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Michael Neals Technical Advice Main / Library / Technical / Model guide / Buyers guide / Guestbook / Photobook / Links / Archive / Specialists

Michael Neals Technical Advice : File 1

Series 3, Stuck Cylinder Heads

To all those struggling with stuck cylinder heads, I'm about to reveal a personal trade secret, just wanted to give the budding mechanics out there a bit of damage control. Let me go through this step by step. A prime reason to run antifreeze/coolant instead of water in a motor is to prevent corrosion. The most succeptible parts in a Series 3 motor are the head studs. If the headgasket develops a leak into the cylinder, they all do, don't keep topping up the system with water! Eventually you will end up with alot of rusty water and no antifreeze, read - corrosion preventor. The easiest way to remove the head is to leave the manifold on the car. Snap On Tools makes a heavy duty low profile stud remover that clears the head casting. The studs are 7/16 x 20 threads. The studs will not break when removed if they aren't rusted into place, see above. This tool is the only one that will work properly. What happens is that the studs are located in the coolant passages and are sealed, believe it or not, by the washers under the head nuts. The coolant residue forms a heavy paste that binds the studs in the holes in the head. The studs will rotate but it is very difficult to lift the head off with the studs in place. If the headgasket has been leaking into the cylinders, i.e. water in the oil, for some time then there may be more damage. Water in the cylinders has a habit of cutting down the lubrication properties of oil. The cylinders are steel sleeves so they don't wear much. The pistons are aluminum and have a tendency to shrink fairly rapidly in these conditions. The easiest way to check for excessive clearance is to rock the piston at TDC. It should not click on the cylinder wall. If it does, then it must be replaced. For those wondering how their headgasket if fairing there is a basic check. Pull the 90 degree boot from the timing chain adjustor cover. Inspect the inside of the boot for a residue similar to white grease. If it checks positive then further testing is necessary, otherwise you're probably fine.

Series 3, Head Stud Breakage

If a stud does break there are a couple options. I've had to repair a number of car's that the local under educated butchers have mauled. The most common incident is to repair a broken stud by tapping the top of the block. Many times the head has been drilled to 1/2" also to put a bolt in. Many times the repair was attempted with the head still on the car. Needless to say, they all leaked. If a stud does break there are several avenues. If you are feeling cheap and pressed for time don't even think about threading the top of the block. Most S3 blocks have a narrow passage between the cylinders that intersect with the stud holes in the deck surface. When the hole in the deck is threaded all it does is spread and will not hold torque. A quick fix is to use a thread-sert, a machined heli-coil basically with a shoulder. Remove the freeze plug for access and insert it upside down up through the stud hole in the deck. This provides a fairly good anchor. Use a short stud like the front or rears and it even looks oem. The correct way to repair a broken stud is to remove the freeze plug for access near the stud base. It may not have broken off flush so the stub may have to be removed. My weapon of choice is a 90 degree die grinder with a fresh carbide bit. With a bit of grinding you can remove the protrusion. Grind it down so you just start to hit block material. This will outline the stud. Use a new titanium coated drillbit welded onto an old stud. Start a pilot hole with a smaller bit first. Don't drill too far or too much off center. Too deep will end up in the crankcase. Of course this is much easier with the head off but I have done it with the head on. With a low speed, high torque drill you can make short work of this. Next, retap the hole. Finish it off with a bottoming tap. These taps will also have to be welded onto old studs preferably with an old cylinder head nut welded onto the top. If you screw up go the next size up. This, however, will require a sized stud to be made, roughly $100. Stud holes must be cleaned and chased with a tap. Vacula makes a air blower nozzle with a 16" extension on it to reach down into the stud holes. Be sure to use a rag on the top of the block to catch the high speed debris. Use a bottoming tap welded to a stud to chase the threads. OEM style studs don't corrode badly using coolant properly. Snap On makes a great stud installing tool that backs off easily once the stud is installed. Installed height is 5 1/2" from the deck for the short studs and 5 3/4" for the studs that mount the brackets. Being a professional Jaguar Certified Technician with a whole lot of experience at repairing these engineering nightmares I have confidence in these methods and tecniques. I worked for a Top Fuel Funny Car Drag Racing as a bottom end man. Basically this is just damage control and maintenance. The motor is torn down after every run! One run puts the stress of 100,000 miles of wear on the motor. It is almost unbelievable what occurs. Worst case scenario is splitting the block into several pieces. From my experience I've found that the average mechanic tends to really screw up Jags. If you have to resort to a mechanic please find someone qualified. Would you take a prostrate problem to a oby/gyn? It's too bad that they don't require licensing to work on particular makes of cars.

