Hey guys, new to the forums and new to being a Jaguar owner. I bought myself a 1971 XJ6 Series 1, but after listening to the engine there is definitely something not right. It sounds too light to be rod knock, but I'm no professional (and have zero experience with Jags).

I've uploaded a video to youtube, any input would be hugely appreciated =]


- Caleb

 

That could be a cam follower guide that's come loose (fairly common, especially on the exhaust side), where the guide rides up and the camshaft lobe hits the top on the way round.

Check to see if your have a "stake-down kit" fitted. On a cold engine, take the oil filler cap off and reach in for a plate that sits on the edge of the follower guides between cylinders 1-2, 3-4, 5-6. If there isn't one there, you probably need a kit. I'd also pull off the cam cover to inspect for any heavy damage.

Either way it doesn't sound good!

 

Noise is bad enough to take off cam covers and have a look. I had a follower disintegrate while away from home, and had to rebuild head. If head is done right a stake down kit is not needed. Stake down kit is used to save money on repairing valve system. The shop I worked for would not install them for anybody. I have a set, ( got almost free ) and will not use them.

 

I agree that it might be a tappet guide and merits a visual inspection.

Personally, and just FWIW, I think the stake down kits are a perfectly viable device. Used preemptively the stake downs will prevent the guide from migrating upwards. That's a good thing.

If a guide has already come loose you might be able to simply tap it downward and then install a stake down to hold it in place. That's a good thing, too.

No doubt a better repair can be made by machining the bore for installation of an over-sized guide with a tighter fit. Naturally this is quite a bit more involved, in terms of labor and dollars, than installing a stake down kit....and thus might not be the best choice for everybody.

Cheers
DD

 

Agreed.

Those tappet clearances are way out.

The guides colliding with the camshaft have a very distinctive CLACK, and I dont hear that really.

Also that timing is a tad advanced, and maybe its my old ears, but it sounds like a 5 cylinder at times.

Nearly forgot, WELCOME to the forum. When time permits please do an intro in the "New Members Area".

 

Thanks for the welcome Grant! And thanks everybody for all the replies, your knowledge is truly invaluable! After reviewing the video several times, it is louder on the exhaust side for sure, and would make sense to be a loose tappet guide as being suggested by everyone.
This morning I took Jagfixers' advice and took the cam covers off to have a look for myself. The car definitely hasn't had anything done to the tappet guides, no stake-down kit or screws as far as I can tell. It all looked in relatively good shape though, no wear on the guides or missing chunks.
I gave each tappet guide a good push by hand but none of them seemed to be loose or raised up above the others. I suppose that hand strength probably isn't enough to move the tappet guide though.
The guy who came to have a look at my car said that the timing sounded off too, so I'll put that on the list of things to get fixed! xD

Questions for you if you have a spare moment:
- To get a stake-down kit installed, can I go to a regular garage, or do I need a Jaguar specialist? The car is unregistered and Jaguar specialists are far away and will cost more in towing.

- I was advised to run the car once a week to stop it from seizing up, should I run it or wait until I have a stake-down kit installed?



Pics:

Exhaust-side overview


Where left is the front of the car, this is tappet 1 and 2


Tappet 3 and 4


Tappet 5 and 6




I'm hoping to keep this thread active and post my progress in fixing this to help others, so there will be more to come! =]

 

Sorry to bump, but have introduced myself on the newbies board Young Newbie from Down Under! '71 XJ6 - Jaguar Forums - Jaguar Enthusiasts Forum

 

OK, since you got the cover off, do a tappet clearance measurement.

#1 cylinder is at the rear, its a British thing, dont go there.

Rotate the engine CLOCKWISE ONLY, and using a feeler strip write down the clearances you find.

You are looking for 0.014".

Looking at the snaps I see no evidence of the lobes clobbering those guides, but the last 2 snaps have oil covering any witness marks on the guides.

Let us know your findings. I have seen some with 0.020 and more due to "strange" people messing with things they know little about.

 

Progress update time!

So I went out and bought 6 NGK BP5ES spark plugs from the local Repco store. Have a feeling that I got the short end of the stick price-wise, with the set of 6 costing me $30. =\

I went ahead and installed them and they look fantastic! Look a bit out-of-place in an old beat up engine but they run well.

Regarding the tappet guides, today I ran my fingernail across all the guides to check for damage, but there isn't any at all, apart from the slightly bumpy surface of the metal. I'm fairly sure that this is causing the tapping sound as no tappet guides have any damage whatsoever and are all very tightly stuck in the head.

I had taken Grant Francis' advice by checking the clearance on the tappets. I've got a feeler gauge coming in the mail that I picked up for a couple dollars from eBay, but I was too eager to wait around so I used a piece of paper.

Folding the paper three times could JUST fit under the 3 of the cam lobe heels that were in position very snugly, however there was a lot more room between cam lobe heel and tappet for cylinder 3. Although this very unprofessional method gave no number readings, I was able to check

My next step is to use the proper feeler gauge and measure each clearance to confirm my suspicions about cyl 3 on the exhaust side and do measurements on everything while I'm here. Hopefully shims aren't too expensive


High quality pictures below!

The old spark plugs below
Spark plugs #2 and #3 were especially bad, as you can see. #3 even missing a 1mm x 1mm chunk... The others were blackened up but not near as bad as those two.




