I have looked at the chain guides that I can partially see and do not see any noticeable excess wear, but I think if I remove the timing cover and a few other components, I would be afraid that I could not get everything back together the right way and have an even bigger problem. I'm hoping that the secondary tensioner replacement will fix the issue I am having. If not I may have to throw in the towel and check with someone with more experience (and time) to work on this.

 

A little pitch for the RealGauge Oil pressure Option:

As bits of plastic from primary and secondary tensioners and guides accumulate in the sump, your oil pressure will slowly drop. Keeping a watchful eye on RealGauge with the oil pressure option can give you a clue that this is happening.

 

I finally had some time to put everything back together. I had read a lot of posts about tips and tricks as well as followed the JTIS manual to a "T" I successfully installed the metal tensioners, new bolts, all new gaskets, new oil pan, oil pickup, and oil pan gasket, changed oil and filter (20W-50) and bolted everything back up according to the torque specs. I primed the tensioners by removing the fuel pump relay, started up, and it sounds normal and I was happy that the job was successful. I honestly spent quite a bit of time consulting JTIS and followed it perfectly, will all proper tools in place.

However, just as before, after about 5 minutes, the noise that was posted in the first video at the beginning of this post was still there, no better, no worse. There are no oil pressure issues, oil was changed during this process, using 20W-50. The car has no noticeable performance issues after a 2 mile drive, and the noise is most noticeable at idle, is virtually unnoticeable at 800-1,400RPM, and above 1,400 you can hear it more. The most obvious sound is at idle round 650-700 without touching the throttle.
After about 30 minutes of full temp operation, the oil pressure gauge reads low. Could this be a sign of another problem?

So, here I am, new tensioners all installed, and I feel better about that, that's a good thing. But my issue still remains. What's next? Some replies mentioned issues with valves? How can I check this, I've never done a compression test, and don't have the tool for that, but I can pick one up if that is the next logical step to get this problem resolved. It would me nice to isolate the issue to a particular area as it is hard to really hear and pinpoint exactly where it is coming from. Any tips are greatly appreciated. I need a break...

 

You found a lot of plastic bits. Your primary tensioners are probably also disintegrating. I'll bet that is the source of your noise.

 

Hi,
thats a shame after all that work. Are you sure the timing is perfect. it could be worth one final check. (dont forget the chains may have stretched, I would check the flats once more)
Try to get codes read, (it could be a coil)

When you blip the throttle, can your hear anything, it could be the primary chains flapping about.

Or it could be valve damage when the original chain jumped a sprocket.

Finally, the point you make about oil pressure could be very relevant. (I cant help regarding that it needs an expert.

hope you pin point the problem soon.

stephen

 

I checked codes with Auto Enginuity scanner, just the expected P1000 after battery disconnect, no other codes.
Coils are good and plugs are new. After I installed the secondary tensioners, the chain is a lot tighter than the originals.
When I blip the throttle I don't notice any noise out of the ordinary, but will have to listen further. I definitely made sure the flats were correct and were well locked down when I put everything back together. If compression test does not indicate possible valve issues, I will likely have to remove the valve covers again for inspection.

The noise actually is not noticeable when I have the engine at about 800-1400 RPMs, I can hear a metallic tap tap tap noise that is consistent, and varies with RPM. Most noticeable at idle, not touching throttle. I did a youtube search for "bent valve" and a lot of the videos appear to resemble the same noise and issue that my car is experiencing. It is really hard to pinpoint the noise and it appears to echo in the upper intake manifold. I will pick up a compression tester and see if I can find any evidence of a bent valve through compression measurements. I looked online and saw that a compression test is rather easy to perform, just remove plugs, install fitting, turn over engine for a few seconds and read gauge, record, and compare cylinders. When I get the tester, I will report the measurements.

If I end up having a bent valve, I'm not sure I'm ready for that adventure myself, just yet. If it is removing the remaining timing components, I feel a little more comfortable after replacing the secondary tensioners, but am still worried it may be a job suitable for someone with more experience, and especially time.

 

To add one more detail, when the car is first started, there is no noticeable bad noise for the first 5-7 minutes at cold start. When car gets warmer, after about 7+ minutes the noise is obvious at idle. Could this be a symptom of a bad/bent/leaking valve where the existing oil/pressure is filling the gap of a bad/bent/leaking valve and subsequently leaks down and pressure is lost?? I'm still new to the understanding of exactly how the internals work together.

 

I seem to remember a post (but can't find it) where this was happening and it was due to the primary chain tensioner leaking.
When the oil was cold it was thick enough to operate the tensioner but as it warmed up it leaked so the tension was lost.

