Normal Oil Pressure??

[Jetmugg]

If the pump is the cause of low oil pressure, then the 36mm pump should help.  People who are a lot smarter than me have instructed me that oil pumps don't make pressure.  Oil pumps make flow.  The pressure is a result of resistance to the flow created by the pump.

The 36mm pump will flow more oil than the smaller pump.  As a result, you will see a higher pressure maintained for any given restriction (bearing clearances, etc), with the upper limit set by the bypass valve in the pump.

Steve.

[ftm1776]

Thanks, Steve.

I remember from my Beetle days that I would put a shim behind the spring in the pressure regulator to boost the pressure a little. I'm not sure if that would be advisable in this application? Any thought on that? I don't want to blow any seals !!!

[ORCoaster]

That is why I mentioned he could pull the pump if he dropped the pan.  Maybe inspecting the whole thing for wear and tear will let him know if his problem is the pump or something like the seals on the Intermediate shaft seals.  If his pressure is low and the pump is good then upgrading will only get him so far.  The new pump may not have any restrictions and pressure will still be low.  But the flow will be higher. 

Putting a spring in the pressure regulator isn't a good fix on the pumps.  What if the pressure gets above the max rating of 110 psi?  I think that is what Mr Bentley says it is.  Is there a problem with blowing oil through the filter and not allowing it to do its job?  Seems I read that here someplace.  Bypass of oil when cold or something of that nature.  Anyone have any idea what pressure it takes to do that?  Maybe with a worn pump jacking the regulator could by time.  I just wouldn't trust the shim to get to a specific pressure.  It's not like adjusting the injector pop off pressure with shims.  That requires a tester anyway. 

Keep working on it.  But the simple fix might be an electric aux pump to get up to pressure. 

[theman53]

http://www.vwdiesel.net/forum/index.php?topic=34730.msg331546#msg331546

Look at this thread. It is the one I was talking about. 90% of vw idi oil pressure problems I would guess are IM bearing issues. The other are varied but the way you treated that thing I would suspect your bearings are shot. I haven't been around all that many vw's but all that I have seen, friends have seen, people I know have seen, no one in my personal realm has ever seen an oil pump gears wear out. One of the people I know has one that the drive shaft on the oil pump was worn down to the size of a small flat blade screwdriver and it still made oil pressure. Many engines in the over 400,000 mile range, and none have had failed oil pumps. I am suspecting either the IM shaft bearings or the lugged out crank bearings as the big issue. If you do find an oil pump is the culprit please post as most you cannot even get the smallest feeler gauge in your set in between the gears after several hundred thousand miles and I would love to see a bad one. If anything I could believe something stuck in the bypass valve holding it open or some numb nuts dropping the foil from the oil container while filling blocking the hole a lot easier than a bad oil pump.

[ftm1776]

I'm proceeding with dropping the pan and taking a look; check out the pump, clean things up, inspect the gear clearances and pressure relief valve function.
My local parts man, who has seen a lot of pumps replaced in these types of German engines (not only VW diesel), has encouraged me to replace the pump so I think I may do that. I can return the new pump if I decide not to use it.
My intention is to just raise the pressure a little to buy time before taking the big bite for rebuild.
Yeah, the cost of new engine could buy me another car........and who knows what other problems would come with it??
Also, I may replace the big end rod bearings.

I don't know where an aux oil pump would be placed on my non-turbo. Maybe the plumbing is accessible if there is an oil cooler??

I will be reporting my progress in this thread.

Thanks for all of the tips.

http://www.vwdiesel.net/forum/index.php?topic=34730.msg331546#msg331546

Look at this thread. It is the one I was talking about. 90% of vw idi oil pressure problems I would guess are IM bearing issues.

NASTY, NASTY, NASTY........I hope mine doesn't look like that and that I avoid it looking like that!!!!!

[theman53]

I have seen and replaced oil pumps myself...doesn't mean they actually needed it. I am not commenting on all German cars, but just the 1.6/1.9 idi and the one 1.8 8v vw diesel I have had or close family has had. Never seen an out of spec pump yet. Since you hammered the bearings lugging it around for the life of it I would guess your bearings will look exactly like the link I posted. Usually those will still yield ok pressure except at idle, it is the IM shaft bearings that usually drop it to the point of no return. Good luck with it.

[TimpanogosSlim]

pretty much what the im shaft bearing looked like in my block when i stripped it down.

I was lucky that the crank had no damage.

i intend to be quite careful with my belt tension.

[ftm1776]

I have a new(rebuilt??) 36 mm German pump; supposedly for the turbo engines. I guess they expect that the bolts will be reused so no bolts come with it. Will I need to get longer bolts for the 36 mm pump??? How long are they?? I assume that mine has the 30 mm gears so 6 more mm would make them about 0.25 inches longer??

[burn_your_money]

You need longer bolts. That's all I know.

[vanbcguy]

You should be able to order new bolts through a dealership.  The bolts from an AHU car should be the same and those will still be in the dealership's parts computer.  With fasteners I've come to the conclusion that getting the 'real' VW parts unless i'm upgrading for some reason is usually the best course of action and is generally no more or less expensive than using generic fasteners.

[ftm1776]

I haven't looked yet, but one of my parts men told me that he thought that the engines with hydraulic heads use the higher volume pump with the 36 mm gears. I'm pretty sure the turbos use them to quirt oil on the pistons.

Any comments on that?

[vanbcguy]

I haven't looked yet, but one of my parts men told me that he thought that the engines with hydraulic heads use the higher volume pump with the 36 mm gears. I'm pretty sure the turbos use them to quirt oil on the pistons.

Any comments on that?

Yes, that's completely true.  Hydraulic turbo engines came with 36mm oil pumps (the biggest size) and there are piston squirters in the bottom of the block to cool the pistons.  The same configuration was used on all the TDI engines that shared the same basic block design as the 1.6 did - the 1Z and AHU in the North American market specifically.  The AAZ in the Canadian market used that same oil pump and piston squirters as well.

Basically VW went to the 36mm pump with the 1.6TD and kept it the same for the next 15 years or so.

[theman53]

Post by: myke_w on January 24, 2007, 10:11:38 AM Ok, So in light of "not high enough" oil pressure on my old Vanagon TD motor, I went searching for a solution.

This was news to me, but I'd guess most of you already know -  the 91 and newer oil pumps for hydraulic diesel motors are a direct bolt on HD upgrade for earlier hydraulic (smaller pump) and all mechanical motors.


That is the info I got from it. The story I have heard is the mech engines got the 26mm? and the early hydro got the 30mm, then apparently after 91 according to myke w they got the 36mm.

Regardless, I think you will find your pump to be ok, or if it isn't then the entire thing will not be helped by 6mm more gears.

[ftm1776]

I've got a new 36 mm pump. So , if nothing else, I will install it when the engine is rebuilt rather than use the old one that has 290,000 miles on it......even if the old one is also a 36.

[theman53]

What did the bottom look like?