So my mechanic called that's fixing the timing chain and says the left cam shaft is all worn so I definitely also need a new head. Then he said it's cheaper to just get a used low mileage engine then to replace the head. Does anyone know if that's accurate? He sourced a 2012 long block for 4,900 with 41k Miles. I have had many other cars and had new cylinder heads done and it wasn't cheap, but no where near an engine swap. Something seems off to me here.

Any advice would be appreciated.

 

You're fortunate there's an engine around at that price! When we looked for a 5.0L SC only found ones $15K and up.

 

It's from a Different model car but it's aj133 SC so he says it will work apparently, or at least he can make it work. I've also found several on eBay that are 6-8k. But what scares me is that I had no idea so many engines blew so prematurely on the early 5.0, and what are the chances that I spend 10k on a motor swap and the engine blows. Yikes. I'm pondering taking a big loss and letting the car go, it's a shame it's in such good condition all around,

My jag mechanic said he had seen so many of these blow the motor. Like 30-40% of the 11-12 sc motors blow before 100k. How could they produce such a bad design in such a beautiful car?? And does anyone have experience swapping heads? Is it really more cost effective to swap the whole motor?

Again, this is all cause by the tensioner issue throwing off the timing. So I feel badly for anyone experiencing the idle variance described earlier in this post. The symptoms were identical.

For now I have told them to stop working on it and I'm bringing it home. It's really a shame because besides the idle variance, it runs and drives perfectly with a ton of power and sounds incredible while not at idle. I might just keep driving it until it blows for good.

 

Did you ever see this damage to the cam/head your mechanic is reporting? Getting some pictures and posting them might help folks on the board identify a solution.

 

I'll ask as I'm picking up the car early tomorrow morning. I should have requested them now that you mention it. He described it to me as where the back part of the cam shaft is suppose to sit has worn a good amount into an egg shape and the cam can actually be jiggled around a bit in place. Also said it's definitely due to driving around with the slack timing chain. Worst news ever. Especially because he was so sure he'd be able to fix just the timing chain, gears, tensioners and guides. But too much damage was done to the cam already.
I'll post pics if he had them.

Thanks

 

Thanks for keeping us posted on your situation - sorry you got tied into this problem as well! I'm curious as to how your mechanic got that data. If that's an accurate, quantifiable statement, then JLR has a major problem on its hands. 30-40% of affected engines could warrant thousands of replacements. I'm beginning to question (just like others such as Mark and Dave) if there really is some sort of major design flaw that is causing these engines to fail in fairly short order (less than 100,000 miles). The timing gears were enlarged at some point during the XJ's run, I believe sometime in 2012 or 2013, where the gears were enlarged from 6.5mm to 8mm and the material composition was changed. Are those engines affected as well or was that the cure?

In terms of your specific symptoms, did you also experience vibration at any specific rev-range or a rough idle?

 

I've know my mechanic for a long time, and I trust him. He actually pulled off all the covers and was able to see where the cam shaft had worn as he described it an egg shape where it held in place at the back side of the motor on the driver side. and this caused a little bit of play in my cam shaft. He said he could do the timing chain refit, but that I'd be wasting my money as the cam will let go at some point and blow the motor anyway.

He explained to me that for some reason, it's oil pressure that tensions the chain, and when oil gets heavy while cold, or just all mucked up after a long period with no oilchange, the tensioner stops working correctly and causes wear to the timing sprockets, and to the chain guides. Once the wear is there, even when the tensioner is working, there will always be play. That's what causes the idle tick and odd noises. And wear to the cam shafts.

He also said it's much less expensive to replace the motor with a newer less mileage engine than to spend 4K on a timing set up, and several thousand on machining and replacing the heads. So we found a great deal on an engine from LKQ. It will be here the 20th.

I don't know where he got his number, or if it's just strictly speaking about the jags he has worked on himself. But I've been researching the issue myself and it does seem there have been a lot of blown motors on these early 5.0 sc jags. And a lot of people still driving around with a loose timing chain as well.