All XJ's, Wire Wheels

Here is my philosophy on wire wheels, If you really hooked on the aesthetics of them, get them. You are going to pay for them however! Dealers charge $2000 a set on new cars. Jaguar Cars of North America says "we're not paying for any repairs related to these wheels!" New car departments make the profits on these installations and the service dpartments end up with the headaches. The best wheels are made by Dayton and are sold by British Wire Wheel. There is an updated 70 spoke wheel that is stronger and easier to mount tires on. I'm only familiar with installations on later cars, 79 and up. It should be very much the same situation on the earlier cars. It takes only one good curb shot to trash a wire wheel and it's off to the bank. These wheels weigh nearly twice as much as an alloy unit. Not only are you purists killing my back, but you are killing your unsprung weight situation. Jaguars finest engineers, sic, designed inboard disc brakes to reduce unsprung weight and then have their car de-engineered with the installation of technological obsolete scrap destined for the scrap heap. Let me repeat myself here, you will have problems with wire wheels, especially on late model cars. If your bank account can afford it then good luck. British Wire Wheel is a good source for Dayton wire wheels. I would recommend only using Daytons specifically the 70 spoke units. Best choise for tires would be 215/65 HR 15 MXV4s. The Tire Rack in Nevada is a good source for these, they advertise in Road and Track. Be sure to get at least a HR rated tire. Anything rated less tends to flex too much and wear too quickly.

4.2 Conversions For Ollllld... Cars

Putting a 4.2 in a earlier car sounds like a great idea. Keep the P.I. (petrol injection). Not only will the car start easier and cleaner you should get a ten percent increase in power and fuel economy. P.I. is so much more precise than carburation. An '83 motor may still have the old style fuel rail which will give you a little more clearance. Sometime in '82 and '83 the fuel rails were recalled and upgraded to the later style.

Series 3, Head Gasket Leakage, Water In Oil

If you do buy this motor that had alot of water in the oil, be careful. When you pull the head and see undamaged cylinder walls don't be fooled. Check each piston at top dead center and see if they rock back and forth and actually click. The excess water from an internal head gasket leak tends to wash off the oil from the cylinder walls and speed up piston wear. The block has steel sleeves in it so it takes quite a bit of abuse to really damage it. Many time now I've simply only had to hone the cylinders and replace the pistons and bearings on motors with more than 150K on them!

XJ40s, Factory Alarms

Jaguar installs a factory alarm system that tees into the harnesses instead of just being spliced on. This is a very good but expensive setup. It is made by Derringer and though the harness ''t's'' aren't included it is a very good system. Beware of cheap systems. Excessive draw will make short work of your battery! Look for a milliamp draw rating of no more than 60-70. Have them prove it! The parasitic draw tends to sulfate the battery quite a bit quicker than normal. Also make sure that they don't add an extra door lock solenoid to actuate the door locks. Some of these idiot installers actually charge you this added solenoid that isn't required. If they actually had a little electrical knowledge they could figure out how to wire the master solenoid in instead.

OEM Sound System

The factory sound system is actually pretty good. There are two subwoofers located under the rear seat. When removing the factory radio be sure to check for a condensation shield that may not have been installed. It is located right above the radio and has two push in fasteners. If there are two empty holes then obviously it's not there. Without it the radio has a tendency to self destruct eventually.

