I had noticed about a week ago that my wife's '99 VDP seemed to be turning over slower than usual. However since I drive it only on the weekends and it's been pretty hot here lately, I attributed what seemed like a slower turnover to the heat.

Then this past weekend we noticed for the first time that the cooling fans have started staying on for a bit after shutdown. Neither of us had ever noticed them do that before...and therefore we are certain they never have.

Today in stop-n-go on her way home from work (102 degrees?) the car overheated and she parked it immediately. When she called, she said that some fluids had ran out underneath. About an hour or more later, we returned to the car with fluids and tools as I fully expected to replace a hose...or that the hose had "blown" off the thermostat housing once again. Although I could detect a hint of antifreeze, I couldn't find a leak. Inspection of the tank level revealed that although it was a little low, the coolant level wasn't off much. I added fluid then had the Mrs. start 'er up to watch for flow. As it warmed up the flow started and eventually the level rose to overflow then dropped back down as the thermostat apparently opened. I closed 'er up and we let it run a bit. No problems found (both fans blowing nicely), I told her to head to the house.

She drove a few blocks with no problems. I then told her to turn on the AC and close things up...simulating her drive home. a couple of quick lights later, she was looking for a place to shut it down. The temp gauge was bobbing up and down from the middle/normal position. I took it over and although the temp gauge did bob up and down, it never got close to hot...until...until i came to the section of road that is a very long and steep climb. By the time I reached the top I had to shut it down and coast down the other side and into a station.

Few minutes later and after finding no leak yet, I drove it another 3 miles home with no AC and ALL ELECTRONICS turned off with no problems. After arriving home and shutting 'er down, the fans continued to run...this time what seemed like longer than normal and with the hood open.

Now I must digress...as of lately I've watched as my instrument gauge lights would take turns going out. Weeks ago it was one intermittently...then another decided to take it's turn and then 2 nights ago I sat in the store parking lot with the parking lights on and car turned off (acc position with radio on) while waiting on my wife, and watched as the instrument gauge lights put on a show for me, one randomly blinking off, then another as the previous came back on?????? We chalked it up as our temperamental Vandy putting on yet another show.

So this evening, the next thing that popped in my mind is a battery issue. I pulled out the old VOM and checked the battery at the posts. 12.2v Checking the battery level revealed all but maybe one cell required fluid, but none were dry down to the plates. Filled each cell appropriately with distilled and connected the trickle charger...pegged the meter at 8+amps charging. I'm going to let 'er charge overnight to get a full slow charge on the battery and we'll see how it fares tomorrow.

After the car had fully cooled sufficiently to open, I checked the fluids once again and adjusted accordingly. About an hour later, I noticed that the radiator hose on the passenger side that has seemed expanded a bit when the car was running at normal temps, was now about 1/2 collapsed in on itself. So now I'm wondering, could I have a hose problem...a situation where a collapsing hose restricting the coolant flow and causing the overheating...or perhaps it was voltage/battery-related and the fans were shutting off intermittently and causing the temp fluctations/overheating...or is it simply the thermostat acting up intermittently?

BTW, I can't seem to find a thermostat at all the usual parts houses? Where have you guys had the best luck in finding one?

Thanx for your thoughts/responses and sorry for the lengthy rendition.

 

My guesses-
Forget the hose, it collapses after the system cools down and draws a small vacuum. I suspect you might have a few different problems.
Labored cranking and loss of fluid almost surely mean a head gasket. Do you see a puff of steam from the exhaust on startup? Maybe someone else can post the best method to identify that if you do not see steam coming from the exhaust. If its not that, I would change the thermostat on general priciples. I would check the fan relay circuit to see if the fans go into high speed when they should. The operate in serioes for slow, then parallel (using relays located behind the left headlight) for fast. Then I would check the bulkhead electrical connections and the fan, engine and battery grounds. Check the archives or check back for more explanation on any of those. Good luck.

 

When driven in very hot weather with the A/C on I have had the fans run after the car is shut off. It does not happen that often - but I know it can when it gets very hot. The hot weather will also take out a weak battery -- on our fleet cars it's always the first hot week that takes out a few - we replaced two last week. So you may have a battery that is failing - and this can cause all manner of strange dash lights and warning.

As to the overheating -- does it still have the original thermostat and water pump? Both can cause strange overheating problems - and both have known problems especially the water pump vanes.

The pressure should also have equalized so that the hose did not collapse -- does your cap look OK -- does it look like the system is pressurizing when it has been running?

A failed head gasket can also cause strange overheating -- one would not normally look to that problem first as it is less frequent then the others -- but obviously that could be your problem especially if you have a lot of miles on the engine or it has overheated in the past.


Many years ago I had a transmission that was overheating -- since the transmission cooler was connected to the radiator -- the car would overheat. It was initially very hard to diagnose. So strange things can occur.

 

Thanx for the feedback gents. I'm pretty much ruling out or not considering a headgasket issue, as I don't really see any of the usual symptoms (steamy butt-end, or traces of oil/exhaust in the coolant, over pressurized system etc. ) of a headgasket problem.

However, today the vehicle is fully charge and I followed the burping methods found in other posts, ran to operating temp then checked heater flow and let cool then checked fluid level again and all okay. Then took car for a spin and it ran down the streets (and up a nice hill) for about a mile, then down the highway for about the same with no problems. Stopped and had lunch for about an hour, then off a couple of miles down the road at highway speeds. All good. Then sat at a light with no problems (again 101 outside temp), then I charged up a very steep but shorter hill than yesterday. No temp changes going up but about 1/4 mile past the temps rose first a hash mark then a full mark (3/4 of gauge) then from that point on at 35-40 mph down the streets for about 2 miles to the house the temp fluctuated somewhere between the 1/2 and 3/4 marks on the gauge. Along the way we stopped to make sure the fans were running...and at full speed. Although the temps moved around and once returned to the normal 1/2 mark, they went right back up was at the 3/4 mark when I parked in the drive and shut down. Half to a full minute later, the fans had the temps back down to the 1/2 mark.

