The larger of the gears (one cam) advances and retards. It does so thru a fairly simple mechanism that works with oil pressure produced by engine rpm and the actuators (if you have them I forget with your model year) at the top and very front of the cam cover... I really don't think this is your problem... Skipping and jumping teeth (unless your sprokets are WAY loose) is the only way (I think) "creep" could occur and still, by then, you and the engine would be up ***** creek!!! I mean, when you remove the covers do the flats still line up,,, or not?

 

Not impossible, there are 2 things i keep coming back to....

1 That damn VVT
2 The 2 gears on the crankshaft.

Having the engine apart and back together upwards of 10 times now, I DONT REMEMBER IF I OFFEST THEM 1/2 tooth.

 

Is wrong head gaskets interrupting coolant flow possible?

 

JayJagJay, because ive had this engine apart and bag together so many times, i cannot remember if i offset the camshaft gears (flipping the outward most gear inboard). I mean the car is def not 100% and I would think 1/2 took COULD cause something like what im seeing.... WHAT SAY YOU?

 

Jay, the holes all matched up.... i placed the new ones ontop of the old and they seemed legit. Good call tho

 

I'm not sure that ALL the holes should match up. Some will and some won't... Jaguar made a lot of decisions about engine temps in the US market that they didn't have to in other markets (globally) (and I'm only TRYING to capture what other much more qualified folks here) about temps in connection with emissions and such. Again, no expert...

Post the gasket information on line here so others can help rule it out...

 

Flipped what gears?

Does/do your cam gears look like this/these?

I'm confused

 

No Jay, not the cam gears, the crankshaft cogs/gears. They keyway match up on the crankshaft but you must flip the gear for bank A so that its 1/2 tooth offset. I DONT REMEMBER IF I DI IT THE LAST TIME I HAD IT ALL APART.

 

Engine timing consideration is fine to explore but typically “ Engine Overheating” is typically because coolant isn’t circulating right.

Have you run the engine, without the coolant expansion cap on? When up to temp. it should be over-topping if coolant system is circulating right. Coolant should be hot to touch too

 

Jay, here's what I'm talking about..... Made this just for you. lol

 

David, At temp I can tell you there is plenty of coolant getting to the overflow res (with the cap off). I can actually see the jet of coolant ingressing from the tower line. Im pretty sure I had the heater on FULL HIGH HEAT to relieve some heat via the heater core so Im not sure that counts as an "over-topping" test because the heater pump would have been wide open. But long story short, I haven't had any weird overflow indicators, with or without the cap on.

 

Assuming that all the parts are installed and timed correctly, I just had a few ideas, the thermostat may be bad, the waterpump may have a reversed impeller out of the box, the belt routing may have reversed the waterpump rotation, you may need to burp the cooling system by running the engine till the fans start with the cap off the system and the heater running on full. this really doesn't explain why the engine is down on power though. Describe the symptoms of this in detail, as it is inconsistent with the overheating symptoms.

 

Rath, I empathize with the struggle to get the cooling system in these cars squared away. In the last few weeks I have pulled out everything (all the hoses, cooling tower, heater pump etc) with the hope that I could finally fix the leaks and get the temps down. While I don't have any suggestions as to the reduced performance from the motor, maybe some of the thoughts below can help with the cooling system.

• Before the work, I had average coolant temps of 206F at 80-90F ambient at idle (measured off of the OBDII port), low fans at 208-12F and high fans at 217-20F. Other members seem to be hitting very similar numbers (it might be worth a poll?). Even with all of the repairs my average has only dropped to 204F at idle. At highway speeds (80-85 mph) in the mountains I am seeing 197F at the lowest with similar ambient temps.
• My underhood temps and engine heat retention experiences are very similar to yours, I am picking up a Northern tool temp reader today and will let you know if my comps are similar.
• Bleeding the system was an absolute bear and required four tries to get it where I think its right.
  • some suggestions: If you have the aluminum cooling tower, remove the cap and fill the system from there at first, making sure to leave the coolant bottle cap off. This was the only way I could get all of the air out of the radiator and top hose in front.
  • Once you get the front filled (coolant within a few mm of the top of the tower, cap it and fill the rest of the system.
  • If you have a bleeding funnel that lets you run the car with the cap off, use it, instead of what I did which was stare at it laying on the ground as a half gallon of coolant spilled everywhere
  • Run the car to temp, wait for the fans to come on and then turn the heat to High and let it run for at least 10 mins. This was the only way I could get the heater to produce heat at first and seemingly clear the lines to it. Once the interior is miserably hot, shut the car down and let it cool completely.
  • Check that the degas bottle in the left fender is at least half full (you have to pull some of the fender liner to check)
  • check the coolant bottle under the hood again and add coolant until it is just at the neck of the bottle.
  • It took three days of driving and checking it cold before I didn't have to add coolant again.
• some members have reported that the newer temp sensors in the crossover (especially the URO parts one) isn't calibrated very well and maybe reading high. It's possible that the temps coming out of the ODBII are somewhat wonky?

hopefully some of this ramble helps?

 

Ex, this car is trying to kill me, im sure of it! Lots of good info in there and I appreciate it. As of 30 min ago, the car is once again stripped down to the heads and timing chains. All tensioners and the A/B primary crank gears are perfectly in place with no skipped teeth n whatnot.

Once i get it back together ill FOR SURE follow those steps to ensure ZERO air in the system.