S1 Series 1 3 XJ6 engine knock

XJ
21

Thank you both Carl and Frank (and others) …

Genuinely appreciate your thoughts and chat…
Don’t apologize…just being funny.

Been away from all of this stuff for so long, remember how nice the forum is here and why I was such a part of it.

What to do what to do… There really isn’t much to it, you know? Especially with all hoses gone, AC out, Air pump gone…
2 mount bolts and transmission mount/connections, that’s it!
Everything else is really good and is working. Although engine bay wiring needs replacement. It’s nothing really…especially with engine out.

I have been keeping eye out for at least couple years and have yet to find one in such original solid shape. They are all conversions or botched, tacky redone interiors, etc. I’ve even seen repainted 2 tone gold and white one!

There is a place locally that sells and swaps old Jaguar parts, motors, etc…
In the States and on Craigslist one can find motors being given away from the S3 often times.
Worth rebuilding one here and taking it somewhere to install for me as I just haven’t place to do so…
Perhaps worth contacting Jaguar club, maybe someone can help.

I just haven’t time for this, not what I should be doing now.
BUT if this is the “keeper” … it should be kept.

Take care…see you around.

PS: As a side note, for the first time I looked at and sat in a late XJ40. I’m considering it. Surprisingly, I liked it very much!? Who knew…

Memories are funny things…sitting within an old Jaguar has its smells, memories of the Mk2, Mk7 etc. …yet the later ones has its smell inside.
Smells like money…wealth. Totally different feel.

…and reminds me of high school, visiting the local dealership and dreaming.
Funny how smells can take you back.

22

You haven’t reported back on the stethoscope or screwdriver listening test.
I’ve found this can really isolate the sound, tell where it is coming from.
I’m voting for the timing chains.

23

Haven’t done it yet, hot as hades lately, but that is a possibility as I hear a squeak as well, not associated with the belt…

It’s a helluva thing isn’t it? Been driving it around, so…

going to look at used engines for a rebuild tomorrow.

24

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Re ‘what to do, what to do’, Demian - drive it and enjoy…

Whatever it is; the damage is likely already there. And in principle, while it may gradually get worse, the repair will likely be the same -, when you so decide. While I’m all for fixing things as they appear, I’m also an expert procrastinator - particularly when there is some uncertainty as to the cause.

We all have experiences with doing a lot of work, only to find we were barking up the wrong tree…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
**

1 Like
25

Well, as an update, I did finally take proper time to look at her…talk about procrastinating!

Once again, it is a US Series 3 motor. Per serial number, I can date it at 1984 I believe per what I’ve found here.
Therefore, 8:1 … fwiw.

While I wanted to do a cursory check to simply determine anything catastrophic, I ran a more proper compression check today.

Did it cold as I don’t want to run her anymore … been running around the neighborhood about 10mins. or so while keeping eye on any possible overheating with the infrared thermometer.

But as mentioned, coolant header tank was plugged at both exits with a u-hose, an a simple blanking cap that doesn’t seal perfectly allowing some coolant escape at pressure.
This was done before me and as received by SOB PO … due in part to rusted/leaking overflow tank as mentioned within other post.
Very short runs should be ok, short testings, but no more as I know it’s not good.

That said, while cold, all plugs removed, throttle open, each cylinder registers a solid 160PSI.
…while ole’ #5 registers 150…fogged it registered 155+

The wiring of the car while generally good elsewhere and original, all other items function excluding some lighting due to rather obvious issues…

However the ignition wiring is hard and wrapped with electrical tape, don’t like …so I cut that off today and exposed the original wires.

Although I simply replaced cap, rotor, plugs, plug wires … the wiring of the distributor is crap.
Never did check for arcing,etc.

So low and behold there is serious arcing of the points opened when ignition on.

Read a good comment, “90% of carburetor problems are ignition related…” or something to that effect.

I thought I tuned the hell out of them, but never could get it to idle well.
Strangely at higher revs ok…and revving generally …no backfires.

i noted it didn’t seem to have a strong spark so I bi-passed coil resistor to test, and noted wetness on the plugs which concerned me … unburnt fuel it seemed…
The spark always appeared weak…

Anyway, brought it in tonight and tomorrow will take it all apart and clean it up.
I have replacement points and LT lead on distributor housing as the fabric wound wire on it seemed older than me anyway.
In time I will eventually replace with an electronic E Type unit.

Hopefully this will resolve some issues.

As for mechanic’s stethoscope bit, don’t have yet. That will be final test, but I believe I have decided I am going to go with it all …stubborn and obsessed as I am. Top end not making any nosies at #5 … I opened oil filler and stuck ear in, all sounds normal up there.

Again, the hose to ear revealed sound from bottom end at pan area at #5.

