Help, again, so far you guys helped me fix everything on this car you guys are great Thanks. So just when i thought everything was all good, no more check engine light everything works the way it should, i started it up to drive to work this morning, and half way down the road the oil gage goes to 0, the light comes on, and the message says low oil pressure, then it shot back up to normal it went back and fourth until the motor got warmer and now its normal, are these motors popular for bad oil pumps or am i looking at just a bad oil pressure switch? Also i swear i hear a little bit of noise coming out of the left cam cover, but only cold and only when you race the motor, i just installed all new chains and tensioners for the primary and secondary, as they were wiped out, any help or point me in the right direction, again, would be very great Thanks, Chris

 

I was going to post much the same issue this afternoon. After sitting for a week my car was very slow to get oil pressure up this morning. Maybe 20 plus seconds. I have seen that before on cold mornings and it was in the 20's today but not anything close to this length of time. I'm wondering if all the oil drained out of the filter is why the delay. Do these filters have a back flow valve?

After pressure got up everything was fine.

 

yes its like it was air bound, and fine after it warmed, but for almost 5 full mins it was going down to 0 the up to half when it normally reads, is there a check valve in the pump maybe? did yours go up and down or just took longer then normal to come up?

 

Just longer than normal and it has 10w30 full synthetic oil. Sorta scary seeing it run for 20 seconds with no oil pressure.

 

I know of only two times when the pressure gauge would fluctuate, once on my car and the other on one of the forums. Changed the pressure sending unit and all was fixed. With the noise / rattle You should look at the viscosity of the oil you are using and consider what is best for your car based on the local temperature. This might help http://www.bobistheoilguy.com/cms/index.php I hope it is nothing major.

 

Thanks, Great article on motor oils, i will try a new sender unit, and change to full synthetic with a lower viscosity, and let you guys know what happens. Thanks...

 

I agree,it is the sending unit.Changing to a different weight will not have a noticeable effect.Change the sending unit first and see if that takes care of your problem.

 

Ok Thanks, i have one coming tomorrow from Rock Auto, and i picked up some 5W/30 full synthetic today, the car been setting for 2 days come tomorrow, i will put in the sender first, try it for the gage fluctuating problem... i will let you know...

 

I put a new sender in tonight and changed the oil to full synthetic, guess what, same problem, it went up to half gage, gave it a little gas when down to 0 then back up, turned the steering wheel when down to 0, although that may have just been a fluke, the motor is quit through all this but i don;t want to run it, any ideas, i know i have to screw in a mechanical test gage to verify, do the gages have a problem??

 

I do know of a few instrument panels that have had problems but the only way to know is a process of elimination. You should get a maniacal gauge installed and see what it comes up with. I do know on my car the oil pressure sensor was changed and with the engine at idle it indicated nearly no oil pressure, I would race the engine and it would go to normal pressure. They (Jaguar) replaced the sensor with what they said was the correct one and it registered properly. I am providing a link to a shop that may answer your questions on the gauge http://www.modulemaster.com/en/servi...t_clusters.php I would recommend not running the engine until you have the gauge on and verify true oil pressure.

I need additional info on this - Oil pressure Sensor - Installed at the right front of the structural sump, the oil pressure switch connects a ground input to the instrument cluster when oil pressure is present. This switch operates at a pressure of 0.15 to 0.41 bar (2.2 to 5.9 psi). Engine Oil Pressure - Note: An integral pressure relief valve regulates pump pressure to a maximum of 4.5 bar (65.25 psi).

 

Gus, yes it is a 1997 with 130,000 mi. yes the switch just in front of the filter, it does the same exact thing as the old switch, i also changed to full synthetic and install another premium oil filter, i rechecked it tonight, start the care 15 to 20 seconds the gage to to a half, then all of a sudden goes to 0 with the light on and a message saying low oil pressure, it only stays at 0 for about 2 to 4 seconds then goes back up, but after the engine runs or idles for about 5 mins or so its fine, it will never do it once warmed up, car sits overnight, it does the same thing, but only when below 40 deg it seems, its 19 deg. now, it seems worse when real cold out. Tomorrow i will screw in a mechanical gage and let you guys know... Thanks

 

did you sort this out?
if not.....

when you changed your tensioners and chains did you get all the pieces out or did any drop into the sump...iv had this same problem before and a piece of the tensioner plastic was getting pushed into the pick up gallery for the oil pressure switch...

drain your oil and take off the sump and check for pieces in there...

 

It is sounding more and more like the switch. I would have thought that there would have been two switches. One for LOW oil pressure, and one to regulate the guage. I would have also thought the LOW oil switch would have shut down the car upon detection of really low pressure.

 

Sorry it took so long to reply, i was away. Yes i changed the switch and went to full Synthetic 5W 30 oil, the gage now takes about 5 to 10 sec to come up to normal from 0, the thing is when it is very cold and i don't put the car in the garage and its like under 20 deg out, it takes about 20 sec to come up and then it with drop to 0 and back up a couple of times, this goes on for about a minute or so, but only when it is very cold, its a lot better, and yes i was very careful to get all the pieces out from the broken up tensioners, any other ideas?

 

Where is the oil sending unit on my 97 xk8. I would like to replace it

 

Threaded into the oil filter housing.
RJ___________
97 XK8 86K mi

 

Synthetic Oil For Engines.....That have imagined it..