As stated there is a level sensor in the sump, pressure sensor in the oil filter housing and the dip stick. Why are you asking? If you have the Orange oil light on it could be the bonnet latch switch or wiring to it. Only reason I say that, is it seamed a strange question to ask?

Hey, that's great. It seems the ASV sensor (038919081K) is indeed brown. Thanks.

1 minute ago, simspj said:

As stated there is a level sensor in the sump, pressure sensor in the oil filter housing and the dip stick. Why are you asking? If you have the Orange oil light on it could be the bonnet latch switch or wiring to it. Only reason I say that, is it seamed a strange question to ask?

Thanks for the reply.

 

OK, last night I drove home and I got the red oil light and 3 beeps. I checked the manual and online forums and I was going to change the sensor as a first step. It seems that failing that, then it could be a blocked intake or at worst a head gasket?

 

Anyway, I added a bit more oil to bring it up to the upper shaded area of the dipstick, and today, no beeps or light. I'm just in 'investigation mode' to see what my course of action could be. I'm thinking that I'll just change the sensor anyway?

I can't say that I have ever heard of an oil pressure switch failing, although possible. If you're loosing oil I would find out where the leak is first before changing sensors. 

12 minutes ago, simspj said:

I can't say that I have ever heard of an oil pressure switch failing, although possible. If you're loosing oil I would find out where the leak is first before changing sensors. 

OK, so I'm not losing oil. My oil level was set with my recent oil change to be at the lower end of the shaded area. I added about 100ml last light to bring it a bit higher. I read on other forums (that use the 1.9tdi engine) that the sensor can sometimes go and it's worth just changing it over to rule out any probability (only about £13 plus some time).

 

What are your thoughts on this? If it's not the sensor, what do you think it could be? Blockage? head gasket, or something else?

Edited 29 June, 20178 yr by Skoda_newby
clarity

Oil pressure switches do fail; the moving part of them lives in a harsh environment.

Visual inspection may be enough to point the finger, if oil is seeping out of the sensor, that would indicate that the internal diaphragm has started to leak. Check that the wire isn't damaged too.

 

Ideally check this before driving the car again.

Edited 29 June, 20178 yr by Wino

I have a 1.9 ASV and in it's 15 years has never had an oil level sensor nor a pressure switch. (Probably just jinxed myself). Mine has a service every year and is filled with 4.5 litres of oil and I never have to top it up between services. If you are regularly getting oil warning lights on it will need a more in depth diagnosis and something that cannot be done over the internet. 

Some nice info and test tips here.

Yours is the normally open type that shorts the wire to chassis when oil pressure is above threshold (i.e. OK).

Edited 29 June, 20178 yr by Wino

Thanks all. I got the warning light last night just the once. I drove home about 10 miles and got nothing more. This morning I drove 65 miles and got nothing more. Fingers crossed I'll continue to get nothing more. I just went out and looked and found the sensor on the RHS side of the vehicle (looking forward) below the oil filter housing. It didn't seem to be weeping at all. I saw that was something to look for on a video I saw last night, so thanks again.

 

I will change the sensor if it occurs again (due to such easy access), and if it occurs again after that, then I'll consult a professional.

 

But will gladly listen to any further advice.....

Hi all, and thanks again for the replies.

By means of an update, I got the warning light again last Friday morning as I set off for work (within the first 3 minutes) and then not a peep. Drove all the way to work - over 60 miles with no further issue. Then I drove home. Nothing. Weekend nothing, and until now, nothing. I did pull out the sensor over the weekend and check continuity, but it wasn't conclusive, so I have a new one on order.

My feeling is that I, with the changing of new oil and driving it on long journeys (it had very little use in the last 8 years), I have dislodged some muck which had temporarily blocked the pickup strainer, but has since cleared itself. I can't think that an oil pump would have a temporary failure and get better on it's own.

Or, maybe there was a contact issue with the sensor, and by unplugging it and re-plugging it, it has bumped off any corrosion or element to cause a brief loss of contact.

I will do some engine oil changes in quick succession and see if I can see any gunk coming out. Sort of tempted to do the diesel fuel in the oil trick, but a bit wary.

2 minutes ago, Skoda_newby said:

Hi all, and thanks again for the replies.

By means of an update, I got the warning light again last Friday morning as I set off for work (within the first 3 minutes) and then not a peep. Drove all the way to work - over 60 miles with no further issue. Then I drove home. Nothing. Weekend nothing, and until now, nothing. I did pull out the sensor over the weekend and check continuity, but it wasn't conclusive, so I have a new one on order.

My feeling is that I, with the changing of new oil and driving it on long journeys (it had very little use in the last 8 years), I have dislodged some muck which had temporarily blocked the pickup strainer, but has since cleared itself. I can't think that an oil pump would have a temporary failure and get better on it's own.

Or, maybe there was a contact issue with the sensor, and by unplugging it and re-plugging it, it has bumped off any corrosion or element to cause a brief loss of contact.

I will do some engine oil changes in quick succession and see if I can see any gunk coming out. Sort of tempted to do the diesel fuel in the oil trick, but a bit wary.

 

Has the engine ever become noticeably noisier at the times that the warning has shown/sounded?

No, not at all. The light came on, a few beeps, then nothing.

Changed the sensor yesterday for a Meyle unit. All OK so far. No lights/beeps for a week. Will do a couple of quick succession oil changes next week.

So another update and this time I feel a little sheepish. Last night I changed the oil filter, and found I'd put the old one in upside down. I'm wondering whether that may be part of the problem?

Edited 13 July, 20178 yr by Skoda_newby
clarity

Hi All, just to close this one off, had no more problems since changing the sensor (and filter). Thanks all for your inputs.