My son left for school this morning & got about 8 miles when it stalled. He checked and added 1 quart of oil, but that didn't resolve low oil pressure. He was within a mile of the shop that's done all my work for the last 25 years or so, and had the wherewithal to pull into the shop.

There was no oil puddle where it was parked, but there was a 2-3" wide trail of oil up the driveway & onto the street. So it was throwing oil only when running.

Don't know exactly what the problem is yet, but the fact that it still starts is a good omen.

 

Hope it did not run too long with low oil. Sounds like if it only leaks while running that it is a function of oil pressure. Can you tell that it was on side or the other or right in middle of car. Of course, where it leaks does not necessarily mean where the leak is coming from. Since it is easy, I would first of all check the oil filter to make sure that it has not come loose along with connections around it. It may also be that the valve cover gasket has spring a leak. Mine did that once though it did not leak as fast as you indicate. Oil could get on wires and perhaps cause stalling. Other than that, I suggest cleaning it as well as possible, fill up with oil and then crank it while looking for leaks underneath and looking for possiblilities. BTW, it could also be the oil pressure sensor. Good luck!

 

I reckon oil pressure sender, mounted on top of the oil filter housing, and easy to get at, NOT. They do spring a leak, and spray oil on the TPS, and its plug. Also when it fails the oil pressure readings are all WRONG.

The loose oil filter, maybe.

 

Thanx cu & Grant. I just spoke with the shop. From a preliminary inspection, it appears to be coming from the vicinity of the oil filter, which shows signs of damage. He suggested it may be a pressure relief valve. He'll know better later today, once he gets it into the garage. I did give him the info both of you supplied, and he appreciates it. I'll post what he finds.

As I said, I've been using this mechanic for more than 25 years, even worked for him for a few years, so there's a lot of trust and confidence in his skills.

I'm guessing a little here, because I wasn't driving it at the time. I think the oil pressure readings were more or less accurate. Once aware of a problem, my son said the pressure gauge was lower than normal, otherwise was running normally & didn't get hot. Fortunately, once he recognized the problem, he only drove about 1 mile (in a strictly enforced 30mph zone) to the shop. And he did add oil for that mile.

Yes, I'm trying to be optimistic here. Anyhow, thanx again!!

 

Hope it turns out well for you with an easy fix and no engine damage. Glad your son was paying attention to the gauges and responded properly.

I am curious about the damage to the oil filter. A pic would be nice. Does your mechanic think there was TOO much oil pressure so that it blew the oil filter? Never heard of such but do not have any idea how much pressure an oil filter can actually withstand.

 

I just got off the phone with him. They put on a new filter, started the engine & the filter swelled up like a balloon. I haven't seen either filter to even describe what the damage was. Donnie (my mechanic) feels certain it's the pressure relief valve stuck, or some gunk stuck in it. He's seen this type of problem on other cars, just not a Jag before.

I purchased the service manual on CD from Jaguar a few years ago. According to the manual, to replace the pressure valve, you simply jack up the car, drain SOME of the oil, then remove the valve plug, and the assembly comes out. The diagram wasn't much help. On another page, it looks like the valve is within the oil pump, which requires dropping the sump. I sent the manual to him this morning.

I appreciate your help & concern. I'm optimistic that since it starts and apparently runs normally that no damage has occurred.

 

Mmmmm.

I know that plug in the sump to access the relief valve.

Our 3.6 had it, and it leaked oil.

My 12/95 AJ16 does not have it, that part of the sump is simply a sealed spigot hanging down, no oil leak obviously, but access to the relief valve requires the sump removal, bugga.

I am not aware of any valving in the actual oil filter adaptor on the side of the engine, as with the earlier XK engines.

 

Well, just got the bad news from the shop. No, it doesn't have the plug in the sump for access to the valve, so the sump will have to be dropped. Unfortunately, during the diagnosis, a "rattle" became apparent, which the mechanic believes is the main bearings going bad. His additional point is that SOMETHING must have caused the pressure relief valve to go bad, and he's afraid that it may be metallic shavings from the bearings. He's questioning whether it is wise to spend several hundred dollars removing the sump, etc., only to find out the engine may have reached the end of its service life. I've had excellent service from that car for the 12 years I've owned it. But his suggestion is that it may be better to "jack up the license plate & put a new car under it", rather than spend the amount necessary to put it right.

