Hello, I LIVE UP IN VERMONT, AND HAVE ALWAYS DREAMED OF OWNING A JAGUAR MY WIFE LOVES THEM TOO, SO WE HAVE BEEN LOOKING, AND RESEARCHING. I FOUND THIS WONDERFUL FORUM, AND FINALLY MADE THE PLUNGE. just bought an 96 xjr, 86000 miles. It needs some attention. Looks like i'm gonna be changing the water pump, need a new washer fluid bottle and the steering rack is leaking a little. But the most serious pressing problem is the lack of oil pressure. I posted about this in the x300 forum, but no reply as of yet. I put a mechanical gauge on it to check it for real. At first it jumped all over, from 25 to 75 back to 45 to 25... Etc. Then i did an engine flush, and drained everything. Replaced with synthetic. Now there is no oil pressure at idle at all, and even with revs only about 20. What should i do? Oh and during the engine flush, it idled at a constant 45 lbs for the whole 20 minutes! I'm baffled. I hope someone can give me some direction.......

 

Hello and welcome,

If you've had no response form the X300 section yet, you must be getting desparate.

I had an X300 a few years ago and ran it to 120K miles with no engine problems. You should get plenty of miles out of yours once the initial problems are sorted.

Jaguar oil pressure gauges are notorious for inaccuracy and generally read normal until the pressure has dropped right off. However, you've by-passed this issue by putting on an external gauge.

I always use synthetic but if you change to this in an engine with some miles under it's belt which has always been run on ordinary mineral oil, you can dislodge quite a bit of c**p. The flushing oil will certainly have done this.

As important as changing the oil twice, did you also change the filter? It could be blocked and causing the fluctuating pressure. The Jaguar filters have a non-return valve built in so the oil doesn't drain back out into the oil pan when they stand to ensure oil pressure builds up quickly on starting.

Graham

 

Thanks so much Graham for replying. Yes, external gauge, and I did change the filter with a premium wix filter, filled with 10/30 synthetic I also added a single quart of synthetic lucas oil stabilizer. could that be the problem? it quiets right down once the pressure builds, but now that it has been flushed its tough to get the pressure up above 20lbs. do you think I should change the oil and filter again? I wonder it a pressure relief valve may be stuck open. before the flush the pressure was all over the place, but constant during the flush, now lacking after. this seems so strange to me. I sure appreciate any input i can get. I love this car, and I've hardly driven it! I hope I don't need to drop the pan, (from what I read the pick up screen may be plugged) It looks like a days work. I'm not sure where I would start with that job! thanks again... Mike

 

Mike,

Much as I'm a fan of synthetic, you may be better to go with a heavier grade of mineral oil until this pressure issue is solved. Jaguar literature advises against additives and to stick with one of their recommended oils.

It's not burning oil at all and no major leaks?

If pressure was originally OK and also good during the flush, you've likely got one or more of the following:

partially blocked filter
badly seating relief valve
partially blocked pickup screen
faulty oil pump

Dropping the pan is a major job as the engine has to be supported from above and the front suspension removed:



I did this to replace a cracked pan. It can be done single handed but it took me two days.

Graham

 

Wintookit,

There are many things that could be the cause of low oil pressure, from a crook oil pump or relief valve, to a buggered main bearing. The first thing I'd suggest is, don't drive the car anywhere until the cause is sorted. Low oil pressure means that under load, the bearings will not be getting enough lubrication, and you will cause some wear to the mains & big ends. X300 engines generally do quite big mileages, but if you run any engine with low oil pressure, everything can start to wear out pretty quickly. If you wish, send me an email to remind me, and I'll ask my partner on Monday morning if he has any clues. He's the mechanic in our business and is more experienced than I. Having said that, I'd agree with GGG that it is more likely to be one of those items he suggested than a main. But I wouldn't recommend trying to solve the problem using heavier oil. That would only mask the real problem, and may cause you a great deal more unhappiness further down the track.

As for the water pump, when you do that, also check your thermostat housing. The car is at the right miles for the bakelite one to be warping. Replace it with an aluminium one (non genuine), not another bakelite Jaguar Part.

Cheers,

Languid

 

Ouch.. great advice above. You might try doing a compression test to see what kind of wear the engine may have. Barring any burning oil, or knocks... Try the simple things above (filter, another flush)... Then cross your fingers and trade out the oil pump. My 2 cents. MC

 

Welcome to the forum,

Good advice above, thanks guys.

You should add your car details to your signature to help others to help you.

 

THE PLOT THICKENS..... SO i GOT ANOTHER WIX FILTER, DECIDED TO TAKE THE OTHER ONE OUT TO SEE IF IT MAY BE FILLED WITH GOO. BECAUSE OF THE SUPERCHARGER BEING IN THE WAY, IT HAS TO BE REMOVED FROM THE BOTTOM. lAST TIME IT CAUGHT HALF WAY DOWN TIPPED ONTO ITS SIDE AND DUMPED ALL UP MY ARM, THIS TIME I WAS VERY CAREFUL NOT TO SPILL ANY, AND WHEN I GOT TI DOWN... IT WAS EMPTY. MAYBE A FEW DROPS WERE IN IT BUT SHOULD HAVE BEEN AT LEAST HALF FULL, RIGHT? GEES, SO IT SEEMS LIKE AFTER THE FLUSH, THE FILTER GOT HARDLY ANY OIL. QUESTION IS, IF THE PRESSURE RELIEF VALVE IS SOMEHOW STUCK OPEN, WOULD THE PUMP JUST NOT PUMP AT ALL? OR SHOULD IT STILL CIRCULATE OIL THROUGH THE SYSTEM, AND JUST NOT PRESSURIZE? NOW IM GETTING MENTALLY PREPARED TO DROP THE PAN ):

 

Not good. Sounds like your pump has failed-- engine is not getting lubrication!! MC

 

welcome wizard! your caps are on

 

Welcome wizard to the forums. Looks like you have some good ideas going on from fellow members.

