Hi everyone,



I used to post here a bit, but I haven't had an X350 for several years. In the past, I've had 3 X350s, and my dad still has one.

I moved a while ago from the UK to Mexico, and X350s are incredibly rare and expensive here. I've been here three years, and have only seen one in the flesh, and around 4 advertised, all with poor spec and near 20k GBP in price.



Last night, I got the chance to buy a 2006 4.2 N/A Vanden Plas with one owner and 65k miles for the equivalent of 3500 gbp, which is unheard of here. I immediately snapped it up, but as with all cheap cars, there's a few issues. It drives as well as any X350 I've had in the past, and has benefited from a full air suspension refresh, but it needs the following:

1) I can't get the bonnet (hood) open. The lever inside the cabin works fine, and one of the two latches (driver's side) unlocks fine, but the other one is totally jammed (passenger side). It's a LHD car. Any idea how I can get it open. I've tried pulling up and down on it while someone else pulls the lever, but no luck.

2) It has some sort of coolant sensor issue. The car doesn't overheat and I'm 99% sure it has coolant, but the gauge never moves off C, and the little red light is on at the top of the gauge. I took a photo so you can see what I mean.




3) The boot (trunk) only opens with the key turned in the lock. The button on the boot itself, and the button on the key, and the button inside the car don't work - you have to physically put the key in there.

Any ideas where I should start in terms of getting these fixed?

Due to the rarity of these cars, I'll have to get all the parts from the US, so this may take a while to get everything sorted. I'm incredibly happy with the car though, and I have no problem investing a fair bit of money in it as I know I'll get it all back and more if I ever sell it.

Thanks in advance

 

You might be able to operate that latch with a tool through the grill, or from under the car (after removing the plastic cover behind the front bumper.) If you can touch the bottom of the latch, you can release it.

My temperature gauge did that a couple of weeks ago, and then stopped. It still doesn't work, it sits about a quarter scale instead of at the bottom, but the light went off. I have a scanner tool and I see the coolant temp between 93 and 97 degrees Celcius, so I know the cooling system is working. As for the gauge, I haven't looked into it since I know my cooling system is OK, and in your case I'm pretty sure it's not indicative of an actual engine cooling problem.

If none of the electrics work for the boot latch, you probably need a new latch assembly, close to 300 dollars. Me, I would check that it has the proper electrical supply, first, fuses, etc., and pressing a button energises the right wire.

 

Thanks. I'm pretty sure I can remove the two mesh inserts of the grill without too much difficulty. By the plastic cover behind the front bumper, do you mean the whole undertray?

In terms of the boot latch, I'll definitely be checking fuses etc when I get the chance, but is this what I'd need assuming power is good? https://www.ebay.com/itm/04-07-Jagua...8AAOSwOVhgLa8a

 

I don't think you can remove the grill without the hood open to get behind it. A long enough rod should be able to reach the latch, though. As for plastic cover, there's a cover not quite a foot wide along the lower edge of the bumper, and that's what's in the way. About 15 or 18 bolts, though, to remove it.

Your eBay link looks like the right piece, and that's as good a price as I've seen for it.

My own operates, but not fully. When I hit the button or the remote, I get a "pre-release," for lack of a better term, but it's still latched. The lid comes up and inch or less, and I can close it and hear the latch motor lock it back down. I still have to use the key to actually open it. I'm fine with it, and keeping the money in my pocket.

 

I had the same bonnet issue. From your description it appears that the cable end is detached from the latch. The cable end terminates in a small metal ball. When the hood/bonnet is slammed there is enough force to dislodge the ball from its lever. It will be obvious to you when you succeed in opening the hood.

The fix requires a flat bladed screw driver with a minimum of a 9" shaft. No need to disturb the mesh grill inserts. Insert the blade through the grill to the latch and twist it against the hook holding down the hood until it snaps open. Then reattach the cable end in its lever and remember to lubricate the mechanism.

 

Perfect, thanks. I'll look into that as soon as I get a chance.

Thanks - I'd be very happy if that was my issue, as I wouldn't have to buy any parts. I've been looking at guides to replace the entire cable / latch assembly and it looks like a nightmare tbh.

 

If you're able to simply push up at the bottom of the latch, I think you'll find that it pops open easily there.

 

What can I say - I can't thank you enough. One of my meetings got cancelled today, so I went outside and did exactly what you said, and it worked. I then unbolted the mechanism, and just as you said, the cable had come loose. I clipped it back into place and it's totally fixed now.

In other news, I picked up the coolant sensor from Autozone and I'll see if I can fit it this weekend. I downloaded the service manual and it seems like it's not that hard to reach on the 4.2 NA engine, but let's see.

 

The coolant gauge red light and no needle response does not indicate the ECT sensor has failed. Did you check with OBDII data to see if ECT is being reported? If the ECT sensor had actually failed you would probably have running issues.

The red light and gauge not responding typically indicates a problem with the IP cluster not receiving the temp data over the CAN bus. Could be an issue with the cluster itself.

