Secondary Timing Chain Tensioners vs. Complete Timing Overhaul
 

Thanks to the forum sticky, the search feature, and the guidance of others, I have read plenty of threads and instructions on how to tackle the job of both using the "zip-tie method" for the secondary tensioners and a complete overhaul of the Timing system. The next questions are not about "How To" accomplish, but more to answer "When does it make sense?" and location of a trustworthy parts/kit assembly.

As "Keeper of the flame" (as Jay Leno would say) the following vehicles are in play and to my knowledge all have original timing components:

2000 XK8 w/ Approx 80k miles - My Uncle now owns, was the last in a long line of Jags my Grandad had so very sentimental.
2001 XK8 Bronze "Craigslist Cat" w/ 18k miles; as detailed in other posts, will be gutting the entire cooling system as need complete overhaul.
2001 XKR Silverstone Convertible w/ Approx 80k miles; great shape, no rattles, seldom driven now other than stretch its legs.

So my first question of "When does it makes sense" does not apply to truly when (as I know Secondary Failures could be ANYTIME) but does it make sense in each scenario to do a FULL rebuild of the timing system on each, or make sense to just do secondary tensioners for now using the "Zip-Tie Method"?

Basically, I'm trying to separate mass hysteria from real life, but also a better time to handle refresh the timing system outside of the secondaries, which I understand are IMPERATIVE.

With the 2000 XK8, I have more limited access to it, but could swap cars and bring it back for a few weeks for a complete overhaul. With the 2001 XK8 "Craigslist Cat", I'm going to be draining and flushing the coolant so does it make sense to go further with the complete timing system with only 18k on the ODO? Different scenario for the Silverstone....

The second question is: are there complete kits, and who do you trust for quality parts? I see wildly different prices on eBay (with complete timing sets) and some forum sponsors, along with the timing tool set? Obviously if I'm staring 3 complete jobs at some point in the face, I'd invest in a timing tool set.

Hope this makes sense; very grateful for the forum and the stickies, posts, and writeups others have done. It doesn't *look* like a terrible job other that time consumption thanks to great writeups. I plan on doing my own writeup/video after completion using "Craigslist Cat" as the Guinea pig.

I did the secondary tensioners only on my 2001 XKR with about 40,000 miles on it. The original tensioners were in great condition with hardly any signs of wear, so I didn't think it was worth tackling the rest. If they had been falling apart I would have done everything.

The time and money saved can be spent looking at other engine killers, like oil lines and the cooling system, or just general preventative maintenance like changing the gearbox oil.

All just in my opinion and I'm sure others will disagree.

At this age and with 80K miles, that's a lot of heat cycles on the plastic timing system components. The primary tensioners are probably still intact as they don't actually see any torsional stress like the secondaries, but rather expect the plastic chain guides to have cracks in them. When chunks of plastic start falling away from the chain guides, then you have trouble. The low mileage Jaguar I would suspect to be less likely to have plastic deterioration yet, but its still possible I suppose. Plastic does deteriorate with age but is accelerated with heat.

I would suggest to pull the valve covers on all of them to inspect the secondaries AND get yourself a borescope with a small diameter head and you can actually stick it down the front timing cover and get at least some visual on the chain guides. I've done it. Can't see everything, but if you do see any chunks or cracks, then you know for sure you gotta do it all. If you don't spot anything then you're still kind of guessing, but you might be able to reduce it from 100% uncertainty to maybe 60% uncertainty. Don't buy the $100+ handheld borescopes at the hardware store, far more expensive than they are worth, rather spend only $30-40 online on one you just plug into your smart phone as its got a far better image screen anyway.