VIN # falls after the range of those listed on the Jaguar TSB with concerns for water pumps. So now I'm thinking thermostat.

As hot as the temps are these days and nights here in S Central Texas, I'm thinking I could just remove the thermostat (center) to create a free-flowing system and see if the temps once again bob up.

 

Have you also seen this TSB????

bob gauff

 

I did Bob and have it in hand. Thanx to you, I just re-read TSB 303-60 that was amended on 04/03 and realized that my car is not outside the VIN range (nor MY range) like I thought. The VIN just fell outside the revision VIN range for checking for specific pumps.

I'm pulling the thermostat to what changes. At 100 degrees around here, I should pretty well be able to determine if it make a difference.

thanx guys.

 

Great...2 bolts come out easily, but the 3rd is stuck and the sleeve in the housing just spins. Stupda$$ engineers!!! Even if I somehow manage to get the bolt out without breaking the housing, tightening sufficiently upon reassembly most likely will not happen.

Anybody got a housing they can overnite?

 

Well guys, just a quick update. Eventually was able to remove the remaining bolt assembly as one piece, without breaking the thermostat housing or outlet flange. Damn engineers!

Anyway, cut the thermostat and used some really good glue to try to glue the female threaded cylinder (can't think of the name right now, I'm exhausted) back into the housing. After allowing sufficient time to expire for the adhesive to dry, I put it all back together with the now "summer thermostat" in place; snugging up the other two bolts before attempting to tighten the third. First bit of tension and it gave way. Wound up using a little shade tree improvisation and found a wall anchor and screw that fit perfectly thru the holes and with large enough heads. Tightened 'er all down and started the fill, burp process all over again.

The road test started by driving 7-8 miles at mixed speeds without the AC (evening at about 90 degrees). The car ran at about 1/4 of the temperature gauge and a few times fluctuated towards the next hash mark but never made it; where it usually runs at about 1/2. After hitting two bank ATM's and the Walgreen's drive thru, we rolled up the windows cranked on the AC and headed down the highway, by this time the temps had risen to the half mark, where it usually runs. I then traveled to the road with the long steep hill from last evening where it did heat up drastically; sat at the same stop light then off up the hill and perhaps even pushing the car a bit harder. The temps never rose beyond the top edge of the half mark. Once back at highway speeds for 3-4 miles the car edged back below the half mark and cooled a little more at neighborhood street speeds (20-35) before we reached home.

I think it was the thermostat. I noticed that the assembly was questionable (loose on the rod and no tension?) when I cut the retaining flanges. I didn't waste time trying to heat it up to check it...as I took it out to gut it to determine if it was my problem and if not, replace anyway.

So now, I still need to replace the thermostat and piece of junk housing. Just hope that the temporary fix on the housing holds until the new parts arrive.

Thanx to everyone for your assistance and suggestions. Early tomorrow morning the search for a new housing and thermostat that can be here overnight begins!

 

One further suggestion ... some people have suggested that debris collects between the various cooling devices and needs to be cleaned out by separating the components and flushing with a hose. Just a thought.

And, can anyone clear up the various designs of thermostats that have been used on the V8 and their application? Apparently, there is even a multi-piece design.

 

With your car being a 99 -- I would do some investigating to make sure you have the updated water pump. When you replace the thermostat if the flow from the pump is not correct you may have the same problem --- It may be wise to replace it with the updated part.

I would also replace the plastic thermostat cover -- they are a ticking time bomb.

I have never replaced nor have I ever had any issues with my thermostat -- if replaced I would make sure it was OE or OEM.

 

Yep, get the metal housing. It seems that all of the plastic ones crack and leak eventually.

 

Thanx for the replies and suggestions everyone. I'm going to move forward and go ahead and replace the unit with a metal housing and a new thermostat.

For all the frustration and cussing that I did as a 30 minute thermostat job turned into a mess, I still absolutely love the car. When I was done with the car work and other chores, I gave Vandy a nice handwashing at about 10:30 last evening. At about 11:30 my wife came outside and found me sitting out in the drive staring at the car. It was a nice evening, after a long day of 100+ heat and no cloud cover, the temps had cooled to around 86 and there was a nice SE'erly breeze blowing in moisture and clouds from the gulf. The full-ish moon shown down on Vandy's lines...and I couldn't help but sit out there at the end of a long day, in the cool breeze and the bright moonlight blinking thru the fast-moving clouds and shining on Vandy and cold drink in my hand and appreciate her beautiful lines and beauty. I've loved the XJ's for awhile, but these model years are my favorite...body-wise.

Everyone have a fabulous weekend...and thanx to all again for your feedback.

 

So glad to hear I am not the only one who stares at my car...

This body style is truly art in motion, I can think of very few cars that I would consider "beautiful" this is on of them.

Which is why I own 4.

 

4 Snyder...wow! I know I definitely have my OCD periods on a regular basis...and thank goodness my wife fully understands and tolerates/deals with the situations. But 4?

I think it would be like having 4 wives...each beautiful in their own right...but I find it difficult enough just to keep 1 happy and running well...and the rest of the time I spend appreciating/working on her Jag!

 

I just love the way XJ looks , good to see we are not alone lol