So, if it is a main due to a spun bearing or something, I don’t want to score the crank worse than it may be.
Hopefully I dream to get away with being able to hand polish it and replace the bearings if in tolerances…

…however, I do get puffs of smoke out the exhaust under revs, so perhaps rings and/or valve guides, seals are necessary too?

Anyway, this car is a keeper. I will not make the same mistake I have made in past selling my classic for a “newer” model …only to regret it. Not this time, damnit!

Although values remain low when one DOES come across a Series 1 XJ6??..how rare are these cars?! Find one in decent ORIGINAL shape … I’ve had my eye out everywhere scanning for past couple years…I’ve come across maybe 2, within the US that is.

It blows me away they do not yet have the market of the E Type and Mk2…it is such an important and rare car.

As long as i focus and look past the paint, she is worth it…funny how paint can make such a difference.

So I will rebuild it, within reason. that is, whatever needs to be replaced, should be replaced, and is out of spec will be remedied…damnit!
I must be crazy!

kind regards

26

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Nothing conclusive as to #5 noise, Demian - if caused by bearing or rings/piston; only dismantling can reveal it, of course…

That noises disappear with increased revs does not mean lot - the xk engine tend to smooth out with higher revs, even with serious faults. However, bearing noise tends to respond to loads - Carl had suggestions tas o provoke audible variations.

It is perfectly possible to inspect the bottom end with the engine in the car - there are two ways. The ‘correct’ one is remove the front suspension - this allows removing the sump for easy access, otherwise impossible due to the crossmember. The other one is to lower the pan with the front suspension in place - raising the engine a bit to improve access slightly. The bearings can then be changed, this has been done - but it is very advanced keyhole surgery…:slight_smile:

To inspect pistons, the same applies - but the head must then be removed to allow pistons to be retracted upwards, for inspection or ring renewal. Bore damage require engine removal of course…

There are no significant difference throughout the range in the bottom end with the xk engines - differences are basically confined to the end seals. Bearing play may be ordinary wear - but damage will ensue if bearing lubrication fails - usually due to clogged oil channels in the crankshaft. If so, the crankshaft must be removed - as it must if any work is to be done on the crankshaft itself. This is possible with the engine in the car - but require detaching gearbox from engine. One can live with commonly worn bearings - whether a damaged bearing can be run as is without excessive damage…only time will tell…

As for the weak ignition. If you do have the original mechanical points ignition, there is merit in changing to the an electronic ignition - the CE system used on later cars are perfectly OK, appropriate distributor and ign amp. As is usually the case with aftermarket systems. However, the mechanical points system works OK, but failure of the dist capacitor and worn/maladjusted points will give a weak spark. As will inappropriate coil for the system fitted…

The bypass resistor on the points system is bypassed during cranking - but the appropriate coil needs the resistor to protect the coil while running…

Frank
xj6 85 Sov Europe (UK/NZ)
**

1 Like
27

Thank you very much Frank…

Yes, i am not into keyhole surgery here. It is just appropriate and screaming to be removed and be done properly.
I need to clean and paint the engine bay, clean the suspension and clean up wiring, detail everything, within reason, so…

Although I haven’t the space, I am going to be a bit crazy and do it in a few days time (hopefully) providing there are no catastrophes. Perhaps drop it into the damn living room!
Get all the parts ready I anticipate and just DO IT.

Yes, the ignition/spark was quite weak. Surprised it ran so well at all when the arcing between the points was so great?!

Kind regards and thank you for your time.

28

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I admire your attitude, Demian!

Frank
xj6 85 Sov Europe (UK/NZ)
**

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Just last week I attended an evening with a very knowledgable guy about tuning twin carbs,this chap has been in the game for a number of years. Mainly dealing with MGs’ but also has Jaguars (commonality being the SU Carbs) the last thing he spoke about after about 2 hours was to say the LAST thing you do when tuning twin carbs is to touch the carbs. If the car is running get the ignition set up properly, apparently .001" gap difference on the points equates to about 1deg of ignition.
Another member of our club has just finished a 25 year build on a F/Glass replica ‘D’. Its been on the road for about a year now. He has just had his distributor rebuilt with new bushes and the advance curve set up to original spec. He states that the car is a totally different animal.
Just backs up what you had been told.

1 Like
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Ditto:

I like that phrase, “just do it”.

I’ll sure watch the developments with interest. At least to see if my “guess” proves out,.

But, more so to see a successful fix.

I started a diversionary project yesterday. It involved a chunk of wood cut from my Hawthorne tree. And my band saw. %$##$^&&%%, Mid cut, the blade came adrift or worse yet, busted. Back to my “usual”, gotta fix busted tools mid stream.

The good part is that both my Jeep and my Jaguar are just fine.

Carl

Carl

31

At least you’ve got the right tools for the job Carl!
You wouldn’t believe what I’ve got to make do with…

Sounds like a nice place to live.