XJ40 Model Year Choices

A 90 is a good choice. A lot of the bugs had been worked out by then. The hydraulic rear suspension is still a problem. On 94 models this suspension was discontinued. If you are interested in an in-depth test of your suspension let me know.

XJS Recalls And Engine Fires

Let's see, burned up XJSs? The dealer in San Francisco that I worked at for a number of years never!!! had one. I ,of course, made great money off of performing the recalls. The recall consisted of replacing the left side throttle plate assembly to allow better control of the evaporation cannister, removing the regulator valve from the breather line and checking to see if the fuel tank was leaking. 99% of the tanks did not leak!!!!

Jaguar Ownership Philosophy

How many of you drive cars everyday that are 10-15 years old? This is the age of the average Jag on the road. I'd say they hold up pretty good compared to other vehicles of similar makes. Sure, Mercedes might be better engineered, but who wants to drive an ugly car without a soul. Series 3s are a huge refinement of the early British cars that make Lucas famous. You can't even compare the XJ40 to those anachronisms of engineering. Let's be honest though, the British have their own idea of "engineering".

Late Model Jags, Lucas Components, Ownership Problems

Almost all of the so called Lucas fuel injection components are not Lucas. They are licensed Bosch units rebadged as Lucas. Many of Jaguars problems in the last few years have been the several year lag between fixes. Many of the components in the XJ40 are made in other countries, France, Germany, Sweden and even the USA. I truly believe that Jaguar has improved exponentially in terms of quality. Dealers are losing business because owners are no longer coming in with laundry lists. Without these people coming in, services don't get sold. One of the biggest problems I've seen is not with the cars, but the people!!! Outright abuse and lack of servicing are just a couple of the problems. One of the most commen problems is people buying overpriced cars. I keep a close eye on the local market and people just don't get it. They buy a car for top dollar and then get it checked out. The last three that I have done "post-purchase",sic, inspections on have needed at least 25% of the purchase price in additional work. The previous owners had neglected the vehicle and then pawned it off on someone who fell in love with the concept of owning a Jaguar. A few have even gone to auctions. Let's be realistic here. Unless you are a used car dealer you are not going to get a deal from an auction. Even used car dealers get burned once in a while. Final word, get a pre-purchase inspection from a Jaguar mechanic, not Joe down at the We Fix Anything shop!!!

XJS, Series 3, Steering, Aftermarket Rack Bushings

The type of polyurethane rack bushings like the ones sold by John's Cars will last easily ten times longer than those rubber pieces of junk installed by the factory. I have had only one person complain about the steering feedback in over 100 installations. If you must have rubber, get the sport bushings that were installed in the '92 XJS. A bit expensive and difficult to install but they have a little better feedback to the steering wheel.

XJS, Early, Distributor Cap Venting, Fuel Injection, D-Jetronic

I tend to block out the late 70s, D-Jetronic, XJSs. These are prime candidates for V-8 conversions. I just don't see any of them anymore. The underhood temperatures were so high that it makes everything rock hard and brittle. Having a car crumple under your fingertips while working on it just makes your day. One particular recall concerned the distributor. The crankcase had a tendency to vent into the distributor body and up into the cap. In extreme cases of neglect, in my opinion, enough gas contamination in the oil would ignite from the secondary spark. The only possible way the oil could be that contaminated is by exteme rich running conditions for a long period of time or for very long intervals between oil changes. This is the reason the late XJSs have a vacuum venting system and shield on the distributor cap. The crankcase still vents up into the distibutor and tends to bind up the centrifical advance. Luckily I started working on Jaguars after the glory years of being funded by the queen's reign. I've seen only constant improvements. I'm not familiar with the fuel rail recall except that there is evidence of changeovers to the later style rail on some 82-84 XJSs. It's great that this group was formed, some of the info found here is invaluable. I'd like to see a group for Jag techs someday. The best source of info on the cars is a conversation between four or five mastertechs at lunch at the training school in Irvine, CA. There is just no substitute for dealing with the same product day after day. So everybody continue on with their love-hate relationships. Jaguar established quite a name for itself in years past, specifically with the XKE. The mystique has carried on to the present. The cars are still quite exotic to the average person. This is all good news to me of course, it reflects directly on my wallet! Life is good.

