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Discussion Starter #1
I've posted a few questions regarding oil pressure on my 1.9 Non turbo H reg (1991) T4. We completed a simple budget camper conversion and all was well. There was hardly any power uphill and quite a bit of black smoke when under stress. Occasionally there was a beep beep beep but oil levels etc were fine and under the rocker cover was saturated(hmm). Then on one fateful Sunday the beep became continuous up a long incline, I had my 2 year old in the van and nowhere to pull over. Then the engine made a rather loud metallic sound. I pulled onto the grass verge and waited for recovery. Green Flag man said it sounded like a valve. RAC man said sounds broken but I'll buy it off you! (Needed 2 recoveries to get it back to Swansea, mine and my G-friends)

On inspection it was apparent that a valve had dropped and one tappet had been smashed to smithereens and tangled up in the cam.



You need to look below the 5th Cam lobe to see a hole where a tappet should be. The cam lobe had big chips out of it and it was also noticeable that no two cam profiles were the same, with huge flat spots on some. Obviously this was not helping the power uphill!



So it was time to take the head off and have a closer look.

Take the the front grill/radiator etc away for ease of access. Drain water and the oil. I say oil but mine was like mud. The clues were starting to appear.

 

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Discussion Starter #2

Remove diesel lines, mark the positions of the cam belt on the pulley, Put cam to tdc, the cam shaft has a slot on the right hand side, this slot is parallel to the head. Remove head bolts. These are expansion bolts and new ones have to be used when they are replaced.


Pulleys come off.


Some belts.



Some wiring needs to come off.



When all is freed up, the head lifts off (pull up forward and right!).

Now you get your first look at the pistons.


Any damage?????

How lucky?, just a little indentation in the carbon where the valve bounced around!
 

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Discussion Starter #3
At this point the plan was to fit new tappets,camshaft, cam belt and head gasket. So the head was stripped down and everything cleaned up. New camshaft and tappets etc purchased. During the stripdown and rebuild it was noticed that there were a few bits missing. The valve springs should be sitting on washers. These weren't there. Some other bits and pieces also. It all went back together in the end and the van started first time......

On test drive however all was not well.
When it got hot the alarm bells rang out again. Low oil pressure. There was only one way to check if the beeper was telling the truth so we bought a pressure guage. (In fact we bought two but one was a flashy lit one that was barely visible). The guage confirmed the beeper was telling the truth and it was losing pressure after a few mins and dropping completely under stress. First thing to tick off was oil pump pressure relief valve. This maybe sticking open. Off with the sump and service the pump. The pump was within tolerances and the strainer was loaded with junk so it was cleaned up and replaced....
No difference.

Bought a new oil pump.


No difference.
Found that the non return valve was missing by the oil filter channel. Put one in.
No difference.

By this time my girlfriend's dad (who is the brains behind the outfit) was pulling his hair out. We took the rocker cover off and examined the goings on whilst it was running. A messy affair but showed that the same bore that dropped a valve before was a bit goosy loosy. We thought it was a bit shafted but maybe ok. This turned out to be a time consuming mistake.
 

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Discussion Starter #4

mmm!




Building up the new head with our new bits from our old head.





All shiny and lovely.


Tensioner renewed with head gasket/cambelt kit.


This book helped with torques and stuff but it did leave a few things out. I already had a VW golf Haynes manual and to be honest the diesel section in that was just as helpful if not more.

The outcome is that it not only holds and builds pressure but the new cam and improved compression mean that I have no black smoke and I zoom up hills. (well 70mph) It's the first of the T4 productions and it's taken my emotions up and down but driving it now puts a smile on my face again. Jobs left to do...
Replace windscreen and fix surround and seal. Replace sliding door roller. Sort out the skimming windscreen wipers. Buy a new grill. Lower it a tad. Watch this space I suppose, fingers crossed the next threads will not be in engine section.
 

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Discussion Starter #6 (Edited)
Massive thanks go out to 'the Doc' who put in hours of work and lost days of sleep sorting this out and thanks to AW Engineering for the head and cam etc who were ready on the phone with help as well as good quality parts sent very quickly.
 
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