Hello all, I am a new owner of a used 2004 X Type, had it now for 2 weeks, and other than some minor repairs issues, which are to be expected on a 14 yr old car, I have come across something that is causing me fits of frustration.

The coolant reservoir cap will not come off. When I go to loosen it up, it initially loosens and then just continues to spin. I have tried applying downward pressure, no luck, and I have tried lifting up while turning, again no luck. I have tried smacking the living hell out of it, and no luck.

Has anyone else experienced this problem? If so, any suggestions or ideas on how to get the damn cap off?

I did some reading on all the previous posts on the radiator reservoir, and found some info about replacing broken caps and the proper replacement cap to use, but nothing about not being able to get the cap off.

Thanks in advance for any help!

 

They are a pain but they do come off. After unscrewing try prying it up around the cap. It should come off.

 

As above, try two flat blade screwdrivers, one each side of unscrewed cap to lift it

 

Welcome to the forum Darcy Nelson,

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Because the cap seals really well on the reservoir it can be a real pain to get off and on again. As mentioned before, trying prying it up with something or use a cloth to help you get a good grip.

When putting the cap back on, you may need to give the cap a tap or two to get the cap on enough for the thread to bite.

 

Thank you all for the replies. I will give the screwdrivers a try and see if it will pop off. Once it is off it will be getting replaced with a new one.

 

When you go to put it back on, make sure the inside of the filler hole is clean, and lube the o-ring with a dab of petroleum jelly.

 

I went out to look at my cap when reading this thread and discovered that my cap has separated into two halves. The top unscrews and cones off in my hand then there is a loose heavy spring under it. Then there is a piece that is down into the filler neck opening that stayed in place. It's in there very solid and didn't want to come out when I tested it by hand. Rather than try to disturb this I put spring back in and screwed cap back down on top of it so it's still covering the coolant reservoir tank. I ordered a new cap which should be here next week. So has anyone had the cap separate like this? It's obviously broken as I could see bits of crumbly plastic and what looked to me metal corrosion between the halves too.

 

Yep, just a few weeks ago...


You can pop the actual cap off with a channel-lock or the two screwdrivers and put the plastic cap back on it. I actually matched the cap up with one from a Caddy while I was waiting for the Jag one to come...and that's where I found out about the 'lube the o-ring" thing...

 

It happen to my cap too, when I try to pry the cap out, the cap came out separated other part still plugged hard in the filler, next time I'll do as wa3ra said smear some Vaseline on the o ring.

 

My replacement cap is a Uro Parts MJA4440BA version that I ordered. The tank looks to be replacement by previous owner and that cap from it fell apart. It looks to have had a metal plate that secured the two halves and sandwiched a spring and that rusted. The plastic piece that remained in the filler neck came out easy enough once I grabbed its lip edge with pliers. I put a little light grease on Oring and seal inside top of threaded portion of the new one. Darcy did you ever get the outer top cap off of your tank?

 

No, I have not removed the cap yet. I have not gotten a replacement cap yet, so I have not messed with trying to remove the cap. I have spent three days hitting the local auto parts stores to no avail, no one has any of the replacement caps in stock, not even in their warehouses. A couple offered to order one for me, but their cost plus delivery would be more expensive than if I order one online, so I just ordered one tonight from Terry's Jaguar Parts - link here: Radiator Expansion Tank: Terrys Jaguar Parts

I went with the Jaguar factory part over the OEM part, was only a $1.34 more expensive. Should get it in a couple days by priority mail.

 

Keep that info for Terry's for future. I have used them several times. Hopefully you can pry that old cap off. Just take your time and once you see your new cap you will see how it attaches better. And there are lots of threads on that cap so don't give up after a few twists. It seems like overkill for as many threads as they have on that sucker. Looks like I have the twin to your car based on your signature photo

 

I had the same problem -cap came apart with one half stuck in the reservoir. I ordered new cap from Rock Auto. Used channel locks to get bottom piece out. Then installed new cap -all is well ....

 

The new cap finally came in on Tuesday evening. My son wanted to help, so he ran outside as I was opening the box to get the new cap out, and he comes back in the house in 3 minutes holding the old cap in his hand. I asked him how he got it off so easily and he just laughed and said he removed it by loosening it completely, then re-tightening it while pushing downwards with a good amount of force, and then when completely tight, he once again loosened it, this time while lifting upward on the cap while turning it loose. We compared the caps to each other and on the old cap, it was clearly visible that the seal around the neck had been sticking inside the top of the reservoir neck. I cleaned it up with some hot water and Dawn soap and made sure to move the seal around as much as possible to get any gunk around it cleaned off, and it looks almost new. My son put the new cap on, with a little silicon grease around the seal to keep it from getting gunky, and so far so good.

Now, the next fix is taking place tomorrow morning. On Sunday night, for some completely unknown reason, the windshield decided to crack on the drivers side, from the top edge of the window, down about 6 inches, and they the crack went to the right for about 9 inches.

The replacement windshield is covered by insurance, won't cost me a dime, and the shop I am using confirmed they have replaced X-Type windshields before, so it should be a no issue fix....fingers crossed and wood knocked!!!

 

I have had this problem in the past , I have found that if you warm the engine prior to a removal attempt it comes of with ease, you need to keep on eye on the pressure building in the large front radiator hose, the pressure build up pushes the cap off . I dont need to infrom you that water under pressure boils at a higher tempreture and scalding is a real possability. never attempt this after the car reaches full temp, as the car heats up the front hose will become harder to squeeze. I guess you have the genreral idea by this post.
I should mention this is an unorthordox way to remove a pressure cap , I beleive the reason for the cap being dificult to remove is due to a vacume. A replacment cap is avaiable from jag at only £11.75. part no MJA444OBA

 

This is sort of another part we tend to overlook. In replacing the upper hose assembly today, friend spun the cap. As it reached "no longer on threads" he kept spinning it in place. I was watching a bit amused. He said wtf is wrong with this thing. I walked over pulled HARD straight up and out it popped. Inspecting the rubber seal, there was hardened coolant? Metal rust? looking stuff around the seal and in the grooves. Cleaned them off with a flat blade screw driver. Reinstalled. Took it back off and it came out easily. It's sorta one of those things that just sits there forever without maintenance unless we are low on fluid or doing a complete flush.

 

Point taken, but in my post I stated that i had this problem of cap removal, this just happend to be last week whilst on my holiday , screw cap came apart fron the part with seal is attached, had to get a replacment hence I know the cost and part number, cleaned the expansion tank cap port where the cap fits (super clean) then used high temp silicone greese, after traveling home some 200 mile I cant get the cap off again and prizing has once again seperated the cap parts, This can only be a vacume that holds it on. I must add this a genuine jaguar part from inchape jag in darbyshire. May be I should add that should you have a problem removing a cap , the warm enginine approach could be tried.

 

Im sort of curious about something. I read a long time ago in the forums somewhere. Guy said he had a problem with "vacuum" in his system as well. Standing in front of the open hood (bonnet), the top coolant hose on the left side would actually collapse as the engine cooled down causing a great deal of vacuum pressure in the system (probably not real great on the hoses as well). It turned out he had air in the system and after "burping" the system it cured both problems (cap and hose).

Searching member "Thermo" you can find an easy description of "burping your kitty".

 

Hi when you do get sorted with a new cap for goodness sake don't lubricate the "O" ring with petroleum jelly. It will rot the ring and cause just the trouble you have had. There are special lubricants for "O" rings.