I just replace the cam cover seals, and secondary chain tensioners on my 1997. I was rushing the job a bit, and so yanked all of the bolts from the cover to replace the seals before I remembered the legend of the special bolt near the cam sensor.

However none of my bolts look unique in any way. Disregarding the 3 along the top with stud for the beauty covers, every one of the standard bolts is exactly the same length, all captive in the spacers, all appear to be magnetic, as near as I can tell they are all the same color.

I did come across a pic comparing the unique bolt to the others, and comparing the tip, ALL of mine look more like the unique bolt than the standard bolt. Did they perhaps use the special bolt in all locations on the early AJ26 engines perhaps? My VIN is in the 008XXX range MFG 01/97. I have not looked for the engine serial number yet.

I have reassembled the car, and put about 60 miles on it, and it is running flawlessly so far. I have searched, and most references I have seen to the special bolt are for newer cars with AJ27 engines.

 

early covers don’t have them don’t worry about it.

 

I have had the cam covers off my 1997 XK8 convertible several times over the last 25 years and have never noticed any difference in the bolts. They have always been replaced at random.

Richard

 

Another point on the bolts I have. In all of the posts I found regarding the special bolt, all of the bolts appear to have a 10mm head.
On my 1997, the studs for beauty cover are 10mm. All of the other bolts are an 8mm head.

 

I just had my valve covers off recently (97 my manufactured in 96, USA)and had the ten mm studs for the engine covers and the rest were 8mm bolts. It was pointed out to me by another member here that the bolts that go on the rear most position of the valve cover(closest to the firewall are different than the rest. If you look closely and compare them the two rear most bolts do not have a “nose” to them. And by this I mean if you look at the bolts where the thread starts they do not have a small portion (about 3-5mm of length)of steel that is smaller than the diameter of the threaded part and is not threaded. The other 8mm bolts do have this “nose”. What I did was take the covers off and leave every bolt in the place it came out of literally sitting in the cover until it was put back on. I did clean them all up and replaced sealing washers/gaskets one by one so as not to mix them up. Pain in the *** and time consuming but using the bolts with the nose where there shouldn’t be one could result in a bolt hitting the bottom of the thread hole and not seating correctly, stripping out the threads or worse case causing a split/crack/or hole in head or block. If any one mixes theirs up and needs to know what bolt goes where on early models valve covers I took pictures when removing mine and will help as best I can.

 

Do you have any theories about why two of the bolts would be such a trivially different design? It would seem to be an unnecessary additional complication.

Richard