XJ40, Steering, Stiff, Power Steering Belts

I just love it when a customer comes in complaining of stiff power steering on an XJ40 and suggest that I try adjusting the belt! The power steering pump is a modified GM type without the reservoir. It is a direct drive pump. Stiff power steering is, about 95% of the time, bad seals on the pinion spool valve allowing the fluid to leak by. Jaguar came out with an upgraded seal kit on the 90 and on models. I have yet to try installing them in the earlier versions. I suspect they weren't offering a kit on the 88's and 89's to keep from paying for warranty claims on the upgrade. I'd would suggest giving this conversion a try, but be ready to buy a rebuilt rack if it doesn't work. You may have to improvise on a couple special tools.

XJS, Ignition, Distributor, Repair

XJS Distributors have a seal in the shaft housing that seals the top half from the crankcase including the shaft bearing. The seal hardens up and the bearing is the first to be contaminated by the crankcase vapors. Imagine the deposits on the inside of a cam cover fouling a high speed roller bearing. So far though, no real problems with the bearing. Getting the pin out of the drive gear takes a bit of grinding and a spot-weld to resecure it. There is a bushing that holds the rotor shaft down on the main shaft. This nylon type bushing is always hard and brittle. I recently saw one distributor that had a free shaft but the bushing was broken. The shaft rode up and prevented the centrifugal advance from working. Needless to say, the vacuum advance diaphragm was also ruptured. This effectively robbed all power from the car. Note that advance units have a very small bleed hole so they are not perfect vacuum chambers. If you don't want to remove your distributor gear you can use emory cloth on the top part of the distributor shaft. I bead-blast the centrifical shaft but you could probably also clean the inside of the shaft with a rolled up piece of emory cloth. The tricky part is coming up with a new bushing to hold the shaft in position. I'd have to check on the sizes but I think it was a five millimetre washer with a thick oring over the top that works great. Timing should be set at 0-4 degrees at idle with vacuum disconnected. You should get at least 18 degrees of centrifical advance at 3000 RPM. If you are going to rebuild the unit properly it is necessary to replace the seal in the shaft. Sorry Kirby. Seeing that a new unit is $745 dollars I'm sure it is worth all the headache to grind and spot-weld.

Battery, Jags

The best battery for a Jag is a sealed unit. Corrosive acid fumes are very damaging and accelerate the endless attack of rust. I've found a battery made by Optima that fits most Jags. This is a lead-acid unit but uses six separate coils instead of plates. So far they have proven nearly indestructible. One was discharged for two weeks solid and after a large dose (2 days on the trickle charger) , was fine. It is about $120 with a 6 year warranty, free replacement within the first two years. I use them in all my vehicles with absolutely no problems!

Series 3, Engine, Timing Cover Access Cover Screen Position

How about a philosophical debate on the position of the crankcase breather screen on Series 3s. I never really paid attention to the position when the cars were new and now I can't remember which way they were. I think the shape is a carryover from the earlier cars that had an access cover matched to it.

Series 3, PCV Valves

The S3 doesn't use an actual valve. Crankcase vapor recovery is accomplished by metal tube that runs from the throttle plate housing area to the front cover. The charcoal cannister line is also teed into this line. It should be removed and cleaned every few years, carburetor cleaner works fine. Pulling the boot off of the timing chain adjuster access cover and inspecting for a white grease type of residue is a good way to check for internal head gasket leaks. The coolant mixes with the oil and collects in this 90 degree boot.
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