Honestly, i awake in the morning and think…i just can’t do this now, it’s the last thing i should be doing now…
The thought of letting the car go is however very heavy and saddening.

Been searching a while…was the keeper.

We’ll see.
Over and out.

32

Reviewing this all and re-reading posts, this is great advice and thoughts Carl.

As a note for posterity I wished to add, as mentioned, when squeezing hoses I felt a crunch crunch…immediately thought dried hoses as car comes form a hot arid environment.

However, there has been continued mud, no particular color, not particularly oily at all, looks like damn dirt globbed around header tank filler at water rail and beneath cap.

Thought oil, head gasket, etc, although I now have upon doing various methodical flushing and cleaning and running of motor I have a solid 160psi across all cylinders.

Again, this is an 8:1 compression US S3 XJ6 motor.
#5 is now 155+ cranked cold…

There may be head gasket issues, however this just makes it all not obvious.

My point is that I am beginning to feel that th SOB previous owner (yes, he was an SOB) poured Bars leak or similar into engine and this is what I am seeing and feeling coating the hoses.

This combined with rust I believe. Straight water in system, cap that doesn’t seal, air+H2O = rust.
Flushed several times, filled with vinegar and and allowed to soak a week and flushed all out again, now I have a red driveway.

So there is that…

What I also wished to add as although oil was ok in appearance when I got the car, and first changing revealed no metal particles, it all just leaves me a bit bewildered as there is no smoking gun.

ALSO, I am not losing oil either …if it were dirt/mud caused by mixing due to head gasket etc, I would be losing oil…

So this leads me to believe it may very well be a bars leak type of crap.
Also the Po included an extra cylinder head, complete … I believe possibly he knew condition and never did replacement. IF I recall there was mention of cracked head…whether it was that one or this one, I don’t know.

But suspicion leads me to believe it may be this one.

Must be taken apart I feel is only way!! ENOUGH!

As noted the knock seemed to come from bottom end at #5 cylinder.
I DO need to get a stethoscope.

Anyway, just came across thiswithin another past message in XK ENgine forum.
Interesting info and thought I’d add it for posterity.
Hoping NOT, but I have never head of this before…

…4.2 cranks are often cracked on the main bearing between
5&6 cylinders due to asymetrical cylinder loading…When they
stretched the bores to go bigger the head stayed the same.
Thus only cylinder #2&4 line up under the combustion chamber
the rest are offset which puts a stress on the crank due to
non centered loading of the piston… Not usually a problem
unless high RPM is used regularly.

Kind regards

33

As a final note for now until I actually take it apart, the introduction of seafoam and even squirting water at high rpm through carbs was to breakup any possible carbon within combustion chamber.

The only other thought I had that could cause a condition specific to one cylinder other than main, rod, or piston rings as Carl mentioned, was the possibility of carbon buildup creating a pre-ignition sort of condition…

It’s been sitting for so long, etc. and who knows its past.

As another side note, regarding past and looking at cars again, boy is it difficult.
One cannot trust anyone. Few competent past owners out there, you know?
I would have to tear all apart and clean, flush all and replace all anyway as I just couldn’t trust any previous owner…trust it was done right, etc.
People lie …yeah, I just re-discovered that.

34

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The ‘…often cracked on main bearing…’ must be taken with a pinch of salt, Demian - it is not an ‘often’ occurrence…

One somewhat odd thing in your case is the 155 psi pressure on a 8:1 engine - this is really a 10:1 reading. However, actual readings relate also to gauge precision, and in some cases other factors - the main purpose of the compression test is really to verify evenness between cylinders, and yours is good in that respect…:slight_smile:

Coolant and oil are to be strictly separated, but if you have no coolant in the oil (which cause oil levels to rise, apart from oil discolouration) - chances are there are no interleaks. Oil in the coolant is not really impossible, but it is a rather scarce occurrence. Problems in the two circulation systems should other wise be treated individually. ‘Barrs’ seems to have been in regular use by Jaguar as a preventative - stopping leaks as they occurred. The drawback in this is that all such stop leak additives tend to clog up the coolant system - it is better to tackle leaks as they occur…:slight_smile:

But there is no point working on the cooling system without clear faults symptoms - basically leaks or imperfect cooling. And rectifying the leaking expansion tank and sorting out the hose connections to it should be attended to first. With no coolant in the oil and even compression your head gasket is likely in fine shape…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
**

Fran

1 Like
35

Wowee, cracked crank at a main journal!!! As a result of a design variance? I don’r know enough to deny it. But, I do know enough to doubt it. But, just mebbe, if highly stressed As in sustained high RPM on an engine with a longish stroke…

  1. I am aware of two busted cranks. Each in critters other than Jaguar.

A. My freshly rebuilt 37 Ford V8, circa 1950. The center main cap was not properly secured. I came loose and mayhem resulted!!! Busted across the center main journal.

