Oil leak

Someone just gave me a 1986 Jaguar XJS with the v12 engine. It had sat for five years in a garage without being started. I got it started, it sounded very smooth, then I noticed oil on the heat shield above the exhaust manifold. It appears to

have leaked out from under the valve cover and started to burn off as the car got hotter. There’s not a huge amount of oil but it did drip down to the floor over the five years, making a pool about a foot in diameter, so it’s not a tiny leak either. Getting to this valve cover looks like some work, I’d rather not do it. Can you tell me if there’s an oil (I was thinking particularly of the high mileage oils - (I use a Valvoline 20 50 in my other car and it has 250K on it and still runs very well) - that might seal this up by swelling the gaskets or something - or whether there’s an oil additive that might work without clogging up other engine parts?

Thanks very much.

You just got this classic running and you are looking for ways to cut corners on the first job? You might as well sell this car if your are not motivated to do the work right.

This is really a pretty rude reply. Rather than dispense patronizing attitude, why not just answer the question? Or, to put it as you might, if you can’t even find the motivation to answer a simple question, maybe you should get out of this forum? And go back to your happy little life.

There are additives at the parts store made to swell old seals, but you need to have realistic expectations about their use. The car is 23 years old and sat for the last five. Seals and gaskets both dry over time (read: shrink) and take a “set”. A gasket properly compressed in manufacture can lose it’s compression and ability to seal after 23 years on the job.

Realize too that the vehicle is loaded with seals and gaskets and they’re all 23 years old and all have been sitting for the last five. You can expect to have to deal with numerous leaks should you try to take this on the road.

The seals I’d be most worried about are those in the brake system. I’d be very reluctant to take this on the road without thoroughly examining and testing the entire system. Blow a leak on the road and you just may get killed.

I have to ask what your expectations are for this vehicle. If you want to drive it you need to expect to put some time and/or money into getting it roadworthy. Additives are not the way to accomplish this.

Everything about a Jaguar is expensive as far as repairs go. If you are well supplied with money you can get the car back in road worthy condition. Oils and “sealers” only work on minor leaks and then they can do more harm than good. I wouldn’t recommend that approach.

The valve cover seals are probably dry and retorqueing the valve cover fasteners is a good place to start. As you get the car running and up to temperature the fluids will circulate and some seals and gaskets may swell and stop leaking and others might just blow out. It’s a matter of dealing with the issues as they come up. This leak is issue #1 and more will follow.

You have demonstrated that the car can run and run smoothly. That’s a great way to start. If you spend some time on the cleaning the inside and outside you might be able to sell the car for a decent profit. I’d expect this car to need a lot more time and money in the next 2 years to get back in solid running condition. Someone with the time, money, and love of Jags could find this a great project car. Selling the car is something to consider.

oldschool normally doesn’t have a light touch about things. Straight shooter he is - and he is pretty much right about this (as is mountainbike).

What I’m going to suggest though is that you don’t just have a simple valve cover leak. If a car just sits for 5 years it won’t be dripping any oil out of the valve covers. Almost all of the oil all settles to the bottom in the oil pan. Without the engine running it isn’t going anywhere & certainly not anywhere near the valve cover. Have you take a good look at the oil pan?

Thanks for the answer, especially about the brakes. I bled the system, pumping it up a lot to get it up to pressure, but without the engine on. It seems to be holding fine and the brakes feel good, but is there another way to test them before I take it out on the road?

Thanks. Yes, I think I will sell the car, is there some forum you recommend? I’m in Los Angeles.

Thank you. I’ll check the oil pan.

Good work. And since you bled tham I’ll assume you dod a good visual also. You also may want to purge and replace the fluid, as it may be long overdue.

You might also want to jack up the wheels, spin them by hand, and have someone slowly apply the brakes whil you continue spinning them. That’ll tell you if they’re grabbing smoothly or not at all. It’s a simple thing, but having neglected to do so once when getting a stored vehicle running again I can tell you it’s a good idea.

The only other thing would be to test them slowly and immediately before going out on a foray with the vehicle.

Will do. Thanks again. I’ll be careful. I’ll let you know what happens.