I miss the days of my little 4 banger. You could see where everything was.

Well I looked for the source of the gusher and it was coming from the trans area. Jacked it up. Trans area was exit point. Followed the coolant to the intake manifold. I can't see where on the driver's side that it's coming out. But when I remove the thermostat housing cap and top the car up it pours out of the mysterious area near the "pillows" on the intake. Then it stops after the housing is emptied. I only see the coolant river on the non throttle side, the throttle side is too packed with parts to see down to the block.

Now I cannot see any coolant coming out the thermostat housing but I know it's dodgy, the cap has been replaced on it and the front header pipe was replaced in the summer. The plastic is getting old.

Question - is the intake manifold heated/cooled by the coolant and if not is the only coolant source between the heads the thermostat housing?

Secondly, when the thermostat housing fails is it normal for the resulting leaks to be seen coming from the trans area?

And for those that might want to replace this thermostat housing? You'll need an 8mm crowfoot to get the rear bolts off. Not an easy task.

 

Which engine?

 

Oh jeez, can't believe I forgot to mention that. V8.

 

No worries. You might usefully add it to your signature

The coolant circuit is (almost certainly - it is for the later V8) in the workshop manual (ebay $6-10). If the 4.0 V8 is fairly like the STR then the TB (throttle body) will be included so there are pipes for that in case it could be one of those.

Member tdc just recently posted great pics of an engine rebuild he did and they include some of the coolant pipes so might help you.

 

Yeah I have the jag CD/manual on my laptop but it's about 100kms from me right now.

I looked at the pipe going to the throttle and it's bone dry. More importantly I located the 1/4 drive 8mm flex socket locally that can help get the damn housing off. For those that may find this thread in the future:

http://www.amazon.com/4in-Drive-Stan.../dp/B000HAVK20

http://www.stanleyproto.com/default....tCatalog=PROTO

A bent cheapie 8mm or 5/16 box end will work too.

I'm pretty sure knowing that the intake doesn't have coolant that it MUST be the thermostat housing only. It is the only logical source for a coolant leak on top of the block since it's make out of wobbly, failed and or failing plastic.

 

For those that will be searching this in the future, there is a coolant hose that runs from the housing UNDER the intake manifold and if split makes the coolant exit in the trans area.

The housing needed replacing anyway but this hose is a freaking pain in the butt. Luckily it's not expensive.

 

The same one that runs under the supercharger on the STR? Excellent repair thread with photos by ttwotees.

 

Yeah, same one. I'm getting a pipe made tomorrow that will never fail.

The amount of plastic in this engine that fails is mind boggling. Seriously, adding a brass coupler/reducer under there would not have added any REAL weight to the engine in the grand scheme of things but could save someone from emptying the block and not knowing it (temp sender reads normal) and blowing the head gaskets or cooking the motor.

Great motor but jeez Jaguar, keep some metal in it in the critical service areas. Oh wait - you WANT us to have failures that you service, that's right. I looked at that pipe and flat out said "design flaw".

At least it's a relatively easy fix. Pull the intake, replace pipe and done.

 

I wouldn't know what kind of pipe to get made or where to go (what kind of place) to get it made, so please give more detail about how I or others would go about it.

 

The pipes don't fail that quickly. They are of good quality. It's the plastic reducer/coupler that fails.

Jaguar erred when thinking that plastic cooling parts was a smart way to save weight. They saved maybe 5 pounds and traded the reliability of a decade old Jag.

Get the intake off, remove the pillow and you'll see the pipe. It snakes under the intake to feed the throttle body. The failed plastic can be replaced by a single brass fitting. One threaded end in 5/8th and the other side of the ****** fitting for a standard 1/4 hose size. This part cost me $3. I got two clamps for good measure at $4. Replace the hose with silicone at this point? Only if you plan on owning the car for quite a while longer or if the hose has ANY bulge to it. Maybe replace it anyway to save the next owner the hassle.

Replace hose and intake. Done.

 

A tad more tricky on the STR

 

Yes, but Cosworth may have a good point, couldn't a copper pipe be made up to follow the hose route?
It could help avoid another major strip down for a hose if you plan to keep the car.

 

I don't know, and as I said I've no idea what kind of place would make one.

An entirely copper pipe wouldn't flex, nor expand identically to the engine, but I don't know if it needs to.

 

I don't see that as a problem as there will be a hose connection each end to take care of flex / expansion, but then I've never set eyes on the problem hose so I may just be full of s**t.
Maybe someone can give us an idea.

 

The pipes are in good shape, so the brass fitting i used will be enough for me. Replacing the hoses with a bit of silicone hose is cheap insurance long term.

I lucked out though, the housing and cap I ordered from teh UK at 1/3 the local dealer price showed up as a full metal housing kit today - at the plastic 2 part order price. I was gobsmacked. Happy.

But even all filled up and air bled with a new DCCV, I still get crappy heat on the passenger side - always have. Sigh.

 

I'm in the UK so where did you order it from please?

With the engine warmed up and heat on max do you still only get poor heat on the pass. side?

Bleeding can take quite some time, so MAY be the cause.

 

Hey congrads on fixing the problem.. I’m just curious / I have 1 question.. Sorry..


Question:
How did you end up removing the two rear bolts? It looks like I’ll need to use a claw tool there? IDK any hints for the newbie?

Quick back story..
I had to order up a new thermostat housing today. I had my choice between the stock “plastic” for $38.00 or the upgraded “aluminum” one for $50.00.. Well I bit the bullet and got the upgraded one, I hope it comes with the gasket??. Damm I really should of checked.. Did your kit come with one or did you have to pay extra?

So I’m just looking for pointers

Thanks for you time

Tdc.