Oil Pump Installation

[rstclark]

I think I know the answer to this but just want conformation on installing a new Oil pump  I'm installing a  new 320i using the 2002 oil pick up in a fresh motor.

The pressure relief tube, spring and piston/ plunger assembly are free floating  at this point, and I am assuming that the piston is stopped by the O ring seal connecting the tube to the pump ?    The reason I'm confused is because on the old pump, the piston was stuck partially down the in the pump housing  Seemed to be a ridge built up preventing the piston to slide the full distance  . Would this explain low oil pressure at startup ?

 

I know from searches to be careful to get the O ring sealed   and locktite the sprocket onto the pump shaft.  Then fill the oil filter and prime the pump by pouring oil down the oil pressure sensor hole

 

Just want to be sure about the pump installation given the money and effort going into the new build

 

Thanks

[kbmb02]

2 hours ago, rstclark said:

I think I know the answer to this but just want conformation on installing a new Oil pump  I'm installing a  new 320i using the 2002 oil pick up in a fresh motor.

The pressure relief tube, spring and piston/ plunger assembly are free floating  at this point, and I am assuming that the piston is stopped by the O ring seal connecting the tube to the pump ?    The reason I'm confused is because on the old pump, the piston was stuck partially down the in the pump housing  Seemed to be a ridge built up preventing the piston to slide the full distance  . Would this explain low oil pressure at startup ?

 

I know from searches to be careful to get the O ring sealed   and locktite the sprocket onto the pump shaft.  Then fill the oil filter and prime the pump by pouring oil down the oil pressure sensor hole

 

Just want to be sure about the pump installation given the money and effort going into the new build

 

Thanks

 

Some info, hope it helps...

 

The 'upper stop' for the relief piston is oil pressure. As the engine runs, the pressure relief piston moves up and down against the spring inside the relief piston bore; over time, the steel piston can wear a ridge into the bore. If my busy-brain serves me correctly, when the relief piston is stuck 'down', oil bypasses back into the pump rather than through the oil galley and into the engine (yep - resulting in lower oil pressure).

 

Also; install the hardened washer behind the sprocket (between the sprocket and the pump, rather than between the sprocket and the nut. It's an alignment thing.

 

Finally; when checking / shimming the chain, rotate the engine through a cycle while checking the tension. It can change, sometimes more than you'd expect, and can result in a chain too loose (noisy, sometimes) or too tight (premature wear of pump). -KB

[rstclark]

Thank you for comments   I don't seem to have the hardened washer that goes between the sprocket and the pump  and I can see how it would tighten down too far on the shaft and not fully on the spline without one

 

Do you happen to know the thickness of the washer ?

[rstclark]

I found a washer that appears to be between 1.5 and 2 MM thick   Pretty sure that is the one.  Thanks for your post   a good catch

[worzella]

Very relevant topic for me since I am about to do the same thing. One additional question about shimming. In theory, with a new sprocket and new chain, should shimming be necessary? I certainly will check the tension and use your tip about the full rotation, but just wondering if shims came on new motors from the factory or is that always a "fix" for old chains and worn sprocket teeth?

 

Thanks 

[kbmb02]

17 hours ago, rstclark said:

I found a washer that appears to be between 1.5 and 2 MM thick   Pretty sure that is the one.  Thanks for your post   a good catch

 

I don't have measurements on that, unfortunately. Will try.

 

1 hour ago, worzella said:

Very relevant topic for me since I am about to do the same thing. One additional question about shimming. In theory, with a new sprocket and new chain, should shimming be necessary? I certainly will check the tension and use your tip about the full rotation, but just wondering if shims came on new motors from the factory or is that always a "fix" for old chains and worn sprocket teeth?

 

The theory / necessity is probably(?) to adjust for manufacturing and machining tolerances of the parts (block, oil pump, crank sprocket, oil pump sprocket and chain). -KB

[rstclark]

Well for one the washer appears necessary to place the sprocket fully on the pump spline and prevent the sprocket from being pushed to far back when the nut is tightened  With the washer in place, it appears to be the correct alignment for the chain lining up the gear on the crank with the sprocket on the pump 

Your tip about the washer is much appreciated. 