B. Decades later. Son had a much modified and as a teen stressed his 57 Ford 312 CI V8. He called me to come get him. Not far away. He told me the engine was running better than ever, but just came apart. Indeed it did. The web supporting a center main just came adrift. Busted crakk, mangaled rod bearings. Son says not going fast at all at the time???

Carl

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Sure sure guys…I understand it is not a common occurance, but interesting note nonetheless, thought I’d add it fwiw as I never heard of that before, and I’ve been around these cars all my life.

Hmm…too high at 155-160psi? Quite sure the gauge is accurate…but…
I’ve searched and seen the same figures elsewhere for these S3 US spec motors in good mechanical shape…hmmm

Anyways…may have to do the keyhole surgery…damnit. That is, lifting the motor and detaching mounts…
But as it is at the front (#5) it will be beneath front suspension and a bitch to get to…damnit…

We’ll see and, I’ll post results whenever get there.

kind regards an dthank you all again.

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The keyhole surgery will allow removal of the big end cap for bearing inspection, and crankshaft state in the area, Demian - but it is not recommended for senior citizens…:slight_smile:

Don’t worry about the compression ratio - it is what it is, it is evenness between cylinders that counts…

Frank
xj6 85 Sov Euope (UK/NZ)
**

38

Yeah, that’s how the expression DPO came about.
This discussion forum and before that the original jag-lovers have always been about accurate and hopefully helpful information.
BTW mechanic’s stethoscopes are $10 in Advance Auto Parts…
Ramps are $50.
Try it before jacking up the engine.

39

He,he!!!

I thought DPO was interesting for quite a while. Then, it dawned
on me that DPO could also mean, “dumb present owner”!!!

A sobering thought. Took me down a notch or two.

I prefer ramps over jack stands. Though, each has advantages and disadvantages. Utmost care needed in the use of either.

I did a “DPO” with ramps, not too long ago.

And very recently, I used them on the rear wheels of my Jeep to get the gas tank down to replace the sensor/pump module. I remembered to chock bot front wheels. Fortunately, no misadventure this time…

Carl

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@Frank, et al: Yes, it is the best method to determine bearing condition quickly. . it may age me, that’s for sure.
Are you sure? That compression of 150-160 is correct for an 8:1 US spec XK motor in strong shape. Although few seem to do it properly.
Nevertheless, as you say, it is the evenness among all cylinders regardless.

I simply wish to cure my curiosity at this point.
Will be interesting to see what it is exactly.

A knock occurring on 1 cylinder, disappears when plug removed.

Stethoscope was not clearer than hose to localize the knock.
It seems to be coming from the sump area and nowhere else.

that kind of knock screams rod knock or main…but in all my years and all the old Jaguars I have had or played with , I have NEVER had or heard a rod knock,etc. on one…not once!

I guess it through me the unbelievability?!

The motor needs to be done regardless at this point with all I have seen, also as I wish to do engine bay and wiring properly.

the strong compression across all cylinders saves me some grief, focusing on bottom end only hopefully. then again, it is also confusing.

What has thrown me so is that this car had been sitting ages, conditions have changed as I have gotten it running/driving, and also new conditions revealed themselves.

I have been bringing it back from the dead, patiently and methodically.

Compression has risen and balanced upon doing all I have due to my understanding of these cars, AND GOOD LUCK! ,but at same time:

*Losing coolant…yet strong compression on all cylinders.

*Hard blips of throttle reveal smoke, not constant white smoke. Not burning oil though…it ain’t blue either. May be poor combustion due to bad points/condenser. . or guides. May be because it has been sitting for so long.

*dirt like dry dark oily mud at radiator header tank cap indicates head crack or gasket leak. Combustion junk and/or oil leaking into cooling system…perhaps Bar’s, rust combination as well.

*Oil otherwise clear, no metal particles when changed. If bad bearing(s) there should be something as much as I have been driving it? Maybe not.
No milkshake.

*Tappets ok , clearances, meh…too tight if anything.
*Damper ok, no wobbles
*Valve timing checked. upper timing chain tightened fwiw.

Regardless, again, one must return to basics with problem solving, it only occurs on one cylinder, disappears when plug removed. Disappears at higher revs.
vis a vis…rod bearing(s) signs.
But there is everything else mentioned too so…

Due to all above it simply needs to be pulled and gone through. No way around it to restore it all properly.

Only other possible thoughts other than main or rod bearings due to it effecting only 1 cylinder, disappearing upon disconnecting, was possible pre-ignition due to carbon buildup within combustion chamber…

I feel it is something unusual and combination things

I will update what I find. May be a while, but I always make it a point to.

Regards and thank you all for your thoughts and time.