My 93 4.0L has oil leaking from the timing chain cover.

I have looked & looked online, but cannot figure out exactly how to remove the cover.

Am hoping it is just straight forward - remove crank pulley, remove water pump - at least 2 of the bolts,
remove some pan bolts, remove cover.

However, 2 aspects below seem to be implied, but are not actually clear - at least not in the info I have found.
For example:
1. Does the pan have to be completely removed?
2. Does the head have to be removed?

Any and all thoughts will be much appreciated, Joe

 

Hi Jbm417,

Are you certain it's the timing cover that is leaking, or could it be the crankshaft seal? It's a lot easier to replace the crank seal.

At the link below you can download a mostly-complete U.K. edition of the Haynes manual, which may answer most of your questions:

Jaguar XJ40 Haynes Repair Manual

My recollection is that you can remove the timing cover without removing the pan or cylinder head (you might need to loosen the oil pan screws), but I can't recall whether it is possible to reinstall the cover without damaging the head gasket and oil pan gasket. Hopefully motorcarman (Bob) will remember and chime in.

Cheers,

Don

 

Thank you for the reply Don
Yes, I am certain it is not the crankshaft seal - leak is well above the crank.

I do have the Haynes manual plus I have the "Jaguar-1993/XJ40 Workshop Manual" - all 10xx pages - in pdf format.

After studying the Workshop manual more last night, it clearly does say "remove the head" & "refit the head". So
my original point about not finding a clear answer is definitely answered.

I see a number of threads below that specifically address the need for head removal. So it is quite clear
the head has to come off.

 

I don't remember removing a timing cover on the AJ6 engines with head and pan in-situ.

The 4.2 Series I, II, III sedans I DO remember dropping the pan and 'sneaking' the front cover off/on.

 

motocarman - thanks for the memories.

They give me hope knowing it can be done, but my skills may or may not be up to the task. I'll give it a try.

 

Haynes has pretty good instructions for removing and reinstalling the head. You don't need to remove the intake manifold - just remove the air intake plumbing and throttle body, disconnect the intake manifold from the head and tie it away toward the left wheel well.

When you have everything disconnected and are ready to remove the head, what I do is lay a blanket or foam pad on the right fender, lay a piece of plywood or Masonite on the blanket, climb up and carefully sit on the windshield and straddle the engine, then lift the head off and set it on the board and let it rest there while I climb down the left side. If you have an assistant, so much the better.

Don't forget to do your valve stem seals - you'll need the right kind of valve spring compressor and an adapter you can make yourself. I can post photos if you need them. Lapping the valves is easy, though some owners don't take this step.

Once you have the head off, carefully inspect the surfaces of the block and head for erosion between coolant jackets and cumbustion chambers, which is common. Small eroded areas can be repaired with JB Weld and carefully scraped flush with a safety razor blade. I also like to spray both sides of the new head gasket with Permatex Copper Spray-A-Gasket sealant, which helps seal small imperfections.

Test the head for flatness with a precision straightedge. I think Haynes gives the maximum allowable warpage specification.

This is a great time to address all the common oil leak areas on the left side of the engine block: oil filter housing, oil cooler bypass pipe O-rings, oil fill tube gasket, dipstick tube seal, etc. I think I have photo albums showing these issues - see the link in my signature.

Also be prepared to replace the water rail gaskets and the coolant hose, often known by various crude names, due to the near impossibility of replacing it with the intake manifold in situ.

If your oil pressure gauge doesn't work properly, now will be a great time to replace the sender/switch, or to at least remove it and thoroughly clean the threads on the sender and inside the port on the block. The sender is a single wire variable-resistance device and the ground path is through the block and engine ground strap. So oil contamination on the threads of the sender adds resistance to the circuit and leads to disconcerting low readings on the gauge.

Also, if you have had any trouble with heat in the cabin, this will be a great time to replace the heater water control valve, since on the '93-'94 cars it is very difficult to replace with the intake manifold in situ.

Cheers,

Don

 

Don, thanks for all the info - it will greatly help. I can get another pair of hands for lifting the head.

Overall, this will be my fall/early winter project. While it ties up my lift, at least the shop is heated.

I'll update the thread as progress is made.

 

Just an FYI ...simple on 93MY and prior year cars, impossible on 94's as valve is very different and also unobtainable.

Larry

 

I think our '93 was like your '94. On '92s and earlier it was easier.

Cheers,

Don

 

In response to a PM request for photos of the valve spring compressor for the XJ40, I use this C-type overhead compressor, which can reach around the head to simultaneously apply pressure to the face of the valve and the valve spring collar. I bought this from Sears many years ago, so it was probably made by a company like KD, Danaher, Lisle, Wilde, etc.




The small section of pipe is an adapter I made to allow the valve stem keepers/cotters to be extracted once the spring is compressed. I cut a 3/4" I.D. iron pipe nipple down to a length of 2-1/4" / 57 mm. Then I cut a notch in the side approximately 7/8" / 22 mm tall by just shy of 1/2 the circumference of the pipe:




Here's a side view of the adapter. In use, the thin ring at the end of the pipe adapter presses down on the valve stem collar. The valve spring compressor has a locking mechanism that holds the spring in the compressed position so the valve stem keepers/cotters can be removed with a magnetic retriever via the cut-out in the pipe:



Cheers,

Don