If anybody has suggestions, I'm open.

Thanx to everyone for your concern and help in this matter.

Ray

 

Grant, I appreciate your input. There is some sort of valving at the oil filter. Unfortunately, cleaning that out didn't solve the issue.

 

Sorry to hear about the bad news for the engine. You don't mention how many miles are on the car but personally if it were mine and the car is still in good mechanical and body condition I would consider a used engine. Pricing for the used engines seems to be reasonable-labor $$ may be the big issue. Always a tough decision!

 

There's 133000 on the car. While there are a few minor issues, it's been real good to us. The only reason I'm hesitant about another engine is the potential longevity, considering the age, not only of the car, but of the replacement engine. I am considering it, though.

 

Mmmmmm.

Very odd at least.

Bottom end failure on ANY Jag engine is a rarity. Not to say in cant/wont happen, but in all the engines I have dealt with over too many years, and some of them have been very sad indeed, the crank and bearings etc have never been "worn out".

Without that access plug, the subframe needs lowering, or the engine near pulled out to get that sump off, HUGE work anyway you look at it.

A used engine, as long as it can be heard running, and all the common sense tests etc done, should give a good many years of service.

What has possibly happened is the valve has "jammed", SHUT, and oil pressure has literally delaminated the bearing, and now you have the fault, as in metal in the oil. I did see this as a demonstration waaaaaay back when doing my engine reconditioning schooling, and 120psi was the damage point in those days. This was easily reached with a standard Chev V8 (283 small block) oil pump with a deliberately jammed relief valve.

 

I'm not aware of any local engines so I could look & listen to their condition. So far, I've found several engines on ebay, ranging from $350 to $750 (with 30-90 day guarantees), and the mechanic quoted $900 for the R&R. That about taps out the overall value of the car as a whole. And that becomes a major factor. I've wanted to get it painted, since the clear coat is about shot on the roof, hood & trunk, but the cost vs. the value has stopped me from doing that.

With your info I'm wondering...did the bottom end failure occur, in part, as a result of restarting it several times to conduct the diagnosis? I can't really say, since I haven't heard it myself.

I've got quite a dilemma here.

 

Im sorry to hear about this, you make a good point about the value of the cars...it is low, but it may work to your advantage if you're in a position to store this one as a parts car and buy another serviceable 40 of the same year.

 

I presume that we are looking at your XJ40 and not the X300, it has not been stated as yet.

What I'm not understanding is that you yourself have still not seen or heard the car running or rattling.

If anyone was telling me I needed a new engine in a running car I would want to at least have a listen to it, if only to satisfy myself that all was lost.

Not saying that your mechanic is not correct but... go have a listen, if you can, otherwise you will always have a doubt.

The top timing chain tensioners can go bad on these cars XJ40, not a major issue, but will cause a rattle, easily cured.

Grant has waaay more experience, but bad main bearings tend to knock loudly rather than rattle, and you say that your oil pressure is high enough to blow up a filter?

Strange.

The harsh reality is that if you do need an engine, then it is all about passion, applies to any old 'classic' car.

The cost of maintenance will always be higher than the value of the car, you do it because you love the car as a hobby and want to keep it.

Snag is, once you start, you almost can't stop.

What do you do when something else needs changing?

Fuel pump R&R = value of car.
Suspension maint' = value of car.
Set of Pirellis = value of car.

And so it goes on.

If it were me and I really loved the car and wanted to keep it as a future classic for high days and holidays, I would look at RUST.

If it is totally rust free, I would consider spending money on mechanicals, but if the rust gremlins have taken hold then that would be it.

Either sell for spares or keep for parts.

If you lived round the corner I would let you have my uncrashed rusty but mechanically very good XJ40 for a few beer tokens. Better still, if yours is unrusty but not running I would buy it off you and drop my engine, box, fuel tank/pump et al into it.

Just a shame that we have a rather large pond between us.

 

Only you can sort the first paragraph.

