1.8T oil pressures

[Superchickenn]

Hi All,

I was hoping you can help

My 1.8T golf has been throwing the odd Oil pressure warning issue.

So this weekend i fitted an oil pressure gauge to see if it was a faulty switch or genuine low pressures.

Well it seems its the pressures are low, on cold the car is great and runs the required pressures.

However when warm she drops to 21 PSI on idle and even as low as 14 for a few seconds.

All is pointing to the oil pump but thought i'd ask here also.

Car has done 192000 miles and i purchased it with a smashed sump.

Thanks All Craig

[GreenV8S]

Oil pressure would normally drop at the lower end of the rev range and it will happen sooner with thinner oil, also sooner on a worn engine. Check the current oil has the correct hot rating and consider going up a grade.

[Mr2Mike]

Why do you suspect it's the pump rather than wear in the main and big end bearings?

[227bhp]

I cba to look back, but is this connected to the 'I've bought a car/engine with a smashed sump' thread a few weeks ago? If so some pointers there.
You need to know the manufacturers spec on oil pressure before going any further, but one bar at 100'c oil temp with correct grade of oil sounds ok to me.

[VAGslag]

1 bar (14 psi) at hot idle isn't actually too bad, and certainly won't make the oil light come on..

The 1.8t's suffer from clogged oil pick up pipes which can cause oil pressure issues... Whip off the sump and stick a new oil pick up on, they're about 12 quid from TPS iirc.

The manufacturer specifications for 1.8t's state 5w30 oil... That's for a "long life" service interval though which isn't much more than a sales gimmick if you ask me.

These engines, particularly one with miles as high as yours, run better on a good 5w40... And more importantly regular changes! (every 5/6k or so)

[Superchickenn]

Sorry all a few busy days ...

Answer to some of your questions

Yes your correct this was the car with the smashed sump.. which leads me onto the other questions.. when i replaced the sump the i checked the main bearings and they were all great. ..

Took the car out for 30 mins tonight whilst noting pressures

68 PSI on cold Idle - excellent

through the rev range it appears its spot on where it should be

once its warmed through it idled great at 14 PSI.

Went to park the car up and BEEP.. low oil pressure.. 11 PSI.. she sat on 11 PSI for another 3 mins with the low oil pressure switch going off.

Now it does have a slight hunt at idle until the revs settle down so im wondering if im "parking it" so gets a little hunt on and moving the power steering drops the revs a little to far maybe and causes revs to dip and oil pump speeds to drop?? sorry for the long post but more of a thought out loud.

[Superchickenn]

VAGslag said:

1 bar (14 psi) at hot idle isn't actually too bad, and certainly won't make the oil light come on..

The 1.8t's suffer from clogged oil pick up pipes which can cause oil pressure issues... Whip off the sump and stick a new oil pick up on, they're about 12 quid from TPS iirc.

The manufacturer specifications for 1.8t's state 5w30 oil... That's for a "long life" service interval though which isn't much more than a sales gimmick if you ask me.

These engines, particularly one with miles as high as yours, run better on a good 5w40... And more importantly regular changes! (every 5/6k or so)

When i had the sump off i fully inspected the oil pick up feed and it was "mint"

Ive also completed 3 oil changes in 100 miles i tried 5w30 and ive even tried this evening 10w40

when shes running hard 5-6k rpm the oil pressures are excellent its the lower rev range is the issue

[Superchickenn]

227bhp said:

I cba to look back, but is this connected to the 'I've bought a car/engine with a smashed sump' thread a few weeks ago? If so some pointers there.
You need to know the manufacturers spec on oil pressure before going any further, but one bar at 100'c oil temp with correct grade of oil sounds ok to me.

Ive been informed by a good source that the idle warm should be between 0.9 - 1.2 bar so as you said im there or there abouts

also great memory with the post

[227bhp]

Superchickenn said:

227bhp said:

I cba to look back, but is this connected to the 'I've bought a car/engine with a smashed sump' thread a few weeks ago? If so some pointers there.
You need to know the manufacturers spec on oil pressure before going any further, but one bar at 100'c oil temp with correct grade of oil sounds ok to me.

