I know there have been a few posts on this but I have a bonnet that is a tad high at the back. Yes I do believe at some point the pedestrian nonsense (yes I think it is nonsense) has deployed, there is however no evidence of distortion or kinking of the bonnet at the rear either on top or the underside, actually no evidence that the bonnet has been touched by anything, the hinges are clearly intact and OK.

Is this image normal - how do you resolve ? - there seems to be no adjustment at the rear possible which seems odd.

Am I stressing over nothing - it is bugging me .... I do not want to blow hundreds on a bonnet to have the same problem.

 

From the shop manual:
NOTE: The hood hinges deform during the pedestrian protection
system deployment process and will need to be installed.
The hood hinge is replaced in conjunction with: Hood

and further on:
The hood hinges incorporate a number of leaves. This includes a leaf attached to the body, an intermediate leaf and a leaf
attached to the hood. During normal operation the hinge opens and closes using the hood and intermediate leaves. These are
attached together by a firing pin. When the actuators are fired the firing pins fail. This allows the hood and intermediate
leaves to separate and deploy the hood upwards.
The hinges deform during the deployment process and will need to be replaced.

 

Read all that but the hinges are new and the 'firing pins' are intact - there is zero evidence of any kind of distortion in the bonnet - I don't do the parts cannont thing and waste money on parts unless 110% certain they're required - and a bonnet is a significant chunk of change. If a bonnet will solve this fine but I need to be sure so am seeking the experience of others that have faced this.

 

When my bonnet airbags deployed in my last XJ I had the hinges replaced and pre-owned airbags, however after fitting the dealer and their technician told me they spent ages realigning the bonnet , they could not quite get it flush, it was about 1.5mm proud but it was due to a very very small distortion across the bonnet about 60mm from the trailing edge right across the bonnet.
I could really barely see the distortion until they pointed it out to me, I lived with mine as no one else could really notice it unless I showed them, I must say however that the amount yours is "up" by is more than mine was.
They did say that two guys had spent absolutely ages getting it to its best so I wonder if a bit more time needs to be spent getting yours to improve.
Maybe take another look and use a short " straight edge" about 6" long to look across the rear edge of the bonnet just to check distortion, mine was so very tiny but it was actually showing the rear edge to very slightly curve upwards in the last 60mm or so.

 

It is a pity there is no way to determine what the profile should be, but I suspect this is the case and it has my OCD fully triggered - I cannot stop seeing it.

 

I will try to put a little straight edge on my current XJ bonnet tomorrow in the daylight and you may be able to use that as a comparison maybe

 

Would be very much appreciated, I've asked somebody that is selling a bonnet / hood in very good condition to do similar - would be so much easier if my neighbour had an XJ so I could put a profile gauge on it - I absolutely cannot see any kink or bend that looks out of place.

 

Well you had to go make me take a look!
Here is mine;



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Wow that seems awful close to rubbing near the light reflection but that is exactly how I want mine to look at the bottom of the A pillar with the curve continuing but shallowing - which gives me an idea (dangerous things ideas though)

 

Yes I got the angle wrong. I was trying to match your view point exactly.
I should have put the camera closer to the ground and took a shot more level with the top of the hood like yours.
No rub and the hood seems pretty well aligned.
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These pics are taken from the offside and then across the bonnet step by step to show the profile of the trailing edge of the bonnet. This may help you to see how your bonnet profile compares to this one that has not had the pedestrian system activated previously

 

That is absolutely astounding - I can use the measurement points on your ruler to reproduce pretty closely - hard to express how much I appreciate the effort taken. I shall repeat your steps and report back.

 

Glad to help , a couple of the pics might be slightly out of order, no idea why but the car had the passenger side parked next to the fence so use that visually to suss out roughly which ones are where., I think they are in order of 1,8,2,7,3,5,6,4, from drivers side to passenger side, sorry but they obviously got shuffled in the upload somehow.

 

Using the images above I went across my bonnet and there's very little in it, there's no real smoking gun I can see so I'll just have to live with this a while, I can't justify a replacement bonnet just yet based on the visual inspection so far.

 

Good to hear you have no distortion in the actual bonnet, it may be worth thinking about possibly seeing if anyone can spend a little time in realigning the bonnet again , I know the technician said to me it was a real pain to get mine ( on my previous car ) to align as best as possible.
Best of luck, love these forums as they help us all out and give us lots of tips with our cars.

 

I had a bit of a play as I had the airbags out but it isn't a task for one person, the optimum way would be to remove the gas struts as they pull everything in ways that are actually fighting you so it would be really difficult to assess what makes the difference without somebody to hold the front of the bonnet. I may have another go at it once I get other things out of the way.

 

Techy guy did say he had to get another chap in the workshop to assist with shifting and adjusting the bonnet so I can absolutely see it would be a two man job.
Yes i suppose if the struts are disconnected it could help a lot in moving it around

 

As a followup for others that may arrive here I have replaced the bonnet and the issue is gone - the bonnet was distorted and that distortion was not at all obvious or detectable.

I can only say from my experience of this is that if the pedestrian protection fires you WILL need a new bonnet, new airbags, new hinges, potentially new latches because mine were twisted and that is in addition to any bumper damage incurred that triggered this mayhem in the first place.and

One thing I would add is that one of the mounting studs came loose in the old bonnet, it had to be cut out so unless you want a lot of hassle treat yours with a decent penetrant and it them with something to clean up the exposed threads.

It is a little too dark now but I will take a picture of the fix and post

 

Ben I hate to ask? But what was the cost of the new "Bonnet"? Were you able to get a used one?
I now wonder is the hood (oops bonnet!) different between cars that have this setup and cars that do not?
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I managed to find a really good condition bonnet in the correct colour from a salvage yard, paid £400 for it so I got lucky.

They are an absolute pig to align though, there isn't much wiggle room and I did manage to scuff the paint at the back so not really a one person job but the marks are easy enough patched and won't be visible for long, I may have another play but I think the alignment is pretty good now though it has shown that the bumper isn't well fitted.


Before and after - it is better aligned than this picture makes it look. There is no gap above bonnet or A pillar if you put an edge across the gap.

The hinges can change hieght at the rear bolt by the windscreen but they can also move front to back a tiny bit on the body bolts. It can also move on the bolts front to back and to some extent side to side on the bonnet itself a little so there are a number of movement plains. When they build these everything must be held exactly where it needs to be clamped because I doubt they messed about in the factory. I do have a video of them building the XJ's. Adjustment is all best done with the gas struts removed, I have a special telescopic bonnet prop. I also found out that the bonnet bumpers (the rubber supports are also toast and had to remove them to get them loose enough to adjust, three of them are cracked so I'll be ordering new ones.

This damage sucks and is my fault. I would recommend when you / if you do such a task that some form of heavy duty tape is placed in this area to prevent this. I'm pretty annoyed with myself for causing this damage but cannot turn back time.

Right hand side


Left hand side


The bonnets I am sure are the same regardless of market as I can find only one part number. I wouldn't want to buy this from Jaguar here it is a little under £2500 - seen them new in the US for $3000+