Rebuilding the 300 TDI: a few questions about the oil pump

[Jode]

1. The WSM states that you must remove all traces of sealant from around the edges of the oil pump cover once its removed; but I can't find any trace of sealant. Is this abnormal?
2. I presume the WSM's reference that sealant 'from the kit' be used when refitting the pump cover is intended to improve suction by preventing the pump from sucking air from around the edges of its cover; I don't have 'the kit', but would a thin, carefully placed bead of RTV silicone do?
3. There is some radial scoring (almost more like polishing) on the inside face of the pump cover that was caused by the spinning of the pump itself. As the engine has done 250K I figure that this is par for the course and I hadn't intended to replace the cover. Does this sound stupid? I am replacing the valve and spring however.
4. Although the WSM instructs 'oiling' the pump components on reassembly, I was intending to pack the pump with petroleum jelly to improve for priming. Would this be a bad idea for the 300 TDI?

Thanks in advance.

[Blknight.aus]

its all good.

if the mating surfaces of the housing and the cover plate are peftectly matched you dont even need the sealing goop.

When I redo any oil pump I completely pack the thing petroleum jelly ensure the mating faces are completely clean and then put a smear of hylomar #3 on the pump housing side of the joint and loctite 243 on the threads of the retaining bolts.

The fine polishing/wear is normal but a hi res well lit macro photo of it will help us give you a go/no go for use but I'm pretty sure the permissable tolerance for wear is in the RAVE, The values havent changed in years so pretty much any of the specs for the oil pump from any of the engine will keep you running.

[Jode]

Dave - thanks for the prompt and helpful reply. I'll take a photo of the inside face of the pump cover later today when it's a bit more sunny (overcast now); I look forward to your review.

Jode

[Jode]

The fine polishing/wear is normal but a hi res well lit macro photo of it will help us give you a go/no go for use but I'm pretty sure the permissable tolerance for wear is in the RAVE, The values havent changed in years so pretty much any of the specs for the oil pump from any of the engine will keep you running.
Dave -
I've attached a .zip file of the photo of the pump cover as well as of the rocker arm (the originals were around 2.4MB each which is too large to insert).

I've measured the rocker at one of the pedestals as well as at each rocker point, and wear is within tolerances (out at most 0.02mm - although admittedly I'm using a vernier caliper). The most apparent wear is scoring caused by the rocker spring rings cutting into the shaft as they rock; however this is after 250K and it seems to me like this wear is not likely to cause problems - perhaps I'm dreaming!

Thanks for your review.

Jode

PS - I see that the website has also attached a small res copy of the pump cover photo...

[roverrescue]

Did you have oil pressure problems prior to strip down?
The pumps are pretty reliable on these things and I would run that one assuming the feeler gauge tolerances are acceptable on the rotor.

No need for anything fancy for the pump when re-assembling. Have a look where the pump sits relative to the sump oil level. Self priming. Just turn the engine over on the starter with the IP solenoid closed (disconnected) before intial start up.

S

[Blknight.aus]

Pump face is good to go as is, you could polish it a little but I wouldnt bother.

bit of vas to ensure initial lube and to help everything sit in place while you put it together and you're good to go.

Ive seen and reused worse rocker shafts than that, my only real concern is the odd wear mark next to the big hole on the left.

[Jode]

Dave -
Not quite sure which of the big holes that you refer to; the biggest holes are of course the pedestal bolt holes. The one on the bottom of the photo (the rocker shaft running vertically rather than horizontally) has a dark spot immediately beside it, which is a very slight pitting in the finish. No worries on that one - looks worse in the piccie.

Thanks again for your help. It's on thing being a weekend hobby mechanic and rather another seeing and working with things like this all the time - your experience is really helpful.

Jode

[Jode]

Did you have oil pressure problems prior to strip down?
The pumps are pretty reliable on these things and I would run that one assuming the feeler gauge tolerances are acceptable on the rotor.

No need for anything fancy for the pump when re-assembling. Have a look where the pump sits relative to the sump oil level. Self priming. Just turn the engine over on the starter with the IP solenoid closed (disconnected) before intial start up.

S
Steve -
No the oil pressure seemed to be ok before the rebuild; I'm rebuilding because compression was down on all four, and one was more than 10% off the other three - and as you can imagine it lacks guts. But I figure if I'm pulling the d..n lump out I'll do some extras whether necessary or not as getting there is such a pain in the proverbial.

As oil pressure is make-it-or-break-it for the engine I figured I'd replace the oil pressure relief valve and spring - a bit pricey as both were LR badged but then again I figure it's worth the peace of mind. I decided to replace all the valves, as well - the old ones were ok but again oem (not lr) valves aren't very expensive.

The feeler gauge tolerances for the oil pump were fine EXCEPT FOR that between the timing rear cover and the outer rotor - this was about twice the allowable when measuring one side but within tolerance when measuring at the other side. As this is driven by the crank - and as I can't feel any looseness (it just spins neatly) I figured I'll go with it; it sits where the crank tells it to sit, so it's probably ok.

Jode

[Jode]

When I redo any oil pump I completely pack the thing petroleum jelly ensure the mating faces are completely clean and then put a smear of hylomar #3 on the pump housing side of the joint and loctite 243 on the threads of the retaining bolts.
Dave -
Hylomar is as scarce as hen's teeth here, we mostly see Loctite products. I googled hylomar 3 - is 'hylomar blue' non-setting sealant what you're referring to? Don't know if that's #3 or not.

I would guess that the loctite equivalent is their 'gasket sealer #2', which is a non-hardening sealer.

Cheers.

[Jode]

My engine rebuild is moving along (albeit slowly as currently only weekends available; and then there's shopping, social life etc.), but I've come across an odd problem that's stumped me (and others).

Although the valve guides seemed ok I thought it wise that, as the engine has done around 250K, they be replaced; there also seemed a bit of wear but I couldn't measure it as my dial indicator's shaft is too short to reach. Got new guides in from UK with various other bits, took them plus new valves, seats and stem seals with head to local engine shop. They called me back later and advised "the guides are the wrong ones". So back I go - turns out the guides in the head measure 14.35mm OD whereas standard are 14.06mm.

Checked with UK supplier, no alternate guides are available; contacted Turner Engineering, they could only suggest that, as head didn't have LR badge, it was likely to be a Chinese or Argentinian replacement, and they didn't know where to source replacement guides.

Anyway, as the engine shop pressed out the guides before checking the OD I now have a head without guides, with no replacement guides available. Anyone know where I might find 8 valve guides for a 300 TDI head that are 14.35mm OD? Otherwise I'll have to buy another head....

Thanks.