Oil rec. for 2001 Passat 1.8T with worn bearings

[Jdun]

Originally Posted By: MaxPF
Seriously, you are considering the expense of adding an oil cooler rather than bearings? My guess is a set of rod and mains should be under $150, probably a lot less. Unless you're incapable of changing them yourself and have to pay a shop, there is zero reason not to try that first.


I realize the original poster says he did not replace them but I did and I am having the same problems. I use to own a machine shop and have all the tools to check the clearances of the bearings, the crank, the main bearing housing, the rod journals. I have also checked the cam journals on my head and it is all within spec. Yet at hot idle I also have oil pressure around 15 psi. I have a manual that says that is within spec for the car, however every once in awhile the car sets off a low oil pressure warning at 1500 rpms. That is what i have been searching out and that is what led me to here.

 

[Jdun]

Originally Posted By: uart
Originally Posted By: Jdun
What I have learned

The oil pressure switch is a normally open switch that grounds at 1.4 to 1.6 bar (20 to 23 psi). The computer is set to ignore this switch until it hits 1500+rpms.

Ok, but the OP said his oil light problem occurs at hot idle, so presumably under 1500 rpm. Do you know if there's a second oil pressure switch that doesn't get ignored below 1500 rpm, and if so what pressure it's set at?


Nope, He basically has the same car with the same code engine as I do. VW seems to do this oil light warning the hard way. once the engine reaches 1500 rpms, if the oil pressure is not high enough to ground the switch, it sets off an alarm in the car and flashes " Stop, Low Oil Pressure" on the window in the gauge cluster.

This is what I have in a Mitchell manual (basically a reprint of VW of America literature). It lists the specs as follows:

Check oil pressure with engine at normal operating temperature. Oil pressure at idle should be is 14-36 psi
(1.0-2.0 bar). Oil pressure at 3000 RPM should be 44-73 psi. (3.0-4.5 bar). At higher RPM, oil pressure
should not exceed 100 psi (7.0 bar).

I am at the lower end but within those specs. I have taken the valve cover off the engine 3 times checking everything and it is getting plenty of oil up top. My only problem is every once in awhile, that oil warning light comes on and it is always at 1500 rpms when I have been crawling thru town at that rpm for several minutes. When it goes off the oil gauge is reading a constant 25 psi as well. Other than this the car runs great.

 

[MaxPF]

Have you and the OP actually checked the oil pressure with a mechanical gauge? You either have a twitchy switch, or the oil pressure is actually low.

 

[Jdun]

I have a mechanical gauge on it. Because of what happened to it previously I included a mechanical gauge when I reinstalled the engine.

I have read every post I can find on this engine and the majority have to do with the sludge issue, but I have come across several like mine that seem to be something other than sludge related. I have reinspected every part I can think of and it all is in specs. Right now I have 1500 miles on the engine and the oil is still clear. It may have an internal leak somewhere but it is not in the normal suspect places. Then enter the conflicting manuals I have seen and I warm left wondering if it is not suppose to be that low at hot idle. Some of the manufactures the last several years have been trying to run with the lowest oil pressure possible in order to meet CAFE fuel mileage standards (so I"ve read).

 

[zanzabar]

Yes, I have a mechanical gauge permanently hooked up and am experiencing the same symptoms as Jdun. I would consider replacing bearings myself at some point, but not excited to do it because of cost of labor (don't have a lift available to do it myself).

 

[Brons2]

I thought of another one, how about Motorcraft 5w50?

 

[zanzabar]

FYI I tried Castrol Edge 5w50 recently and it seems to be the optimal mix of maximizing hot idle oil pressure and providing ok cold start flow to the head - I can tell this latter is occurring because the cam chain tensioner does not rattle nearly as much as it did with 15-40 or RotellaT6 + Lucas stabilizer.

Adding the Lucas stabilizer was doing ok for a while in the warm weather but when the mornings got colder recently the car had some pretty noisy starts from that cam chain tensioner. And I don't even live in a cold climate (we're talking 40 deg F temps overnight at the lowest). I really don't recommend anyone use that stuff in truly cold climates!

I am planning on replacing the main and rod bearings at my earliest convenience, but not sure when that's going to be. The engine does seem a bit 'rattly' from the bottom end underr light loads so I'm not really very comfortable with its long-term reliability.

 

[asand1]

Replace your bearings if the pressure is low (or at the low end of spec). It is not hard with some hand tools and a set of ramps. A set of bearings is not really expensive, and it is a DIY weekend job.

If the only problem is a wonky idiot light system, and you have a real gauge installed, I would personally disable the idiot light by disconnecting and/or grounding the pressure switch wire permanently.

 

[zanzabar]

Finally got around to swapping out the bearings. Everything was looking fine until:

The middle main cap had massive damage, the thrust washer was gone on one side, gouged out the cap and part of the block, and the bearing spun. If the block and cap hadn't been too badly worn I could have just replaced the bearing. Crank journal looks not too terrible. But since the face of the block that abuts the thrust bearing on this cap is worn away, even if I put a new thrust bearing in it'll just fall out again. I tried to think of a way to weld it on to the cap, but that would be a bandaid at best. Block is toast - I'm parting out the car.

Oh, and I have been driving it like this for quite some time! 1000+ miles probably. Never made much in the way of bad noises.