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1971 Jaguar XJ6

Back Home – The 1971 Jaguar XJ6 Heading Home

The 1971 Jaguar XJ6 which had some engine work recently has gone back home to its owner after everything has been completed on the car.

The Bridge Classic Cars technicians worked on replacing both fuel tanks on this stunning light blue XJ6 late last year before discovering the engine also needed some work to be done in order to get it running 100%. The team cleaned out every coolant galley in the engine block while the cylinder head was being repaired.

With everything complete and tested on the XJ6, it was held out our secure storage facility, The Hangar, while it waited to go home. Just before, we pulled it out to take some final photos with this wonderful piece of Jaguar history.

Back at It – Preparing the 1971 Jaguar XJ6 Engine and Cylinder Head

The cylinder head for the 1971 Jaguar XJ6 is back at the Bridge Classic Cars workshop. This has been away at a local specialist to be assessed and repaired ready for the car.

Some may remember that our in-house restoration teams found a large chunk of material missing from the leading edge of two valves in the front cylinder. Also, it was discovered along with this that a blown head gasket had been what caused the misfire and running issue noted on the straight-six.

In preparation, Jonn had cleaned up the entire engine block which was discovered to be completely packed with sludge in every coolant galley and water jacket. Jonn has spent hours clearing out all the debris and flushing through the engine block to ensure all is ok when the engine is finally fired up for testing.

Now, it is down to Paul to install the cylinder head on top of the straight-six. For that, he will prepare the new head gasket and double-check all tolerances before the head is finally bolted down.

Expect to see more on the 1971 Jaguar XJ6 here on the Bridge Classic Cars news page very soon.

Thorough Clean – Further Cleaning of the Engine of the 1971 Jaguar XJ6

Jonn, one of the Bridge Classic Cars in-house restoration technicians, has been working on cleaning out the engine block of the 1971 Jaguar XJ6 currently in our workshop.

In the last update, Jonn had discovered the block of the straight-six packed with brown sludge.

Jonn has been working on thoroughly cleaning out every passage inside the engine as well as cleaning up the threads of the head studs. Jonn has methodically worked his way through the entire engine from front to back, cleaning and flushing through any remnants of the dirt.

With this complete, Jonn is confident that the engine block is now completely clear and ready for the next stage of the work to begin.

Clear Out – Cleaning out the Engine Block of the 1971 Jaguar XJ6

A while ago, you may remember that our in-house restoration technicians were looking into a misfire issue on the 1971 Jaguar XJ6 that is in at Bridge Classic Cars. It was discovered the head gasket has failed and damaged the cylinder head which was sent off to a specialist to be remachined.

With the return of the cylinder imminent, our in-house restoration technicians have been preparing the rest of the engine block to receive the head. After Jonn had begin to inspect the block for assessment, he discovered that most of the coolant galleys and water jackets were packed with thick, brown sludge..

Jonn has spent a considerable amount of time to carefully remove the blockages and the sludge. Using a series of tools and removing the core plugs to get better access to remove the debris, Jonn has managed to remove the majority of the sludge from the straight-six but the last few bits and pieces will need to be flushed out and then the passageways rechecked for any remnants.

Considering the level of blockage in the engine, Jonn has done a great job in making sure that when the cylinder head for the XJ6 is ready to be fitted back on that everything else will be at the same standard to ensure a happy and long life for this wonderful piece of British engineering.

Following Along – Diagnosing a Head Gasket Issue on the 1971 Jaguar XJ6

As with any classic car, you want to try and exercise a certain amount of reserve and caution when working on them. Try to be sympathetic to their age and their condition. So, when the 1971 Jaguar XJ6 that we have had in at Bridge Classic Cars developed a misfire our in-house restoration team did everything they could before having to dive deep.

The XJ6 has had its fuel tanks replaced, new fuel lines and was tested by our technicians. Before the tanks were replaced this classic Jaguar had real trouble staying running. Now though, it will run for as long as there is fuel in it. However, now that it was running long enough, Dave noticed a misfire on the big straight-six.

Originally Dave thought it to be connected to the ignition system. It would arc out to the nearest metal point. We also discovered exposed wires in the connectors that join the condenser. Those were all then replaced along with the HT leads but to no avail. It had got marginally better but the misfire was still rather prominent.

With that, our in-house engine guru Ady was called in to take a look at the straight-six. The only thing left to do was to gently remove the cylinder head. Carefully and patiently, Ady eased the head from the block to expose the pistons but more importantly the head gasket. On the cylinder closest to the firewall, the gasket was in tatters. The XJ6 had blown a head gasket. Also, Ady had noticed coolant marks down the side of the block. Another sign that the gasket is not sitting correctly between the cylinder head and the engine block.

With that, it also damaged the chamber of the corresponding cylinder in the head. A large chunk of material is missing from between the leading edges of the valve. But, all may not be lost. The head is currently in the process of being stripped down and assessed so that a plan can be made to get this wonderful straight-six back in action.

Once the plan for the XJ6 engine has been confirmed, work will begin to get the car back to its former glory.

