Hello, and thank you for this wonderful forum. I probably wouldn't have bought a Jag without this resource. I just bought a 96 XJR. everything looked good. although very little recent history available, it only has 86000 miles. there was a slight noise at about 2000 rpm coming from the supercharger area, but I think that it is still working since I can here that supercharger hi speed whine. just a rattling sound. the engine is smooth and the oil pressure looked good both times that I went to look at the car. drove home two hours, she ran great, loafed along at 70mph and 2000 rpms. very quiet. and good power. the next morning...... upon start up, no oil pressure. and some pretty nasty rapping at the top of the engine..maybe because it was starving for oil i felt sick...after a few minutes of idling the pressure came up, and most of the noise quieted down. now Im terrified that I may need(among other things) a new oil pump..I've decided to do an amsoil engine flush, and fill it back up with synthetic 10/40 amsoil. do you thing this will help? or should I just be prepared to shell out the money that I thpought I was saving by getting this car for $2000? everything else on the car appears to be okay, well, except the radio display is only half there. But that I can get by with, since up here in vermont, we have few radio stations... and even fewer Jag mechanics.. WHAT HAVE I DONE! please advise

 

Bump!

Guys! We let a new member down! He had to retreat into the new-member section to get some answers - further detail over there:

https://www.jaguarforums.com/forum/n...-please-68031/

Wizard, what was ambient temp on your cold-start? They will make a bit of noise on a very cold morning.

 

Well it was around 35 degrees outside that morning. but if anyone has read my posts, they will know that at this point I'm losing hope. I probably carried a thread too long in the new member area, this is my first forum, and I guess I may not be following proper etiquette.
Hey everyone, thanks so much for your advice, I really don't understand how a mechanical pump could go bad like this but it seems like that may be the case.
I'll go over the history briefly. so I bought this car last week. Its beautiful and clean, doesn't really look mistreated or neglected...looked at it twice, it was a two hour drive from my home. I Did see that it needed a water pump and the steering rack had a small leak,and the engine made a slight rattling noise at around 2000 rpm. but we negotiated the price down to $2000 which seemed like an okay deal. drove it home, no issues seemed to go well, no smoke, good power, good oil pressure on the electronic gauge. the water pump didn't leak at all (which was my main concern) the engine ran just under center on temp. gauge. The next morning, temp. around 35 F. there was no oil pressure on start up. and after about 1 minute of idling it finally came up, but not much. I of course became very concerned, pulled it into our garage, bought an external mechanical gauge and the reading was bizarre. first it was high, like 75lbs, then it would drop down to say 20lbs, then back to 40 then 30 then 60 etc. I decided to do the engine flush, and the entire time that it idled during the flush the pressure was a constant 40 or 45. not fluctuating. I figured "good sign" then I drained it all out. It was quite black (it had looked clean on the stick earlier, so I know the treatment did some cleaning) and still pretty heavy. replaced it with 7 quarts of 10/40 synthetic, and one quart of lucas oil stabilizer. after that, I figured the pressure would improve. It did not. In fact there was no pressure at all... even with revs the pressure gets to maybe 20 or 25lbs. disgusted and worried, I gave up for the evening... this morning I decided that maybe there was still some goo in the engine, and it got caught up in the filter. so I went into town, got another premium wix filter, but when I removed the other one, ever so carefully, it was EMPTY. there was less than 1/8 of a cup of oil in the filter. now I don't understand how the pump could have failed between the time I turned the car off after the flush, and the time that I started the car after refilling. I am baffled but preparing myself now for the seemingly inevitable and difficult task of dropping the pan. I suppose I could pay someone else to do it, but that takes money, and right now I have more time than money! so any advice would be helpful.. Reaching out. THANKS IN ADVANCE! Mike

 

Sometimes the oil pump can "lose prime". Not very often, but often enough that the technical section of the Fram catalogue has an article about it directed at lube shops.

The most common cause is an extended interval between drain and fill. Thinning the oil with flush agents wouldn't help matters.

The fix involves two things. Filling the oil filter where possible. But the important step is to manually fill the oil passage between the oil filter adapter and the oil pump using a manual oil squirt can. This primes the pump again. They point out that once a pump loses prime, no amount of cranking will fix it without repriming.

Of course, the above is just one possibility.

The fluctuating cold oil pressures "feels" like a sticking relief valve or a bum pump drive.

 

Wow, this gives me hope. it seems entirely plausible since the car is on jack stands( leaning back) and because I waited about 1/2 hour to refill. it just seemed to drip for a long time. so... today I will put the back half of the car on stands to level it off, then devise a way to refill that tube. Thank you soooo much, for your excellent info. I feel like it it the only explaination to at least getting some pressure back. I will keep you all postedMike

 

A half hour should not be a problem. However, if it puts a smile on your face ...

Please be sure to research which is the inlet and outlet at the filter face. You want to fill the passage between filter and the oil pump. The usual method is one of those oil cans with a squirt pump and trigger.