Ive been informed by a good source that the idle warm should be between 0.9 - 1.2 bar so as you said im there or there abouts

also great memory with the post

So this is also the one where you didn't check the mains and your mate put the axle stand through the new sump?

Is the idle speed correct? Have you tried a different brand of oil filter?
Idle speed needs to be stable and the correct speed otherwise it can show a warning light if it dips too low on an old engine.

[Blaster72]

It has done a lot of miles, not unusual for a worn engine to have slightly low pressure at idle.

I had similar with my 120k Audi A4 1.8T but lucklily for me it was just the pressure switch gone at the time. The switch on at 1.2 bar - 1.6 bar according to GSF.

https://www.gsfcarparts.com/931vg0080

[Superchickenn]

227bhp said:

Superchickenn said:

227bhp said:

I cba to look back, but is this connected to the 'I've bought a car/engine with a smashed sump' thread a few weeks ago? If so some pointers there.
You need to know the manufacturers spec on oil pressure before going any further, but one bar at 100'c oil temp with correct grade of oil sounds ok to me.

Ive been informed by a good source that the idle warm should be between 0.9 - 1.2 bar so as you said im there or there abouts

also great memory with the post

So this is also the one where you didn't check the mains and your mate put the axle stand through the new sump?

Is the idle speed correct? Have you tried a different brand of oil filter?
Idle speed needs to be stable and the correct speed otherwise it can show a warning light if it dips too low on an old engine.

No, this one i did check the mains when i put a new sump on... the one that the axle stand went through was my mates PD golf (we have a few between us)

Idle speed seems spot on, but the more im reading it seems as though the pressure is just that bit low on idle... i may bite the bullet and buy a pump this weekend...

[Superchickenn]

Blaster72 said:

It has done a lot of miles, not unusual for a worn engine to have slightly low pressure at idle.

I had similar with my 120k Audi A4 1.8T but lucklily for me it was just the pressure switch gone at the time. The switch on at 1.2 bar - 1.6 bar according to GSF.

https://www.gsfcarparts.com/931vg0080

i have changed the pressure switch and it still went off hence me putting the gauge in... that's interesting they say that because i was told by a guy that builds these engines that the idle is 0.9-1.2 bar and switch comes on at 0.75 bar..

[anonymous-user]

I had this same engine in an Audi A4 and the plastic dipstick tube broke and sprayed oil all over the engine. I replaced the tube and changed the oil and after that the oil pressure light warning would come on when driving.

Eventually dropped the sump and the oil pickup was actually pretty clean. I ended up replacing the pickup and oil pump and this appeared to fix the problem. I sold the car soon after as it was one issue after another, but it according to the MOT history it is still going.

I have had this engine in two cars now and in my experience once the problems start it is one thing after another. Not a fan at all, the oil capacity is very low for a turbocharged car so if the owner is not on top of maintenance the engine sludges up and causes all sorts of issues.

Having had multiple issues with an A6 and an A4 I don't understand why people get so excited about the "build quality" of VAG cars. As far as I can tell there is a thin vaneer of quality on the interiors but the rest of the car is junk. I don't understand how it is apparently acceptable for a VAG engine to burn a litre of oil every 1000 miles, yet my shed Renault never burns a drop.

Next door neighbour has had the power steering warning light appear on his 07 Audi A3 and has been quoted £2k to repair. This is a garaged, owned since new, full Audi service history car with 60k on the clock.

Edited by anonymous-user on Friday 22 June 08:24

[Kccv23highliftcam]

Joey Deacon said:

I had this same engine in an Audi A4 and the plastic dipstick tube broke and sprayed oil all over the engine. I replaced the tube and changed the oil and after that the oil pressure light warning would come on when driving.



Not a fan at all, the oil capacity is very low for a turbocharged car so if the owner is not on top of maintenance the engine sludges up and causes all sorts of issues.

Edited by Joey Deacon on Friday 22 June 08:24

Can get 5l in with the big transporter filter on right.

Oil if fuchs [nee silkolene] titan race pro 5w-40 ester btw...

[Superchickenn]

Kccv23highliftcam said:

Can get 5l in with the big transporter filter on right.

Oil if fuchs [nee silkolene] titan race pro 5w-40 ester btw...

That's a good idea I'll have a look at the bigger fillers thank you