Hey Everyone!

Here I was all set to change out the valve cover gaskets on my 1997 XK8 convertable this weekend. I got the gaskets and the spark plug seals. I'm seeing that I need 28 valve cover stud grommets also?

Are these absolutely necessary? Can I use the old ones? The gaskets I bought seem to have rubber grommets built into them. No body in this area can get new ones until at least Tuesday.

Help! Save my tinkering weekend!

Nick

 

As I recall, those grommets go on the top of the studs. If they are not hardened they should work okay, but you can always use a little RTV to play safe.

 

Thanks RJ

Nick

 

The grommets are not sealing washers but provide 'clamping-force' on the cam cover gaskets.

When the grommets collapse, they do not compress the covers/gaskets. The gaskets sometimes start leaking soon after they are replaced, not because they are not pliable but because they are loose.

I guess you could shorten the metal spacers and get the same result?????

Jaguar refers to them as 'isolators'. I always replace them but I don't like 'come-backs' and have to do the job again for free (warranty repair).

bob gauff

 

I bow to your experience, Bob.

 

Thanks for the info, Bob.

After doing the job this weekend, I found that the spacers were pliable and had retained their shape. The engine was professionally rebuilt in 2008, 30K miles ago, so I'm thinking they were replaced then. I was also glad to see the tensioners were replaced back then also.

I cleaned the underside of the engine of all the oil that was on it, drove the car for awhile and then parked it over cardboard overnight to see if there were any leaks/drippings. There were none as of this morning!

Thanks again to this forum for the advise, tips, and for saving me a couple hundred dollars...again!

Next project-that pesky ABS/Traction Control light

Nick

 

Excuse my long post, but having experience on these motors, its very important any one doing their valve covers know this, as this can turn into a ROYAL NIGHTMARE

Jaguar made the valve covers out of very cheap plastic. And most of us will see, as the covers are removed, cracks,chips,missing plastic etc.

The most important part of the job is to have the valve covers hot tanked to visually check for deformities, check your upper tensioners for plastic or metal, and noting any issues with a pen and notepad.

If deformities are found,rtv silicone(black) is now going to be involved as no one wants to spend $500 bucks on more cheap covers lol,and is a little tricky for someone just looking to throw gaskets on and solve the oil leak or OIL VAPOR SMELL as its not going down like that.

The mating surface of the head must be thoroughly cleaned with clean towels and brake cleaner,until its just shiny metal. This may take time, a SOS pad helps the process.

Apply the black rtv to the damaged areas of the cleaned valve cover in a healthy fashion(not too little). Take your gaskets thrown them in your dryer for 5 minutes to soften them up.

After 5 minutes the black rtv is "tacky" the gaskets are "soft",install everything, careful not to over tighten the valve cover bolts and crack the cover. Note this part heats and cools with the engine, expands and contracts. Overtightened bolts will crack the covers.

Now, very important, you will notice oil residue in your spark plug galleries.

This gets hot and turns into oil vapor causing that idle /slight stumble feeling. You may think you don't have this issue, but the truth is either your body has become use to it, and or the ecm has RETARDED TIMING to smooth out the misfires.
Remove the plugs, gap them to specs, install new plugs.

Remove the coil boots by hand, spray them out with brake cleaner to remove the oil residue inside and let air dry for ten minutes.

Next spray the springs of the coil off WITH ELECTRICAL CONTACT CLEANER NOT BRAKE CLEANER. And wipe with a towel until they look shiney new, and use a q-tip for the insides with the cleaner.

Next slightly stretch the springs as the new valve covers are redesigned and thicker than the original, meaning your coil springs may not make firm contact with the spark plug tips ,as they have been resting in one position for so many years.

Now instal the coils, , most of the time the electrical connectors will break to them. If they do, you can buy more connectors pigtails and solder them on, or simply destroy the connector, tighten the pin with pliers somewhat, then push it on the correct coil pin firmly.

The wires will never come out of the coil, as the valve covers have holes at the top that holds the harness firmly and place, and the wires do not move whatsoever when driving.

Some Jags, with OEM coils over 70,000 miles should be replaced as the windings are out of useful service. If you cant afford all eight, replace them a few at a time within 12 months.

Enjoy your new misfire free, oil leak free Jaguar for another 10+ years.
Remember, skipping any of these steps out of ignorance will come back to hunt you in a very unpleasant manner. I blame the engineers for using such cheap plastic parts in this car.

I have emailed Jaguar engineer's my findings with photos and statements.
Their response "The items in question are wearable components and considered maintenance components" , we do use recycled plastic to minimize production cost, and while some parts may not be the quality compared to other vehicles, we try to maintain a "marketable product" to benefit our customers and dealerships.

Its very important you notified us of these issues so we may improve future design.

My response, "make all under engineered parts and redesigned parts discounted to the consumer". Their response "Prices on parts are controlled by the dealerships themselves, and so are the sources of those part, not Jaguar"; any part with a Jaguar marking, does not mean it came from Jaguar, but from an "authorized distributor".

However, if your car is serviced at any jaguar dealership, we will offer assistance with pricing and dispute resolution or settlements on the final repair bill and comply with any NTSA findings>

Yours Truly,

Jaguar Executive Customer Service.

 

When I was having the condensation problem causing misfires in 3 cylinders in addition to cleaning everything up really good I also used a Q-Tip and put a little dielectric grease in the plug boots were they contact the plug body and coil.
The problem has never returned.


Dave

 

Thanks for the info aode06 and Dave.
The old gaskets were soft and pliable when I removed them and looking back at service records given to me when I bought the vehicle, the engine was completely rebuilt by a reputable shop in the area (Abacus Racing in VA. Beach) in 2008 (30K miles ago)
Fortunately, after doing valve jobs and head gasket jobs on my old Mercedes, I was aware of most of the tips you guys brought up and being one who is meticulous when it comes to details, the rest was easy.
But then again, I've never done it on a Jag. I'll keep my fingers crossed

Nick