Here is the update I promised after removing my oil cooler.

As some of you know a few weeks ago I removed my oil cooler from my 2005 XK8 and fitted a loop on front of engine to replace the oil lines.
Today I left home when air temp was 87 degrees and drove 5 miles or so to town at one point in slow traffic stopping several times behind a school bus. The engine was warm as it had been driver on another trip a little earlier. I drove around town very slowly stopping at every intersection. After completing two laps around town oil temp was 212degrees. After the third lap it was still 212degrees. We then left town in about 1/2 mile the temp went up to 215 degrees and then dropped down to 190 for the rest of the way home. The air temperature in town when making laps was 89 degrees.
We set at intersections at idle quite a lot.
Don't see need for cooler yet but will keep a close check on it and keep those interested informed as my experiment goes on.

Jack

 

My so called real world driving environment would ask you to test when the ambient air temp is 100-115 F
(38-46 C) and you are stuck in traffic for 5-10 minutes not moving.

For example, I just drove about 1,100 miles round tribp to Austin TX . My coolant temp was 186-200 F and the oil temp was 202-220 F . But the ambient air temp never got over 75 F and there was no traffic.

Last summer when I took the same trip the air temp never got under 110 F and the traffic was horrible. The coolant got up to 218-225 F and the oil temp hit 240-250 F repeatedly. At those temperatures the oil thermostat was open most of the time.

if you don’t drive in those temperatures then you might be fine, especially with a synthetic oil as those handle higher heat better.

But for driving when the the oil thermostat is open all summer long makes me glad I have the cooler.

Z

 

I'll keep up with the oil temp all summer but will never see anything over 95deg most likely.
I modified an oil plug to accept a temp sensor connecter to an autometer gauge. This gauge actually reads 20deg lover that the Autofix diagnostic tool my son is using while I'm driving. I'm guessing the one that reads the highest is correct or close. I'll use the gauge while I'm driving just to make sure I don't damage my engine. At least I know my oil lines want blow out..

Zray, you mentioned earlier that you wish someone would come up with a better hose system.. I've been looking into that and have found that one could easily use 10AN PTFE Nylon braid hose with no joints except on the ends. One of the problems is the weird ends Jaguar uses. One could have ends made to fit engine block with 3/8" NPT threads with an JIC 45deg elbow screwed into block fitting. Then purchase a Setrab Swedish made oil cooler (Should be able to find one very close to original size) that AN fittings fits, then run hoses and your done except for hose hangers. There is plenty of room to do this on my 2005.
PS You obviously need an oil cooler

Jack

 

I’m following your experiment closely, and will keep tabs on my highest coolant and oil temperatures this summer.

Slightly off topic:

I used to have a 1970 Rickman-Triumph Street Matisse (motorcycle). In the late 1960’s / early 1970’s I was working at Triumph M/C dealership in OKC, and got to see the results engines and engine oil getting too hot.

of course back then synthetic oil was something that was just a rumor, we all used Castrol GTX, a 20w-50 oil that was good for one cross country trip before it broke down. I put an oil cooler from a Triumph Trident 750cc 3 cylinder on my Rickman-Triumph 650cc twin. It helped in all areas, performance, mpg, and longevity. So I was won over pretty easily.

That Rickman-Triumph was a sweet handling machine, the best handling 2’or 4 wheeled vehicle I’ve ever had the pleasure of riding / owning. It was the first production motorcycle with disc brakes on both wheels (Lockheed made them).

 

It would be nice if there was a plug and play kit to replace the oil cooler and it's lines with something more durable.

 

Thanks for the Info zray.
Kuddlesworth, a kit could be made up with the parts made for the engine side and JIC fittings with PTFE nylon braided hose, AN10 fittings and a new relatively inexpensive oil cooler that accepts AN fittings. I thought abut tackling the project myself if it turns out that I need the cooler.
as you probably read, zray stated that his oil sometimes reaches 150deg F. I don't know how hot it has to get to start effecting engine life. If my oil reaches 130 degrees anytime this summer I will put the cooler back on.

Jack

 

I have a supercharger so the oil is known to get a lot hotter so the oil cooler has to stay on for my car.

 

Absolutly.
I been looking at Setrab oil coolers. They make a 6 series with identical deminsions except for height because of 3 extra rows, as my 2005 oil cooler bolt holes and all. Their # 50-610-7612 cooler has a 10 row core and mine has 7. Theirs is rated for 90-130 HP. Looks like the Jaguar coolers are a little punny.
With special fitting made for engine block and this oil cooler, looks to me to be doable and with PTFE nylon braid hoses and AN fittings it would be very dependable I would think. AN fittings is what racing teams and Military use for those not familiar with it.

Jack

 

Yea those coolers look like a good radiator really. Not expensive either. I did look at some AN fittings and those don't look terribly expensive nore do the hoses really. Not sure what fitting would work with the engine block though, I assume you want an alluminium fitting so it's aluminium on aluminium and not steel as you would get galvanic corrosion? I would probably see if it can be converted to just two hoses one in and one out instead of having 4 seperate hoses, seems a bit silly really. Stainless steel braided ones maybe so they won't fray on anything as I assume that is what the steel/aluminium sections on the OEM hoses are for. Not sure why Jaguar just didn't use a better system from the start but then it seems to be a fairly common oil hose in the car industry.

There are some adapters by Setrab some with 2 barbs some with 3 barbs I assume the more barbs the better with a clip on the outside to make sure it's tight on. The push type like this 90 Degree Adaptor Fitting for Setrab Coolers (merlinmotorsport.co.uk) I could get a couple of them for the cooler and a couple straight ones for the engine block but I'm not sure what fitting would actually fit the engine block.

 

One would have to get a machinist to make fittings for the engine block similar to what I made for my loop. The factory ends are make of steel, they are in oil so I don't think corrosion would be a problem. as you know all the bolts going into the aluminum block are steel and under normas circumstances they do fine.
The only problem I see with the AN10 fittings is that the smallest opening in them is .402 and the smallest opening in factory tube is at the middle joint where they bolt together with one bolt and it's .437 which would be a slight restriction would probably not be a problem. AN12 fitting are quite large and might be a problem adapting at engine end and the larger hoses don't bend as tight but might still work. A lot more research could be done on this. As zray said if someone could work this out and just list parts to make the change or make a kit. If I end up having to have a cooler I might try do something.
I saw somewhere, a man changing engines found his hose ends were too large for the engine he was installing. If that's the case the earlier ones may be different. The cooler on the 2005 hangs from the top of the cooler and I've seen pictures where it looked like the older ones mount on the bottom.

Jack

Jack

 

I think those push lock fitting would more fitting (no pun intended} for automatic transmission lines. Iv'e never seen them used on engine oil lines, but I sure don't claim to know everytning.

Jack