Closer Look – Investigating a Misfire on the 1971 Jaguar XJ6

The wealth of knowledge held in our workshop is incredible. Centuries almost of combined experience allow Bridge Classic Cars to look into a wide spectrum of issues on classic cars.

Take for instance this 1971 Jaguar XJ6. Recently it had its fuel tanks replaced with us but during the setup, our in-house restoration team noticed that it had a pretty bad misfire. This needed to be looked into more in-depth. Dave, one of our most experienced technicians, began to dive deeper into the straight-six.

Dave had noted that the HT leads and the coil was arching to the closest metal object. So, with that and his experience he elected to replace the leads and the coil as the first port of call. However, after startup, the misfire was still prominent. At that point, it was decided to perform a compression test. 5 out of the 6 cylinders were all within spec. However, 1 of them was suspiciously low. With the classic cars, it can be a myriad of things that can cause this.

Dave then pulled the rocker cover off of the intake side of the engine to gain access to the rockers and more importantly the valves. With the help of our in-house engine builder Ady, Dave checked each of the valves for the correct lash. Originally they would have been between 10-14 thousandths of an inch but on Ady’s guidance, he is happy to see them between 8-10 thousandths with a vehicle of this age and mileage. All of the valves however fell within those guidelines. Nothing was noticeably out of place.

With that, Dave then found the leads had begun to arch again. This time through a set of pliers and straight to the cylinder head, which was worrying. So, Dave is going to rebuild the distributor with new points and condenser along with a completely new set of HT leads again.

Expect to see more of the progress of diagnosing the misfire on the 1971 Jaguar XJ6 at Bridge Classic Cars very soon on the News Page.

Back In The Swing – Refitting the Fuel Tanks to the 1971 Jaguar XJ6

The replacement fuel tanks are now secured in their new home at the rear of the 1971 Jaguar XJ6 at Bridge Classic Cars.

After much hard work and careful approach by our incredibly experienced technician Dave, the XJ6 can now start to be fitted back together. As you may have seen previously, Dave was working on converting a set of later style tanks to work on this earlier car. Some of the fittings and placement for a series of vents and inlets were in slightly different places over the production run of these wonderful cars.

As you can see from the photos, the tanks nestle up under the rear quarter panels in a very tight fit. Dave worked his magic gained from years of experience to ensure they were safely fitted and secured for the owner.

There’s more to come from the XJ6 so keep an eye out on the News Page of Bridge Classic Cars.

Fully Fueled – Replacing the fuel tank in a 1971 Jaguar XJ6

If you’ve been following along with the progress of the 1971 Jaguar XJ6 we have here at Bridge Classic Cars, you’ll know of the trouble that our amazing technician Dave has had with getting the car to fuel properly.

What began as a simple carb rebuild and set-up has grown into making the fuel system work (and look) just as good as the rest of this underappreciated classic. The old tank once removed looked fine from the outside, but after one look inside Dave knew he had got onto the right track. Rust. The dreaded oxide that plagues all classics but something that we here at Bridge Classic Cars are well used to dealing with and overcoming for our amazing customers.

Replacement tanks are available for this generation of XJ, but this being a very early XJ6 our technician Dave noticed some changes between the two. This is no problem thanks to Dave’s unrivalled skills. He has swapped out the supplied fittings for the return style system (for use on fuel injection cars) on the new replacement fuel tank to a returnless style need for this particular XJ6 with its wonderful set of Webers. Dave has made new plugs for the lines that are no longer needed for this beautiful classic.

Along with the new tank is a brand new set of fuel lines. Because of the rust issues that Dave found through the fuel system, it is best practice to replace the lines from front to back for the longevity of the car. Now the next step, get the new tank fitted up into place along with the new carefully made lines to begin testing to make sure that this XJ6 runs as good as it looks.

More evidence of Jaguar’s dirty fuel line!

You may have seen the blog post from last week about the fuel line problems that Dave discovered on the 1971 Jaguar XJ6. If not, here’s a link straight to it. Here are some more photos and another video to show just how bad the problem turned out to be.

Jaguar’s dirty fuel line…

Dave has been investigating the 1971 Jaguar XJ6 because it wasn’t running very well. He found that the carburettor tubes weren’t the same height as each other, and there was a new one and an old one. This is all why the carburettors couldn’t be set up. So a kit was purchased with all new ones in, the same height as each other. The choke had to be modified because the car had been changed to a manual choke in the past, whereas it’s meant to be an automatic one. Dave installed a better return spring for this. He put the car back together but the car still wasn’t right… It would only run for a limited time and it started to run badly again. After another investigation, he found that it wasn’t getting enough fuel in fast enough. It was soon realised that there was dirt in the offside fuel tank, which could be found without even getting into it properly. This car has got twin fuel tanks and both were the same. Dave has drained the fuel out of both of them, remarking that it smelt like rum! Not quite right then… There’s a video at the end of this post showing him at the start of draining the offside fuel tank.

New in, 1976 Jaguar XJ6!

New into the workshop is this 1976 Jaguar XJ6. It’s got issues with its carburettors, meaning the engine isn’t running right. Ady will be in charge of looking over this one for us, being our engine expert.