Yep.

Radiator OUT, drop at the radiator shop, who remove the tanks, rod it out, retin the end plates and refit the tanks.

Pressure test the unit, paint it Black.

If it fails the clean test, a new core is fitted. However, since I always recore the radiators on the older Copper/Brass units when I FIRST get said car home, the chances of a new core later in my ownership is ZERO.

 

All good input here. I'm curious what this costs? In the bay area, just a cleaning is over $100... I would think that every 10 years for this would suffice, as long as it is flushed every 2? Just my experience with other cars. ....currently the radiator on my 91 v12 is working at 25 years and what appears to be a flush of fluid. There is a ton of gunk down the spout (bars leak) but it is working. The temp gauge is usually just at the lower part of the N. It is definitely due for the service you mention...

I'm going to suggest 10 years for a full service in my new maintenance guide that I will create after getting more input. Maybe we could say 35k miles here?

Why did they recommend bars leak in the first place? It seems odd that a dealership would recommend this. Are there that serious of leaking issues that they need to do this? Would a better quality radiator solve the issue?

 

Jaguar's (not dealer but factory) love affair with bars leaks goes way back as far as l can remember. I have no idea why as there is no inherent problem with the quality of their radiators.

 

Bars leaks was a stop gap preventative item, just in case sort of thing.

Many manufacturers do it, NOT Bars Leaks, but the "Pepper Pellets", which have NO residual affect.

The later XK6 and the 12 engins had some weeping of coolant from under the NICE CHROME dome head nuts, they were not just a sweet looking item, standard nuts leaked, as the coolant is right up there, and the Bars Leaks stopped the weep.

RTV was not invented in those days.

 

Remember that a lot of the gunk in a V12 cooling system is from the dissolving head gaskets.

That engine is an "Open Deck" design, and the gaskets are exposed directly to coolant, and they dissolve over time, and fall into the engine block, and there they stay, MOSTLY. Then when odd things happen, such as overheating (or close to it), this gunk gets stirred up, and ends up in the radiator.

The radiator being a cross flow style, clogs up from the bottom.

My findings is that a radiator that is 25% clogged/restricted, will have that engine running hotter than it should.

This gunk is near impossible to remove without stripping the engine, removing the liners, and digging it out.

My HE had more than 1KG of this gunk in the block, mainly around the 2 rear liners on each bank. The car had impeccable dealer service records, but still the gunk, and I know for fact it was NOT all Bars Leaks.

My recores were $600+, and I live with that. The new radiators for the 2 S Types were $350 each, and that was sweet.

An overheated V12 will cost you $7000 easy, plus a transmission, your choice.

 

Another thing that I would of never even thought of with this engine. Gasket material breaking down. Would head gasket replacement be on the maintenance list? ...I'm going to focus on more solutions here.

Is there anything additive that cold help break things down in the engine bay into a liquid.

Any reason not to go with this? Will it even work with a 91 xjs?

3 Row 62mm Core Thick Pro Full Alloy Radiator for Jaguar Series 3 XJS V12 XJ12 | eBay

Or this to help catch the gunk?

http://www.v12performance.com/Tefba.html

 

Head gasket maintenence, NAH. Do them when you rebuild the engine at a million kms.

Nothing will really stop the breaking down. The damage is done and dusted, live with it. Its just how it is. Nothing sinister is going to happen as long as the coolant spec is kept right at the top of that spec level.

Much of the damage has happened due to water being added for top up, and thus diluting the coolant, and this is long before you got the car.

The head gaskets are a composite "cardboard type" material, except the "fire ring" that sits on the top of the liner, and the rest of the outer edges that are sandwiched between the head and the block, so coolant cannot get at those bits, The rest is open to attack.

The engines were never envisaged to still be motoring along, MY OPINION, so the design life of that engine from the engineers is long gone.

Component failure is an accepted thing now, obviously, and frustrating as well.

The snake oil stuff that claims to clean it out is a rather caustic, mostly, and I steer clear of it.

Top hose filters can help, but if they clog, the wallet is going to get thin.

Dont overheat it, its as SIMPLE as that, and all that gunk will stay exactly where it is. HARMLESS.

Flush the metal header tank annually, you will be amazed at the gunk that ends up in there. Remove it from the car, do it properly, it is the only way.

