Hello,


I've just picked up a 2002 Daimler Super V8 (XJR) with 145k miles on the clock.


Oxygen Sensors

It's throwing a check engine light for a P0420 code. (Bank 1, low catalyst efficiency) Thanks to Hatfields Jaguar in Sheffield for pulling the code and clearing it free of charge. It doesn't reappear immediately, but will after a long journey/when fully hot and in traffic.

Most of the miles (100k) were in the first 3 years of it's life, and it had all four oxygen sensors replaced under warranty at 69k miles (Bank 1) and 72k miles (Bank 2) due to P0420 and P0430 codes.

The catalysts don't rattle at all, idle is smooth, and the car pulls like a train so I don't think there's much mechanically wrong. Common for these sensors have reached end-of-life at about this age?

What type of sensors are they? It looks like the upstream ones are an expensive linear/wideband type. Does the car *really* need the downstream ones to run properly?

Where's best to get them? I'm UK based but Jaguar parts/support is better stateside...

I've used these guys in the past to good effect, and they're cheaper than Rock Auto for the front sensors:
Jaguar XJR 4.0i Oxygen / Lambda Sensors :: Application List :: Gendan Automotive Products
4-wire Linear Air Fuel Ratio Oxygen Sensor for some Jaguar models
4-wire Denso Oxygen Sensor for some Jaguar models


Cold Engine Tap

Other warranty engine work - new thermostat at 35k miles, conrods replaced (!) at 75k miles due to a knocking sound when cold.

There is still a tappet/lifter type sound at tappet type frequency on tickover after a cold start. It disappears after 30 secs or so, and it's only when in D/R and the revs drop, not present at regular idle speed.

It's a May 2002 car, so should have the Gen3 tensioners/be immune from timing chain issues as far as I know. Supercharged, so it isn't the variable valve timing gubbins taking time to fill with oil. I'm going to take a look at the accessory belt tensioner and an old belt, perhaps tensioner is loose/belt is stiff or similar. Any other suggestions?


LPG Conversion

Probably a question I'm better asking over on the UK forums. This thing is big and thirsty, so we're going to be converting it to run on LPG (propane; mostly) as the taxes on this fuel are substantially lower.

The experts say that "these supercharged Jaguar engines" suffer from valve seat recession when running on LPG, but all the examples I've seen are no later 4.2 engines in Range-Rovers and it's debatable whether they were caused by the LPG or by poor installations that run lean at high load and burn the exhaust valves. Has anybody ever seen exhaust valve seat recession on one of these 4.0 engines?

I'll be fitting a "flashlube" kit - doses the engine with a lead substitute to reduce valve seat recession - but don't want to go too nuts with it as it'll compromise/plate out on the oxygen sensors and catalysts if you overdose.


Thanks,

--
Marko

 

Just answered on the UK forum dude!

 

Update:

Knock sounds like this:


Not like this:


I've got secondary tensioners to replace as a matter of course (we'll chuck the old ones on the convertible with shagged nikasil engine), but any ideas what that first knocking could be?

Doesn't do it in park/netural. Only in drive/reverse, under load, at low revs. Disappears by 1,000 revs.

Not VVT as it doesn't have any.

 

I'm sure once you've whipped the passenger cam cover off all will be revealed.

It sounds completely random, no rhythmic knocking which is a bit odd.

No VVT? how so?

Air con pump clutch working? that's on the passenger side low down is it kicking in and out when the air con is activated?

 

The video is somebody else's with a similar sound. (forgot to take a vid before I tore this one down for the LPG)

Cam covers off - spotless. Ridiculously so for 145k. That's what 35k/year and main dealer servicing for the first 3 years does I guess! (5-6k/yr since then) Latest generation tensioners, all tensions good. All shims present, all valve clearances good. "Sump" off and it was clear of both sludge and nasty surprises. Drivebelts off and all ancillaries seem to spin nicely and without noises, so I'm fairly stumped!

It can't be anything too bad though, so I'll just nail it all back together with fresh oil and a fresh drivebelt and ignore it for now...

