MoneyFunnel is seeming to have deep seated oil pressure issues where it drops to 0 hot at stop lights. I can compensate in the usual ways, but the idea with buying this car was for the wife to drive as her toy. I have come upon a 97 xj6 and am wondering -in a simple yes or no way- if I could swap the entire motor and its ecu into mine. I would also consider swapping just the block, but if I read the relevant posts right I think the AJ16 does not have a distributor....
As I say, simple answers are fine. If it Can be done, I Will figure it out. if not, that's ok, but I don't need the frustration. thanks all!

 

Are you using great gobs of oil or is it just the gauge showing Zero? - mine did that too, there was nothing wrong with the motor - it's usually just the oil pressure gauge - a common fault - Just pick one up from Rockauto or somewhere and fit a resistor - Both Jim and my car had the issue and the new sender fixed it.

good luck

Larry

 

Hi Jerry,

I agree with Larry - unless you're losing oil rapidly your problem is just the oil pressure sender on the left side of the block under the intake manifold. It's a very, very common issue on the XJ40 and is due either to failure of the sender itself, or oil contamination of the sender's electrical connector or the sender's threads where it screws into the block.

The sender electrical connection is by just one wire, with the ground part of the circuit passing through the engine block and ground strap, so oil on the sender's threads interrupt the ground path. Between our '88 and '93, I have replaced the sender four times, and after some period of time the dash gauge has once again begun showing no pressure at idle or when stopped at lights.

If the sender weren't so inaccessible, I would suggest removing it, cleaning the threads and electrical connector, and seeing if that solves your problem. But to do the job without detaching the intake manifold from the cylinder head, you have to remove parts of the air intake plumbing and then work blind with a crows-foot wrench, bending over the fender and working by feel under the manifold. It's challenging even if you have a good idea of where the sender is, but it's doable.

I admit that I'm tired of doing it and when I finally get around to it, I'm going to figure out what resistance centers the needle on the gauge and just wire a resistor from the sender's harness wire to ground and be done with it. In 20 years of XJ40 ownership and forum activity, I've never heard of an XJ40 actually suffering from low oil pressure, so I'm willing to risk it, especially since I do check the oil on a relatively frequent basis.

All that to say, your wife is at little to no risk of engine failure due to low oil pressure despite the reading on the gauge.

Regarding the idea of swapping an AJ16 into an XJ40, it might be possible, but the X300 electrics are far more complex (OBDII vs. OBDI), so I don't think it would be as "simple" as just swapping the engine and ECM, especially since the EMS is completely different from the XJ40 (Lucas/GEMS vs. Lucas/Bosch). The AJ16 is a more modern distributorless coil-on-plug design with knock sensors and a camshaft position sensor in addition to the crank sensor. The transmission in the X300 is the same electronically-controlled ZF 4HP24 as in many XJ40s, but the TCMs are different to interface with the new EMS and comply with OBDII.

How bad is the '97 X300? If the price is right, why not just add it to your collection?

Cheers,

Don

 

OK. Thanks for the "it wouldn't be that simple." I suspected as much. The guy has it listed on craigslist, it is in Portage Indiana. We looked at the car last night at dusk. It looked nice- at dusk. He wants $1500, and says It needs a left rear wheel bearing- too bad I already used my spare one on MoneyFunnel. It has been sitting outside 18 months and so smells moldy. It has been smoked in. On the plus the tires are near new. Planning to go see it in light today, but as I wont bother using the motor it seems.... an unproductive use of the money and space to buy the whole car. I may just buy the wheels and tires since my wheels and tires aren't very nice and I don't have a spare for MoneyFunnel.
My oil pressure is fine on cold start- almost midway. I drive about 6 miles to work on country roads and in light traffic, in that time it gets hot enough that the light comes on at idle in gear. It does burn some oil, enough to smell in the garage while its running but not enough to see in the mirror and there are no more large leaks. Believe me I hope the sender is the problem. Rogers pressure drops some when its hot, but not that much. I do think that the sender is the problem there and haven't worried about it. But as for moneyFunnel, it seems like there is that almost perceptible change in the idle when the oil drops- like a bit more hollow sound. Maybe its psychological. or as I saw in the threads I was looking at last night- I need a new Brian in my cranium.
Again Thanks for the input.

 

Those are the exact symptoms we had Jerry, change the sender and fill her up with some GTX 20/50 and a Wix filter and you'll be golden.

Larry

 

Yup,+ one on the sender idea.See the thread,"oil pressure sender",hook up a guage and know for sure!

Cheers,Jim.

 

I hear and understand. I promise I will try 2 senders on 2 cars. Thanks!
I looked at yet another xj6- a 93 that I was hoping would yield many more parts 'for me' than a 97. It was a basket case- everything I wanted or could use was already used up- so I took a pass on it, then drove over to the 97 unannounced and asked if he still wanted 500 for the "new" tires and wheels. Bought those and arranged to pick up the remains when hes done with it for under $200- as he put it, the price of scrap. I plan to try to part it to the forum once I get it, but we shall see. All in all a pretty good day I'd say. And again, Thanks for your input.