Our PreHE has 540000kms, and untouched engine. I am simply NOT that brave (or stupid). It goes like stink, runs cool, leaks oil, guzzles fuel, has the BIG radiator (as all PreHE did), thermo fans, and had the same service procedure I mentioned earlier. It now belongs to a collector in rural Australia, and he drives it HARD.

 

What are the steps in checking this resistance? Multimeter involved? Where would you put the positive and negative?

 

What year is this? Is it a Marelli?

 

Ok Grant, lets talk about those pics of your clean looking engine bay, shall we?

First off is that a Pre HE we're looking at? What model year?

I see you've dumped the CC and gone to a smaller ac compressor (Sanden?), and we've previously heard you say that you like to relocate the coil and amp to above the radiator. Got pics of the way you're routing the wiring? Single coil or dual?

I see the FPR is a single unit as you've described, and the fuel cooler is gone. The fuel temp switch on the rail is gone too, so no bumping up the fuel pressure under hot rail conditions.

I see the overrun valve for closed throttle air is removed, wont this cause backfires ? I understand the later cars had this function moved to the ecu which cut fuel under closed throttle.

It appears that you've plugged up most of the vacuum lines that typically cross the vee, and have a single line that follows the contour of the fuel rail. Can you please provide a little more detail on what you did and it's effects on driveability? Jaguar added more and more of these lines for a reason I take it.


In general, I'm trying to declutter my engine bay (88 XJ12), but i don't want to do anything that kills the refinement that attracts me to the V12 and Jaguar. I've removed the air pump and air rails, as well as the CC since I don't use it. I also want to retain some "quaint" features like the fuel cooler, dual FPRs, dual coils since it's what gives this beast it's Quixotic character if you will.

 

This is going into an excel sheet and will be followed religiously as long as I own a V12. Its meant for the 'lifer' V12 owner.

1. thermostats/ coolant hoses/ belts every 7 years.
   
2. radiator flush every 2 years or 20k. clean banjo bolts. clean debris all around radiator.
   
3. new radiator or recore every 10 years or 40k. debate-able /some do every 5 years. depends on many factors including climate, amount of sludge in system.
   
4. brake fluid, transmission fluid, and power steering fluid, every 2 years or 30k.
   
5. Engine oil every 3k miles.
   
6. New Fuel hoses every 10 years or 40k
   
7. Check fuel harness every year until replaced, then 5 years after replacement start checking again yearly for cracks.
   
8. Spark plugs and wires every 5 years or 40k.
   
9. Distributor cap and rotor every 5 years. Marelli, check for abnormalities everytime oil is checked. For Marelli only, use silicone in rotor to prevent a fire.
   
10. Oil cooler and trans lines every 20 years.

 

1) NOPE, 1985 HE.
2) Amp out the front, alongside where the 2nd coil once lived. The wiring was simply part of the 100% rewire of the engine bay a very long time ago, which included the removal of the shielded wire inside the engine bay. The wiring simply runs up the RH inner guard, around the brake booster, and along the rear, before routing onto the LH inlet, and the distributor connector. It runs a single coil.
3) Correct, never had an issue. I run a PreHE unit set at 31psi.
4) Never had a backfire. The car has a 16CU ECU fitted, coz the 6CU died, as they do, and I simply grabbed the 16 from a 1988 wreck. Plug and play fitment.
5) I dumped the AVV, and the balance pipe, so the hoses down the fuel rail are for the ECU vac supply. The engine breather is to the outside, so no PCV, etc. The rest of the vac lines were once for emission stuff, and it was all very sad, and since no smog testing, gone it is. Jag added more and more for USA emission numbers, we dont have that stuff. Driveability, AWESOME, goes like stink. Remember, it also has the BIG throttle discs, and free flow exhaust, and obviously NO Cats (not applicable down here in 1985).
7) Declutter wil depend on the laws in your market, ours are simple compared to USA.

Most of this took place when I went in for the EFI loom rebuild, and decided to move it up top, and then other wires "cracked and crunched", so I ripped it ALL out at the bulkhead connectors, and started from zero.

A/c compressor, thermo fans, cruise relocated outside the engine bay, EFI ballast outside the engine bay, other electrical stuff also moved outside the engine bay, atmospheric coolant tank relocated inside the engine bay, trans cooler removed from the radiator, p/steer cooler removed totally, ignition amp out the front of the radiator, fuel filter relocated inside the engine bay, TPS replaced with an XJ40 unit, the throttle capstan spacers were shortened, and the fuel rail lowered by shortening the hoses, COLD air intakes installed, foam medium air filters made and installed, HEAPS of things looked at too many times, and relocated, removed, altered to suit MY needs.

