My 94 disco 3.9L petrol was a pig when I bought it from the back of a dealer yard. It over heated on the way home and then dealer fixed it for the short term. Well it is over heating again, actually got a couple of trips to the mountains out of it, but now get about 10mins driving before engine light comes on, luckily we went to the mountains for MTB and so ride our bikes most of the week, and only use on weekend to get groceries. We should have got a wheel burrow.

Anyway theres the history, and I have for that reason been thinking of fixing it myself for a while as i'm tight (bycycle rider ...) and last mechanic I went to ripped us off and lied, he'd said he changed the air filter but the problem is when I looked the sponge part of the old filter had appeared to go thru the engine and old the mesh remained.

So anyway on sunday I got out the wrenches and stripped off the intake manifold and rocker covers and everything else that got in the way.

QUESTION 1: The rockers and rods etc. were all coated in burnt black oil, the consistency of hard toffee. I take it this is bad or is that how it looks? So I am going to pull them all apart and clean. What is the best way to clean them once I have them out? Keeping in mind this is diy with out a garage, the degreaser I got apear to have limited effectiveness and I am using a lot of elbow grease to clean the parts.

QUESTION 2: As I said the old air filter went through engine, and made a big mess on the way, especially in the ram housing and intake manifold. I have these off in one part and they are stuck together pretty solidly. Should I try to pull these apart to clean?

QUESTION 3: Also even worse there is a small nossle in the water system fixed to the intake manifold just by the thermostat this has rusted pretty bad, and is nearly broken off and needs to be replaced, can this be replaced either by welding or does it come out and can replace another way?

QUESTION 4: How powerful are the rocker springs? I have the official LR engine overhaul and disco manuals will know the proceduce.

QUESTION 5: I plan to strip it back to the block, e.g. taking off the heads but don't want to go into playing with the cyclinders/orings ... if at all possible. Seeing as I will be going that far should I strip it further? Will it ever end?

Well that is enough for now, help will be very much appeciated. I would be great also if I could find a mentor ...

Thanks.

 

paging disco mike...disco mike...

 

If it's not too late ... you should keep all the pushrods in a piece of cardboard so you know which ones go where, same with the lifters. Cleaning with solvent and one of those two sided dishwashing pads, sponge on one side, green stuff on the other. Soak the lifters in marvel oil while they're out, but again, don't mix them up. Take the heads out to a good machine shop and have them do the works on them - complete valve job, mill if necessary, check the springs, shim if necessary, etc. Buy new head bolts. The head bolts on these things stretch, so you do not reuse them. Get a good top-end gasket kit, new hoses and clamps. I did this about three months ago, and I'm pleased as punch with the Disco now.

 

I recommend you go to my site at www.eurotekapg.com and read the tech info section relating to the powertrain. To answer one of your questions, the dark brown "staining" of the valvetrain components such as rocker arms, pedestals, push rods, etc. is considered normal. If indeed you have black gummy deposits on these components then the indication is that this engine went a long way between oil changes, probably had cheap high paraffin-type oil put in it, and was run hot more than once. This "bakes" the crud in suspension in the oil--- all over the components. This also affects valve sealing, piston ring sealing, and shortens the life of the oil pump. You may get lucky with a valve job on the heads, a skim cut to make sure they are flat, and careful re-assembly. One test to make sure the cylinder rings and bores are in fairly decent shape is to turn the engine over so all pistons are some distance below TDC ---then pour some ATF into the bores to completely cover the piston crowns. Let it sit overnight and then observe if any cylinder has lost the ATF. If all are holding all, or almost all of the fluid, you are probably okay in that area.

Regards,

Geoman
www.eurotekapg.com

 

What about that seafoam stuff, isn't that suppost to clean the internals pretty well?

 

I've used Seafoam to good effect, but it is not intended to be used as a universal solvent to clean parts by hand. It does a good job in removing varnish and combustion by-products from inlet tracts, injectors, valves, top rings, etc. by adding it to the fuel tank, and by giving the inlet tract a concentrated dose by letting the plenum vacuum nipple with a hose attached--- pull it into the engine. Then you turn off the engine immediately and let it soak.

Geoman

 

does anybody have a part # or information on where I can get shims for my resurfaced heads on my 96 Discovery?..already have top end kit

 

This is the Discovery II forum. You have a Discovery I.

Also, there is no need for shims on pushrod motors unless you've done some over the top decking.