I'm still in the process of putting my 2002 XKR back together (currently waiting on delivery of the CORRECT timing cover gasket - The Ford Lincoln LS gasket isn't correct). I would recommend doing the full replacement of timing chains, tensioners and guides for peace of mind, and you definitely only want to do this job ONCE. My XKR has 104k miles and the upper tensioners had been replaced with the metal bodied ones by a previous owner. The right bank secondary chain had also been replaced. However in my case, the left bank primary tensioner was completely collapsed (plastic) and the right bank tensioner was questionable. The left primary chain was extremely worn, and there where several spots on the timing cover where you could see the chain had been making contact. Much of the plastic "wear" surface on the guides was missing, with many cracks. I still need to drop the oil pan and clean out any chunks and bits of plastic from the guides. I finally got a full kit from Terry's Jaguar Parts with new chains, metal tensioners, and metal chain guides (Gen 4). I think it was about $377 US. I tried ordering some parts off Rock-Auto, but so far everything ordered from them has been incorrect (gaskets, water pump, etc. ) I also am waiting on a new serpentine belt idler pulley from Jaguar (again, Rock-Auto sent the wrong part). On a car of this age, it is a good idea to do everything you can "while you are in there anyway"...

I have had good luck with Terry's Jaguar Parts and they have good customer service. I cannot stress enough that you will need to have your engine serial number, not just your year/make/model/VIN, in order to get the correct parts (ask me how I know). ;^) I needed a borescope in order to get the engine number (located on the left underside of the block above the power steering rack) as it is completely impossible to see directly from underneath the car.

Since the tensioners are a known weak point in the engine, I feel that if you're in the area, address the issue. I wouldn't leave the plastic ones in no matter their condition because you're going to have to replace them anyway.

The problem is the top tensioners are not in the same area as the rest of the timing chain components. To do the uppers you only need to remove the cam covers and you don't need any special tools to do any of this - its pretty easy DIY mechanics, with tools most of us will have. To do the rest, you need special tools and you need to get to the front of the engine, so its a much bigger/longer job.

Indeed, secondaries easy, primaries difficult. The front crankshaft pulley has to come off. It is attached with something the Jaguar engineers call a "collet", which the more force you use to pull it off, the tighter it gets. It basically isn't coming off without God's intervention so in that sense, the primaries are not a DIY job. ;)

I've read through the blackonyx description of removing the front cover a few times since I'm facing replacing that gasket sometime soon. It sounds difficult but not impossible on a DIY level.

Tmingi chain and tensioner replacement

All,
I'm purposely repeating the below post in order to get more eyes on it relative to this thread. Need help. Primary chains clattering around and I'm sure in need if new primary tensioners. 1997 XK8 with 158000 miles. Secondaries were replaced 10 years ago. I have everything out of the way to get to the crank pully. Would really appreciate more suggestions and/or information including on removing the radiator in the most efficient way relative to loss of transmission fluids and disruption to the AC system.

=leftSo I bought the biggest chain wrench I could find (24") and laid in a ribbed serpentine belt for protection and grip and had at the crank shaft pully with that and the 24" breaker bar. The nut seemed to be turning, (The tools were moving) and the chain wrench wasn't slipping, but no progress on the nut. I had my son-in-law (truck builder) come by and we worked it together but found that the outer ring of the crank pully was slipping relative to the inner hub which was still staying with the nut. In effect, the harmonic balancer was giving up, and there was resulting movement (total of less than one half turn) of the crankshaft in the counterclockwise direction. First, I did hear some clicking inside the upper left bank that sounded like it could have been the chain skipping on a sprocket. Second, could the crank movement have done other internal bearing damage?, 3 What's next to get that pully off? I'm thinking that I may have to pull the radiator in order to get enough room to go in with an aggressive air impact wrench. Any other suggestions? Is there any issue about pulling the radiator relative to the transmission lines or AC condenser?=left
Thanks,=left
Mark

