I was told by the dealer I need a new engine..... anyone experience the same problem? Knocking starts at about 2100RPM and gets louder as you increase the RPM. Funning thing is if I was deaf I would think the car was running beautifully. Hope its not the engine only has 50,500 miles

 

Sounds like rod knock. When the bearings seize the rod will break and poke a hole through the block. If you get it looked at before it does you might be able to save the engine block. It can't be rebuilt if a piston rod goes through the block.

Check this thread. https://www.jaguarforums.com/forum/x...rprise-191825/

 

Welcome to the forum FrustratedXKR Owner,

I've moved your question from General Tech Help to X150 forum. This is the place to post technical questions about your model.

Engine knocking is often caused by worn bearings but it's repairable provided it's caught in time before anything lets go.

You need it looked at by someone who knows about engine rebuilding and not just how to sell cars.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Need a bit more info - what does the dealer say is actually wrong with the engine? They must have told you more than "You need a new one".

Loud knocking noises are never a good thing, but there are a lot of potential causes.

 

To the dealer, an internal noise equals swap engine as it's simplest and quickest for them. Without knowing the OP's ability to work on it or diagnose the problems you are probably stuck following their advice. Personally I'd be probing around with an old broom handle or long screwdriver to try and isolate where in the engine the noise is coming from. Might be worth while to stop at an independent shop for a 2nd opinion.

Strange that another 5.0 bites the dust.

 

I don't think the OP has enough info on what is wrong. Also what lead to this assumption. Low on oil or over heated or what. Any compression or leak down test taken. I would like more info and another opinion . Remember "trust but verify".
Ranch it's hard to determine if this is a 5.0 issue considering there is insufficient or no data to determine that.

 

I'm just going by the assumption that if it was external to the engine that the dealer would say a bolt on component needs replaced. The common theme on 5.0's in the short time I've been a member is they run low on oil and nuke themselves and some times a sketchy aftermarket tune helps the process along. My assumption is a little end rod knock at the piston wrist pin since it's more noticeable as RPM's increase and also realizing that the little end is lubed by oil splash, points to not enough oil in the crankcase vapor.

Do the 5.0's have oil nozzles to flood the wrist pin area with a jet of oil?

 

Ranch I must be reading a different form as I have not seen/heard of any engine issues with the 5.0 other then a operator error on overheating. I haven't seen any oil usage issues and considering the number of 5.0 engines produced don't see any internet data supporting it. This form has a small group of posters and as normal any problem issues becomes blown out of proportion. Even the supposed water pump discussions don't have major supporting data. As I mentioned I would challenge the dealer requiring more info .

 

In the case of rod knock, can you hear this at idle rpm, or only in the higher rpm range like the OP is experiencing?

Thanks

 

Find the JVIII thread in the F type sub forum. Because he argued that the tune wasn't culprit folks dug up other supporting threads of tune / oil consumption related 5.0 kills. Most of the dead 5.0 threads were created by 'fly by posters' so we never know the postmortem on what really happened.

Bottom end knocks at idle, sounds like a wooden mallet on a chunk of cast iron. Top seems to only come in above idle. It could also be something in the valve train. Really need to hear if it's at base or 1/2 rpm to help determine what it is. Again, probably outside the OP's experience level.

 

There have been multiple 5.0 supercharged bottom end knocks.

At this point, I think it may have to do with G-force or Windage conditions in the oil pan causing the pick up to go dry, even with the proper oil level in the car.

Territory where a car can accelerate with nearly as much G-force as it can brake or corner is fairly recent to street cars. Tuners would make modifications to oil pans with baffling, crank scrapers and windage trays to avert disaster, but how is the XKR's oil pan?

 

[QUOTE=Tervuren;1829234]There have been multiple 5.0 supercharged bottom end knocks.

I guess I haven't seen or know where to look for the data. Maybe you can point me to it. Does your info identify the percentage of failures based on the number of 5.0 engines produced. It would be nice to see it so we have some history to work with. Thanks

 

Originally Posted by CatScratchFever View Post
In the case of rod knock, can you hear this at idle rpm, or only in the higher rpm range like the OP is experiencing?