As for vibrations, my car really is only noisy at idle. Under power it drives perfectly. But at idle there is a misfire and a definite wobble to the motor. He explained to me that the variance comes from different cylinders misfiring at different temperatures and that causes there to be different ticks and sounds to the Motor at idle at different times. I also have 3 distinct types of idle. Just like the original poster.

It's also odd that a mechanic that works on all foreign cars seems to have a better understanding of the motor than mechanics at the dealers that routinely tell people that nothing is wrong with the ticking sound at idle.

I'll post once my motor is in. And I have my block, supercharger, and one good head from the passenger side for sale if anyone is interested.

Chris

 

My car always shivers at idle (Started a thread on that). And yesterday, the engine warning light turned on with error code P0201 (Started another thread on that). The app describes the error as "Injector Circuit Malfunction - Cylinder 1". Have not contacted the dealer yet, but keep wondering if those 2 things are related.

 

Well it's hard to believe one mechanic can claim a 30%-40% failure rate but yet on a forum 100% devoted only to Jaguars we are not seeing this?

Yes there have been some engine failures and we are trying to learn why but these forums would be on fire if there was anywhere near that rate of failure.

Just try to think a minute about that? It simply can't be true.
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I know that sounds high to me too, and didn't mean to mislead. and he's just going off of his own experience with this motor and also how many new motors were swapped out at dealers while his one mechanic was still working at the so dealer so there definitly is some sort of issue. Also, How many on here are at 100k miles? I know quite a few on here have the early timing chain knocks and odd internal sounds. Hopefully your right and they all make it to 100k, and well past it as it's a seriously expensive problem. I got lucky and bought mine with a known motor issue and it was factored into price. Mine actually didn't totally blow either. Still drives great, but the knocking at idle is very prevalent. He just said it was much better to put in an updated motor, 2014 on, AJ133 SC with e as the 8th digit, then to put money into timing and cam, and machining, etc, And that I wouldn't even make it another 5-10k miles without complete failure. At which point id be in the same boat without a good motor to part out to offset the cost a bit,

i got lucky and he found a 2016 sc 5.0 motor with 4 miles for $9,200, I almost bought a cheaper one with 45,000 but couldn't pass up a 4 mile engine. Sounded too good to be true but I paid for a carfax on the vin, and the car was never even registered. Damaged in transit to dealer. I have the contact for Noel at LKQ if anyone wants it. He is great at searching for parts. And LKQ was going to lost that motor for 11,600, so he was able to get it for me at huge savings. Anyway I'm hoping there won't be any install issues being the motor is so much newer. But he assured me it will work. He also ordered A pulley, intake tube and exhaust and then we are flashing the ecu once everything's installed. He said I should have roughly 515hp once it's all said and done, but who knows. I never trust hp gains without a dyno so we'll see what that says when I finally can go.

It's a Very costly problem, and I already spent 18 on the car so I'll be into it 35k by the time it's on the road. Yikes. Could have just bought a much newer model, But it's in incredibly good shape and looks amazing, and will have 4 miles on the motor with added power, and I also updated to the new lights. Also, If anyone is interested in the new lights I have contact info for a shop in the U.K., They come plug and play all set up for the pre 2016 wiring harness. Lights were 1200 for the pair, and conversion was 500ish.

Anyway I'll keep you posted. Can't wait to actually drive this car finally. All I've been doing is working on it. Lol....

 

Thanks for the update and you have said what I am trying to follow up on and that is when or did Jaguar update the 5.0L engine?

You also backed up what I have heard that 2014 and up 5.0L's do not have these problems and there is evidence of this because the timing gears and chain were increased in size. As well as the tensioner components changed.

I did see that the changes supposedly were done starting with the 2014 model year and up starting with VIN B52041.

No real proof just a lot of reading to see what I could find out.
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As the 3.0 L six shares the block and many other components with the V8, is this an issue?

 

That's a good point and no so far I have not seen the V-6 suffer from this.
But maybe?
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