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A little over a year ago I had the upper timing chain and tensioner changed to new. Was a big job.
I took the car in today to have them diagnose a burning oil smell and listen to the rear differential as it is starting to howl.
(About 2 years ago I had the passenger side axle bearing replaced because it was howling big time)
So they reported back today that my oil pan is leaking and it will cost $1,400 to fix?
They also said all the bearings in my differential are bad and need replacing. Another $1,600?
They mentioned the steering rack is leaking which I've known about for a while.
But here was the shocker. From the very same shop that replaced my cam timing chains too.
They said that on start up the engine made excessive noise and I was looking at engine failure soon?
My car has 177,000 mile on it and is very well maintained since 1996 when I bought it.
So I took it to another shop that works on a lot of XJ6 Jags.
He listened and immediately said it was a loose timing chain and said it needs to be fixed ASAP.
I told him I had another shop replace them already and he said they need to make it right because sounds like the tensioners have failed.
I called the shop back and they said they would warranty their work.
But I'm confused as to why they didn't know it was the timing chain.
They actually recommended that I junk my car! It actually could be the lower timing chain which they did not replace.
1. The shop that suggested you scrap your car should not get any more of your business.
2. Anyone that knows the X300 XJ6 will be well aware of the upper timing chain issue of the AJ16. Start-up rattle does not indicate an impending engine disaster. This matter is well covered here in the forums. Even a new upper chain and tensioner can still allow a chain rattle at start up. That is often caused by too "thin" oil, like a 5W.
3. There are a number of locations known for oil leaks on the AJ16, commonly the oil cooler bypass o-rings and the cam cover seal. Easy fixes. Fix the easy ones first and see where you stand. Yes an oil pan seal replacement would be expensive since the subframe has to be lowered from under the engine.
4. The lower timing chain is not known to cause much noise or give trouble. The 3rd and lowest chain is really only the oil pump drive chain, trouble or failure down there is quite rare and unlikely in a well maintained engine.
5. Rear end: the true source of the howl must be isolated. The pinion bearings of the differential input are known to make noise and that is a big job. Wheel bearings and U-joints back there can also make noise. Axle bearings (at the differential) replacements are not too involved and don't require removal of the differential. At your mileage, some of this work might be needed and it is not cheaply done at a shop. But you don't want to pull a differential unless you are absolutely certain it is failing.
That is a great looking XJ6. Should have lots of life yet.
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That sadly seems to be the way with a lot of so called 'garages' these days, you really need a shop that actually has at least a little experience with Jags(or at least knowledge) otherwise it ends up with these silly diagnostics and/or quotes, even though X300 is a really simple car to work on and parts are generally affordable.
Apart from what Richard already said above, I'm just going to add a few things.
Definitely do not use the garage that suggested scrapping your car, unless to redo their work on the chain tensioner and even that I'm not sure I'd feel comfortable with. Even if they have to replace the tensioner again for some reason, it really is a simple job and tensioner itself is relatively cheap.
When you say you had the upper timing chain replaced, could you elaborate what they have done? I fail to understand how you can do it but not replace all the guides including for lower chain which would be the main reason for chain noise at your mileage(they all have it but its not catasrophic to engine itself) apart from the chain tensioner which of course could theoretically fail again but would be pretty obvious on startup and when reving the engine. Chains generally should be ok to reuse in most cases but guides will have plenty of wear by now and that's where slack and noise comes from.
If oil pan is leaking you need to find where, I dont think you need to drop the subframe to reseal it as its all sealed up with silicone and just undoing it should leave enough room to get it sealed up again. That said, its quite common for these so called 'garages' to crack the pan while tightening the sump drain bolt when changing oil. Ask me how I know.
That would then need dropping subframe indeed and would be a major job.
That said, as Richard mentioned above, its more common for the AJ16 to leak elsewhere from above, then oil just ends up on the sump anyway and from there coats entire underneath of the car including boot floor and exhaust. Cam cover gasket is most common, front seal and even as was case on my car recently - a leaking oil pressure sensor, just next to oil filter housing. All easy and cheap fixes.
Re diff bearings, it should really be done by a specialist I think, if its the output shaft bearings then these can be done relatively easily with the diff staying in the car and I'd be tempted to check and replace these first, but if its pinion bearings than differential would have to come off unless you're just replacing the outer bearing without replacing its race, which considering pre load issues dont think would be successfull. In this case sourcing a replacement diff might be cheaper and could be good opportunity to source an LSD diff at the same time along with other parts to refurbish rear suspension that would have to come off anyway at the same time.
Rack itself isn't difficult job either and replacement arent that expensive.
Considering how nice your Jag looks and how rust free it is I'd say its definitely worth looking into resolving these issues, you just need to find a good shop to do it.
I'd cut my losses on that first shop. They clearly didn't fully know what they were doing and they may have botched it. The second shop sounds like they know what they're doing and I would have more confidence paying them to do something the first time, than I have in the previous shop doing it the second time.
Perhaps you have a good relationship with that first shop. Perhaps that would be worth having them take a second go at it, but I'm not sure I would use them again after that. Katar is correct, these are straightforward cars, sounds like the first shop is unnecessarily complicating things.