The second is a tad simpler. I think the valve has jammed, WHY, dunno, and oil pressure has gone AWOL, delaminated a bearing, exploded an oil filter, and who knows whatelse. The starting and running for diagnostics is doubtful to have done any more damage, due ONLY to the fact you have been told the replacement oil filter bulged considerably very quickly, so oil "pressure" is there, as apposed to NO oil pressure and all sorts of damage being created by the lack of that oil.

The dilema is felt, even down here. I had a good shot of JD last night, just because. I would consider the advice already mentioned, get another one, shed this one, sell bits etc to anyone who needs them, and there will be many, and recover the costs that way. I did that long ago with my MK10, and a S2 Daimler, emotion had hold for a "short time", but not too long.

 

Thank you, everyone, for your input.

Richard makes several excellent points regarding decisions. Yes, we are talking about the XJ40, which we've owned for nearly 12 years. Bought it on a lark from an ebay dealer at the same time that I "won" a BMW 735i from him...longish story. It was my wife's "Kitty Kar" which she proudly drove daily until about a year ago. We did maintain it well all that time. Other than paint (no rust) and some interior wood trim, it is in good condition. Fuel pump & associated wiring harness was replaced within the first few months of ownership. Shocks, some suspension bushings and tires replaced within the last year. Never felt bad about the few oddball repairs over the years. I was fully prepared to spend the $5-600 to drop the sump for access to the relief valve, but engine replacement?-not so much. I'm going tomorrow to have an in person tete-a-tete with my mechanic.

The input from Grant & Richard is most helpful.
I'm considering my options. First, do I really need the engine, or just the relief valve repaired? While I trust my mechanic, a personal visit to the shop is in order. Second, I'd probably part it out. That way not only would I recover some of the cost & value, but would help other Jag owners keep theirs in serviceable condition. Third, buy another XJ40 and make one good one out of two. Fourth, sell it whole as a parts car.

Richard-Very sound and rational advice.
Grant-Wise and pragmatic advise.

I appreciate it very much. Grant, thanks for the JD toast. I'll have a Chivis to salute you.

ps. Yes, it is too bad that two very large ponds separate all of us. Could be a fun evening at a pub.

 

Best of luck.

Try to grab a pic or two of that exploded oil filter. I've never seen one. In all my years of tinkering the oil has always found a different method of escaping.

If you can, it might be worth getting a sample of the sump oil and having it tested. If it is full of bits of bearing, this will show.

Of course if it is knocking like a cash for clunkers just before final meltdown, this will also be an indication.

On that subject, if you watch a few Utube vids of XJ40 CfC, you will see just how much these engines want to survive before the bottom end gives up.

At a pinch, I suppose that if you came across and Grant came up I could arrange the beers. Kind of meet in the middle as it were

Hope you have a decent day.

 

Well, I've made an initial decision. After listening to the engine run, I strongly feel that the bottom end isn't at issue. The puzzled look on Donnie's face indicated he felt the same. It is freely throwing oil from the filter, but sounded mostly normal. We've decided to drop the sump, then closely inspect the innards. It started effortlessly, and the only noises I heard (mostly ticking) seemed to me to be from the top, possibly because it had only 1/2 the oil in it (just enough to do a quick listen). Part of my decision is based on the encouragement of Grant & Richard about the vitality of the 4.0 engine. It gave me the confidence that this route wasn't an expensive roll of the dice, rather, the expense I would have either way, without the risk of someone else's problem engine being installed.

No, I didn't get a pic. The shop had already disposed of the "blown" filters, and the one on it for the test listen had blown the gasket, so not much to photograph. Anyhow, I'll know in a few days the result of the inspection. Worst case, I'll get the car home & part it out. Best case, solve the pressure problem & run the car a few more years.

Richard, I like your idea. I've long wanted to visit the "Continent". Hopefully in just a few years when I retire. In the mean time, I'll try to get Grant a little JD (distilled less than an hour from my house) and Richard the beer he would enjoy (would that be Guiness?) Thanx again!!

 

I'm worried, you trust your shop and they know it.

The millennium event exploding oil filter has been disposed of, 'before you get to see it'! Can't be even considered reasonable.

Your so called mate, wants to put a new engine in.

And yet, starts and runs fine.

For me, new oil and filter in, and a blast down the road;

If it self immolates then, maybe, you might need an engine.