 

This morning I took a 2 foot length of clear plastic tubing, and fished it into th center hole on the oil filter housing, it went in about two inches without a problem. fished the other end up into the engine compartment and hooked a very small funnel to it, then proceeded to gravity feed the oil into the funnel. it was a little slow, so I helped it along with a large syringe. after about 1/3 quart it was full and dripping. then I filled the filter to about 1/2 full, and screwed it back into place. started the car and IT WORKED! the pump needed to be primed. thanks so much for that good advice. sad news is that the pressure still jumps around. at idle it drops to almost zero psi but with revs up to around 2000rpm it climbs to around 40 50 even 75psi then drops down lower, not zero though unless its idling. I'm thinking of doing another flush, and replacing the oil with 10w/30 mineral oil. this will probably not change anything, but it may be worth the effort.
QUESTION: I think I may have the original upper timing chain tensioner on the car. wondering if its possible that it is badly warn and causing the oil pressure to drop and rise. just a thought. It looks original because its kinda grimy but how would I know for sure, since as I understand it, the updated one cannot be removed without removing the camshaft cover? Thanks, Mike

 

I think I answered my own question about the tensioner. Looking into the TSB section of the large file area, I see that they look different from the outside of the engine. mine looks more like the new style than the old style. Mike

 

Glad it worked out for you somewhat... Maybe your relief valve is sticking, so another flush isn't going to hurt you. Generally, your pressure will go down because the oil pump itself wears out, or the journals (bearings) get worn and let too much oil blow by because of the sloppy tolerance. What was the oil like that your originally took out? Does the crankcase look grimy and sludgy or pretty clean. The PO's care and feeding of the engine probably will answer your quesitons. Although it masks the problem if the engine is worn-- I would try stepping up the oil to a thicker grade. Maybe 10-40 or 20-50 and see what happens. It isn't going to hurt anything. Short of dropping the pan and looking at the intake screen, and making sure the oil pump hasn't worked loose, or worn out... not much you can do. Good luck.. Mark

 

Today, I decided to pull the camshaft cover, and see what I could see. Not much, except to find out that two of the bolts were stripped and already loose, and one was broken. no leaks though, the rubber gasket is fine. I don't know why anyone would want to tighten them so tight as to strip them. But it tells me that the car HAS probably been neglected and the victim of poor workmanship. I also checked the plugs, and upon removing the coils, I noticed that 5 of them had broken rubber boots with electrical tape on them. are these boots replaceable? or do I need to buy the entire coil? the plugs looked so-so kind of black around the edges, but cleaner and more normal looking at the electrode. they seemed gapped a little wide too, but I just put them back in for now. I need to get a compression tester, and I will get new plugs after that. The oil that I took out was quite black after the first flush. I'm going to get some 20-50 tomorrow and flush it out once more and try the heavier oil. That will either bring the pressure up If the bearings are warn, or down if the strainer is clogged. It will also give me another chance to confirm that the pressure was steady and good during the flush, I'll see if that happens again! On a positive note, I found a loose bolt on the heat shield covering the exhaust manifold. It was causing some of the rattling noise that I mentioned before. although I still hear something going on either in the front top of the engine or the supercharger. maybe the upper chain slapping around, but it makes no noise except certain rpm's. don't know what this would sound like. A steth-o-stick isn't helping me much. hope my posts aren't too long. I just want to be detailed... till next time..Mike

 

Hey Mike-- Unfortunately, I am not an expert on THIS engine. I can only chime in in a general fashion. As long as you understand that. If the engine has been neglected, most likely you will hear top end (tappet) noise as the top end could be oil starved in the past. If that isn't the case, you may have bearing wear, or rod knock. Best way to hear it (if it isn't obvious)... is to put the car in gear with the brake on and give it some throttle (load) against the brake. Compression test is a good idea too to try to test the engine's health. Being that the oil was cruddy, I would think the impurities may have worn the gears in the oil pump... this is a bit evident to me since it lost prime (and couldn't suck well). If everything else checks out-- I would personally pull the pan, and replace the oil pump and pickup screen purely as general principle. Anything bigger than this becomes BIG BUCKS. Hope this helps. MC

 

Mike,

I tried Valvoline 20w-50 Racing oil last winter in mine and when temp was below 30 it made a pretty good racket on start-up. Not sure what you get in Vermont but it could be an issue. I finally settled on Shell's Rotella T6 5w-40 synthetic to commonize with my Excursion. "Brutal" is a highly-regarded tech aboard here and I believe he has posted about running a bit of ATF in the crankcase for a number of miles before you change the oil as a flush. Sorry I don't know the time/distance and I think the qty was a quart, but really unsure about that, too. You may want to look into it. Also, Brutal recommends a dose of Engine Restore for these mills and says he has seen improvement from it first-hand. You may want to search through his posts...though I'm sure it's a tall-order...he has to be in the thousands if not tens of thousands.

 

For the ATF, it was a quart.

At this time, an additional oil change might be a good thing. But, a flush might not be a good thing because it thins the oil. That might lead to another priming session.

 

I changed the oil out to 20/50 oil. it made no significant difference, actually lower pressure and not as jumpy, but near zero at idle.. so... I'm digging in. Many thanks to GGG for sending fantastic detailed photos and description of this pan removal job. I'll let you all know what I find....Mike

 

Hey everyone, looks like the problem is a broken oil pick up tube. This explains a lot.. but leaves me with a few questions too. like Why did Jaguar make the pick up tube from plastic? Still checking other parts of the engine, It was actually not all that difficult getting the suspension off, Just nuts and bolts with good instructions...Mike

 

Hello all, just thought I would wrap up this thread by letting you know that After replacing the broken pick up tube, and re assembling the car, It runs beautifully with great oil pressure, and no nasty engine noises. I took it out today and it went really well. I't's got a few other quirks to deal with(for another thread) but the car wonderful. I love it so much I really want to sell my BMW and buy another x300 XJR. (this one is officially my wife's car...)

 

Outstanding! Glad we could help, and it wasn't a bigger issue. Good job! MC

 

Hi Can you repost the photos? many thanks and glad you got your issue resolved, so yoru cat is purring again, congratulations and enjoy your ride.

 

Well done and glad you got sorted. Another thumbs up for the best Jaguar Forum on the net!

 

with every oil change i do,i ad 1/3 quart of oil to the filter.this is to prevent dry suck,thats a very bad thing to have happen...steve.