88 xjs v12 trouble
 

Hi there
Jag in 15 min over heats oil pressure drops to zero starts runs drives and 10 to 15 min car goes nuts OIL ON THE DIP STICK VERY CLEAN BUT WHEN I REMOVED THE OIL COOLER RAD THERE SEAMED TO BE NO OIL IN RAD AND WHAT WAS COMING OUT OF THE LINES WAS BLACK OLD AND ONLY A LITTLE BIT DRAPED OUT OF THE LINES WHEN I REMOVED COOLER RAD CLEAN ON DIP STICK BLACK DIRTY AT RAD LINE ONLY 90 K ON THE CAR SO I'M REALLY STUMPED CAR BOILS OVER AND DIRT OIL VERSES CLEAN ON STICK MAN SOMEONE HAS TO KNOW I HOPE I'VE HAD THE CAR 4 years still trying to fix it and every year I get to drive it 15 mins so got at least an hours enjouyment at this point I'm hoping to get 16 or maybe 17 min next year lol even at that I know I'm asking to much so please if u can help my phone number is 9022975469 nova Scotia Canada thank u and all the best cec

You have to find out why the oil is not circulating. I suggest you remove the plugs, remove the oil filter, turn over the car on the starter and see if oil roars out of the filter head fitting. If so pump working, if not not. If working, then the oil cooler lines must be checked by first blowing them out with compressed air. They may be blocked but this would not prevent oil circulating as there should be a bypass system. If that is Ok then it gets harder as the engine main oil galleries are next, and they could, i suppose, be blocked. It would also be worth removing the oil filter head after this set of tests to see if there is a visible blockage in or behind it.
Post again with results if you get to this point.


Overheating: first remove the rad and get it checked/rebuilt/replaced if necessary. Also clean all the rubbish out of its fins which WILL be there. Ditto the aircon condenser and oil cooler. Change the thermostats and check the water pump belt is tight enough. Also check the pump is pumping.


Lack of oil pressure and overheating is eventual death to any v12 (or any engine for that matter), so this has to be tackled carefully, sequentially and systematically. Any other approach is pointless.

To greg from cec
 

Thank buddy well said will check all the points u said it is weird though both the oil and cooling system out of control the oil ceding unit on top does that make the oil flow through the car as it suppost to if that is wore out would that make oil not cerculate and are there censors that could be bad that would make these things go wrong buddy

Radiator blockage due to debris, leaves, trash, etc... getting caught between A/C condenser and radiator is very common. Those two are fitted very closely and spoiler forces everything low on the road up there. One up longed in there is no room or forcing function to remove it. Best to take the hood off and using a portable power washer or a hose with a nozzle direct the water spray from the top down to remove the garbage build up between the two components. Getting all that stuff out from between them allows for proper air flow over radiator to allow it to cool as designed. You may have other issues as noted but this is an essential thing to do no matter what.

Firstly, Welcome to the Forum.

Please do an Intro in the New Members Area when time permits.

Not knowing where in the world you and the car are, I will generalise.

I reckon you have TWO (2) distinct issues.

Your have had the car for 4 years, yes.

What servicing of the cooling system has been done in that time???. The system is now 30 years old, and needs some serious catch up work.

Depending on the market the car is in, it "may" have the ByPass oil cooler system which does have a lot of Black oil building up in that cooler core. That cooler is NOT drained when the engine oil is drained, so it simply sits there, NOT good, but thats the way it is. I looked at a drain plug on mine a loooooong time ago, NAH, too hard. Still OK and no ill effects. The "Full Flow" system is the same, still not drained when the engine oil is drained.

Oil pump etc issues on a V12 are able to be counted on less that one hand, the pump is huge, and strong. Only weak spot is the o/rings on the pipe work in the sump, and that is not a service thing, sorted when the engine is out for any reason.

The thermostat are well documented to jam shut, and you have 2 of them.

The radiator issues have been discussed well above.

Once you give us a heads up of what has been done in the last 4 years we will all have a much clearer picture of what may be wrong.

DO NOT stress, its a Jag, and a V12, and its is strong.
DO NOT drive it AT ALL, until the overheating is sorted.
Overheat a V12 badly, and you will need your countries National Debt $$ to repair it, fact.

Cecil from Canada
 

I'm in Nova Scotia Canada with 88 v12 I will do the due dilagence that you nice guys have recommended until then I want to say how great full I am for your time thankyou