1998 XK8: Oil leak from rear crankshaft oil seal - Any tips?
 

Noticed an oil leak and took it in. Here's what my local mechanic has sent me:

The 2 main sources of engine oil leaks are coming from both of the valve cover gaskets & the rear crankshaft oil seal. Unfortunately the rear crankshaft oil seal requires the removal of the transmission to gain access to replace it so the cost to do so would be around $1,750.00. Both the valve cover gaskets would be $641.61 to replace. The stalling/check engine light issue is likely due to the fact that the air intake duct was not secured to the throttle body properly allowing unmetered air to enter the engine. We have re-secured the duct & erased the diagnostic fault codes.

Does this sound right? Is there any way to do this other than by removing the transmission? If we do need to do it, is there anything else we should consider doing while the transmission is removed?

Thanks,
Napoleon

Well, for my money, I would do the valve cover gaskets first (very common leak area with age), and see if the oil from the rear seal "lessens" afterward. (In other words, some of that leaking may be coming from those valve covers, and running down the backside of the engine.) Just a thought. It shouldn't change the labor to remove the trans any. Just a bit more of an inconvenience for you since you would have to return for a second repair. I realize that you probably have limited service available in HI, or I would recommend a second opinion on that crank seal. Not that I don't believe them! It's just a lot of money. How many miles on your XK? I don't see many crank seal problems. If you should decide to pull the trans for that seal, they will likely check the rear mount while there. It's easy. Not much else you can't get to otherwise, unless a front trans seal is also suspect. Might be a good time for a trans service if you are due. Probably no real savings there though!

Thanks Chopr, that makes sense to me. I'll start with the valve cover gaskets first as you suggest. The XK8 has 68,000 miles on it. By the way, when they open the valve covers, will they be able to see if it still has the original red tensioners (and if they're cracked?).

Yes they will. If they are the originals you should change them no matter what condition.

Those are fairly common leaks, although I must say that the pricing you are being given is quite high. I realize you may have fewer options in Hawaii, which is likely driving the price.

I have a rear seal leak as well...oil collects at the bottom of the torque converter. On most cars it's usually a slow leak that can often be left for a good while with no problems, just watch your oil levels. To fix it, the transmission must be disconnected from the rear of the engine, as you say.

The good independent shop in my town charges $ 700 for this service, so you can understand my reaction to the pricing you've been given.

If you're reasonably good with a wrench, there's no reason why you couldn't replace the valve cover gaskets yourself, for around $100 or so.



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Just sharing my experience...long story, short. My rear main seal blew out shortly after I bought my car. Between age causing the seal to shrink and headed plus crankcase pressure build up by way off a plugged pcv system (let jag and others call it whatever they want) it wasn't much fun watching a puddle grow in my friend's driveway one night. My main point is that if I hadn't spotted when I did I could easily have lost my engine to oil starvation as I had no idea until I noticed the lake off oil under my car. I'd be a bit wary of blowing off this repair.

call around for better prices, that's way too high for the job. I did it myself in about for hours. I get off work at 3:00 and was home drinking beer by 7:30.

Damn Swype errors, sorry. I think you get the gist of it though.:-)

Hey Beav-

I'm new to this whole rear seal thing...please educate me on something if you can.

I'm curious as to how a full "puddle" could form under your car so quickly with this type of leak. Although there's certainly a bit of oil in the exit from the crankcase, it doesn't "pool" there as far as I know, certainly not when the engine is shut down. So it seems the leak could only be drips, not a "flow" of any kind. Am I right?

Was your seal just completely shot, with so much oil blowing out while driving that it then pooled when you parked?

I've had my rear main seal leaking for about 9 months, but even so, I'm only losing about 1/2 quart every 3,000 miles or so. But I'm watching it.


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A lot of good info on this topic but lets not blow by Beav's (no pun intended) tip on the PVC system. It's a quick, cheap and important fix.

Also consider that the advancement in chemical technology has led to superior adhesives and other automotive synthetics.

Case in point: ....I had a customer in the body shop that asked if I'd fix her oil leak in a late model Chrysler, just out of warranty. I explained that was not my main line but had a technician capable of the work.

When I consulted the labor guide to quote a price, even I was SHOCKED.

I suggested we try a LUCAS brand product that swells neopreme seals, first.

Turns out it worked like a charm, following the instructions to a "T". We kept a close eye on it, and it's held for over two years now.

Sorry Tarheal, I missed it. What was Beav's tip on the pvc system?

So, if oil is still leaking after I replace the valve cover gaskets, would you recommend that I try a product that swells neoprene seals?

PVC tip is post #6.

I'm new to Jaguars, but have made my living in the automotive field for over 30 years.


YES, I would TRY the Lucas product for the main seal problem AFTER changing the valve cover gaskets (and tensioners if needed), AND DEFINATELY after checking the PVC pressure issue.

I assume the product is Lucas Engine Oil Stop Leak. I am planning on changing my oil next week and just ordered a couple of qts. on ebay. I also have a small rear main leak.

With the seal completely blown back from the block all the oil from the rear of the final crank journal was exiting onto the pavement while the engine was running. By the time I had noticed the puddle the engine had pumped out most all of the oil along the road and on my friend's driveway. I mean, who drives up and immediately shuts their engine off? I figure most of us probably shut it down after 10-15 seconds of coming to a rest. That's a lot of oil at the rate it was leaking. Then there's the flow factor, what had started as a puddle had flowed/settled out into a small pond by the time I saw it.