“Bottom end knocks at idle, sounds like a wooden mallet on a chunk of cast iron. Top seems to only come in above idle. It could also be something in the valve train. Really need to hear if it's at base or 1/2 rpm to help determine what it is. Again, probably outside the OP's experience level.”

If it were a worn bearing/rod knock and the knock was occurring at idle rpm, if the knock slowly went away after idling a few minutes, would you still think it could be the same problem? I ask only because I have had what I call a knock (which I queried in some of the supercharger discussions) sounds like it’s underneath and sounds exactly like you described as a wooden mallet striking a piece of cast iron. Not present at cold startup, but almost always after a warm restart, say after getting gas. I’ve had it looked at by the local dealer who first says that’s just the sound of the R exhaust, but after I’ve pushed they have said it was the idler on the supercharger and have done the snout repair twice now. I still hear the same knock however. Thoughts?

And thanks again

 

Have you replaced the isolator tension spring in the supercharger and done a rebuild on the supercharger AND snout bearings?

 

If I were to guess one thing, I'd suggest something fed by the oil system bleeding down when shut off warm and taking a bit to pump back up. I don't know how the block fuel pumps work on the 5.0's and assume the cam timing is similar to the 4.2's. Again I assume the check valve in the oil filter is working correctly. Have you looked into the 5.0 Service manual for advice?

Piston slap happens when cold and stops when it warms up. Rod knock shouldn't care how warm it is, if anything get louder as it gets warmer.

 

Gents:

How prevalent is this rod bearing issue? I'm looking at a 2010 XK-R with about 45K miles. The last thing I want is drama with this car. Should I just run away?

Feff

 

This is the first discussion I've seen about it. The main weakness on the 5.0 XKR seems to be the water pump, and even that's not affecting the majority of cars. There are also occasional issues with the supercharger torsion isolator and the timing chain tensioner ratchet - neither are fatal (unless you just ignore them long-term)

Don't be spooked by what you read on forums - remember, people come here when they have problems, so you will always see problems.

 

True - obviously the vast majority of owners don't have this problem and aren't going to post to say they haven't.

However there is a thread on the Jaguar Drivers Club on Facebook right now - 2011 XJ 5.0 S/C with 100k miles - failed con rod. £18K to fix at Jaguar with a new engine or £6.5K for a second hand unit.

There is a 2011 5.0 XKR 32K miles on BAT right now with a new engine courtesy of Jaguar due to an oil problem - $40K in replacement engine costs if the advert is to be believed.

There may be something in common with these failures that perhaps could be fixed to prevent more happening.

 

The 5.0's have a jackass designed electronic dipstick. The common theme is they need to sit a certain amount of time (15 minutes I think) before the display will actually let you see if it's OK. It won't actually tell you until it's too late. Oil pressure and coolant temp gauges offended the designers principles so they were left out. The XF shares the XK's gauge cluster so those guys are driving in the blind as well.

Old school says you buy gas and check the oil level while it's pumping. 5.0's need to sit longer than it takes to get fuel so they just don't get checked. How often do you see folks actually checking the oil level in their vehicles at the pump?

As part of the combustion process there's a little blow by of combustion gasses around the piston rings. Add a blower and 100k miles and it's noticeable. That blow by carries oil out of the crankcase and it's burnt in the engine via the PCV system. So the older the car is the more oil it consumes between oil changes. Now add in a lifetime of not checking the oil and no way for the engine to tell you it's about out of oil and you run into oil starvation problems. On old school '60's V8's the lifters would tap before the bottom end starved and you'd know you needed oil, NOW. On new school V8's the bottom end starves and the bearings die.

OP's vanished so doubtful we'll ever know the rest of the story.

 

I usually check my oil the 1st thing before starting for a ride of the day. Check coolant once a week when car is in use but also have a temp gauge running all of the time during drives. I as others don't like not having gauges but having found a work around I can live with it. Also as I understand there are approx. 25,000 to 30,000 XK's with the 5.0l not to mention the other models and LR. So the question would be what percentage are failures caused by engine defects and what percentage cause by failure to maintain the car. Would be nice to see the data but doubt it is available.