 

Ah, that's annoying. I didn't actually check if it was sending a signal over OBD but I'll do that ASAP. Assuming that it is, what are the steps to troubleshoot this? I'd really like to avoid tearing the dash apart if possible. Might I just be better off leaving it and buying one of those plug and play OBD temperature gauges?

 

If OBDII data shows the accurate coolant temp then next step will be to scan IP module for codes (will require SDD or a dealer-level scan tool). If you don't have a Check Engine Light I will bet your coolant temp is being reported to the ECM correctly. My guess is the IP will have stored a code U2199 "invalid data for engine coolant" which sends you to the CAN bus troubleshooting section.

Like wfooshee, I also had the red light and no temp gauge, but after 1 day it went away on its own. You might get away with a battery disconnect and reset. If the fault remains, then I would start digging into the CAN bus. If you're not inclined to do that or can't find the fault, then an OBD temp indicator would be a good investment so you can keep an eye on the cooling system.

 

Thanks. I have a basic scanner, but no dealer level one, and it will be hard finding somebody other than the dealer who does have one over here. There's no check engine light, and the car runs fine. I'm going to check to see if the OBD is reporting the temperatures when I drive it later today, and on Saturday I'll try a battery disconnect and reset. As I've already got the sensor, I'll fit it regardless and clean the connectors etc.

 

Unfortunately the ECT sensor is on the back side of the coolant crossover pipe (aka thermostat housing)... which means you can't access it without removing either the coolant crossover or the intake manifold. There is a junction connector on the LH valve cover bracket where you can disconnect the ECT and measure the resistance.

 

Yeah, return the part you bought and don't worry about it. You've got good coolant operation, and dicking around back there is just as likely as not to introduce its own problems.

BTW, I drove my car for the first time in a bit over a week, and the temperature gauge behaved perfectly. No light, no stuck at 1/4-scale; it climbed slowly from the bottom to midscale as the car warmed up.

 

I’m going to keep listening to you guys as you’re bringing me more and more luck.

I decided to return the sensor, then disconnected the battery and held the cables together for a while - coolant sensor is now working perfectly. Did quite a few miles in it today with several start cycles and no more issues. I’ve noticed in the live data that it’s running a little lean so I’m going to clean the MAF and run some injector cleaner through the tank. Any other recommendations?

 

What makes you think it's lean? What are you comparing it to?

No offense, but you seem to be actively looking for things to fix that might not need actual fixing. You got the hood release done, now go drive the car!

As for lean, I'm thinking the ECU will keep it just on the lean side of perfectly stoichiometric, simply for emissions; rich is "smoky."

 

Just by looking at the fuel trims. I actually took your advice and decided to give it a long run late last night before doing anything, but it looks like I might be correct because when I checked this morning with the scanner, I have a pending P0171 and P0174. I cleaned the MAF so maybe that will sort it, but I was wondering if it might be something to do with these seals, what do you think? Like you say, maybe I'm being too picky and worrying about nothing - the car does drive fine, but I'd like to get it perfect.

 

There are many potential air leaks on this AJ V8 that you can check, but those 2 seals pictured are for the VVT solenoids and not likely going to be your issue. They will leak oil and if you replace them only get OE replacements, the aftermarket will not last. You need to thoroughly clean all the oil oil before installing the new seal (read: clean it until there's no more oil, then clean some more).

Easiest way to diagnose your lean condition is with a smoke machine. Some other things to check include: cracks in air duct between MAF and throttle body, cracked PCV hoses, bad PCV valve, leaking o-ring at PCV to valve cover, broken vacuum lines to fuel pressure regulator and/or AIR injection solenoids. Could also be leaking intake manifold gaskets themselves--there are silicone gaskets between the plastic and metal portions of the intake.

Note that the PCV valve on these cars does make a hissing sound normally, which can be confused for a vacuum leak, but it's one of those things you'll have to hear a working unit to distinguish from an actual vacuum leak.

 

Thanks so much for your continued help. I tried to get a smoke machine but couldn't get hold of one. I also thought about blowing smoke from a cigar in there, but I can't work out which hose I could blow it into without the motor cutting out. I could hear a loud hissing from the PCV valve, and a slight hissing from where the PCV valve connects to the front / center of the engine, so I decided to spray throttle body cleaner around all of the hoses and monitor the fuel trims.

When I spray it around where the PCV connects to the front / center of the engine, the fuel trims go like this






And when I spray it around the PCV valve itself, they go like this





Any ideas?

 

So the big dips in the red graph line are when you are spraying the TB cleaner? That would be normal--the solvent spray is acting like fuel and the O2 sensors see this, so the ECM tries to pull back the fuel trims (make them more negative) to reduce the fuel from the injectors. If so, you've found (part) of your problem.

The hose from the TB to the PCV has o-rings in those connectors. You can try and replace them if you have suitable sizes, or as a temp repair. Otherwise that PCV hose is available from Jaguar and may be the better solution, since the plastic hose is known to crack with age.