Oil level low, followed by low oil pressure

T6NOMAD

T6NOMAD

@RobNomad
VIP Member
T6 Guru
Hi guys,

My van, a 2019 T6 CXFA engine, has been having an interesting phase of issues lately. Let me post them, hopefully they are all related to the oil pressure sensor.

1st problem: When its cold, sometimes it doesnt start on first key trurn. Its as if the starter turns, then immediately cut. I turn off the key, turn it, wait and then full turn and she fires up. I thought its the glow plugs that are aging so when the car went in for its recent service i asked the mechanic to change them. He didnt seem too excited to change them, saying that they are prone to breaking and it becomes a tricky job to remove them. I thoguht ok, they arent faulty.

So the van has 197,000km, it was sent in for a full service which included cambelt change, water pump, serpentine belt, oil, fluids & filters.

2nd problem: After the service we drove from Poland to Switzerland which is about 1,500km... The last 50km of the trip I had an error message pop up saying oil level is low.... I pulled over, checked the oil level with the dip stick and it was fine. Oil is clear from the oil change. Fired her up and continued driving home without any warning lights coming up.

3rd problem: When I fired her up the next day I got a low oil pressure warning....

Can anyone give me some guidance on fault finding here? I have OBDEleven, VCDS and ODIS..

ChatGPT reckons it could be one of the below:
  1. Most likely: oil level / temperature sensor in the sump
  2. Oil pressure switch (very common)
  3. Oil specification - Ill check what oil was added later today when i get home from work
  4. Oil pump
 
The glow plugs are very easy to test, the mechanic should have known this, I certainly wouldn’t remove a glow plug on the off chance it’s defective unless the cylinder head is already off the van.
It’s very hard to determine an accurate oil level on an engine that has just been stopped as it hasn’t drained and settled for 30 minimum of 30 minutes.
You need to verify the oil pressure, it may well be linked to the earlier warning of low oil level, if the engine has been run more than a minute under no load without adequate oil pressure the damage is already done.
 
DXX said:
The glow plugs are very easy to test, the mechanic should have known this, I certainly wouldn’t remove a glow plug on the off chance it’s defective unless the cylinder head is already off the van.
It’s very hard to determine an accurate oil level on an engine that has just been stopped as it hasn’t drained and settled for 30 minimum of 30 minutes.
You need to verify the oil pressure, it may well be linked to the earlier warning of low oil level, if the engine has been run more than a minute under no load without adequate oil pressure the damage is already done.
Click to expand...
i'll check the oil level when its cold... Will see if i can find a oil pressure gauge and do a test on it.

:)
 
Last edited:
Check the oil level yesterday with car cold, and it was half way through the dip stick range.

I have ordered a Oil pressure gauge, high pressure switch and the valve, new oil filter with seal and new oil. Im hoping by doing all of the above I eliminate the problem in a 'best case scenario'.... Will update this post on my findings...
 
I took a video when starting her up, no knocking sounds. The oil pressure immediately climbs to approx 3.5 bar constantly

IMG_1260 (Resized).png

Then after about 5 seconds drops to a steady 2 bar

IMG_1261 (Resized).png

This seems to rule out low pressure in the oil system.. I have ordered both pressure sensors so will replace those and lets see how this goes
 
Good news, I haven’t looked at the T6 oil pressure sensor but I’ve seen bad connections to the switch cause an issue, doesnt help that it’s normally an unsupported single wire.
 
So, I have drained and replaced the oil, replaced the oil filter to make sure the fault isnt there, replaced the lower sensor... the error is still there :-( so it means its likely the upper sensor...

Question, is this the right sensor? The Workshop manual says its at the back of the CXFA engine but this is in the front? Am I being a chop and missing something?

Screenshot 2026-03-24 152136.webp

Screenshot 2026-03-24 152147.webp
 
Updating this thread, I have finally found where the Oil Pressure Regulating Valve is on the CXFA engine, and its NOT where the workshop manual says it is :-( Strange

I reviewed about 20 listings of engines for sale online, this was the easiest way to identify where it is. Im going to try change it later today and will give feedback.

Its on the front, above the front engine mount - seems like I will have to remove the front engine mount to get to it. In the photo below you can also see the Oil pressure sensor on the right side on the oil filter housing with the brown plug.

Screenshot 2026-03-30 112521.webp
 
Right, so I have found the regulating valve and its as mentioned previously, just above the front engine mount. The mount needs to be removed..

I have also found the problem, the value body was broken. The long thin piece is stuck inside the block and the back piece came out.

Please, does anyone have any tips on how to get the thing out? I have tried a self tapping screw and pulling it out - no joy. Im thinking Im going to have to drop the oil again, remove the oil sump and hopefully i can push it out from the inside,..... Can anyone confirm if this is doable? HELP?!

IMG_1348.webp

IMG_1349.webp
 
Im thinking that the snapped spigot in the block is plastic , like the body of the sensor you have next to the new one?

Get a coarse wood screw or similar cherry red , the sizing of the screw will be important, when the screw is cherry red quickly screw it into the remaining nozzle and let it cool off , then try removing.

You could try bending a hook on a few lengths of welding rod etc , like a fish hook , feeding it down the hole and pull it out, maybe while even applying a small gas torch on it to soften the plastic.

If its metel tap it etc.
And good luck
 
with the locating hex bolt removed , its now just a push fit held in situ by a rubber o ring, shouldnt be too difficult.
( famous last words )
 
manfrotto said:
Based on this facebook post you wont get access it from inside the engine block:

www.facebook.com

VW TRANSPORTER OWNERS CLUB | Hi anyone replaced n428+valve on a t6 transporter mine snapped clean off inside the block so drilled it out but now I'm confused as have I drilled to ... | Facebook

Hi anyone replaced n428+valve on a t6 transporter mine snapped clean off inside the block so drilled it out but now I'm confused as have I drilled to far as there is now a hole right at the bottom of...
www.facebook.com www.facebook.com

View attachment 321380
Click to expand...

Ah man, that just complicates it even more. Problem is access there is a complete nightmare, so have to move the rad pack forward or get a 90 degree drill adapter....

I've reached out to Ben from this post, hoping he can give me some insight/ support on this

Meh
 
DXX said:
Plug the orifice in the broken part and start the engine, oil pressure should eject it. Going to make a mess though.
Click to expand...
Now this is an interesting idea... Going to have to put some wood infront of it so it doesnt fire a hole in my radiator... :D:D

The effort to clean the mess might just be less than the effort to get it out...
 
Last edited:
DXX said:
Plug the orifice in the broken part and start the engine, oil pressure should eject it. Going to make a mess though.
Click to expand...

Just tried this and no luck... its proper stuck in there. Even tried a flat ended steel rod, tapped it with a hammer to loosen it and then start her up. nothing, no joy there...

Any other tips before i drill into it?>
 
T6NOMAD said:
Just tried this and no luck... its proper stuck in there. Even tried a flat ended steel rod, tapped it with a hammer to loosen it and then start her up. nothing, no joy there...

Any other tips before i drill into it?>
Click to expand...
I would avoid drilling it as it will put debris into the oil gallery and that won’t end well.
Also avoid anything that is going to cause it to expand and get tighter, like a screw or tapered ezi-out.
You can get parallel ezi-outs which maybe worth a try.
 
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