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frenchyd UltimaDork
6/8/21 11:50 a.m.
Darel said:

I had the same issue with mine.  I sent it to the body shop for a complete strip and glass-out respray, and I wanted them to reinstall the glass because I didn't want the responsibility.  They called me and said the gasket's too big.  I ordered another, same thing.  I told them to just try it and sure enough it went.  I bought this stuff specifically made for windshields by Permatex, it's like a really thin, runny silicone.  I went around the whole gasket with a bondo spreader, lifting it and running a "bead" (seriously it's almost water-thin) of this stuff just as a precaution.  No leaks ever.  And my floorboards were a moldy swamp before.

Wait until you have to do the rear window.......

That's because the body shop that assembled the bodies for the factory  wasn't very careful. The factory eventually settled on  2 different sized windshields. Plus sealant as needed.   For a while in the late 70's early 80's nearly every single body had to be reworked by the factory. The absolute definition of hand built. 
    Also production in the 1970's rarely exceeded a 1000 cars a year!!  Making the PreHE version very limited. It wasn't until the mid 1980's that standardized body work became the norm.  

dannyp84 New Reader
6/8/21 1:00 p.m.

In reply to frenchyd :

Italvolanti steering wheel?

garethashenden New Reader
6/8/21 3:21 p.m.

In reply to frenchyd :

This isn't some universal radiator I'm adapting to fit. Its exactly the same as the factory radiator, except made from aluminum. And with two big electric fans. Thanks for your concern.

frenchyd UltimaDork
6/8/21 4:02 p.m.

In reply to garethashenden :

If you  cut your factory radiator in half. You  will see the divider that forces  the coolant to go up and back effectively making 3 passes across. 
    The radiator you have will simply allow water to go across one time. 
  I have no doubt it's a quality radiator.  But it's likely not going to cool as well.  
     The other point.  Have you checked your distributor?   What happens when a distributor sits for years is the advance mechanism seizes up and thus the timing is off causing overheating.  On page 65 ( I think) of my owners manual they talk about the need to oil the distributor.  It's a simple process.  
  Finally. The gauge. I think N is about 165- 185 degrees. Water boils at 212. When you add coolant it doesn't boil until much hotter, and then with a pressurized system it's even hotter before it boils.  As long as coolant  isn't boiling it's removing heat. 
  In short N means normal. 

Darel New Reader
7/6/21 12:25 p.m.

You're finding all of the most common XJ-S issues.

All of the radiators are plugged, because the FACTORY service instructions told dealers to add stop-leak with every service.  So by taking care of their cars, owners were unwittingly filling their radiators with garbage.  When I pulled mine and stuck a hose in it, I barely had a trickle coming out.  Had it boiled out and my rad guys were shocked at what came out of it.  But, for $50 my cooling system was good as new.

Good point above about the dizzy, mine was seized tight and I couldn't free it.  Had to pull it out and rebuild it on the bench.  I then blew up a $100 distributor cap by doing something stupid like spraying the contacts with contact cleaner and reassembling it without letting it dry, then firing the car up immediately.  BOOM!

One more common failure - if your transmission won't kick down when you floor it, FLOOR IT HARDER.  The way the kickdown works, is there is a microswitch right there on the throttle quadrant.  Stepping on the gas pulls the throttle cable.  Then, stepping harder pulls the actual sheath on the cable, which trips that microswitch to kick it down.  This sheath is almost always seized.  When I freed mine, I was on the highway and I planted it HARD, and it let go with such a bang I thought I blew a con rod or something.  But it worked fine after that.


frenchyd UltimaDork
7/6/21 5:16 p.m.

In reply to Darel :

Amen to the stop leak.  The system works fine if it's not leaking and often  after a lot of heating and cooling minor leaks would develop.  ( there are a lot of coolant hoses).  The factories solution wasn't right but it often got cars out of the warranty period. 
     You need to understand just what a small company Jaguar was.  There were years when less than 1000 Jaguar XJS's were built for global sales.   Sir Lyons always felt he had to make cost cutting savings because even when sales were good if the pound devalued too much in relation to the dollar Jaguar could lose on each sale. 
  While Sir Lyons owned the company employees understood the company and management.  Once sold to BLMC  and empty suits were now making decisions  without the employees knowing why, that bond disappeared and labor troubles were rampant. 
     Because of low volume proper mass production. And quality control wasn't possible.  The body's was outsourced and quality control virtually non existent. They had to have two different sized windshields and 4 sized moldings to deal with all the variations. Even then enough problems occurred that they had to add a leakage check for every car not just the prototype and an occasional spot check. 
       Jaguar bought GM's paint system TPA. THERMO PLASTIC ACRYLIC.  Basically paint was sprayed on and then melted.   The problem was to correct the flaws in the body stampings. The factory used lead.   Which melted only a few degree's higher than the paint flowed. 
as a result every body had to be refinished by hand at the factory.  Very very expensive.  

Darel New Reader
7/20/21 5:21 p.m.

I just noticed something - on the AL rad it doesn't look like it has a bleeder?  Maybe it's just the angle.  You are going to have some real problems if it doesn't.  These cooling systems are notoriously hard to bleed air out of because of the way the rad is lower than the rest of the engine.  Basically there is a plug at the top-driver's side.  You have to jack the car up so that the plug is the highest part of the system.  It's a lot - parking on a hill helps.  Then run the engine, burping that plug intermittently until no more air comes out.  This is harder than it seems and it involves putting it on high heat AND making sure the HVAC cam doesn't shut the heat off before you get it bled, squeezing various and sundry hoses to keep the air moving, etc.  

You need to have a SOLID FOUNTAIN of coolant coming out of the bleed plug - if it's just sort of "spilling over" it's not all out.  

Make sure that rad has a bleed plug - if not you're in for a long day.  Even with the stock rad it took me hours.  

Folgers New Reader
7/20/21 7:12 p.m.

Neat as hell OP. 

Frenchy, let it shine! Its good to hear from someone who’s seen and solved these problems in the real word. Knowledge, of this kind, will be scarce not too long from now. 

frenchyd UltimaDork
7/20/21 9:28 p.m.

In reply to Folgers :

The factory's system doesn't work for a race car.  Instead of picking up the water at the front of the engine to go back into the radiator and just assuming it's gone completely through the engine. my race cars pick up the water at the back of the engine. It's also the highest part in the car to ensure all the air is out. Then I run an aluminum tube back up to the radiator. 
  The block is massive in its ability to carry water. The pump is more then big enough to pump the coolant through at the correct speed.  While my approach isn't traditional it solves the two problems beautifully and what's more it's simple to work on. You're not wedged under the front of the hood.  It's close to the oil dipstick, close to the area's that cars typically need attention too.  

Darel New Reader
2/5/22 7:14 p.m.

How's the Jag coming along?


frenchyd UltimaDork
2/5/22 8:42 p.m.

In reply to Darel :

Thanks for asking. Check my Jaguar progress posting.  The guys helping me decided to try to make the Challenge this year. 

frenchyd UltimaDork
2/5/22 8:55 p.m.
russde said:

There's one local to me for sale with a missing title, 44k miles, white w/ white leather that looks really good...$2500 asking


I'm VERY tempted

That's about $2000 over the selling price without a tittle. ( assuming it doesn't run) if it runs on a bill of sale it's worth about $1500. 

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