Bull Bar Cowboy

Gas is about 10 less efficient than Petrol so that wont help…….. Cams on the later engines tend not to wear so badly ………. But the timing chains still stretch to the point of being silly slack ……… this will retard the cam and the engine loses all bottom end / mid range grunt ……… However, unless it has been well looked after, a Rover V8 on 122K will be long past its best and many will be long past their sell by date.

The plastic module is probably a Vacuum delay valve .......... did it look like a miniature top hat ? These were used (some years ago) to improve economy and emissions ........ it would seem blocked because it is a restrictor with a very tiny office ........... this gives the effect of a step in the vacuum advance.. i.e not vac, then almost full vac......... I have seen a few on mil engines and LR export engines……….. Its Ok to bin it...........they never really worked well ! Also it might have been a non return valve. These were used to stop any carb backfire pressurre from reaching the dizzy ....... these were marked at the ends with either 'Carb' or 'Dis', some of them, also had a small red band on the carb side of the capsule..... not a very common fitment......

Yes agreed ………… sounds like ignition amp which is a known failure, but more info is required…………

Yes, composite gaskets are standard on 4.6 engines & late 4.0 engines W/pump should be OK ………. They are simple enough to change if not, but they go on for a long time. Yes, fit a new 88 deg thermostat……..you will need a housing gasket. Just gently take the raised edges of the mark ………. I would carefully do this with a scraper (or Stanley blade).

That is only a light mark .......... it will be OK........ The evidence of blowing is not strong without seeing the head gasket .........

Yes, it wouldn’t hurt to do both sides ……….. I would leave the hoodies (valve stem seals) as they are neoprene and last well………… Go here for parts and download the Rover pdf ……… http://www.realsteel.co.uk/ They have excellent service with good technical backup………….

Right ……. Lets go back to basics with the brief history that was passed to you…. The car overheated due to a split hose (I would assume the top hose) ……… then a compression check was done and two cylinders were reading low……… OK …… The above makes some sense and gives me some comfort that it was more then likely a headgasket failure, however, it could have been a chain reaction with a liner fault causing pressure build and the head gasket gave in when it got hot …….. but I don’t think so ……..note, I said ‘liner fault’ ……. The issue is generally a crack behind the liner and then gases are forced between the liner / block and into the cooling system on each compression / firing stoke ……. On the other strokes the cooling system fights back and releases some of the pressure as coolant / steam into the cylinder. The term slipped liner is often not evident and often not the true cause. The fact that the front piston is cleaner then the others is that the water jacket is also at the front and this is a common point for H/gasket failure …………..have a look at the inside of the plenum & rocker covers and see it there is evidence of mayo ? I guess in your position I would want to get the engine running as quickly and economically as possible to evaluate the rest of the engine and car. It looks like you have already checked the head ………. I assume that you placed a known ground straight edge diagonally (corner to corner) across the head in two directions and then checked for any gaps with a feeler ……… If the head is OK, then at this stage I would be inclined to just rebuild it with a new H/gasket (yes, 10 bolt Compo) , new valley gasket / rubber seals, and new exhaust manifold gaskets. Also use new headbolts ...... they are cheap. Fill cooling system with 50/50 mix of coolant ……. Start engine then hold your bowls and pray to the lord ………. You have a PM…..

Jay ?

Well Done Donald ……………….. change the oil / filter asap and you will be good to go. Not only should it be smoother, but also a little more torque as well.

To rebuild your 3.9 correctly with a rebore you are looking at the thick end of £800. If you want to start gaining more hp and upgrading then allow a budget of £1200 – £1500 Most of the readily available pistons will be for 9.35:1 CR ……………. If you want the lower CR or 8.3:1 then probably they will be dealer only availability as there is not a lot of call fro them. The old Rover Vitesse 10.5:1 pistons were almost flat topped but I would hazard a guess that these will be harder to procure then rocking horse sh!t. If you take off 40 thou from the head then the CR will be about 10.5:1, but will drop to 9.9:1 because you will use composite gaskets………… I am assuming here that you have 3.9 heads. If you take off 60 thou the allow for the composite gasket then you will also need to have 15 - 20 thou taken from the inlet manifold faces for it to fit. Also you will need to ascertain if the heads have been skimmed in the past as this will effect the above calcs and also has other implications. However, if you shave 40 thou from the heads you will then need to check the lifter preloads to ensure that you don’t end up with a slightly open valve ……… you may need to shim the rockers to achieve the right preload of about 60 thou. See here (preload measurement is on page 3) ........... http://forums.lr4x4.com/index.php?showtopic=14006&st=40 [/url

