ThreePointFive

4.0 GEMS engine swap

Recommended Posts

Thanks for the suggestions, turning the 15mm nut clockwise did it (a bit counter intuitive though!).

I wonder if this belt isn't for those without the idler pulley then, because while the belt does now fit, the tensioner is very far into the travel, more than I would have thought normal. The other belt had about 6 inches more but I think that would be too far the opposite, and at £50 I don't want to be experimenting too much.

A picture and a thousand words and all that:

DSC_0417_zps7fa736a9.jpg

DSC_0418_zpsfa781237.jpg

Can't believe even a simple belt change could be such a pain in the arse.

Share this post


Link to post
Share on other sites
Bingy    5

The tensioner pivots on the bolt on the Ally casting.

On your last pic, if you would have moved the socket and bar 90 degrees anti-clockwise

you would have in effect increased the length of the tensioner.

Then by pushing the bar towards the engine, the increased length would have made the tensioner a doddle to move.

Where you have shown the socket and bar, you are risking shearing the bolt and pulley off whilst trying to move the tensioner.

Hope this helps

Share this post


Link to post
Share on other sites

I get what you're saying but don't forget that the picture shows it in the final position - it did start off more than 90 degrees to where it is shown. The tensioner was incredibly easy to move once I had confirmation it was meant to go that way, any stress was very minimal.

It's the fact that the bar went through such an arc that made me concerned - the distance the pulley traveled is far greater than it looks from the photos and hence my concern it was too far to be correct.

Share this post


Link to post
Share on other sites
Bowie69    382

Looks perfectly normal to me :)

At that position you get most tension on the belt.

Share this post


Link to post
Share on other sites
Bowie69    382

In fact I think if you look at Rave, it gives marks on the two tensioner halves that should line up if the belt length is within spec (i.e. not stretched). I *think* these are the two flats you can see in FF's picture.

Share this post


Link to post
Share on other sites

Thanks for this chaps, I'm happy it's as it should be now - being a new belt it makes sense it would be at the very tightest setting and will of course stretch with use. I'll keep an eye on it but it's only very slightly more than FF's picture.

Funny to see how far this has come since I started the thread, for now that's all the mechanical side accounted for - "just" the MS to get done.

Share this post


Link to post
Share on other sites
Rangie46    3

On my 4.0 I had the same issue with the non air con belt being really tight and couldn't get the belt on, I ended up removing the pulley just under the power steering pump and so far all has been good and had no issues

Share this post


Link to post
Share on other sites

Did I say the mechanical side should be sorted for now? :rofl:

So when I put up that picture of the inside of the rocker cover, I can see why everyone was saying it wasn't that bad. I now know what a bad one looks like, and it was sat a foot away the whole time.

DSC_0449_zps319aebb7.jpg

That is after I wiped it thoroughly with a rag. I have just spent four hours cleaning them, and they're not even finished.

This was just one bit of inside the rocker housing:

DSC_0450_zps9daad9db.jpg

Inspected it with a screwdriver just to make sure it was really full of carp. Yes, yes it was.

DSC_0451_zps7cb41f7d.jpg

These are the covers now, one bottle of fairy powerspray, one brillo pad and a sizeable blister later:

DSC_0464_zpsc18d3d74.jpg

Only to find out that it has small cracks, sort of a crazed pattern. They are present on both covers, but they only seem to be on the surfaces which are closest to the plenum. The outside edges are completely smooth.

DSC_0460_zps90b71374.jpg

This is clearly not a new engine, and I'm not saying I need to rebuild it but I am concerned that there is so much gunk on one side but totally clear the other. I'm also just curious about the crazing marks, anyone know what this is?

Lastly, and as earlier in the thread, I have some tubes I cannot identify and no one else seems to know what they are. Having stripped some more pipework away there is now a better view of them, so if anyone can shed any light:

DSC_0437_zpsb952537b.jpg One for each injector by the looks of it. There are four each side, but one is missing on the offside, shown here:DSC_0446_zps1e49d6da.jpg

I'm assuming they're some kind of breather, but do I need them and what is the best way to deal with getting them sorted out?

Double points if someone can identify the nozzle at the top fo the photo, looks a bit like a valve of some sort, sounds stupid but quite similar to a tyre valve.

Share this post


Link to post
Share on other sites
Bingy    5

The pipes on each injector look like they are for a LPG, unless someone more knowledgeable can itentify other wise

Share this post


Link to post
Share on other sites

That's interesting, hadn't even considered that. So given it's been retrofitted, and I've never had LPG on my original engine, is there anything else I now need to be looking for which would be have been added for this?

I'm guessing there couldn't be much else, but a sensor or something? This is just one more reason the vehicle could have been junked I suppose. Can't wait to get a compression test.

Share this post


Link to post
Share on other sites
Bowie69    382

Yup, LPG injectors.