Can we take this discussion over to the proper x300 section.

Enjoy all the site has to offer!

 

Welcome Wizard. Sorry, missed your post on the x300 section. C'mon back over....we really are a friendly and (normally) responsive bunch. Not very common for the AJ16 to be sans oil pressure, though. Dry filter sounds troublesome...

 

Mike,

tried to send to your email address, but it 'bounced'.

Re your last question: Don't we all?

No, I doubt that you'll wear out your welcome, the Forum bunch are pretty forgiving of just about anything.

It would seem to me that you have been 'conned' by the vendor of the car.
The problem now is, what to do about it.

A compression test is not a bad idea, as I will give you an indication of the general state of health of the engine. It's been a long time since I did a compression test on an engine, and because different markets have different compression ratios but I'd guess that you should get figures around 150 (min, worn) to 200 psi. Most important is that they should all be around the same and within about 5psi overall. To identify whether low compression is caused by valves or rings, you test the cylinder, put a couple of good squirts of oil into it, and immediately retest. If the compression comes up, it's the rings. If it stays the same, it's a valve.

But part of the problem is that you don't know how long the problem existed before you bought the car, nor how far it has been driven with the oil pressure down. The bit about the drop when cornering would indicate that the pump wasn't picking up enough oil from the pan which could be due to not enough oil in the engine, blockage in the pick up (coarse) filter, or a crook pump. The lack of oil in the filter means that there is no point in trying a different oil, as the pump is clearly not working properly for whatever reason.

Regardless, I'm afraid you are going to have to drop the sump. Once you have done that, I'd recommend that you pull at least a couple of big end bearings & mains to see what condition they are in. There is a better than even chance that they are badly worn. If the compressions are not good, and the bearings are worn or the crank journals scoured, you are faced with either rebuilding that engine, or buying a replacement. There would be little point in doing a 'patch up' job by replacing bearing shells unless the compressions are good & the journals smooth & clean, as you would more than likely end up stripping the motor back down in the relatively near future.

There is another item to be checked before you make the decision: the car is from the 'Nikasil' era, and if the engine is the original it has Nikasil Bore linings. Poor compression figures can be due to the top of the bore having eroded when the fuels used are not very low in sulphur. The miles on the clock are also in the failure range. Jaguar stopped using the Nikasil about April 2000, but many of the engines replaced under warranty did still get Nikasil bored engines as replacements. (The bean counters weren't going to throw them away, were they. And where better than to use them than as warranty replacements where, when they failed the cars would be out of warranty). My understanding is that they cannot be satisfactorily rebuilt.
Send me your engine number, and I'll be able to identify it.

If you do decide to repair the engine, yes to timing chain tensioners, (be careful, you have to take the front timing covers off, & there are no marks to align the camshafts up as the engines are variable valve timing (unless supercharged). Replace the tensioners with Ford Lincoln ones. And check the thermostat housing as well. If it's Bakelite, replace it with an aluminium aftermarket one, not a 'genuine' from Jaguar. Look up Brutal or Tarhealcracker on this Forum for where & what to buy for both in the USA.

It could be worse, you might have paid out more than $2k and still been conned. Unfortunately it's ****** like the one who sold you the car that give many Marques a bad name. Pity we live in an over-regulated World - when I was a wee kid, we didn't have lambing rings, we used a small knife with a very sharp hook curved blade, and a cauterising iron.

Cheers, and sorry to bear such god-awful news,

Languid

 

Languid? Nikasil in X300's? First I've heard of it. Thought that was introduced with the V-8?
As to thermostats, of course every rule has its exceptions, but generally, I-6's stick open (no heat, rich fueling) whilst V-8's stick closed (overheating and worse for Nikasil than the sulfer!)

Wizard, I bumped your post over in X300 and linked back to this one so everyone can get the additional details from here. Hopefully you'll get sorted out soon. Languid has laid out a sound troubleshooting plan...though I do wonder if perhaps he quaffed a pint o' ale before composing those last couple of paragraphs...sounds like maybe your "XJR" reference threw him off and he went all X308 on you.

 

So there ia still some hope. I will continue this on the x 300 thread, thanks again..Mike

 

aholbro1,

You are right, I did get thrown by the XJR reference, and forgot that they did start with the I6; a long rough week & and enough unwooded chardonnay's to misread. I should have gone to bed first, and started the reply after, in stead of the other way around!
Sorry Mike, but the rest still stands. To run the process of elimination, you have to have enough facts to make the judgement, and I don't know of any shortcuts. Until you know the state of the inside of the engine, there is little point in fiddling around the edges.

Cheers,

Languid

 

No worries Languid, I'm still hoping for the best. The car starts right up, doesn't smoke, and makes no funny noises when the pressure is actually true. I will end this thread here, and continue the one in the X300/XJR section. Thanks so much for your consideration and advice. Mike