Oil pressure readings 1986 gti 8v

[reebo]

Ok, at operating temp 3k rpm = 4.5 bar and idle= 6 bar
My oil 5 w 30 with 1 liter of Lucas oil additive. I put in the additive due to my leaky lifters.
Will 20 w 50 lower idle pressure?

[ps2375]

Why don't you try some 15/40 or even 10/40 and skip the light weight oil w/ the thickener in it. You might actually save enough money to buy a Bently Manual for the car.

Did you type that correctly, 6 bar at idle and 4.5 bar at 3K rpm and both are at operating temp? That does not seem possible.

[reebo]

Yes I typed that correctly.

[WaterWheels]

First where are you taking this reading from? Second, what are you using to measure the pressure? and last, which the last question might answer, is this mechanical or electric (the measuring device)?

[antichristonwheels]

1 switch to 20W 50

2 4.5 bar at 3k is about right, about 70-75 psi is normal

3 I would hope for close to 2 bar, about 30 psi at a hot idle, if you get below 1.5 bar at a hot idle something is getting tired..

[WaterWheels]

We are talking about a hydraulic follower cylinder head, if the 86’ original head is being used, so mechanical follower pressures don’t correlate. Engines with mechanical followers normally have a higher oil pressure, at least during idle, than engines with hydraulic followers. At normal operating temperature an engine, VW anyway, with hydraulic followers can have oil pressures as low as 12psi (less than 1bar) and be 100% fine. The pressure reading will depend on a few things so there is no real “normal” pressure. Although low pressure is a real concern for obvious reasons, pressure too high should also be a concern.

Why have you added the Lucas oil additive? Is it something like that old STP crap which thickens the oil? Why a whole liter of the stuff?

The pressure reading you have just doesn’t make any sense really. There is nothing really wrong with having a 3000RPM pressure of 4.5bar (~65psi), a little high for a hydraulic engine I think, but having the pressure increase to 6bar (~87psi) when it drops to idle is really strange. High pressure is not always good as it indicates that there is a restriction (clog) which is slowing down the flow. Much better to have low pressure and lots of flow than high pressure and weak flow. So knowing where the reading is coming from and the equipment being used can help.

Maybe it’s just me, some people always say it is, but I don’t follow the logic of switching to a thicker oil if the pressure is already too high (presumed or otherwise). If 5W-30 is being used and the pressure is high then switching to 20W-50 will increase the pressure a little more, no? 5W-30 is a little light for an older Volkswagen engine so I would go to at least 10W-30 or 10W-40 in any case just to keep the engine healthy, but not to lower the pressure any.

[reebo]

I fished around in my garage and found a vdo 5 bar sender and that did the trick. 1 bar at idle and 3 bar at around 2500 rpm so this is sounding a lot better. Im now switching to 20w 50. That should help with my leaky lifters as well. The sender is on the head by the way.

[WaterWheels]

Im now switching to 20w 50. That should help with my leaky lifters as well.

Seems it was your electrical sender the whole time then. what was the values of the one you swapped out and did you also swap gauges? 20W-50 oil, if it is not needed due to where you live (temperature), really does nothing good. I know that some people will post a picture of the recommended oil chart or direct me or us to it, but it is a matter of not reading the text or understanding what"s said. That chart does not tell you that this or that oil is required, just which ones will work and are recommended for different climates. Putting a thicker oil in your motor if your area does not require it just covers the problem and does not fix what's wrong if that's the reason you did it. Hydraulic followers that are leaking down too fast, they all leak to some degree by design, are worn out and should be replaced. Using some additive to "thick up" the oil or useing heaver weight oils just covers the problem and the parts still continue to wear and not function correctly. If they are noisy then first try using some ATF or Marvel Mystery oil to clean out the gunk as they may be stuck. If that fails to work, replace them.

[reebo]

I hear you, thanks for the help. I have replaced litters before, still have that engine... I have oem lifters that have been sitting in an oily bag, or aftermarket lifters that have been sitting in an engine with a blown head gasket ..... Which to use?

[Glegor]

I hear you, thanks for the help. I have replaced litters before, still have that engine... I have oem lifters that have been sitting in an oily bag, or aftermarket lifters that have been sitting in an engine with a blown head gasket ..... Which to use?

is either set BRAND NEW, or MATCHED TO THE CAM YOU WILL BE RUNNING?

if they are just random used lifters, out of mystery engines, without the matching cam, then the lifters are garbage.. used lifters are USELESS without the cam that they have been worn to..

so, as i said, neither set is of any value unless they are brand new, or have the cam shaft with matching wear patterns, and all lifters were marked as to where they came from, so they can be re-installed in another engine, and be riding on the same lobe on the cam as when they were installed in a previous engine..

[Seax_Smith]

Seems it was your electrical sender the whole time then. what was the values of the one you swapped out and did you also swap gauges? 20W-50 oil, if it is not needed due to where you live (temperature), really does nothing good. I know that some people will post a picture of the recommended oil chart or direct me or us to it, but it is a matter of not reading the text or understanding what"s said. That chart does not tell you that this or that oil is required, just which ones will work and are recommended for different climates. Putting a thicker oil in your motor if your area does not require it just covers the problem and does not fix what's wrong if that's the reason you did it. Hydraulic followers that are leaking down too fast, they all leak to some degree by design, are worn out and should be replaced. Using some additive to "thick up" the oil or useing heaver weight oils just covers the problem and the parts still continue to wear and not function correctly. If they are noisy then first try using some ATF or Marvel Mystery oil to clean out the gunk as they may be stuck. If that fails to work, replace them.

BG's MOA does amazing things for clearing up lifter tick and you don't have to use it every oil change, but it goes make for a quieter engine.

[reebo]

Well the litters in the engine only have 200 kms on them... I would take the risk, it's a quick job. By moa, the shop that I used to work at used these products, anyone know who carries the by products in Canada ? Ill drop by my old shop and see if they will get me some.

[WaterWheels]

If they only have about 200km on them the you are going to have to explain what you mean by "leaky lifters". I was under the impression that they were noisy due to age and that was why you used an oil additive of some kind. Hydraulic followers with only 200km of use should not be leaking down, at least over night or even after maybe a week, unless they have become damaged. So are they noisy? Have you done some cylinder head work?

[reebo]

Whoops, sorrynabout that. The litters with 200 kms on them are in a parts car , I blew the head gasket in the parts car shortly after changing the lifters. The 86 has lifters that are potentially 300 k old. These are the noisey ones.

[Glegor]

Whoops, sorrynabout that. The lifters with 200 kms on them are in a parts car , I blew the head gasket in the parts car shortly after changing the lifters. The 86 has lifters that are potentially 300 k old. These are the noisey ones.

well, if you take the lifters out of the parts car, be sure to mark their positions before removing them, and ALSO, take the cam that they are running with.. do not switch cams. you need the cam that wore to them..

and its LIFTERS.. not litters... or, more accurately, cam followers..