Was doing a coolant level check and when I unscrewed the cap the bottom part of the cap was broken off and fell into the reservoir along with all the seals, rings, etc. they were all in pieces having corroded some how.
I used the shop vac to suck out the coolant and pieces and then took apart the hoses and sensor to get the reservoir out. the end of the cap was stuck in there and it took quite a while to fish it out.
I noticed the plastic tube that runs over the engine separating the hoses as being very brittle so I removed that as well.

A few questions I have are is there anything I should keep in mind when putting all of this back together after installing new hoses(the smaller ones) and that plastic tube that runs over the engine.(MJA4560DB?)
Would you recommend me doing a coolant flush soon since some particles from the broken seals/gaskets in the cap may have gotten into the main hose coming from the bottom?
Last question....Having trouble identifying the solid plastic thin tube that has a kink in it that connects from the reservoir and runs across the engine towards the radiator, I think it is part # MJA4560DB is it not? Sorry I think the parts diagrams are not detailed enough for me sometimes
Would really appreciate any advice or answers.

 

If you got all the broken pieces out before running the engine again, there is no reason to do a flush. Your Jaguar uses Extended Life Coolant and the recommended change interval on this is five years. If it's been in for longer than that, a flush is due anyway.

Is this 'solid plastic tube' the one shown here (arrowed in red)?



It's listed as a Bleed Hose. My parts Manual shows it as MJA4560BC for the normally aspirated engine. It's worth noting that suffix letters in part numbers are often changed when an improved part is available.

When the Expansion Tank cap has already disintegrated and the Bleed Hose is brittle, it would be wise to consider replacing the Expansion Tank. These are frequently reported as developing small cracks and even more often for the coolant level sensor failing. A new tank comes complete with cap and sensor.

Graham

 

yes that is the one! I am waiting for the part to come in so I just ran a rubber hose from expansion tank to the port by the radiator and completely took out the bleeder hose because my brilliant friend broke it trying to get it off. Seems to be running fine with it, but do you think this is an unwise decision even though it will only be like this for a few more days?
Thanks for answering all my questions. Very much appreciated.
Love this car

 

Not a problem using a temporary rubber hose in place of the Bleed Hose assembly. Just be sure it's not trapped or flattened with the bonnet shut.

The last Bleed Hose I purchased was complete with new 'Norma' clips on each end, Here's one of the rubber connector pipes off a Bleed Hose:



There's a special tool to fit these but they can be opened and closed with pliers. The clip on the right is closed. It is opened by squeezing 'shoulders' (arrowed in red) together. The clip on the left is open. It can be closed by squeezing the 'shoulders' (arrowed in blue) together. It doe NOT require much pressure to open or close.

You'll have read on the forum how cooling is so important on the Jaguar V8 and damage can occur very rapidly if the engine overheats. As you've had problems with the plastic cooling system parts, it's a good plan to inspect the rubber hoses very closely.

Graham

 

how would I check if its trapped or flattened with bonnet shut? sorry I am not much of a mechanic myself and don't know exactly what you mean, the hose isn't kinked, that's about all I know haha

Thanks again for all the info, really needed it. I am going to inspect hoses tomorrow closely and look into ordering a new expansion tank. Cant have this baby overheat

 

Make certain you route the temporary hose in approximately the same location as the Bleed Hose fixing clips. Avoid letting it lie anywhere near the area outlined in blue:



This is the Inlet manifold. At the front there is no clearance between it and the bonnet liner when the bonnet is shut. You can see where the top of the second black tube from the left has been polished from contact with the bonnet liner.

Graham

 

thanks for the pictures, yes my hose is routed in about the same position as the bleeder hose was except its just one hose from expansion tank to the front bleeder port. I am going to read up on the cooling system issues with Jag v8

 

Can't think of any possible reason Jaguar didn't use an all-rubber hose for that bleed hose instead of two sections and the clips to hold it together. Your solution is less expensive and more reliable.

 

It seems like my solution is more secure but do you guys think I should still return the setup to like it was before the the bleeder hose broke?

Also I forgot to mention my expansion tank cap that I bought from Jaguar as a replacement yesterday does not screw on to my tank(somehow I got the wrong cap and they dont open till monday), so right now I am using the old cap which the bottom part of cap with the pressurized parts & spring is missing because it fell into the reservoir, so really what I am using is just a screw on cap at the moment with none of the pressurized rubber rings, spring, etc. in that housing on the cap, is this dangerous to drive with for a few days. have a hundred-150 mile driving expectation for this weekend

 

I took a pic of where I connected the hose in place of bleeder hose but my main concern in this pic is the coolant that leaked and dried onto some part i'm not sure the name. When I run it with hood open there is no visible leaks and the fans aren't coming on so I believe the coolant system is working fine. but that previous leak worries me despite that coolant that spilled out of something then dried to the metal. This coolant in the picture was there when I bought the car so it did not just happened and ive put a thousand or so miles since I bought the car , but still concerns me.
any advice on what to check to see if my cooling system is free of leaks and in proper working condition

 

I would go with OE Jaguar Bleed Hose. The reason they used two rubber hoses with a rigid intermediate is twofold:

1. it can be securely fixed
2. the rigid section is smaller diameter in a location with little free space between the top of the engine and the bonnet

You should not drive the car for that distance with a damaged expansion Tank Cap.

As the coolant heats and expands, the 'spring' inside the Cap lifts and allows excess coolant to flow into the Atmospheric Recover Bottle in the front wing. As the engine cools down, this excess is drawn back into the Expansion Tank.

With a damaged Cap, there is nothing to prevent unlimited coolant being pushed out into the Atmospheric Recover Bottle from initial startup.

This is a low volume cooling system and risking overheating must be avoided.

Graham

 

The bleeder comes in on monday.
thank you for that important info, I kind of figured I shouldn't be driving far. After your explanation I definitely wont be driving it this weekend very far.
Glad

 

Graham, My cap on my 98 is super hard to screw on and off. I did a coolant flush, new water pump (my original plastic impeller was ok), filled with OEM jag coolant, replaced the plastic T-stat housing with metal (plastic was ok), and and a beck arnley t-stat. Do think it's in my best interest to replace the expansion tank cap as well ? Thanks If so, should I go to the dealer, or online ok?

 

Aloha. That leakage around that area might be due to a cracked housing, loose cap, or leaking hoses. Try to clean it all up and then watch to see if and where it comes back. The answer may become obvious. A small brush and a bit of soapy water should take it right off.

 

+1

Definitely been a leakage but it may have been fixed by the PO. Try cleaning it as mike66 suggests.

If you do need to replace the Thermostat Housing, a popular upgrade is an aftermarket aluminium version:



The aluminium aftermarket one on the right is far better than the OE Jaguar type on the left.

Graham

 

The Cap should screw on very easily until it's just tightened. They aren't like the old fashioned radiator caps which had to be tightened until they clicked.

There's been more reports of failed Expansion Tanks than there has of failed Pressure Caps. As you know, cooling is absolutely critical on the V8 so it's not worth taking a risk if you're not sure the Cap is good.

The last time I checked the cost of a Pressure Cap from Jaguar, it was around half the cost of the Expansion Tank which comes complete with Cap and Coolant Level Sensor.

If you're intending to hang on the the XK8 for a while, it's worth considering replacing the complete Tank but hanging on to the old Tank and Level Sensor for spares.

Graham