Thread: Help to fix our RR Classic please

Failure of the inlet manifold gasket is quite common because most people forget to check and retighten all the bolts after a few weeks. The metal of the gasket has thin paper stuck to both sides, and this is what fails and is sucked into the ports. Replacing the inlet manifold gasket is not a very difficult job, after you've undone the 6 allen bolts to remove the top section of the plenum chamber.

Thanks Bee !

On your wdvise I stripped her down to inlet manifold. The rockers look pretty damn gungy however the cam and valley look good from what I can tell though I'm no expert. The inlet manifold looked OK being metal but the bolts weren't very tight... Rocker cover gaskets are cardboard type and I think that could have been part of the issue but I'm not sure so will replace both if the rest looks ok ?

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A friend has suggested to now remove rocker gear before going further to look at the cam...

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Oh dear,,,
I wonder how many years since anyone has changed the oil,,

The camshaft looks badly worn with the centre of the lifters hollowed out and running on the edges of the cam. You would probably be wise to replace the head gaskets too at this stage, the tin gaskets that were used on the RRC's of this vintage can leak quite badly without actually failing catastrophically. And of course the heads can be thoroughly cleaned at the same time so it goes together and stays healthy for a while.

G`day ,

what is your Range Rover you say flapper so i guess between 1986-89 but you also mention points which would make it much earlier ?

before you pull anything else apart , i would suggest you price parts to put it back together .

Your compression test of an even 120 across the 8 cylinders is not a bad figure specially if cold but a hot and wet test would have been also helpful .

It is always better to diagnose before pulling apart .

The amount of gunk on the overhead gear doesn`t tally with the lack of gunk in the inlet ports .

The gunk on rocker arms/shafts suggest they will be worn but here at least a physical inspection will tell the story .

The gunk on the overhead would suggest that the timing cover will also be full of gunk and the timing gear well worn .

The cam shows its wear by the discolouration on the lobes but by doing a vacuum test before it was apart would have been helpful .

If the inlet manifold bolts were all tight the gasket was probably ok , the inlet manfold gasket suggest is for latter engines and when they fail it will be normal to find the bolts loose specially at the rear it seems .

What i would suggest you do is decide how much you are prepaired to spend on this engine , then price some parts .

Each time you pull something apart you are spending money if it is to go back together .

This may not be of concern to you but it would be to me .

You will of coarse take on board what you will and dismiss what you will and that is you choice because it your vehicle and your money .

Cheers .

If I had it my way, I wouldn't be going any further into the engine. I did the tests I felt with my knowledge that I could do before cracking her open.

It is an 89 model RR.

120/130 was when cold... unfortunately was difficult to get her to run without jamming flapper open.

How would I have tested the cam via vacuum test ?

It is a concern as the car is not in exceptional condition and needs work in other area's, so far I would say to put this engine right, I would be looking at about 500/1000 off the top of my head.

It is more of a project than anything I would use daily, I was hoping that it was going to be something simple like a gasket but if the cam is worn it probably isnt worth going much further besides looking investigatively to find all the parts that need replacing.

Is there anything else I should check that's easy or based on this, sell her for parts ? If I am correct in saying 500/1000 min would be the figure to repair ?

G`day ,

is yours a 22D prefix , (the start of the engine number ) , on the flat near where the dip stick exits ?

it seems your looking for a mechanical fault when your comp test suggests it may not be .

There is a breather on probably the back of the left hand rocker that if air pressure was put into the valley would want to try and escape through if your air leak was in the region it may have been just that .

If you look at the cam and can see the point of each lobe clearly by rotating the engine by hand and they all look similar pointed shape , i`d leave it as is , if you find a rounded lobe that will obviously be lower than the rest you`ll need to decide .

If you can`t see the lobes clearly you could rotate the engine by hand and note the height the lifter/tappet body ( the actual cylindrical bit that moves up and down in the block , not the internal the pushrod sits in )
Same thing if they seem the same height leave it , if not decide .

Basic things like checking spark plug colour can give an indication of whats happening .

Things like a faulty coolant temperature sensor can make them run rich . ( not the sender for the temp gauge ) Though it should start ok initally but not want to run cleanly when hot , as in not smoothing out but getting rougher .

If however you can`t get it to run properly enough to run hot it can load the plugs up progressively so`s it wont want to behave .

Does yours have a 10 mm welch plug under the tps ( throttle position ) just like the ones in the block only small ?

If you google how to read a vacuum gauge it should have something they are also good to set timing with because it takes into account the wear in and engine related parts but that is my opinion other may not agree .

The money side i don`t know as i buy stuff when i see it cheap , cams i would price from a builder/grinder rather than off the shelf , i`ve been using GM type lifters for more than 20 yrs without problem , where as others even those that do the work for a living sometimes malign them but i`m of the opinion if the engine is assembled properly there is no reason for them not to work .

I should mention i was once upon a time a full time mechanic but not for a long time so my ideas may differ to some here .