The new spark plugs in and looking fresh






I had also started the car up and let it heat to try and discover why the right side exhaust is blocked/'not exhausting'. It appears to not be a muffler problem as I first suspected, as the muffler and the pipe before it were stone cold and other side was very hot (being the smart cookie that I am, received a nice burn! ).

The pipe seems to go upwards and I was unable to follow it without getting the car on ramps and it was getting late Where does this pipe lead to? What would cause only one side to be blocked?

Right side exhaust

 

Well done.

A Jag owner with an imagination, how good is that.

Its really a South Aussie thing, we grew up thinking OUTSIDE the square, HA.

That #3 is suspect with me now, and I bet you end up with 0.020 or more on that one.

That exhaust pipe goes UP and thru the cradle, and connects to the silencers tucked up inside the rear 1/4 panel.

One side cool and the other hot, or one side "puffing" and the other not an an XK 6 cylinder is odd at best. OK, the manifolds are split as in 3 and 3, but the 2 pipes at the front connect to a single pipe to travel past the transmission, then branch out to LH and RH. Those large rear silencers do clog up with age and lack of use.

 

RRP on those are $5.95 each.
I paid $3.55 each at trade price.

 

Either number, USA $'s would be a steal around here for name brand
spark plugs.


Way back when, our neighbor was a Brit guy. He worked as a boiler maker at the local Southern Pacific RR maintenance shops. All steam at the time.


Their family car that took them through WWII was a 38 Plymouth
dour door. One day it was "misbehaving". So, he decided to apply
some shop skills. Clean the flue!!!! He removed the entire exhaust system, piece by piece, from the manifold back. Scrubbed and beat piles of soot out of them. Put it back, the old beast purred... I wondered about that for decades.


Four brothers lived up the block. Very different guys as to personalities. One laid his hands on a very decent 31 Plymouth.
He didn't like it so he drove it sans coolant to see how far it would go.
amazingly, quite a while before it seized in front of their house. Step dad robbed it of the tires Rationing on and he was a tire repair guy.


Ed latched on to a more than decent 36 Ford coupe. Black with a nice pair of tear drop fender skirts. well, he busted a spring. so, he swapped them for a weld job. Still not sure how that could be???


Then, he decided the engine was "carboned up. Laborously, he dropped both manifolds. Two of us younger kids went for a ride with
him. That V8 firing right out of the block created a sound that started it all.....


Well, Ed couldn't get the manifolds back on!!! Sold the thing and joined the navy as did his brothers. December 1941.....


All came back when it was done, safe. Very tough on their Mom that had a tough time raising them.


The old days.


Rough and ready clearances. .o14 inches is about the dimension of a thin dome or a paper match book cover. Set point gap by that.
A tad rough for valve lash, but indicative.


That compare method has value, for sure. Kudos. Takes a bit of getting on to it to feel with a feeler guage. Just the right amount of drag.... I was never really good at it!!! More than pleased when I got my paws on a dwell meter....


last summer I set the flywheel magnet to coil gap on a pair of one lungers. A sheet of paper!!! Hard with a guage because of the magnets. Son said he just "eye *****" his. He is a talented machinist.


Ways, differ, to be sure.


That Jaguar 'through' the cage system is joined. Parting the joints could be real fun. My way would probably be a recip saw...


Carl
Carl

 

@JagCad Good read! Seems like you've been around some very nice cars. Old Plymouth's are always really stylish, you were lucky to have grown up with one!


Just a quick update on the build, (I know the title is about the engine noise, but saves me creating a new thread :P ) I got a clearance gauge in the mail. Took cam covers off and tested one on the exhaust side and it returned 8mm.

I'm not overly confident in the cheap Chinese gauge, but if it were true something has definitely been tampered with here.

Yesterday I had found the time to replace the globes on the rear brake lights and reverse lights and they all work well, however I have came across a problem.

The metal container for the light that lights up the license plate on the back is a rusted wreck. Bulbs were shot, but even when I took what I could apart it wasn't giving any voltage off.
Anyone know where the wiring for that light comes out of? Is it one of the rubber-coated wiring tubes that connect to the fuel pump?

Cheers again!

 

8mm????? Thats close to 5/16 " thats enormous. Something is horribly amiss!

 

A rather large clearance on one tappet could indicate a bent valve. On engines nor run for a long time, and hence little oil around the valve guide, it is possible for the valve to be a bit "lazy" in returning under spring pressure, and get knocked by the ascending piston, Yes, it happened to me ! Only cure is head off, replace valve and put head back on.

But before you pull the head off, test each cylinder for pressure. None on the one with large clearance almost certainly indicates a bent valve.

 

Arr, what have I said! Something in that post was indeed horribly amiss!


My apologies, I mean't to say 0.008 inches (0.02mm) of clearance, which is too tight.

I managed to check a few without doing the whole process, only the 3 or so were at the correct position, all were reading 0.008 inches.

I didn't even think of the possibility of a bent valve, but it would make sense if someone had put larger shims it would increase the possibility of bending a valve?

I'll have to look into testing the cylinders for pressure, I haven't ever done that before, but it will be my next step forwards I believe.

Thanks again =]