You really need the proper tool to secure the crank pulley. Some people have posted on here how they made their own tool. I made mine. But even once you have the bolt out, the standard universal pullers really don't do the job because there is a collet that actually clamps tighter the more force that is applied to pull it off. Its a real bugger to get off so having the Jaguar tool in retrospect is probably worth a purchase. And further, you don't want to accidentally rotate the engine backwards during the process of wrestling it off or especially putting it back on. When you rotate the engine in reverse, it tightens the chains on the opposite side collapsing the primary tensioners because there's no oil pressure and then its just possible the chains can slip. They probably wouldn't slip just turning by hand with the plugs out, but very likely while cranking the engine during a subsequent start-up before the oil pressure builds to restore chain tension. I think what you are hearing tho as you rotate the engine by hand is the vvt unit. If the tensioner has collapsed, there's no tension on the chain and no oil pressure in the vvt, then it sort of takes up its own slack and releases it periodically from the tension of the valve springs working against the cam lobes, thus making a clicking noise in the vvt unit.

"I wedged a pry bar between the drive plate on the engine and the torque converter via the transmission access hole. The handle of the pry bar was than placed on a jack to keep it from moving. The crankshaft setting tool nor the camshaft setting tools should be used to hold the crank in place for the pulley removal, nor should they be installed at this time." -- the blackonyx link above

What is the consensus on using a pneumatic impact wrench? Big one. Also in order to do that I would have to remove the radiator to get more room in there. Any tricks with that? How would I retain the tranny fluid that would want to escape? Can I blow that into the tranny to minimize leakage before removing the radiator?

I'll also look into access to the torque converter as suggested by Volkris.
Thanks,
Mark

Mark,

You'll still need to hold the inner part of the damper, (particularly using an impact gun to avoid transfer shock damage into the engine). Since you stated in the other thread that the rubber between the inner and outer parts of the damper was slipping, you may want to figure out a tool to hold the damper from the inner portion attached to the crank, no matter what tool you decide to use on the crank bolt. See https://www.ebay.com/i/352601771277?chn=ps - This would allow you to just use a BIG breaker bar on the crank bolt and avoid removing the radiator. Sorry the chain wrench didn't work out.

Don'tcha just love how a weekend project turns into a several months-long ordeal? I'm still waiting to get back out in my garage and put my XKR back together (waited for parts, sent back wrong parts, ordered more parts, ordered tools, got the flu, had to remodel a bathroom, now recovering from broken ribs).... Such is life.

My point about not replacing the secondary tensioners only is based on the assumption that the primaries will have to be replaced also, so it's more work in the end to do them separately compared to doing them at the same time. I am at a point in my project where I see how much easier and tempting it is to change only the secondaries but I'm a masochist so I'm forging ahead.

Today I removed the crankshaft bolt and damper. With the proper tools they came right off. I did have two foot 1/2" breaker bar with a pipe "extender". No power tools. No drama.
This is not a reason to avoid changing the primary tensioners. Chains wrapped around the damper, impact guns, no. Don't do that. The proper tools are not that expensive for this job and they are all in one kit.
I have a thread where I'm documenting this job if anyone wants to see pictures.

@stu46h , where did you source your damper tool? It looks good. I too will be buying the proper one as three XKs in the family I more than likely will be doing this job a few times.

I also bought the cheap kit off Amazon to compare it to the expensive OEM manufacturer kit of one of the suppliers and will report back what I find.

I bought the tool kit from Christopher's Foreign Car Parts in Egg Harbor Township, NJ. It really made the job no big deal. FYI, the Adapter they mention in the manual is not needed, and in fact there is no space for it. I think it's already incorporated into the tool. The purchase price was about $150 but Christopher has a deal where you can rent it for about $50. Whether you buy it or rent it, you need it.
Greg

On my car the secondaries were in almost perfect condition, so I didn't think there was any need to tackle the rest. I agree though, if the secondaries are falling to bits that is a good sign that the primaries will be also.

The only way to check the secondaries is to remove the cam covers and once they are off, you may as well change the tensioners, whatever state they are in, hence why I changed mine, but nothing else.

My secondaries where new (a previous owner had changed them) but the primaries where shot. Only way to make sure is to get in there and look at the condition of all components.