No one has mentioned it yet, but my understanding is that the secondary tensioners don't rattle, just fail. It's the primary tensioners that like to rattle.

They will not eat the engine if they fail, so not talked about as often, but they certainly wear out. Might be worth a look at these while you're in the shop.

Can't speak to the VVT issue, but the O-ring on mine leaked. Simple fix and never a rattle before or since.

 

Thanks for your reply. As I've mentioned before my mechanic did look at the top and tensioners and they're fine normal wear no abnormalities the bottom tensioners we don't know obviously we didn't look but were pretty much 99.9% sure my mechanic that it is the Vvt cam gear and it may just be the seal itself so we'll see when he gets to it and takes it apart. Thanks for your help

 

Is there anywhere online that will tell me how many hours is needed by mechanic to do a particular or specific job. I just got my estimate on my timing gear cam VVT replaced of nine hours.

 

That doesn't seem to bad, I think Alldata gives time estimates for some work but you will need to subscribe.

 

Jag 4, the vvt O-ring you speak of is it on the solenoid or the cam gear? My situation is the cam gear, so is there a O-ring there that may be a simple fix?

 

The one I replaced was the VVT seal on the valve (camshaft) cover. There is one on each cover.

It was about $12 from the dealer and took maybe 5 minutes to R&R with a small screwdriver. Pops out, pushes in. Leak stopped.

Get everything around it really clean before you start.

 

Thanks for responding, yeah my situation is actually camshaft gear on the cam. I believe there is an O-ring in there as well but I'm not sure.

 

I am following the discussion but would comment that very, very few, if any VVT units have actually failed. Far less than have been replaced. Wear, yeah, with some slight pinging, ticking described but never rattling which usually is resolved by thicker oil.

I would not expect that the VVT or tensioner to hold oil pressure overnight.

I know you have replaced the oil and ensured a correct filter but has anyone actually measured the oil pressure at start up?

 

Update. Got a hold of the original owner of the car and apparently the car had sat for two years with Less then a thousand miles driven on it. I'm guessing this could be the cause of the VVT gear failing. A knew issue is I still have not received title from the dealership I think this is very strange and it's almost 30 days. I was told at one point that I was supposed to have the title in hand but since it was went from dealership to dealership that this is an issue at times. I will keep you posted.

 

Title and plate came through in just the nick of time. However I still have the issue of the camp gear. As stated before it's going to be about $2200 to replace. Please keep in mind that the car has been diagnosed of the actual camp gear is the failure. This diagnosis already has cost me $400 to open the engine of the car and find the failing part. It is my belief knowing overhead cam cars, chain tensioners and in this case cam gears, the fact of not drivin in reasonable time frame these parts begin to fail. The fact that the original owner told me the car sat for two years with less than 1000 miles drivin, my mechanic and I understand that the lack of driving this engine is the cause of this cam gear failure. Just want to know your thoughts on this issue, having not driven in the car the cam gear is unable to hold oil pressure over time (overnight) to operate crrectly on cold start, this the root failure of this part? This is NOT the Vvt solenoid . What are your thoughts please?

 

CAM gear?

You have lost me. What camp/cam gear?

 

I am sorry but I think it is time for you to get a second opinion. With the car sitting for 2 years and oil that appeared to be thick might be part of your problem. As for the tensioners oil pressure is what operates them and when the engine is off you have no pressure. As for the VVT clicking many problems were corrected after a few oil changes. We are willing to help but the information that is given to you and you passing it on to us just does not make sense. My suggestion is for you to get a second opinion from a known Jaguar shop with a good reputation.

 

OK as stated before the oil has been flushed and changed. The cam gear is a gear that is on the overhead cam that changes due to timing situations to optimize power and fuel efficiency. We know this is faulty because the engine has been torn apart and investigated and found that it is not holding the oil pressure over several hours thus the rattle on fresh overnight starts. We know the problem is the camp gear, on fresh cold start valve cover off starting the car you see air bubbles coming up before oil comes up into the cam gear. This indicates there's a draw down of oil within the cam gear. Sorry for confusion of "camp" and "cam" gear, voice typing/texting.

 

Help me. There is a double chain 'sprocket' on the intake cam, there is a VVT device there also. There is a chain sprocket on the exhaust cam plus the tensioner itself.

The 'cam gear' you seem to describe is the VVT.

The oil system does not maintain 'pressure' over night. It may maintain oil but not pressure.

I agree with gus, you need another opinion.

 

If your mechanic actually believes that the tensioner and vvt hold the oil at pressure for more than a few minutes after shutdown his knowledge of oil seals and engine construction is faulty.

The valve in the oil filter stops the oil from draining down after the engine is shut off, which means pressure is rapidly restored when the engine starts, but there is nothing that prevents the pressure from dropping.

As suggested above, another shop would be a good move.

 

Yes, my mechanic told me today it was a VVT on the intake cam that is faulty holding the oil pressure. So are we all saying that that's not true and that has nothing to do with holding the oil pressure? They changed the oil and the filter with anti-back flow filter (k&n). If I go for a another Indy for a second opinion do they have to tear the engine apart to find the problem?

 

Rick,

Give me a call when you get the chance-------sooner then later...


Chuck

 

Chuck, i don't have your number so I pm you my number
Rick

 

I'll just add, you don't have to tear the engine down to get to this, it's a 15 min procedure to pull the cam covers to access the VVT. I see sngbarret has this GEAR for $588 and I'll suspect is part of his price. BUT listen to the guys above they're combined knowledge is priceless to us jag owners.

 

It is pretty simple to attach an oil pressure gauge at the oil filter to check the pressure at start up. That will tell you a lot more than staring at the VVT after removing the valve cover.

Or you could install the RealGauge converting the temp/oil idiot gauges to true gauges. About XK8 / XKR / XJ RealGauge - TheJagWrangler