I thought I had an oil pan leak as well. check the horseshoe under the oil filter, some later cars don’t have it all but your 95 probably will. on my car the oil pressure switch right next to the oil was dripping out oil and it sprayed all over the exhaust and dipstick area
diff carrier is a pretty involved job, $1600 isn’t too bad if they use a rebuild kit and not a used unit.
I called the second shop today. I trust him because he works on Jaguars. He asked what oil I was running. I told him 10/30w synthetic. He said to get that oil out and replace it with Kendall GT-1 10/40w and then add Lucas oil treatment additive and drive the car for a while with that. He said sometimes the valves and piston in tensioner can get plugged and stop working properly. He told me if I am lucky the change in oil with the Lucas treatment will help the tensioner work again. I did that today and after driving a while I was surprised at how quiet the engine is. Even at idle no more rattle.
I also had the differential oil changed which was black and it is leaking and appears to have moisture intrusion. Still howling.
I really want to keep this beautiful car. It has no moon roof so fits me well. Back in 1996 when looking to buy an XJ6 I almost did not because my head hit the moon roof headliner. Then I test drove this one with the extra head clearance and that was the deciding factor. So I can’t just buy another because most have the moon roof. Not only that I know this car inside and out.
30 weight oil is too thin. You should always stick to a w40 or w50, depending on temps. If you are in California, south of San Fran, I don't see why a w50 oil wouldn't be ideal. I run a 0w40 because I see winters. Your manual has a chart, I'd take a look at it and follow what suits your climate.
Following what your mechanic recommended is certainly headed in the right direction.
I had what I thought was an oil pan leak, and it ended up being a leak from the oil cooler, which is a common problem, as the washers age out and start letting oil get by. Deleting that cooler is common, clearing up some space in the engine bay. It really isn't needed with the 6. The washers should be replaced with longer lasting viton washers. I have a post where I tell you what size you need. If you decide to keep the cooler, I think you need four washers instead of two. I can't be sure.
Just to add to the excellent feedback you've already received, here is the oil specification chart from the Vehicle Care Handbook showing the recommended grades depending on your climate:
Jaguar did not specify synthetic oil for the AJ16 and I personally prefer to use conventional oils in these engines and to change the oil and filter every 3,000 miles. Keeping the oil clean helps reduce problems like sticking chain tensioners. Jaguar recommends Castrol oil, but any of the major brands is fine as long as you use a correct viscosity for your climate.
I assume the additive you used was Lucas Heavy Oil Stabilizer? It's an excellent product that I have used for decades to help improve or resolve various issues. Just don't overdo how much you add as a percentage of the overall fill since it significantly increases the viscosity of the oil. In an AJ16 I wouldn't add more than 1 liter out of the total fill, and in a differential I wouldn't add more than half a liter unless the diff is really noisy and you're trying to postpone a rebuild.
Yes I used the Lucas Heavy Duty Oil stabilizer and I just realized I may have overfilled the engine by half a quart (473 ml).
I filled the engine with 8 quarts (7.5 liters) of Kendall GT-1 10/40w which left room for half quart (473 ml) more.
I put a whole quart bottle (946 ml) in. So I overfilled the engine. Will this do harm?
This morning on the cold start the engine made a big racket.
Once it warmed up it quieted down.
Half a quart is probably not a major problem, but overfilling can lead to the crankshaft making significant contact with the oil in the pan and aerating the oil into a froth that the oil pump cannot properly pressurize, leading to low pressure and oil starvation in the engine. It can also lead to excessive oil being drawn into the crankcase breathing system, which can lead to excessive oil in the air intake, throttle body, etc.
If you have a siphon pump with a long rubber hose, you can probably remove half a quart via the dipstick tube.
Update: Took my Jaguar back to the shop last week and braced myself for some expensive news.
This morning I went to the shop and the mechanic told me the noise in the engine no longer exists.
He cold started it for me and I heard no noise. So my only guess is that the Kendall GT 10w-40w oil
combined with the Lucas oil stabilizer did some good.
I told the mechanic to check the differential bearings because the familiar howl is starting back there.
Not a loud howl yet but I know it will become one because my passenger side axle bearing made the same noise.
As I looked at my Jaguar this morning the 25 years of history we have together came flooding in.
Been through so much with this Jaguar and I know everything about the car as I have kept it very well maintained.
Couldn't bear to part with it.
See Jaguar Technical Service Bulletin link below for the timing chain rattle
The revised tensioner will have a large arrow in the heavy casting
You can find these revised tensioners at the salvage yard , need the new bolts off the donor car as they are longer
Oil viscosity helps on this nuisance that is just noise and not a mechanical problem
There is a common steering fluid leak on the hoses just below the steering fluid reservoir . Cut off 1 inch of each hose and reinstall
The steering rack leak can be helped by changing all the steering fluid with fresh which reinvigorates up to a point the original seals , gets rid of the noise as well
This leak will blow fluid all over the place
The outer most seal on the rack can be replaced without removing the rack ( cost and if they are competent enough to do it right )
12-22-2020, 09:06 PM
Repairs needed on my 1995 XJ6
