Thread: Disintegrating rocker cover gasket (and other problems)

Hi Paul,
If the rocker cover is causing the loss of compression that would be a first. This sounds like a sticking valve. If it is I suspect it would be an exhaust valve, by the sounds of things the head doesn't sound tat clean. If you get a straight edge and run this down the valve stems with the rocker shaft off you might find one stem lower than the rest. In the past I have sprayed the stem with WD40 and tapped lightly with a copper hide mallet, the hide side.
If you can't find anything there yeap, head off and check, if the problem is a piston you would know when you turned or ran the engine with the oil filler cap off, I would have thought.
As for the gasket, sounds old maybe someone tok the R/C off and just put sealant on rather than buy a new gasket.

Cleaning the sump out sounds like a good idea you dn't want that black pellet type stuff blocking up your oil pump strainer.

Cheers Marty.

Dont hate sealant because of idiots,,
you should at least glue one side back on when you replace the gasket.

Originally Posted by Nomad9

Hi Paul,
If the rocker cover is causing the loss of compression that would be a first.

Thanks Marty. I wasn't suggesting that the rocker cover itself was the cause, more that the damage to it had led to the cause but even that seems a bit extreme to me.

Originally Posted by Nomad9

If you get a straight edge and run this down the valve stems with the rocker shaft off you might find one stem lower than the rest.

Good idea. I did actually tap the springs to see if any of them sounded different to indicate damage but they look, feel and sound OK. I like the idea of trying to measure the height of the valve stems though. I gave that a go but there was no discernible gap between the straight edge and the end of the stems.


I'll take the other rocker cover off later and do a quick spray around and clean up then redo the compression test just to confirm it's still there before taking the head off.

Either way I am going to have to flush the engine out and clean the sump. Cleaning the bits I take off is easy enough but what do people recommend for flushing the engine itself to clear out whatever I can? Kero? Diesel? Vodka? :-)

Paul
1998 D1 V8i
2003 D2 V8i S

Hi Paul,
No malice intended with my comments about the rocker cover, until I get to know or at least get a feeling for peoples level of expertise all bases have to be covered.

Uuuuuummmmm engine flush, me personally not so sure about, the Vodka option, not to sure about the lubrication qualities of Vodka.......might work On a more serious note. Different schools of thought here, me I used an engine flush on an older engine and it disturbed all sorts of crap, when you wash all this stuff out of the engine your only defences are the strainer on the oil pump for the big bits and the oil filter for the rest, additionally on the TD5 you have a centrifuge filter.

Cleaning an engine out now I go for a synthetic oil and change the filter more often. Personally I have found that syntheics will clean en engine up over a couple of oil changes. After that I change the filter every 5k and the oil after 10k.

I did some oil analysis on the old oil when I bought a D2 300tdi which had had its service intervals stretched to the edge. The first change with a synthetic the oil was really grubby and the filter wasn't far behind, no point analysing the first sample the evidence was clear. After that for the next two lots of 5k the sample cleaned up significantly. Additional to that the engine developed a couple of minor oil leaks which is one of the downsides going from a mineral oil to a synthetic, however still manageable.

If I was going with anything as a flush I would use diesel, that's what I would use.

With your compression issue. With the plugs out pour a small amount of engine oil in the plug ole(s) spin the engine over to get rid of any excess and then check your compressions again see if anything has improved. No improvement would mean a bigger problem than the rings and bores. When you do the compression test is there any reading or nothing at all?

Could be an issue with a hydraulic lifter, that would explain the ticking noise, still gotta take the head off unfortunately.

Cheers Marty

With the rocker shaft off and the spark plug out of the offending cylinder, apply a length of heater hose to the plug hole and blow. You should be able to hear where the air is going, out the head gasket, out the inlet valve, out the exhaust valve, out into the sump. You can also make a hose adaptor out of an old spark plug and use compressed air.

Hi Bee utey,
Every day is a school day.................... Ha! Good one. One of the many reasons I choose to drive Land Rovers.....

Cheers Marty.

Yes bee utey, I did that already - we actually had the same conversation a while back about my D1.

Compression test was still zero-ish so I hooked up the pipe and blew. Seems to be escaping somewhere underneath the intake manifold. I was hoping for a bust injector/o-ring at first because there was a definite smell of fuel when I blew. However, the fuel rail is off now and I have blocked up the air intake, the injector port and the exhaust outlet and I can still blow so I guess the gasket is gone under the intake manifold somewhere.

Inlet manifold will be the next thing coming off...

Paul

1998 D1 V8i
2003 D2 V8i S

Inlet manifold and valley gasket removed. The valley gasket has definitely seen better days. Tried bee utey's little blow down the tube trick and straight away could feel a draught coming from almost directly below the intake for cylinder no. 3.

Off came the head (some of the stretch bolts didn't feel very tight) and the offending article was removed (see photo). At least I know what it is now.

I also removed the RH rocker cover which was pretty much welded on (even more than the LHS). The good news is that there was no sign of the debris from the disintegrated RH rocker cover gasket anywhere else :-) Plus, as I wanted to feel like I had achieved something today, I did manage to fix the driver's door lock so it works with the key now and refit the door trim :-) :-)

I will now no doubt be a victim of Christmas, waiting for the necessary parts to get back on the road - good job I still have the D1. I also have rather a lot of bits to be cleaning.

Paul

1998 D1 V8i
2003 D2 V8i S