MartinM Posted June 20, 2010 Share Posted June 20, 2010 Recently serviced the old bus and changed the spark plugs and ht leads because they were a tad corroded. To cut a long story short afterwards I have "enhanced rough running" so to speak on cylinders 1 and 7 (up to about 4.5 on my MSV Extreme - Testbook equivalent) and slight roughness on cylinder 2 (about 2.5). All others are running with 0 rough and the whole is reporting 0 misfires. ALOT WORSE THAN BEFORE I TOUCHED IT!!!!! To add to the fun its also now developed a whistling blow on the drivers manifold (possibly unrelated). I need to put the MSV Extreme back on and check the MAF readings as I have heard adirty sensor can cause rough irregular running, but the exhaust manifold is a pain as I only replaced that about 20 months ago. Just thinking this might be something serious though (head gaskets, porous block etc) ... does anyone have any thoughts before I troll over to a Landrover "specialist" who will doubtless change every part on the car before telling me I need a new engine!!! Mileage is 100.5k and its a 4.6 Thor (MY 2000). If the concensus is it's not good news then I'd be tempted just to take it to JE Engineering who are good, if a bit pricey. Before we go too far though can anyone confirm that the LH cylinders are on the passenger side (perversely the rhs when working on it from the front) and the sequence is 1, 3, 5, 7 from front to back with 2,4,6 and 8 on drivers side? I'd be a right dumbo if I've connected the HT leads sequenced arse over tip! Martin Quote Link to comment Share on other sites More sharing options...
vougese39 Posted June 20, 2010 Share Posted June 20, 2010 1,3,5,7 is o/s of the car 2,4,6,8 is pass side standing at the front who's leads did you use and what plugs and gaps. whistle normaly means air leak Quote Link to comment Share on other sites More sharing options...
MartinM Posted June 21, 2010 Author Share Posted June 21, 2010 Well that has to be a good start as the leads have back to front already - though it maybe we are wrong at both ends (i.e. distribution cap and cylinder banks)- we'll go back to first principles on this ... as usual the Workshiop Manual is less than clear - maybe I've not find the right page! Only thing is that the vehicle is running albeit with the roughness and odd power distribution. I'm using a set of leads from P38 Spares - their reference GW102 which is for the Thor - that said the ones I took off were really green and not as tight a fit on the plugs as these are so not sure what they were! Air leak sounds likely - its a periodic (rev related) "psst" sound though it becomes more throaty under higher revs which is why I'm tlking manifold - any thoughts where the seat might be if it's not an exhaust manifold gasket? (The manifold was replaced two years ago as it had corroded and was blowing - but the sound this time is different!) Really appreciate the feedback - facing anything between a £1.5k to £5k bill at JE is motivating a bit more play around with this and this is helpful! Martin Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 21, 2010 Share Posted June 21, 2010 Why on earth would you spend £5k on a Rover V8? Sounds like something basic to me, usually is especially if you've tinkered with it. Could be you've disturbed a pipe which is now a bit loose, or split due to age. Aerosol carb cleaner is a good way to find an air leak, spray it at likely candidates and see if the revs dip. For the brave, a plant sprayer full of petrol also works. Quote Link to comment Share on other sites More sharing options...
MartinM Posted June 21, 2010 Author Share Posted June 21, 2010 Not sure I would go to the £5k end (though thats a fully rebuilt and guaranteed engine) ... though as the rest of the car is known condition it may be easier than buying another truck and starting from scratch on Aircon, EAS, shocks, bearing, exhaust, etc etc etc etc Sequencing is confusing - VogueSE39 seems to suggest Bulkhead 7 8 5 6 3 4 1 2 Radiator I have Bulkhead 8 7 6 5 4 3 2 1 Radiator Elsewhere I think I've seen what I have which is that the LH side is the NEARSIDE on RHD and the RH side is offside (i.e. as viewed from rear). Certainly that's the way LH and RH works on info centre for doors and windows. Truck doesn't misfire but reports rough on 1, 2, 7 with 2 being about half as bad as 1 and 7. Any chance others could advise on HT wiring sequence - or tell me which section of the manual I need to RTFM!?? Like the idea of garden spray with petrol! (suspect not that brave or stupid!!) Thanks Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 21, 2010 Share Posted June 21, 2010 This is correct, and as mine is wired: Bulkhead 8 7 6 5 4 3 2 1 Radiator All this stuff about what the testbook reports - don't be misled. It can only report what it can see, and often that's a symptom of some other problem which it can't know about. When you say it "reports rough", what does that mean, what does it say on the screen and how is it working it out? Quote Link to comment Share on other sites More sharing options...
MartinM Posted June 21, 2010 Author Share Posted June 21, 2010 OK - so I'll leave the leads as is! I'm using one of Blackbox Solutions MSV Extreme units which is good at reporting information. Accessing the engine ECU there are readings for running with reports for each cylinder for misfires and rough running. I have 0 against all (no misfires) but a roughness figure that runs up to about 4.7-5.0 (not sure what units) for cylinders 1 and 7 and intermittent roughness on cylinder 2 up to about 2.4 ish. All other cylinders report clean. Need to check what the Oxygen sensors are reporting, but I appreciate what you are saying that this is a report of a symptom rather than a cause! I'll see if there is anything on the Blackbox Forum regarding this! And whatever happens I'll update this post! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 21, 2010 Share Posted June 21, 2010 Without knowing what this "roughness" value is based on, it may as well be telling you how banana flavoured each cylinder is on a scale of 0-5 Quote Link to comment Share on other sites More sharing options...
SteveRK Posted June 21, 2010 Share Posted June 21, 2010 If these cylinders are not reported as misfiring then could the 'roughness' be referring to 'knocking' or pinking? Do these engines have knock sensor/s? Quote Link to comment Share on other sites More sharing options...
MartinM Posted June 23, 2010 Author Share Posted June 23, 2010 Well the blow on the drivers side is clear now, and having determined that the maf sensor seems to behaving ok it's looking like it could be the head gasket. Though its not drinking coolant and all is still pressurising ok, so it may be the exhaust manifold gasket. Probably going to limp up to Coventry to JE as the truck has their low restriction cats on. Their fixed price (850) for doing both sides is the same as the "starting from" price from my local independent. I'll update this to close when I get more news. Quote Link to comment Share on other sites More sharing options...
MartinM Posted June 23, 2010 Author Share Posted June 23, 2010 Of course all this assumes it doesn't break further!! Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted June 24, 2010 Share Posted June 24, 2010 It's unlikely you can blow the head gasket by changing HT leads and plugs. If it is worse now than before you serviced it, then it is something you have touched/fitted incorrectly. Are you sure the spark plugs are tight? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 25, 2010 Share Posted June 25, 2010 Seems likely to be a waste of 850 quid to me, although chances are whatever's wrong will get fixed as a by-product of taking it apart and putting it back together again. Quote Link to comment Share on other sites More sharing options...
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