Boroscope inspection of secondary tensioners?
2000 XK8 convertible, 30,000 miles, no codes, runs well
I bought the car in the fall and put it away for the winter after driving just a few hundred miles. I am getting ready to get it out. I want to verify that the secondary cam chain tensioners have been replaced. Can I use my boroscope to go under the valve covers to see the tensioners (like maybe through the oil fill opening), or do I need to remove the covers?
Thanks
Bill
I bought the car in the fall and put it away for the winter after driving just a few hundred miles. I am getting ready to get it out. I want to verify that the secondary cam chain tensioners have been replaced. Can I use my boroscope to go under the valve covers to see the tensioners (like maybe through the oil fill opening), or do I need to remove the covers?
Thanks
Bill
It's funny that people are mentioning this as of late... this is the second similar discussion around borescopes. I think it's due to the massive amount of cheap borescopes being sold on Tiktok and other social media. The commercials seem to be working! I thought about getting one and fiddling about, but I think I'm just going to pull one side's cover and inspect. This will give me a chance to look at lifters as well, and inspect the chain. I'd gladly pay a mech to do it but I don't trust any of them locally.... the rent is high, times are tough and everyone is in "how much money you got" mode.
I guess you might from the oil filler hole if
you're unbelievably lucky and;
the end doesn't get coated with oil.
Better to lift a cover to check. The RHS (your passenger side) is easier as you won't have to fight the dipstick. I suspect they will be the original tensioners with such low mileage.
you're unbelievably lucky and;
the end doesn't get coated with oil.
Better to lift a cover to check. The RHS (your passenger side) is easier as you won't have to fight the dipstick. I suspect they will be the original tensioners with such low mileage.
Worst money I ever spent on a tool was a Milwaukee borescope (used the same battery as other tools). Its got a terribly narrow focus distance so you've got to get it positioned just perfect. Its low-resolution, not sure if its the screen or the camera, but its very grainy. And the light is either not nearly bright enough in big, dark cavities under the dash or way too bright and washes out any hope of seeing detail inside a cylinder. That was hundreds of dollars many years ago. Now you see these on Amazon for around $30 that plug into a smart phone. I know at least the screen on my phone is good so its tempting to order one to try. Tho I doubt the suggested application is reachable, any DIYer will find dozens of uses for such a device around the house and garage. As awful as my Milwaukee is, I still try it several times a year, once in a while with success.
Ok. Ok. I needed one anyway for diagnosing my water heater so I just ordered one. It'll be here tomorrow. I have some strategies on how to get over to the secondary tensioners... I'll let y'all know, likely with an accompanying video of me cursing by tomorrow afternoon.
As a new X100 owner, I see and understand the cam chain/tensioner issues with the early iterations, but I'm wondering whether the same concerns apply to the 2003-onward cars (less the upper tensioner oncerns) ?
Mine is a 2004 model.
Mine is a 2004 model.
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Ok. Ok. I needed one anyway for diagnosing my water heater so I just ordered one. It'll be here tomorrow. I have some strategies on how to get over to the secondary tensioners... I'll let y'all know, likely with an accompanying video of me cursing by tomorrow afternoon.
Yup. No clearance and the metal sponge is in the way. But now I have larger issues. Goddamned partial load breather pipe disintegrated when I was inspecting the top hose, and I don't know where it terminates.
From a 2008 post on the forum:
Information provided by Andre Voss (Belgium) reveals that the production commencement of aluminum bodied timing chaintensioners and multi-row timing chains was with engine number 01 08 13 0000. There is no direct correlation between engine number and VIN: however, the engine number is a date code. So engines built after August 13, 2001 are uprated to the latest specification.
The change happened before the 4.2L engines in MY2003. I have read that blower engines got them before NA.
Information provided by Andre Voss (Belgium) reveals that the production commencement of aluminum bodied timing chaintensioners and multi-row timing chains was with engine number 01 08 13 0000. There is no direct correlation between engine number and VIN: however, the engine number is a date code. So engines built after August 13, 2001 are uprated to the latest specification.
The change happened before the 4.2L engines in MY2003. I have read that blower engines got them before NA.
Thread from 2023 has a TSB on the pipe.
https://www.jaguarforums.com/forum/x...eather-170039/
https://www.jaguarforums.com/forum/x...eather-170039/
Unfortunately, I have seen secondary timing chain tensioners fail on the AJ33/AJ34 as late as MY2007 on the X150.
From a 2008 post on the forum:
Information provided by Andre Voss (Belgium) reveals that the production commencement of aluminum bodied timing chaintensioners and multi-row timing chains was with engine number 01 08 13 0000. There is no direct correlation between engine number and VIN: however, the engine number is a date code. So engines built after August 13, 2001 are uprated to the latest specification.
The change happened before the 4.2L engines in MY2003. I have read that blower engines got them before NA.
Information provided by Andre Voss (Belgium) reveals that the production commencement of aluminum bodied timing chaintensioners and multi-row timing chains was with engine number 01 08 13 0000. There is no direct correlation between engine number and VIN: however, the engine number is a date code. So engines built after August 13, 2001 are uprated to the latest specification.
The change happened before the 4.2L engines in MY2003. I have read that blower engines got them before NA.
Last edited by Throwback; Mar 12, 2025 at 05:55 PM.
2000 XK8 30,000 miles.
Ok I gave up on the boroscope approach, and took off the valve cover. Look at that, an original plastic tensioner, in 2025! Who would have guessed? And it's in great shape, but for how long? Looks like I'll be doing an upgrade.
Given the age of the vehicle, replace the primary chains, tensioners and guides as well as the secondary chains and tensioners. Quite often the primary guides and tensioners have cracks or missing pieces of plastic that find their way into the sump, so that should be removed as well if there is evidence of broken primary tensioners or guides.









