When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
1986 XJ6 beauty. Runs hot enough to engage the aux fan when AC is on, otherwise seems to be fine. I had the coolant checked. I used a IR therm to confirm coolant thermostat opens, and it appear to, Coolant level appears normal. AC seems to run fine though it is not very hot -- though I am running it.
Is there a way to know if the AC compressor is moving smoothly? Any other ideas?
1986 XJ6 beauty. Runs hot enough to engage the aux fan when AC is on, otherwise seems to be fine. I had the coolant checked. I used a IR therm to confirm coolant thermostat opens, and it appear to, Coolant level appears normal.
The aux fan kicks in at about 200ºF (or 94ºC)
In and of itself there's nothing wrong with that.
But what are your ambient conditions? In most conditions the engine should run 88ºC to 90ºC. If it goes higher than that in mild conditions you may have some issues to sort out.
On hot days and/or city traffic it will climb up a bit.....which is no big deal unless it keeps going up-up-up.
AC seems to run fine though it is not very hot -- though I am running it.
Not clear on what you're saying here
Is there a way to know if the AC compressor is moving smoothly? Any other ideas?
Remove the belt and spin the pulley by hand is one way.
But usually a problem in this regard come with a rattling or grinding noise
The thing is that its been pretty cool and the big issue is that it changed. Used to never go high unless hot summer days with AC on. Now, even when 50, temperature to the very tip of green unless I turn off the AC. So even writing this, I'm thinking that the thermostat may not be opening all the way or something. Maybe I try changing the thermostat.
The thing is that its been pretty cool and the big issue is that it changed. Used to never go high unless hot summer days with AC on. Now, even when 50, temperature to the very tip of green unless I turn off the AC. So even writing this, I'm thinking that the thermostat may not be opening all the way or something. Maybe I try changing the thermostat.
The XJ6 cooling system is very ordinary and so are the problems and fixes
Yes, possible thermostat problem.
And/or clogged radiator (internal or external clog)
Drive the car until it gets good -n- hot. For example, when the aux fan kicks in. Turn engine off. Give the fan a hand spin. You should feel a bit of resistance. If it spins more than one revolution, the clutch is weak. If it spins free, the clutch is shot.
Other than the fan running, is there any indication the engine is actually running hot?
He said the gauge needle is touching the green band, which begins at 90ºC
There's nothing alarming in that, nor in the aux fan coming on. It's just that, in the mild ambient conditions described, neither should happen. This suggests that some aspect of the cooling system isn't performing at 100%.
To recap: over a month -- car runs warmer than it had. SF highs have been 50F, maybe 60F. Never used to have the coolant temp almost out of the green zone towards the right side of the scale. Aux fan came on when outdoor temp was 58F. Running temp would go back to normal when AC off or when not in stop and go traffic.
Thermostat seems ok using IR gauge.
I flushed and replaced the coolant
Fan clutch seems ok on visual inspection and does offer some resistance. It doesnt seem like its different resistance to me when hor or cold, so that could be a contributor.
Then I review what I've done over the past couple months. I added some insulation to the bonnet underside. It is tight and actually was touching the top. Especially towards the bow. I'm wondering if the combination of a marginal clutch and the extra insulation is the issue. I'll find out in the next week or two. Ordered the clutch.
If anyone remembers for the fan clutch -- Is it easy to loosen the manifold? Where are the screws and how does one access them? This is an 1986 -- So I loosen the 4screws holding the clutch, but am I taking out the fan and clutch as one piece? Is that how it works?
Never used to have the coolant temp almost out of the green zone towards the right side of the scale.
I misunderstood your previous remarks. I thought the need was just entering the green zone. What you described now is not good at all!
If anyone remembers for the fan clutch -- Is it easy to loosen the manifold? Where are the screws and how does one access them? This is an 1986 -- So I loosen the 4screws holding the clutch, but am I taking out the fan and clutch as one piece? Is that how it works?
Yes, fan and clutch come out together. Tricky job. You'll have to loosen the fan shroud to get the wiggle room to remove the fan and clutch assembly. Get some extra fine threaded nuts as you'll likely drop a couple into the bottomless abyss when removing the clutch
A likely culprit is the thermostat. May that are specified for the XJ6 are actually wrong. The foot doesn't extend far enough to block the bypass, so the coolant circulates within the block and never goes to the radiator. The problem is the same with the V12 engines, as they take the same thermostat. Lots of discussion about this on the XJS forum. Bottom line is you want a thermostat that extends from the bottom of the foot to the mounting flange 42mm when hot. See a diagram here: https://www.jaguarforums.com/forum/x...8/#post2725628
A Gates 33188 works, you do need to drill a small (5/64" or 2mm) hole for an air bleed. If you need an application at the parts store, it fits a 1992-95 Ford Crown Victoria.
Changing the clutch was as challenging as everyone said
Removing the nuts that hold the clutch to the water pump
- You need two 1/2 spanners -- the longer the better. One to prevent turning the wheel and the other to loosen the nut. As mentioned by many - you need to slowly loosen the nuts one by one or you'll have to go backwards -- no clearance otherwise.
- There might be way to remove the fan and the clutch (after removing the 4 nuts that hold the plastic fan molding) without disconnecting the upper coolant hose and the small air bleed hose, but I do not believe its worth it. If you remove the hoses, it comes out pretty easily.
- Post-mortem on the old clutch was interesting -- crusted rust on the small metal circular element that heats and expands. Its amazing it worked at all.
- Tricks for reseating the nuts on the new clutch/ fan assembly. Slow is smooth and smooth is fast. I used a surgeon forceps to first place the nut on the nut and pushed the fan slightly rearward to trap the nut against the bolt and slowly and carefully seat the seemingly impossiblly small bolt. I used the forceps to get it started just enought to prevent it falling off. Then did one at a time. I used a loaner fan wrench from the local auto store to turn the water pump placing the next target at the 1200 position and repeated the process. Oh - helps to place cardboard between the radiator and the fan to push the fan against the waterpump and prevent it falling off. Definitely buy extra nuts as mentioned above ahead of time. That was great advice. To tighten, you'll use the two 1/2 spanners. I had bought a new upper radiator hose ahead of time and glad I did. It was harder to remove the old one without fraying it and likely ruining it. Use vaseline to lube the new hose.
It's not hot yet -- but the old clutch had the same resistance cold and hot -- so I'm optimistic this will help. Again, I was fine on the road when moving over 35 MPH. It was stop and go traffic with AC on when hot outside that was my problem. So the clutch does make the most sense to me.
Thanks to everyone who chimed in.I considered showing a photo of my hands. The blood did indeed help lubricate and ease extraction of old parts.
New prob: Runs hot with AC on