I'll play with the A/C when it goes back together. If it were that I could rest at night. It smells like ****, but that's the interior side giving us legionnaires rather than anything mechanical, heh!


Best place for supercharger oil in the UK? May as well drain and refill with it sat on the bench.

 

Update:


Secondary timing chain tensioners absolutely fine, and of the latest type. Primary ones are fine too. Engine pretty spotless internally:






Engine sump dropped and sump also pretty clean; with no nasties: (145k on the engine)






Noise is present with both the S/C belt and ancillary drive belt removed, so not the 'charger/ancillaries.


Both cats have been removed and are in good shape so not those rattling. The studs on the Bank 1 cat were mashed - some impact wrench wielding cretin has clearly been in there before. Warranty log reads:

17-Jun-04 69357 remove r/h exhaust catalyst replace both r/h faulty heated oxygen sensors refit catalyst warning light now goes off

Warranty log also says:

11-Aug-04 72957 fault code p0430 indicates lambda sensors faulty on bank 2 remove downpipe assy replace sensors refit downpipe warning lights now gone.

(Creamer Jaguar Kensington)

The oxygen sensors were also of interest. The upstream sensors are denso 192400-3101. The serial numbers are 03F24 and 09E24. When tested with this method:

Oxygen Sensor Information

The 03F24 sensor was noticeably slower than the and 09E24 sensor. Ditto the upstream sensors (denso 065500-4961) with 06D19 (slower) and 09E09 (faster).

I've refitted the "fast" ones to Bank 2 (as access is difficult with the expansion tank and heatshield in place) and the "slow" ones to Bank 1 for the moment - will see what happens with P0420 and P0430. Annoyingly, I forgot to check which sensor came from which side.

The fuel trims appear sensible (almost identical both sides) so I'm assuming that the upstream ones work perfectly well enough. If it throws another P0420 I'll try the downstream sensor.


This doesn't leave much to knock on the engine! The con rod warranty work says:

3-Feb-05 (75050) check oil ok,tracee noise to bank 1 remove drive belts & check sill noisey, check cyl compression warm & cold ok checked spark plugs ok,disconnect ign coils one by one ok,checked egr pipes, spoken to dts sent enginer from jaguar advised to replaced con rods & any worn bearings. replaced con rods. Cust complaint please check for knocking from engine when cold.

I really don't buy this as the current knock as it sounds nothing like a con-rod. I wonder if it could be the autobox?


Sump was dropped and fluid removed (approx 4.5 litres). Fluid was brown and smelly but contained nothing nasty. Cooler lines were removed and the cooler drained before reconnecting. 5 litres (to allow for cooler contents) of fresh fluid was added to the sump (original filter) and the engine run/gearbox cycled through P-N-D-R a few times. Sump was dropped again, fluid removed, filter removed, and a new filter/gasket (genuine) fitted along with 4.5 litres of fluid. I'm using the Fuchs fluid (Titan ATF4134) which carries the MB 236.14 approval and is supposed to be backwards compatible with the older MB standards. I will top-off as required when a dipstick and the diagnostic equipment is available, but it's close.

Knock/clack at low engine rpms in D and R is still present. Disappears by 850 rpm.


Could it be a damaged autobox oil pump? (low pressure/relief valve that's clacking at low rpm?)
Damaged torque converter clutch?
Damaged torque converter flexplate?

Any transmission specialists familiar with the Mercedes 'box in the Jaguar application?

 

Three very tight grade 10.9 bolts visible through the access plug/blanking plug holding driveplate to the torque converter. Driveplate appears striaght and true.

Do these ever break? Anything else that rotates with the engine, with the car stationary?

What is the stall speed of an XJR torque converter supposed to be?

 

I'm thinking torque converter sprag clutch after some reading:


MOTOR Magazine Article | MOTOR Information Systems

Lift Truck Engines, Transmissions, Torque Converters - Joseph Industries


722.6 Info:

722.6



Stall speed test should confirm if it is slipping always; perhaps it just slips at lower rpms though until line pressures are higher?