01 xk8 coupe, 63k
Hi, I just did a long trip, 400 miles, no problems but when I stopped the car in the driveway to unload after I came back out to repark the car. Upon startup I heard this screeching noise and saw coolant come out all over below the car. After turning it off and opening the hood I saw that the lower hose, below the thermostat hose, had popped off and let out the coolant. It was not cracked, etc it just came off with the Norma Clamp still attached. There was never any service light or movement of the temp gage from normal.

I reattached the lower hose with a regular hose clamp and it started up(filled with water but still had orange coolant in it). I'm not sure what would have caused it to pop off once the car had been stopped? Could it be the thermostat like I've read in other posts? Or is it that they are the original clamps and hoses as far as I can tell(12 yrs old). What should be my next steps?

 

The OEM thermostats fail abruptly, even at lower mileages. I'd Replace it before doing anything else. Maybe replace the Thermostat Housing with a Metal one at the same time.

 

I have had this before and did exactly what you have done..... Cause in this case we put down to a rubbish clip, never liked those sprung hose clips after a period of time they corrode and loose there spring and become ineffective

 

You're a lucky man. Imagine that happening while you were still driving down the road. You could be kissing your engine goodbye....

Continue checking that new hose clamp area for a week or two just to ensure that all is well. Make certain that your 12-year-old hose is not disintegrating around it....

 

Oh man, I'm glad I replaced hoses and clips this week. I changed the OEM ones for the ones you tighten with a screwdriver. Those are orders of magnitude better than the OEM spring loaded clips.

I second Paul about the thermostat housing. The OEM plastic unit is total rubbish.

Also, if you notice your hoses are puffed up, very soft or brittle, it is time to replace them.

 

If you want to be really secure, use a nut driver or socket to tighten larger screw type clamps. It does a much better job.

 

Interesting discussion - OEM Norma clamps v. screw type.Personally I always thought the Norma clamps were the result of lean manufacturing practices but I read somewhere on here one the techs say that the spring type are better since they maintain constant pressure whilst the old style do not and also they cannot be overtightened and break the plastic stubs at the hose attachment points. Despite that I always fit screw type when I change hoses :0)

 

The new hose clamp I put on is the screw on type. I will replace all the ones that I can see are slipping a bit. I think you have to special order Norma clamps right? Hoses actually LOOK ok. I'm going to replace the thermostat, the housing is the plastic one but I see no leaks or cracks on it. I'm thinking the long trip I took to a more dry climate where it essentially sat for 2 weeks may have effected it but who knows. Another possibility is that I did push the car at certain times along the drive and it's not used to that. Hard to want to do more involved work as this is my only car in a city where I am basically alone.

 

I've read that the hoses blowing off on our cars is a sign of an overheat problem rearing its ugly head (NIgel Thorley). So great advice on changing out the thermostat. Clamp style shouldn't matter much in an automotive setting. just dont overtighten, esp. on that plastic housing. Marine experts tend to like solid vs. perforated clamps for more even pressure and corrosion resistence. In cars under normal conditions, ??? Norma clamps are much quicker to install during factory assembly, = $$ saved.
Good luck

 

I didn't know that bit about the hoses blowing off meaning an overheat problem, mike. I checked my thermostat today just to make sure, mine is made out of metal. I'm guessing my dad had it changed a few years ago. I changed a couple of hoses recently. One was puffed up, the other had cracked. I'm watching the rest of them, they seem to still be in good conditions.

 

giandaniel, If the thermostat was changed a few years ago it would be a good idea to do so again, and change the hoses also. The risk of catastrophic damage occurring due to overheating is too high to be complacent.

 

RJ, my car's thermostat is virtually new. There's only been 6k miles since the last time it was changed. The car has mostly been garage kept. What worries me is the timing chain tensors. I have to replace that soon, but I don't have the expendable money.

 

Are you planning on changing them yourself? Not a big expense using Lincoln LS1 parts. By the way, what is the color code of your car? It looks a lot like my 97.

 

Just some housekeeping...OEM spring clamps are not Norma clamps. Norma clamps are typically the stainless steel band worm scew type (they have a lot of other clamp types too, but no cheap spring clamps) Norma also makes the plastic quick connecting coolant hoses too.

 

I assume you're talking to me. Well, it's the cheapest way. So, once I can buy the parts, I might change them myself, but I've also got a friend who has an uncle that can change them for me at a lower price. I don't happen to know the color code of my car, but I'll check it out as soon as I can and I'll let you know.

 

RJ, it took me some time because of school work and distractions. Paint code on my car says PED. A quick google search reveals its Athracite Metallic or Athracite Pearl clearcoat.

 

I am replacing the hoses and thermostat but jagbits doesn't carry clamps. Can anyone suggest where one can order them for the two radiator hoses?
Thanks

 

Index of /Parts_Illustrations/XK8 97 ON/1_OF_3
fiche 1 H 5

4 at Jaguar Parts - Direct JPLV Porsche Parts.com

 

This hose popping off has happened to me as well in both of my Jags (including my XJ a few days ago) and other vehicles. And it seems to happen after stopping the vehicle because of a buildup of pressure that doesn't seem to happen when coolant if flowing. It seems that a faulty thermostat is nearly always the culprit, and as a relatively inexpensive part, is the first thing I have replaced each time it has happened to me. The clamps, no matter what kind is on the hose, seem to work just fine after the thermostat is replaced. Consider it a warning of a bad thermostat when the radiator hoses come off.

 

Its unusual for the lower hose to pop off, as it is a suction hose. The upper hose is the supply hose and is under more stress, and it is the hot water hose as well. Changing the thermostat is a good idea at 60K anyway, that is the limit of their dependable life. More than likely, the clamps are the fault in this case. At this age, the car should have all its old spring clamps replaced.