This has been a tough job for this old man but worth it.
I've been working on this project off and on all winter and completed it this past week end. I've driven it about 50 miles with no leaks or any other issues.

Jack

 

I’d want to be checking the oil temperature on the hottest day of the summer when the car is stuck in traffic and the engine is at its hottest.

second guessing the engineers who designed the lubrication system is a perilous endeavor.


my oil cooler is in operation nearly all the time; with oil temperatures reaching the oil cooler thermostat’s opening point of 103 C (217 F) on all but the coolest fall and winter days….



Z

 

I checked my oil temperature last summer on a hot day after running from bottom of the Blue Ridge mountains to the top at a very fast but not dangerous pace. Elevation change of about 1500 ft in just a few minutes. Oil temp at top of mountain was a little over 180 F and oil cooler lines checked through the front lower opening were cool. No oil was going through them. I drove about 15 miles to reach starting point, so engine was up to temp.

If you are stuck in traffic the oil cooler will be doing very little sitting in front of the radiator in still air. It isn't where the engine fan could have much in any effect at all.
I will be checking temperature through summer though just to make sure everything is all right.

The manual says the Diverter valve in oil pan start to crack open when oil reaches 225 degrees F sending oil to cooler. I don't think it will ever get 8 quarts of oil in this little aluminum engine that hot.. Time will tell.

Thanks for your input zray, Much appreciated.
PS I thought of this myself but later found out that others have already done exactly the same thing with great results.
Thanks
Jack

 

Where did you source that custom piece, and what was the price?

 

It would be useful to know the criteria that determined whether the oil cooler was fitted or not.
Apparently an option on the early XK8:- mine doesn't have one.

I imagine it is more important on the XKR given the ~27% increase in power. Were any Rs not fitted with one?

 

I made it. My oldest son furnaced brazed the parts together for me. The tubing is seamless steel 5/8" OD. Very difficult to bend that tight.
I don't know what the cost would be. If it works out with no problems and if my son would help we might make some of them. It would be easy for a tubing specialist to make tubes but it's a pain for anyone else.

Jack

 

Mine had the oil cooler fitted. 21 yr old hoses. scared me every time I drove it. My jag is a 2005 made March or April 2004.

Jack

 

I reread your post and now understand. It would be good to know which ones had the cooler and the ones that didn't. I think it was someones opinion that all the 4.2's had them but I don't know that for a fact but wouold like to know.

Jack

 

I’m using the workshop manual (1999) for reference. Stating the oil diverter valve opening at 104-107 C (217-225 F). So it appears you are quoting the higher number

Or do you have a different source ?




In any case, your engine is running much cooler than mine.

My oil temp is usually 20+ degrees F higher than the engine coolant temperature. In the spring and summers my oil temperature is routinely reaching 220 -240 F (104-115 C). And higher yet when the ambient air temperatures are over 90, which is 5 months out of 12.
So my oil cooler is being utilized on a regular basis.

 

Same as yours zray

Jack

 

I understand anyone of being Leary of this project. I wouldn't dream of it without doing a little research first. I look at it as an experiment for now. I won't know if it's ok without cooler until July or August when I can drive it in the heat and report temperatures to you all.
Sure hope it works.
The 4.2 only produces a little more power than the 4.0. If some of those had them and some didn't that's a plus for now all things being equal, which they may not be.
I'll be the Quinne pig in this experiment.
Everyone please comment positive or negative. All good for thought. The more info the better.
If it doesn't work, it's not the first stupid thing if gotten myself into. Ask my wife.

Jack

 

Here’s a photo of my oil temp taken today, a quite cool day, taken after the car had been idling for a while.

(car is a 2002 XKR)

The oil does get quite warm indeed.

 

Would you mind telling me where you got the guage. What brand ect?

Thanks
Jack

 

I got it on Amazon. It gives out a lot of the OBD-II information.

I verified the readings with another OBD-II reader I have and they appear to be 100% accurate

The one I bought, the Autool 60 is showing currently unavailable. It may have superseded by another version .

But the same exact gauge is sold under different labels. Here’s the same looking one on Amazon

https://a.co/d/iNGk9cs

PS: Amazon is showing these gauges as “frequently returned”. But I’ve had mine for 3 or 4 years and it’s always worked perfectly. So go figure.

 

Jaguar installed an oil cooler for a reason. It might be fine but Jaguar aren't going to isntall something that isn't going to make them more sales of the car if it's pointless and costs money, it's not like it's a cheap system to install on an engine.

 

I do admire the desire to find a more reliable way to deal with aged and sometimes troublesome oil
cooler lines.

But doing away with the oil cooler entirely comes with another set of risks, especially since many of the XKR models show a propensity for alarmingly high oil temperatures that beg for some mitigation.

what I’d like to see is an all metal line arrangement that does away with the rubber line sections. I certainly can live with a few o-rings here and there joining aluminum or steel line segments.

So how about it, you engineeringly gifted among us. You produce and I will buy.

Z

 

Thank for the information zray. I ordered one last night that looks like your. I'll use it to make sure is doesn't get hot.
If mine were and XKR I definitely would not think about doing this. The XKR sprays oil up to the piston tops (I Think) and that could add heat to the oil I suppose.

If this doesn't work I'll try to replace the rubber section of the lines and reinstall the cooler.


Kuddlesworth, Jaguar may have realized later on that even the first 4.0's would have benefited from an oil cooler, and could be why some had them and some didn't. It would be interesting to know if the early oil cooler was just an option or did they start using them all at once on all 4.0 engine.

The reason I decided that it (Might not) be needed was after in the 80 plus deg weather last summer after running the car pretty hard and reaching the top of the mountain I pulled over at a look out, reached through lower opening and could hold the aluminun line on either side of the oil cooler with complete comfort. They were just warm and not hot at all.

I'm going to get the oil temp guage and make sure I don't damage or destroy my engine. We are getting older now and love this car. I don't want to loose it over a blown out rotten rubber hose. That's my driving force in this project.

zray, someone mentioned in a post on repairing old cooler lines a while back that one might use just the hose in one piece. After looking at mine I think that might be possible using a smaller hose. The original hoses are .750 ID and the smallest place I have found in aluminum joints is .4375 leading me to believe that smaller one piece hose could be used. of course it would have to have more hangers. Just something else to look at.

Jack

 

The OBD-II device I use can be set to display many different parameters: battery voltage, oil temp as noted, coolant temp, intake air temp, etc. it can also be programmed to have an audible alert if the coolant temp gets beyond a certain threshold.


there are also two smallish displays at the screen bottom that are also here selectable. I have mine set to the long term fuel trim numbers. But they are so small as to be useless when driving.

the reference made to the other recent topic on the cooler lines is relevant. There is some concern by hydraulic line repair and manufacturing shops that I’ve spoken with regarding the re-crimping of the original aluminum line ends. This does stretch the metal a
2nd time. Which these experienced people cautioned me against doing.


Something to be considered.

Z

 

I have two comments:
my 2005 xk8, man 3/04 does have an oil cooler

my aftermarket display (zrays type) 'failed' in short time but I pulled it apart and repaired a broken trace strip on the circuit board...the crack location was very close the the area where one would plug in the cable. I assume the board flexes a little too much and that led to the crack.
wj

 

Mine was made 4/04. I think I read somewhere that all 4.2 engines had oil coolers.

Jack