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Mike, Mechanic
Category: Car
Satisfied Customers: 39198
Experience:  Hi, I have been a Car/vehicle mechanic 34 years. 29of -running my own repair/diagnostic business.
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RANGE ROVER P38 4.6 VOGUE: Range Rover P38 4.6 Vogue 1999 GEMS

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Range Rover P38 4.6 Vogue 1999 GEMS engine auto, petrol & LPG gas. I was driving without incident and no warnings, started to accelerate in SPORT to overtake and the engine died. When I got it restarted it was very rough and would not do more than 200 rpm with misfiring. It then kept dying away and was undrivable. It had plenty of petrol and LPG gas in the tanks. I have had no previous problems with the engine. Tried again after recovery home but same problems - starts but very rough and misfires and clatters. Oil OK full and changed last June. I need assistance with diagnosis of fault and then probably guidance with repair. Would prefer response from a Landrover technician. Reasonable rate paid for guidance through the problem
Hello and Welcome to justanswer..

My name is XXXXX XXXXX Im happy to help you with this...

While it sounds like it may have suffered a mechanical issue / failure - have you run a fault code scan to see what has been registered on the Ecu's fault log - ? If so, what fault codes have you retrieved?

Too - what mileage has this done -and what is its service /recent repair history?

Rgds, MIKE................................
Customer: replied 4 years ago.

Hi Mike. I do not have the ability to run engine fault code diagnosis, I only have air suspension s/w at the moment. I may have to get it or get it done. Mileage is 144000. Serviced regularly by myself, recently had both Lamda sensors replaced and a full LPG overhaul about a year ago. Oil is good due for a change in June. Has suffered some recent overheating due to a coolant leak now repaired. Did not exhibit any problem at that time. My next move may be to test cylinder compressions but I have not started that yet as it is somewhat fiddly to get to all cylinders with a handheld device and fault may lie elsewhere anyway.

Hello Julian - Thank you for your reply..

I understand what you are saying yes - that all makes sense. A compression test is a good step - but.. that said - I would suggest to remove the rocker covers first -and check carefully for any broken rocker arms or such like.. as that is not uncommon.

It may have stripped teeth on the cam shaft drives too - but Im afraid that is a case of having to physically strip to check - What needs to be done in this circumstances, is to check the most obvious / easiest first. Thats what we would do as above.

A fault code check can give you a good idea sometimes which is why I asked about that - but yours does sound mechanical --so it may even be misleading as if the engine has "thrown" - it could throw up lots of knock on codes as it were.

So I would suggest the first move Julian is to remove the rocker covers and check physically whats happening in there - rotate the engine etc if needed to see exactly whats happening..... I think you may well find something there..unless its dropped a big end or something - ion which case, the sump would be the next to remove if there is nothing there... Let me know how you get on -Im always happy to help more if needed...

Let me know if you need anything more on this at all -

>> >> Meantime -- Please click on the OK rating to Excellent ratings service for me now, Thank you for that... and you can get back to me anytime if you need / wish..

Best Rgds, MIKE.

Please note, you are rating the content of my "answer" - my help to you - not the "system" which can experience delays etc which are not under my personal control -or delays caused by "time -off" which we all have on occasion - Thank you.

Customer: replied 4 years ago.

To get to the Cam shaft drives and chain does all the kit at the front of the engine have to come off first - aircon compressor, water pump alternator etc.

Hi again Julian -

Thank you for your reply -

Yes Im afraid that is so in general. There are of course specific procedures "in book" - but we always take off as little as poss enough to gain access... but yes - there is all that - Thats one reason I suggested starting at the rocker cover - not least because its not uncommon to get a broken shaft / rocker / dropped valve etc ...

Best Rgds - MIKE..
Customer: replied 4 years ago.

OK I will tackle the rocker covers first and then check compression. My feeling is the RH bank is the problem area as that was where the misfires came from. I can more easily check compressions that side as well. I will probably come back to you as I progress.

Hi again..

Check also - especially if the fault is there, the amount of oil in there - compare with the other side if you need - Its not unknown for an oil blockage to one side / head to cause such a problem..

Indeed yes - you can get back to me as much as you need Neil ...

Please do click on the OK ratings for me now at this point so that Im credited for helping you....and Thank You in advance for that...

You can get back to me anytime at all - clicking the OK ratings does not stop you getting back to me at all if you need -

Best Rgds, MIKE.
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Customer: replied 4 years ago.

Got the rocker covers off, nothing broken, all valves seem to be working in sequence. Compression's generally good 130 - 150 psi, 1 lower at 110 - No1 on RH bank. No evidence of coolant getting into cylinders - all spark plugs sooty/slightly oily none looking pressure washed! Any other suggestion please?

Hello again Julian...

The lower compression cylinder isnt terrible but coupled with the "clattering" and misfiring you mentioned - it does sound like something mechanical...

Can you tell if the clatter is from the lower ( big ends etc )..end of the engine - or frontal / rear etc ?

Rgds - MIKE................................

Customer: replied 4 years ago.

I can't be sure now whether it was a clatter from the engine vibration against the frame of the engine bay or from the engine, but I could not really say if it was from the bottom or the front/rear. When engine turns over on starter - all plugs out - it sounds OK

Hello again Julian - sorry I missed you yesterday.

If it were something clattering against the frame etc, that wouldn't cause your lack of power output etc ... so your initial description of the fault certainly tended to direct us to the insides of the engine / mechanically as it were -

As I did miss you yesterday - have you progressed any - ? Where are you are up to now with it ?

Rgds, MIKE.......................................
Customer: replied 4 years ago.

Hi Mike

So far I have checked all compression's and inspected both rocker shafts - no obvious damage and everything working OK when cranked round. (I have lashed up a remote to the starter relay) I have also confirmed there is a signal from the crankshaft sensor. So I think I have eliminated mechanical faults so we have to look at the electrical system. A friend is bringing a data code reader so I can have a look at the fault codes - I have a full list. Anything else you can suggest on the mechanical side or electrical side?

Hi again Julian -

Initially the "clatter" you mentioned - and the subsequent severe power loss led me to think this would be mechanical - and certainly you have done the right things then in checking what you have.

You didn't mention that the engine management systems warn light had come on at the time so I assumed not - but if it had , then yes a fault code test would really have been the first thing to do - but it wont do any harm to do that now anyway.

Let me know what you get with that Julian and then we can go from there -

Best Rgds, MIKE.
Customer: replied 4 years ago.

That's right there was no engine management systems light so a mechanical faults was indicated but I will see what the Fault codes show.

Its leading you a merry dance this one Julian !

Let me know how you get on - Im always happy to help more if I can -

All the very best - MIKE