Thread: 300tdi valve lash caps disintegrating

Some additional info on the oil pressure.

From cold start 20C in the garage i have the following.
At the filter T piece Lo Idle 57Psi Hi Idle 80Psi
At the rear of the cam Lo Idle 19Psi Hi Idle 30 Psi.

With the oil at operating temperature i have the following.
At the filter T piece Lo Idle 32Psi Hi Idle 60Psi
At the rear of the cam Lo Idle 9Psi Hi Idle 18 Psi.

The pressure at the T piece is as per the manual, their is no spec for oil pressure at the rear of the cam, their is a plug id the block that i removed and installed a test fitting, so i need data from another Tdi for comparison.

So i think the oil pressure is OK, however their is a chance their is and internal leak or restriction that is limiting flow to the rocker shaft.

the lash caps are about the last thing in line to get oil, so oil flow is still on my list of suspects.

PS, sorry for hijacking your thread, i think we are both working on the same problem.

Hi Guys, new to posting here so here it goes,
I have had the same issues with turning valve lash caps into donuts. 2 of the caps were not worn at all and the others were all stuffed. So i ran a file over them all to see which ones were still hard or not. The 2 that had no signs of wear were hard enough not be affected by a file while the others filed easily. Here is my solution. I bought a set of Crane Cams after market lash caps, cost $85 for 16. Cannot buy 8. These are 8mm NOT 5/16 .Only about 3 thou difference and twice the price but tried the 5/16 caps and had to take them back because they would not go over the valve stem. 8mm caps fit perfectly.I put the feeler gauges between the bottom of the lash cap and the top of the collet and had at least 10 thou. Good enough for me.I ran a file over every new cap and could not mark any of them. Uniformly hard. Perfect.
All fitted as expected and adjusted as normal.
Now for a few kms to see how they fare.
Crane Cams part number 99425-16
Give them a try ,I think you will be happy.
Cheers
Russ

Just to add..
These caps have a very small hole in the center which i believe will help lubricate the top of the valve.
Cheers

Originally Posted by rleggett

I bought a set of Crane Cams after market lash caps, cost $85 for 16. Cannot buy 8. These are 8mm NOT 5/16 .Only about 3 thou difference and twice the price but tried the 5/16 caps and had to take them back because they would not go over the valve stem. 8mm caps fit perfectly.I put the feeler gauges between the bottom of the lash cap and the top of the collet and had at least 10 thou. Good enough for me.I ran a file over every new cap and could not mark any of them. Uniformly hard.

Hi Russ

For those who what to follow up on your posting here is a link to Crane Cams.
Crane Cams Australia

CONTACT DETAILS

Automotive Performance Distributors
35 Chapel Street Norwood
5067 South Australia

Ph. 08 8363 5566
sales@cranecams.com.au

Originally Posted by AlexC

Some additional info on the oil pressure.

From cold start 20C in the garage i have the following.
At the filter T piece Lo Idle 57Psi Hi Idle 80Psi
At the rear of the cam Lo Idle 19Psi Hi Idle 30 Psi.

With the oil at operating temperature i have the following.
At the filter T piece Lo Idle 32Psi Hi Idle 60Psi
At the rear of the cam Lo Idle 9Psi Hi Idle 18 Psi.

The pressure at the T piece is as per the manual, their is no spec for oil pressure at the rear of the cam, their is a plug id the block that i removed and installed a test fitting, so i need data from another Tdi for comparison.

So i think the oil pressure is OK, however their is a chance their is and internal leak or restriction that is limiting flow to the rocker shaft.
the lash caps are about the last thing in line to get oil, so oil flow is still on my list of suspects.

Hi AlexC and Russ

There could be a loose lump of hard crud in the oil galley leading up to the small hole in the head gasket, see this extract from my previous posting.

Originally Posted by wrinklearthur

My guess is there isn't enough oil getting fed through to the rocker assembly.
----------------------------------
Having the last motor that I renovated set up on a test bed, using the starter motor, I had it turning over without the head on and was surprised to find a hard lump of crud come out of the hole that feeds into the oil galley in the head.
Given that the size of the hole in the head gasket is smaller than the oil galley, as soon as the oil flow lifted a bit that hole may have been blocked, if the head was put on first that lump would have still been in the oil galley in the block.
.

Further to this discussion.
About 10K ago I went to adjust the clearances after a 20K interval (longer than I like but it did incorporate a long trip and just didn't get around to it). What I found was the caps in a really bad state, two were worn through, some badly pitted. These were aftermarket ones, I think were Britpart. Not having any choice, I reinstalled the old ones (fortunately kept) which I replaced before the 20K mentioned above, shiny, with some wear (all circular marks so at least rotating properly). Now 10K later I just put a new set of genuine caps in (LJC 100270) and will see how they go.

The set I took out, the previously reinstalled used set, after the 10K, still look reasonably serviceable and all the clearances were still good. See the attached photo. The ones on the left are the ones that have been used twice and have done at least 30K maybe more, the ones on the right (mixed up and in no order) are the aftermarket ones with 20K. I tested one of the bad set with a file, and could make a groove pretty easily.

I think this a good case for poor quality caps over lack of oil.

Simon

Just following up on the lash caps. I did a valve adjustment the other day after about 10K km and inspected all the lash caps. All seemed to be as good as new. The only wear was the original blue worn off the top of the cap. Problem solved. Hope this helps somebody else.

Cheers mate.

FWIW I've also heard of someone using Volkswagen 8mm hardened lash caps successfully too.