Bad move…………. Yes you can use them but unless you have the later 4.6 heads you will lose some compression ratio as the dish on the piston crown is larger.......but it would still be a 3.9 .............. 3.9 / 4.2 / 4.6 all share the same bore size of 94.5mm (3.720 inches), and the CC variation is done by altering the stoke …… i.e all the crankshafts have a different throw. Stick with good quality 3.9 pistons to give you a 9.35:1 cr

Off the top of my head IIRC you should have four wires on the EFI loom, you need to connect, Brown to permanent Battery Live White / Red to a Cranking Battery Live White to Ignition Battery Live White / Purple is the live feed to the pump……. Don’t forget to connect the multiple earths in the engine bay ……….

Later engines with the pump in the timing cover are fine and do not suffer the priming issues ........... best to pre-fill the filter so the system sees oil on one side of the pump.......... it also cuts out the finite time it take for the pump to fill the filter, so oil is immediately pumped into the galleries.........

The 50mm blanking grommet is part number 338028 The 30mm blanking grommet is part number 338024 and the 25.5mm grommet is listed as trim plastic .......... 338023

There are only four belts listed for the P38 and two of those are for Air -Con, however the other two are, ERR4461 from VIN WA PQS101470 from VIN XA ......... for this part number it gives a belt length of 2081mm Pre 95 there is one serp belt list for 4.6 aircon .......ERR4623 HTH Ian

There you go Ross ……… I was hoping that Si would stick his hand up as he his the ideal person ………….. well done Si……….however I guess the 4.6 auto as posted would cost a young'un like you a fair wedge for insurance Si.........tell those g!ts at Kidlington that more visitor parking is needed !

I not so sure the length is fixed as other variables come into play…….. 200 or 300 tdi ? ........ although they will be very, very similar. The correct way is to measure the boost pressure by fitting a T piece into the actuator hose and a pressure gauge onto the T section……..IIRC for the 300tdi the correct pressure is 13.5 to 15.5 psi at 2500 – 3000rpm.

Be absolutely sure to get all the engine parts that have been removed !

Again we see a total lack of understanding of the subject matter…………. Please research your facts before posting. Although OBD leads and PC software are cheaply available, most of them will only allow you to read and maybe reset a minority of the common DTC’s ………. To gain access to all the interesting stuff you need the manufacturers implementation of the OBD interface (i.e.EOBD). OBD I or II cannot reset the odometer mileage ……… it can reset the ECU mileage which is something totally different CAN-bus cannot reset the odometer mileage (although it’s a lot more intelligent than the OBD standard) ……….. OBD I just gives access to a standardised series of DTC’s and the ability to reset them. OBD II (forget about OBD1.5) was produced to provide a standard pinout and an extended set of DTC’s (allows for manufacturer DTC customisation). CAN – Bus is part of the EODB standard and the DTC’s are still accessed via ODB standardisation. CAN-bus just allows multilayer communication between the various controllers in the vehicle…… The normal way that reprogramming of odometer mileage is done is to read the serial EEPROM and either erase it or reprogram with the correct mileage info.

There is a large possibility that the head gasket has blown as liner trouble rarely (if ever) shows up as low compression readings, however, a blown head gasket will 9 times out of 10 give itself away by lost compression and this would tie in with the split coolant hose……..…….. Well, the other head needs to come off and you are looking at about £30 each for facing and about another £30 for gaskets ……… then you should be good to go. If its mega cheap then fine ………….if not then walk away

Not enough info really ………….. Did the coolant pipe split due to age or because it was pressurised by compression gases getting into the coolant system ……….. I suspect the latter…….. What was the head gasket like ? ………….. sounds like two cylinders have blown into each other and also in the coolant system …….. not at all unusual What were the cylinder compression readings ? The head (s) will need skimming as well…………..

Makes no difference, do it either way ………….. but …….. but ……. Running a RV8 on inefficient LPG is sacrilege

Yes, you are about right although there should be only 3 wires + maybe a suppressor capacitor, but that is normally bolted to the back of the alternator. The large live output feeds back to the starter solenoid then onto the battery, the W is the tacho feed and the other wire is the ignition or battery light ......... some alternators are marked IND.......some are marked I..... and some are marked L.......... HTH Ian

James …………time to get back to basics………. forget all the original belt settings and set the true mechanical timing positions of the crank, cam, & FIP ……. then fit the belt

3.54:1 .............