It took 2 months.

This was a Daily Driver, and also took us twice around the coast road of our island (25000kms each time), and it did what it did 100%. One oil light switch was all that failed in all that travel. The beast returned 11.2l/100kms economy at the same time.

That is why I get a tad testy when people bag the V12, and the XJ-S, it is NOT the car at fault here, it is the previous shortcomings of the person/s looking after it, and mine was no different.

Sadly I sold it due to my physical disability making entry and exit way too awkward and painful. SAD SAD day, and it si still missed. Our 2 S Type V6's are awesome in their own right, but that V12 is something not easily replaced.

The PreHE I was referring to is "Sir Arthur" in my garage, a 1976 S2 XJ12 Sedan, which was "her" daily driver.

 

Thanks for the details, Grant.

So without an AAV, did you do a manual "choke" type cable to help when the engine was cold?

 

NAH.

I am a tad more fussy than that, haha.

I had 2 of the solenoids that once lived in the backing plate of the RH air cleaner and were used for idle up during warm up, and emissions timer (that 15 minute fiasco we all read about), that some markets got. We did.

I fitted them, one on each side, and switched with a small switch hidden under dash bolster. Flick it ON to start, and OFF when the temp gauge just "cracks" the cold peg.

Also can be handy to switch them ON for HOT start, as that little bit of extra air does appear to help.

Greg in France has gone a different way, and it is AWESOME.

He is writing it up, but the necta of the Gods does get in his way from time to time, and shelves in the kids bedrooms are now at the top of his to do list.

He will do it, trust me and him. You will like it.

 

It isn't unusual to find a V12 owner, faced with a dead AAV, to do nothing at all....and not suffer unduly because of it or, in some cases, not even realize it isn't working. My experience is that absence of a high idle is a non-issue until the dead of winter when the ambient temps are outright cold. On those frigid mornings you'll have to hold the throttle a bit until the engine stabilizes.

On mild or warm mornings you can start the engine, drop 'er in gear, and go....and nobody's the wiser, so to speak, for lack of a high idle.

But, I like Grant's idea and look forward to hearing what Greg did.

Cheers
DD

 

Good to know that Doug. Now then, we'll just have to wait for the French connection

 

Use the specifications of the coil. This will be different for Marelli and Lucas. The Lucas dual coil is actually 2 coils in parallel, but Jaguar only paralleled the primary not the secondary. This reduces the resistance of the primary coil by sqrtR=R1^2+R2^2

As an example if coil R1 is 3 ohms and coil R2 is 2 ohms (3^2=9) + (2^2=4) = 13sqrt = 3.6ohms

Multimeters are not accurate enough to substitute coils, because of the high voltages 1 ohm difference can be 1000's of amps. Lowering the coil primary resistance too much will effect ignition Dwell, in other words the coil will charge too quickly, once the coil is fully charged it has to dissipate the heat generated, this can cause premature failure of the coil.

A multimeter can be used to see if the coil is short or open circuit.

 

So where can one get push on hose? I have SAE30 R9 thermoid hose. I called the manufacturer and they said it is not push on hose. the only place I could find something that claims is push on is push-lok hose from jegs, which is not good for all fuel types.

It seems like others are just getting fuel injector hose and pushing it on? no issues with this?

I will most likely have severe barb damage. I replaced the hose on the fuel intake to the rail and the barb was so damaged I had to file it practically off to remove the damage. the knife marks were insanely deep. the guy just didnt pay any attention at all to not damaging the barbs. so regular non push on hose should work. however, if I find the barbs are perfect on the rail, I will be trying to find push on hose that is SAE30 R9. if such a thing exists.

 

Regular R9 hose of the correct size is all you need along with the relevant ferrules. If however you find the barbs are seriously damaged l would suggest deliberately filing the very sharp barb edges slightly and then use the EFI clamps on them.
I would not use clamps on unmodified barbs, those edges are like knife blades.

 

I am prepared for whatever comes at me with this. I am still a bit concerned as to why the hose manufacturer said not to use the hose on a push barb. this is the hose I purchased. I am waiting to hear back from them to answer my question of what hose should I use.