How do things that seem so simple turn out to be so detailed ?

[PaulTWinterton]

2 hours ago, worzella said:

wondering if shims came on new motors from the factory or is that always a "fix" for old chains and worn sprocket teeth?

 

Curious about this as well.  Both my tii engines have a single shim.  I did not put it there.  Is it factory or added by POs?

[Preyupy]

I have seen engines from the factory with shims under the oil pumps.  If you don't put the washer behind the sprocket on the pump shaft you will only have about 40% spline engagement with the shaft (sooner or later you will shear off the splines and the pump will cease to turn!!!).  Pouring oil down the oil pressure sensor hole in the back of the head will only "prime the pump" if you PUMP about 1.5qts backwards through the engine from that point.  It is the absolutely furthest point from the oil pump in the entire system.  If you are worried about new engine start up oil pressure, pre-lube the oil pump with assembly oil before you install it,  once the engine is assembled and installed fill the oil filter with fresh oil and remove the spark plugs fill the engine with oil and spin it on the starter with the plugs out until you get pressure.  Install the plugs and start the engine.

[kbmb02]

8 hours ago, rstclark said:

Well for one the washer appears necessary to place the sprocket fully on the pump spline and prevent the sprocket from being pushed to far back when the nut is tightened  With the washer in place, it appears to be the correct alignment for the chain lining up the gear on the crank with the sprocket on the pump 

Your tip about the washer is much appreciated. 

 

For those following: thickness of factory hardened washer is 0.067" (a bit over 1.5 mm). Photos of various washers, nuts, a replacement I use for the OE washer, and what non-hardened washers look like when they come off the pump shaft. -KB

 

 

 

 

[rstclark]

I used the thinner washer.  The sprocket engaged the spline better and the chain alignment with the crank sprocket was best   Also used the thinner nut but used red Loctite on it   Regarding the shims,  with new chain and sprockets,I used one thick and two thin shims to get a good smug tension.  The chain meshed and fit with the  sprockets with equal contact  It was surprising that it required that much shimming, but that's how it turned out. Just the way these parts assembled.

Edited June 1, 2017 by rstclark
adding comment

[torquewrench80]

17 hours ago, Preyupy said:

I have seen engines from the factory with shims under the oil pumps.  

 

23 hours ago, PaulTWinterton said:

 

Curious about this as well.  Both my tii engines have a single shim.  I did not put it there.  Is it factory or added by POs?

 

On 5/31/2017 at 8:02 AM, worzella said:

......wondering if shims came on new motors from the factory or is that always a "fix" for old chains and worn sprocket teeth?

 

Thanks 

 

Agree with Preyupy. Always saw engines from the factory with shims installed. And why not? How else to get the tension right?

[Marblehead]

Gonna reinvigorate this older Discussion as I'm into "exploratory surgery" of the underside of my '74 tii engine.  I'm actually in the process of doing a full R&R of the front suspension and removed the subframe while keeping the engine secure in the bay.  Historically wet motor and pulled the pan, intending to replace the pan gasket.

Watch the attached YouTube clip:

 

Needless-to-way, the lateral lash in the pump gear is concerning and I've yet to pull it to check for a shim on the backside.

I'd sure welcome any thoughts/ideas on how to best address this.

Thanks!

[tme]

Have you checked for the hardened washer behind the pump drive gear as mentioned above?  It certainly looks like the pump splines are not engaged with the gear.  Any need for pump shims would need to be determined after the gear to pump play is removed.

[PaulTWinterton]

The upside to the loose sprocket is that it's very easy to access.  I only have knowledge of the 3-bolt version, but I'd say you shouldn't have any problem sorting this with help of the FAQ.  Once you've addressed the slop in the sprocket also confirm that your chain only deflects horizontally approx 5mm (side-to-side).  A common occurrance is "chain rattle" as the loose chain slaps the oil relief valve housing.  Easily remedied by adding shims under the pump support and/or replacing the chain and (maybe) the sprocket.

 

 

Edit: Just noticed the text in the photo says "Chain shimmed", it should say "Pump shimmed".

Edited November 23, 2019 by PaulTWinterton