On the way home really digging on how my xjr6 just smoked a corvette I noticed that the light flashed indicating I needed radiator fluid, it then turned off. I looked at my temp gauge for clarification and it marked normal, so i decided to go on my way home. A few miles later, going about 70, the light turned back on and stood on so i decided to get off the next exit and look for a gas station to add some coolant, the gauge still marked normal. As I exited the fwy and came to a stop my car turned off, the gauge still marked normal, as it overheated. Ends up the water rail hose broke open and I had no fluid in the system. My car only has 110k and it ran like a champ! now it just isnt the same, no power. I fear I need a new head, I should have never trusted the temp gauge!!!!! Does anyone know where I can get a brand new head ready to go at a good price, I once new of a website that had new heads on clearance for very cheap but now I cant find it. any ideas?

 

There is a new one on eBay for 400.00 . Look under "AJ16 supercharged"

 

I took a look and purchasing it right now! best price ever, thank you....

 

The water temp gauges on XJ's are set up to work like idiot light, i.e. either "on" or "off". Contact Stever at <steve.klonsky@comcast.net>. He makes and sells Real Gauge that turns the temperature indicator into a "live" gauge. As far as I know the Real Gauge is for XJ308 and XKs. However, it won't hurt to ask Steve his opinion. He is a super nice guy and a pleasure to deal with. Plus his product is outstanding.

 

I use the Realgauge in my XK8, while for the XJ6 I have an Ultragauge, which tracks the temp. and fifty or so other parameters. It also has an alarm, which I have set at 215 deg. and is also a code reader.

 

That's a real let down hearing that jerimiahjaguar its not just jaguar with crap like that
The oil pressure gauges on our XJR,s are crap as well
My Jeep has these things called tpms (tyre pressure monitoring system) last week while 1800 k,s from home my my dashboard signals that the tyre pressures are low
I think ill just nip into the service station 100 meters up the road and pump up the tyre
I drive over the tram tracks and hear metal on metal pull straight over the tyre is not low its flat luckily I have a miniature air compressor I pull it out connect it up get on google look for the nearest tyre joint 1 k away
The tyre shop say its got a screw in it easy repair he fixes the hole pumps it up puts it onto the balancing machine the tyre walls are stuffed I need a new tyre okay the tpms only told me that the tyre needed air when the tyre was actually stuffed thanks tpms
To make matters worse I cant get a tyre in all of Melbourne The tyre shop was so nice they lent me a customers puncture repaired tyre
I drove to Sydney 950 k,s away as the only tyres of the size and load rating I need are in Sydney and if I waited in Melbourne they would take 2 days to get to me
I asked the tyre shop if they had a shop near the tyre distributors warehouse in Sydney they did
I got the tyre delivered there drove from Melbourne to Sydney got a hotel and had the tyre fitted the next morning and drove home to Queensland another 980 k,s home

At least my xjr is going to the panel shop on Tuesday looking forward to driving it as the weather starts to cool not real keen on driving it when its so hot she doesn't go as good as when its winter mind you our winter's don't get bellow 25 degrees C during the day be lucky to get under double digits till the early hours of the morning

Maybe you should get the old head crack tested and repaired in case

 

This, I'm afraid, is a common story.
As soon as the coolant light comes on STOP and sort it out.
To make matters worse the sender for the temp gauge is placed so that it isn't covered by water once the level drops a bit so doesn't 'see' the hot engine.

 

Is there anywhere else the temp sender could be located to give a more accurate reading when the level does drop?

 

Im about to do a compression check on each cylinder, can anyone let me know what are the proper readings for a xjr6. And what if any is the difference from a compression test with a cold engine or testing after the engine has warmed up? Thanks guys appreciate your help.

 

Looking in the service manual (which you should probably have) it says 9.5-11.0 bar (137-159 psi), warm engine, plugs out, throttle wide open with no more than .7 bar (10 psi) difference between cylinders.

I'm not sure how much difference "warm engine" versus "cold engine" would make, or why. Maybe a "cold engine" won't have oil on the pistons rings and would result in a lower reading?


Cheers
DD

 

What model year and engine was the Corvette and did the driver know there was a race taking place ?

Cheers
DD

 

Actually that's not quite how it's *supposed* to operate.

It's design to stay on "N" over a wide temperature range and then start moving higher after "X" temperature is reached. I'm not sure what "X" temperature would be....probably too high for our liking.

I've checked mine against the scan tool. On cold start the needle gradually climbs (as expected) until it hits "N" (actually just a tick below) at 174ºF and stays there until at least 205ºF. That's as high as I've been able to check, so far....never been able to get the engine any hotter (knock on wood). So there's at least a 31º range of operation where the needle doesn't move.

The oil pressure gauge, except on the earliest 95s, is indeed "on-off" in operation.

Cheers
DD

 

the corvette was early 80s model they are rated at 205hp and up to 230hp for the 85 version, not sure exact year. And the youngster that had it chased me down in order to catch me at a light in order to provoke a little friendly competition, boy was he surprised. I give thanks to the andy bracket and the new sc rotor plate made by magnum powers, this increased air flow by 10% and lowered air intake temps, this really made my car fly. I prefer the stock tb over the ported one at 80mm, car just ran a lot better, my 2cents.
now my compression check is as follows:
1. 110 2. 110 3. 120 4. 120 5. 120 6. 120
now that seems low when compared with the numbers given above, the car was cold when the test was given. when you say "plugs out' do you mean I should have all plugs out at the same time when I check? I allways have just removed one plug at a time and replacing it when done then moving on to the next. Maybe tomorrow I should check it warm, plugs out.

 

Ok, that makes sense then.


Below spec, and well below the optimal end of spec. I can see why you'd feel a loss in power.

Cheers
DD

 

All plugs out. If you put a few drops of oil in each cylinder, you can do the check with a cold engine and get a reasonable reading.

 

new readings are alot better but still on the lower end of the scale, what do you think?. After hours of kicking myself in the rear end noticed intake temps are hot, a quick check revealed ic pump not working. maybe went bad because it ran dry for a while? who knows. Still dont like compression but still within limits. will place a new ic pump and pray for a better outcome, still bought new jaguar cylinder head, 400 bucks cant beat that anywhere!!!!
1 140
2 140
3 140
4 145
5 140
6 145

 

Those are good numbers. Has your gauge been calibrated? There is often error in gauges. I would have been worried about the head gasket more than the rings, and no indication of trouble there.

 

Might need to look at this mod.

However, if the gauge is "on or off", why does the needle sweep during warm-up and cool-down?

 

It's not the warmup phase that's cause for concern. I don't want to guess about who the provided this information, but one of the professionals on the XK8 forum stated that the temp gauge read mid-scale until 230 F, and then rapidly moved to the red range, often to late to save the engine. That is why I have Steve's Realgauge, with the oil pressure addition, in my XK8, and the Ultragauge in my XJ6.

 

thanks for the info on the ultragauge, well worth the money. i will get mine this week because im keeping my jag!!!!!!