Hi folks,

Looks like I'm replacing my cam and I'm debating finding a used cam vs a new cam. I've got an '87 300e and the parts suppliers only have the new hardened cam and rockers (and misc. other parts that are required for the swap) available. Apparently MB upgraded the original chromed cam for a hardened shaft at some point. If the original is replaced with the hardened cam the rockers have to be replaced too. The parts alone are $900 for this repair. I suspect that the original cam and rockers were susceptible to extreme wear as occured in my car and changed the whole setup to avoid what happened to my car.

I'll spend the money on the new stuff if recommended, but I'm just wondering if anyone can lend an opinion to this situation.

Thanks,
Bob Kopicki
Massillon OH

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We do plan on keeping the car for some time. My wife just loves it. 8 years ago I bought her an '85 XJ-6 and I've got that car to as close to the pinnacle of maintenance perfection as could be expected. We replaced the head, entire a/c system, all rubber firewall forward, rebuilt front and rear suspension, rear brakes, stainless steel exhaust, chrome Jaguar wheels with new rubber, and on and on and on! It's too nice to drive now and we don't dare drive it on a salty road here in Ohio. I'm selling it in the spring and the 300e is it's replacement. I just love the galvanized steel on the MB!!! We've got a '67 TR-4, '76 GMC pickup and a '97 VW Cabrio in the garage too.

I'm leaning toward the new parts but the compressions on the engine are so good that the valve seats must be darn good so all the work for replacing the head just seems like overkill. Also, it seems that most MB rebuilt heads come WITHOUT the cam and rockers!!! So I'd be buying them anyway.

I'm just wondering if anyone else has had similar problems with the "soft" chromed cam and rockers or has someone actually performed this "improvement" and has some tips to share.

Thanks as always for ALL opinions!

Bob

I've had to replace the cam and a few rockers in my 1989 260E at 245K.
I went with the original-new-improved cam as the original chrome was no more available.
prices then: $435 for the cam and $45. per rocker. (3 years ago)

Jackd,
Did you feel that the rest of the head was in good enough shape to replace the cam and rockers and not replace valve guides and seats? Did your cam and rockers look like mine? How did the new cam fit in the old cam bearings?
Thanks,
Bob

Hello Bob,

This will go against consensus, but I would keep the cam and set-up you have now and just drive it, at least for a while. What oil and weights did you use? Maybe going to a synthetic HD Diesel Oil, like 5w40 Mobil 1 Delvac or Shell Rotella, will help for a while. If it keeps valve clearances OK. Just a thought on another way to go.

If you do go with the new cam and rockers, I would do a complete valve job, guides and springs too, to get the benefit of the new cam. It's a tough call.

Good Luck.

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Thanks Ellington, it's too bad our XJ-6 isn't green! My wife and I love the XJ-6 and though it might not be kind to say it on this forum we still think it is the prettiest 4 door sedan ever made.

I've always kept a log book of the maintenance I've done on all of my cars (my lawn equipment too - wife says I'm way too anal) and the XJ-6 is 13 pages long. There is always something you'd like to do on old cars but it's pretty comfortable right now. Compared to the 300e though the Jag does show its 1948 heritage, the 300e is more refined.

That said, don't let anyone tell you that Jags of that vintage are not reliable - ours has been one of the most reliable cars we've owned and all with a few very simple maintenance practices.

One of the reasons I like these forums is because of the wealth of information available. I was able to learn on the Jag Lovers forum all about the deficiencies in the head design and make a necessary modification that completely eliminates a likely failure mode from the XK head. I was kind of wondering if anyone on this forum had information on the 103 head since I was obviously going to be doing some work on it.

Working on the 300e has been a pleasure (even though it seems to need so much done on it right now), all except the differential bushings!

Thanks for the kind words,

Bob

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I think the XJ6 was the best looking 4-door ever made, too - but only the ones up to the point that they ruined them by getting rid of the dual gas caps, the chrome details, etc. At one time, I entertained the idea of installing a small block/turbo in one - there were kits that contained everything you needed. Nonrunning Jaguars were available all over the place for practically free at one time. My (wealthy) boss in Atlanta leased one in the early 80's for his wife, he had to buy her another car and the XJ6 stayed in the garage because she refused to drive it because it was so unreliable.

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The cam damage is something of a mystery. I did not have any symptoms that would have led me to think there was something wrong with the cam. I originally took the valve cover off to replace the valve guide seals due to very high oil consumption. Prior to pulling the cover I ran the engine to operating temp and then ran a compression test. All cylinders were in the 170's at least indicating good rings and valve seats.

Being that I've only had the car for about 2000 miles, bought it from a friend who bought it at an auction, I know very little of its history. In fact it has a TMU title (true mileage unknown) due to the very common odometer being inop. From the carfax I've been able to estimate that the car probably has 130k to 150k based on 10k to 12k per year added after the last reliable mileage report on the carfax. That story told, I don't think this car has been starved of oil. It has good oil pressure, only 3 of the cam lobes are bad and I can find no other damage in the head.

So I guess I was hoping to find some info on whether this was a common problem for the 103 head. You reference early cam issues in your note, these are not mentioned in my 300e bible (which is my only historical reference for this car other than this forum), so was this kind of damage common in this vintage 103 motor?

Thanks,

Bob