 

Hi,
A compression Test sounds the best next step. Perhaps someone could offer suggestions regarding the oil pressure drop. did you clean the oil pick up screen, was this broken, if so could the pieces have travelled further and blocked the oil pump ?.

Steveinfrance suggestion may well be relevant if you have a low oil pressure, perhaps the gauge is similar to the temp, ie not a lot of use. what about the oil filter?.

Best Wishes

Stephen

 

Steve,
I'm damned if I can find this post (it could have been on another forum) but I believe the drop in oil pressure was due to the leak.

 

I bought a compression tester from Harbor Freight yesterday afternoon. I removed all the plugs and coils, plugged in adaptor, connected gauge, turned over engine for 4-5 seconds, measured, nothing. The gauge was a piece of junk. After reading some online reviews, many customers mentioned the same issue. $15.99, I shouldn't expect much.

On to Autozone, I rented a compression tester (they didn't have any for purchase in stock, I live in a small town), did the same, but the hose adaptor hose would turn freely so I could barely get the adaptor to screw in, and definitely not secure enough to have accurate readings. Cylinders showed 30-60psi, and the adaptor hose was well past its life expectancy, so I know these measurements are not anywhere near accurate.

Just not my night for testing compression...two tools, no good. I'll check around other stores and see if I can buy a more quality compression tester. From what I've read, the compression should be around 165psi on my 98 XK8 or so, correct me if I'm wrong. Also, should I be checking the compression with all plugs out, and engine cold, or engine warm?

 

Happy would be anything over 150 psi.

Are you propping the throttle butterfly open? Stick the handle of a screwdriver it to keep it open. With it normally closed not much air can get past to pump up a gauge.

The hot/cold test will tell you something about oil flow. All plugs out helps the starter but is not absolutely required. Try one with the throttle open and the fuel relay out.

 

I hope you pulled the fuel pump solenoid before testing compression. If not, you are injecting fuel into those nikasil liners and compression could go to near zero.
If that happened, you need to add a little oil to the cylinders to bring the compression back up. Do a search for cylinder wash for further information.
RJ________________
97 XK8 85K mi

 

I hate to say it, but listeneing again to the video, it could indicate a rod knock if the valves are okay. No one seems to have noticed this, but that may be why fixing the tensioners didn't stop it. Its possible that the plugged oil intake lowered the oil pressure to the point that a rod bearing cooked. I would have a pro listen to it in person.

 

Thanks for the tip. I picked up another compression tester today. I will test compression and report back with results. Thanks for the tip on keeping the throttle open, I was not doing this, just turning the key in the ignition.

 

Thanks for the tip. I actually had the fuel pump relay pulled, but forget to mention that. So no "no start" for me.

 

I hope its not a bad rod. I'll keep digging and probing to find the source.

 

Thanks for the tip, WhiteXKR. I bought a mechanic stethoscope to further pin point the engine noise. I probed a lot of places in, around, and on the engine while it was running. From listening closer, the engine has no major metal noise at any of the cylinders that appear out of the ordinary, the intake plenum is more of an echo of a noise from the front of the engine. The VVT area closest to the front of the engine (both sides) is much more noticeable (at least I think so), and the I might describe the noise as a metallic slapping noise, definitely metal on metal.

I started the car up this morning, on a cold start, 65 degrees outside, hadn't been started in about 12 hours, and for the first 3-4 seconds, heard a rattle in the front of the engine. Then it went away, car ran smooth, no odd engine noises. Like a crazy person, I tempted fate and drove it to work 20 miles. It runs ok, and oil pressure was okay, and dropped down, at idle only, after about 30 minutes, but was otherwise fine while moving. This situation definitely has me considering WhiteXKRs suggestion of primary tensioners and likely the guides. Only way to tell is to remove the timing chain cover. Sounds like a winter project to me. I wish there was a Jaguar mechanic nearby. There is always the Jaguar dealer, but not sure I can afford that one right now.

 

Based on what you have acomplished to date, I have no doubt you can do this yourself. Just do your research, accumulate what you'll need and go for it!

This article is a good start: Jag-lovers - Jaguar World Monthly articles reproduced with permission

 

Thank you very much for the positive words of encouragement. I think I will dig deeper and get to the primary tensioners and replace all the chains and guides, seals, etc, just not anytime soon. I need to let my wallet fill back up first. I like to have all my parts ready before I start tearing everything apart.

I plan on running a compression test later this week and will report results.