Good morning.

Couple days ago I noticed the upper radiator hose was slightly collapsed after an overnight cool down.

After some basic research, I decided to start by changing the reservoir cap.
This morning, (after an overnight cool down), the hose was collapsed even more so than with the previous reservoir cap.

My next common sense move would be to change the upper radiator hose.

It's been 35 years since I changed anything in my garage, but this seems pretty straightforward.

Anything I should be concerned about after simply removing the spring clamps?
I ask because the hose is only about 10.00, but repair pal estimates the job at 200.00.. I'm wondering if changing the hose is more complicated than it looks.

I wouldn't mind a step by step walkthrough to change the upper hose.

Thanks

**Also, if the culprit may be anything other than the hose, please feel free to chime in **

 

Unable to delete the thread

I've decided it's best to have all hoses and thermostat, as well as radiator flush done by a professional.
After further inspection, it seems that both hoses, and the little bypass hose are softer than they should be.
Also, noticed that upper hose stayed rather cool for a good period of time after temp gauge showed normal operating temp. IMO, thermostat may have taken longer to open then it should have. Finally after a half hour of idling, did the hose heat up and expand..

Rather not nitpick, I'd might as well refresh the entire system.

 

Anthony, there is one hose under the intake manifold assembly. PIA to get to, but I hope they are changing it as part of the job. I'm not sure how to frame this. Just take it as a friendly fyi. It is not visible. It's expensive to get changed though. At least you.can ask about it John

 

Have your cooling system pressure tested, 100Kpa is about 14.5lbs, and well within the capabilities of most manual pressure testers sets. If the hoses are in poor condition, it will be obvious. Don't spend money without a proper diagnosis, that's just throwing money away.
Regards,

 

Anthony, beware this could turn into an expensive 'while you're in there' job if you're looking at the full monty.

There's the valley hoses as John says - Alldata gives 2.4 hours for but it took me a lot longer than that (TSB 303-48). Then there's the octopus they connect to, thermostat tower, crossover pipe...


Mike

 

I made an appointment with one of the better technicians in the area. They specialize in high end exotic cars, and seemed like a good starting point.
He offered to take a look at it and see if anything is obvious.

Those valley hoses concern me. For they could very well be the culprit behind the very feint smell of coolant I've had for the past 6 months, and the loss of about 8oz of coolant during that span.
I'm allowing a 600.00 budget for this, and hoping it's enough.

 

The 'collapsing hose' when the engine cools is a symptom of a vacum building up and not just an ageing hose.

It could be coolant isn't being drawn back into the Expansion Tank (reservoir) from the Atmospheric Recovery Bottle behind the RH wheelarch liner but is more likely to be caused by a sticking thermostat.

Graham

 

Thanks Graham.
The thermostat and obvious hoses are a good starting point and need to be changed regardless.

I remember once reading something here about "not all thermostats are equal" even though it's a proper fit for my car.
something about having a jiggle pin to assist in air removal.


Can you or someone point me in the right direction and show me the correct thermostat. I'll purchase and give to whoever works on the car for proper replacement.
A quick search on rocauto.com gave me 5 different thermostats.
I want to be sure I get the "right and best" one.

 

Remember when installing the thermostat the "jiggle pin" has to be at the 12 o'clock position when installed for it to work.

 

Jaguar part # is AJ86484. You can see the giggle pin on the top LHS.

HTH,
Mike

 

...... and it is fitted this way up:



Graham

 

Perfect.

Thank you

 

Suggest you drill a small hole ( 1/8") in the thermostat to supplement the jiggle pin, I have seen jiggle pins that got "stuck" with gunk, we always take this extra step.
And add a water wetter, cheap insurance if you live where it gets hot. anything to help save the 'valley" hose...