Nothing else is likely to be added to the engine. I'd unscrew the nozzles, and fit some very short bolts in their place though. M6x1.0 is a common thread size.

Share this post


Link to post
Share on other sites

Thanks a lot all, I'll try unscrewing. I may at some point want to go for LPG so keeping the option open would be ideal, though I've read far too many threads on running problems and they seem to make engines run lean, not sure I'll be doing it any time soon.

No one has stated the significant difference in burnt oil/carbon between one bank and the other is of concern, it's now or never in terms of getting it looked at in more depth so if I can take that as the usual "probably ok" then I'll take it and run.

Share this post


Link to post
Share on other sites
deep    18

Thanks a lot all, I'll try unscrewing. I may at some point want to go for LPG so keeping the option open would be ideal, though I've read far too many threads on running problems and they seem to make engines run lean, not sure I'll be doing it any time soon.

No one has stated the significant difference in burnt oil/carbon between one bank and the other is of concern, it's now or never in terms of getting it looked at in more depth so if I can take that as the usual "probably ok" then I'll take it and run.

The only thing that comes to mind is worn valve stem seals, worse on one side. It's possible, with some motors, to replace those without taking the heads off by making a fitting to allow compressed air in at the spark plug hole. However.... if it was my engine, the heads would be coming off now. This is the time to check valves, guides, cylinder bores, cam followers etc. Good quality head gasket, new seals etc. and you'll have more confidence for the next few years. Not that I did that when I changed the V8 in my Land Rover last year! (I was lucky.)

Share this post


Link to post
Share on other sites
elbekko    47

Don't be too afraid of LPG systems, most of the problems with them come from bad installations that seems to be almost mandatory amongst the licensed installer crowd.

Share this post


Link to post
Share on other sites
Bowie69    382

Don't be too afraid of LPG systems, most of the problems with them come from bad installations that seems to be almost mandatory amongst the licensed installer crowd.

Exactly.... LPG is no dark art, very simple in fact, as for running problems and running lean, well yes... LPG does run at 15.5:1 rather than 14.7:1, but that's what it needs!

If I was doing the mileage I would go with LPG.

Share this post


Link to post
Share on other sites
poohbear    1

The LPG system will have used a number of the existing sensors so the wiring loom(s) may have been hacked about where the LPG ECU had been spliced in.

Obviously not a problem if you aren't using the existing wiring.

I'd second keeping an lpg option open - decent sequential systems are perfectly OK and easy to service, keep running.

Dave.

Share this post


Link to post
Share on other sites
Bowie69    382

I've not known an LPG system use any existing sensor other than the TPS.... and even that was optional.

Clearly though they normally interrupt the injector harness.

Share this post


Link to post
Share on other sites
elbekko    47

Mine has an RPM reading (tapped from the cruise control RPM wire), the 8 injector wires and the injector common live.

All the rest is through the LPG systems's own sensors (coolant temp at the vapouriser, MAP from the manifold, gas pressure from the gas line, gas temp from the gas injector manifold).

Share this post


Link to post
Share on other sites

I'm going to keep an eye out for anything not used in the MS'ing of the engine but having now removed the LPG pipework it looks a lot simpler and most sockets/plugs are accounted for. I'm hoping, and it appears, that it was just these pipes that were added - the loom is a mess and in its current state I'm thinking about just salvaging the plugs from it and binning the rest. As I don't need it I don't want to spend time working out what is original or not.

I'm going to try to look up the layout of a P38 engine bay because it looks like a lot of the pipes that are staying are the opposite sides to a Defender, i.e. the heater and steering pump, I also seem to have an extra hose for coolant so I need to find out what is going on there. Unless any of you 4.0 P38 owners have photos on hand?

I'm now trying to get hoses and radiator sorted but as this isn't a standard configuration it's proving a little difficult to get off the shelf components - 50th anniversary radiators are just not obtainable - I can't even get a radiator maker to knock one up!

As ever, thanks for the guidance, I'm slowly getting somewhere!

Share this post


Link to post
Share on other sites
poohbear    1

From recollection apart from piggy-backing the injectors mine read MAF & both Lambda values, I think the wiring was intercepted at the gems ecu multiplugs. It had it's own sensors for absolute manifold pressure, fuel temp, can't remember any more.

Dave.

Share this post


Link to post
Share on other sites
Rangie46    3

For the radiator in my 4.0 90 I used a new n/a doozel radiator and has been fine, the 4.0 and 4.6 have a pigs hart fingy for thermostat so on mine I used one of Nigel's restictor plates on the inlet man water outlet and the engine stays nice and cool motorway driving about 70 deg, fans do come on tho when in traffic and in the mud. The extra water outlet on the inlet manifold on the left hand side when looking at it from the front can be removed,and I blocked it off with a standard house radiator cap as it has the same thread, and the smaller outlet on the right side I Plumbed into the radiator to expansion tank hose with a tee piece so it can bleed itself, will try and get a few pics for you a bit later

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now