The back two cylinders look a little clean to me. Water injection from a head crack?
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The back two cylinders look a little clean to me. Water injection from a head crack?
I had another look at it this morning. Still can't see any crack, but I also can't get the injector out. I was going to make up a slide hammer but I couldn't find a nut the right thread and missed getting to the part shop before they closed. Going to be a Monday night job.
I did a bit of photo editing to give a clearer view of the cylinder walls and the head surface.
The intake valve on cylinder 1 has some sort of caked on chalky stuff around the edge. This is the cylinder that had totally worn through the valve lash caps. I'm guessing the build-up was caused by the valves not opening enough. The cylinder walls look really good. You can actually see the honing marks if you zoom in.
https://www.aulro.com/afvb/images/im...14/10/1113.jpg
https://www.aulro.com/afvb/images/im...14/10/1114.jpg
Cylinders 3 & 4 have some odd marks on the walls. In 3, it looks like something brown has dribbled down the wall, but I couldn't actually feel anything and it didn't wipe off with a rag and WD40. Cylinder 4 has an oval mark on the wall that really stands out. The face of cylinder 3 has a bit of a scratch across it where it fell over while I was trying to get that injector out. Its very shallow, so I'll polish it out if I reuse the head.
https://www.aulro.com/afvb/images/im...14/10/1115.jpg
https://www.aulro.com/afvb/images/im...14/10/1116.jpg
One thing I'm wondering is, if these heads are so easily damaged by overheating, why does the head gasket have restrictions in it (circled) where the water flows through?
https://www.aulro.com/afvb/images/im...14/10/1117.jpg
I have recently replaced a head on my '97 Tdi after an overheating episode that caused a .012" warp between cylinder 2 and 3, the replacement head I used was off a '95 tdi engine that had run a big end bearing some years ago and had been kept as a "just in case" spare by a mate, so the head was still ok even though it had already done about 300,000 odd Klm on another engine. The head was refitted using a "Victor Reinz" MLM gasket.
The advice most will give here is that "these heads cannot be resurfaced if warped" and that appears to be borne out by the number of recurring head and gasket failures that take place a short time after having a head resurfaced then refitted to the engine, it seems a bit inconceivable that a head should be scrapped in my thinking, small corrections maybe ok up to .005" I have also been told.
My advice would be to have your original head checked for flatness first, if it is flat or at least within reasonable bounds then have it pressure tested, the deposit on that valve on cylinder 1 (is it) is a bit sus, maybe a port crack? But if the head checks out ok refit that head using a Victor Reinz MLM gasket with all new head bolt set.
You indicated that the head bolts were not all as tight as you would have thought they should be and that could have been also a problem or more to the point "the problem", make sure to tighten the new bolts strictly to the tensioning procedure in the manual using the tension wrench/rotation gauge method. There are some good instructional youtube vids on the 'net also. Gaz:)
Thanks for that.
When I said that 7 of the head bolts were able to be undone with one hand on the breaker bar, I should have said that I could have undone them with a spanner. Any looser and I could have just used my fingers.
Once I get the last injector out tomorrow, the guys we share our shed with are going to crack test it and do a hardness test for me.
If I have to replace it, I think I'll get one of the newer design heads from Autopost in the UK.
Does anyone know where I can get the hardened lash caps in Australia? The part number is EMPI 00-4006-0 and they were for the 1600cc VW engines. The local VW agent here had no idea what I was talking about and the only ones I found online were in the US.
Tank used Crane Cams caps i believe, i bought my head/kit from Autopost and i was happy with their service and price.Quote:
Originally Posted by Ravvin71
Crane Cams Australia, I think they are in South Australia, cost me $87 delivered, you get sixteen lash caps, if I remember they are the 10mm caps, just ask the bloke at Crane, they seem to sell a lot of these caps to Land Rover owners.Quote:
Originally Posted by Ravvin71
Anyway for all the info and sizes search "Valve Lash Caps" in the search engine at the bottom left of each page, Regards Frank.
Thanks for that.
After checking the head out I ordered a replacement from Autopost. Ordered Tuesday afternoon, my time, and received it Friday afternoon.
I can't get freight from Queensland that fast.
I cleaned everything up and fitted the new head. I found out that it's a good idea to fit the glowplugs before putting the head on as otherwise
you have to unbolt the air-conditioner compressor to get the front glowplug in. Oh well. Got it all torqued up and the rocker assembly back in.
I have all the pushrod adjusters backed off as I had to wait for the new lash caps. I got the hardened ones for the VW engines.
As I had pulled the intercooler out to clean, I did the radiator as well. I found the gap between the radiator and the aircon radiator totally packed
with dry crispy locusts. Definitely not from down here. The timing belt kit arrived so I read up on how to fit it.
The crank pulley bolt undid fairly easily with a breaker bar and 4' length of pipe. While cleaning the threads out in the pulley so I could get a puller on it,
I realised it was loose. It just slid off with hand pressure. behind it was the thing in the photo below. I can't find it in the Rave manual or the TDI repair supplement.
I think its a dust shield. Whoever removed the pulley previously seems to have screwed bolts right through the pulley and dented the dust cap. I'll hammer it out a bit if I have to refit it.
https://www.aulro.com/afvb/images/im...14/11/1163.jpg
I'm really hoping its not that important as I have put most of the engine back together now and noticed it on the floor.
What do you all think? I'll put it back if its needed, but I'd need to pull the front belts, tensioner, crank bolt and pulley off to do it.
The timing belt/tensioner/sprocket/new seals/idler assembly went in fairly easily and all appears to be lined up.
Something that concerns me is that when I took the front cover off, I had about 1 tablespoon of diesel run out.
It looked like it had been in there a while. I've had the Discovery for 5 years and about 120,000kms. I didn't realise there was a drain bung in the bottom of the housing.
I have read about fuel pump leaks being caused by the lack of sulphur in modern diesel. Supposedly it acted as a lubricant or preservative for o'rings and seals.
I have only recently started using an additive with each tank of fuel, so maybe this diesel leaked in earlier on. I'll check each fortnight
for a while by taking that drain bung out to see if more has leaked. Has anyone else had a leak like this happen?
I've done a few belt changes and have never come across anything like your dust shield. Leave it off, the front seal is a dust seal anyway.
As for diesel in the timing chest......just keep an eye on it as you suggested.
I don't think low sulphur diesel was a big problem for the TDI.
I've had mine since 1996 and went through the low sulphur introduction without any problems.
And the drain bungs (wading plugs) should be left out and only put in when your going for a swim.
Good, less work is better.
And yes, you are correct. The 300TDI Engine Overhaul Manual shows it as a wading plug on page 12. It's in the bottom of the front timing cover.
I didn't even realise it was there until I was cleaning the mud, oil and gunge off the cover before putting it back on. Mine has a copper washer similar to the sump bung but smaller.
I'll leave it in and check for more fuel leaks occasionally. I wonder why the previous owner left it in?